Detailed Description
Hereinafter, preferred embodiments for performing the present technology will be described with reference to the accompanying drawings. Note that the embodiments to be described below each show an example of a representative embodiment of the present technology, and the scope of the present technology is not limited thereto. Further, in the present technology, any one of the following examples and modifications thereof may be combined.
In the following description of embodiments, terms with "substantially" may be used to describe a configuration, such as substantially parallel or substantially orthogonal. For example, "substantially parallel" means not only completely parallel but also includes substantially parallel, i.e. a state that is offset from a completely parallel state by, for example, about a few percent. The same applies to other terms having "substantially". The drawings are schematic and are not necessarily strictly illustrated. The scale of the drawings is exaggerated to facilitate understanding of technical features. It should therefore be noted that the scale of the drawing and the scale of the actual device need not be identical.
In the drawings, "upper" means an upward direction or an upper side in the drawings, "lower" means a downward direction or a lower side in the drawings, "left" means a leftward direction or a left side in the drawings, and "right" means a rightward direction or a right side in the drawings, unless otherwise specified. In addition, in the drawings, the same or equivalent elements or components are denoted by the same reference numerals, and redundant description will be omitted.
The description will be given in the following order.
1. First embodiment of the present technology (example 1 of measurement apparatus)
2. Second embodiment of the present technology (example 2 of measuring apparatus)
3. Third embodiment of the present technology (example 3 of measurement apparatus)
4. Fourth embodiment of the present technology (example 4 of measurement apparatus)
5. Fifth embodiment of the present technology (example 5 of measuring apparatus)
6. Sixth embodiment of the present technology (example 6 of measurement apparatus)
7. Seventh embodiment of the present technology (example 7 of measuring apparatus)
8. Eighth embodiment of the present technology (example 8 of a measurement apparatus)
9. Ninth embodiment of the present technology (example 9 of measurement apparatus)
10. Tenth embodiment of the present technology (example 10 of measurement apparatus)
11. An eleventh embodiment of the present technology (example 11 of a measurement apparatus)
12. A twelfth embodiment of the present technology (example of bioinformation measurement apparatus)
[1. First embodiment of the present technology (example 1 of measuring apparatus) ]
[ (1) Description of the technology ]
Conventionally, in photothermal radiation measurement, an object is irradiated with a laser light having a predetermined wavelength. The object may be, for example, human, animal skin, etc. At this time, it is known that the temporal change in the intensity of the radiation light radiated from the object varies according to the absorption coefficient of the object. This will be described with reference to fig. 1. Fig. 1 is a graph showing an example of a temporal change in the intensity of radiated light. Note that the absorption coefficient refers to a constant that represents the degree of light absorption of a specific medium when light is incident on the medium.
In fig. 1, the horizontal axis represents time, and the vertical axis represents the intensity of radiated light. The solid line represents the temporal change in the intensity of the radiated light in the case of emitting laser light having a wavelength with an increased absorption coefficient. The broken line represents a temporal change in the intensity of the radiated light in the case of emitting laser light having a wavelength with a reduced absorption coefficient. Note that the light to be emitted is not limited to laser light.
It is assumed that the object is irradiated with laser light at time t. As shown by the solid line, in the case of emitting laser light having a wavelength at which the absorption coefficient of the object increases, the irradiation light is strongly absorbed near the surface of the object, so that the near the surface of the object is strongly heated. On the other hand, since the irradiation light is strongly absorbed near the surface of the object, the light is less likely to penetrate into the interior of the object. With this arrangement, the temperature inside the object is unlikely to rise compared to the temperature near the surface. As a result, the temperature gradient from the vicinity of the surface to the inside of the object increases, so that the temperature of the object rapidly spreads. At the same time, the radiation light radiated from the vicinity of the object surface is also rapidly reduced.
On the other hand, as shown by the broken line, in the case of emitting laser light having a wavelength in which the absorption coefficient of the object is reduced, the irradiation light is less likely to be absorbed in the vicinity of the surface of the object than in the case of emitting laser light having a wavelength in which the absorption coefficient is increased. Therefore, the temperature near the surface of the object is less likely to rise, and light easily penetrates into the interior of the object. According to this arrangement, the temperature gradient from the vicinity of the surface toward the inside of the object becomes small, and therefore the speed of temperature diffusion of the object is slow. At the same time, the time to radiate the radiated light from the vicinity of the object surface is long.
As shown by the solid line and the broken line, the degree of change in the intensity of the radiated light varies according to the absorption coefficient. The absorption coefficient of the object is obtained by sequentially plotting the intensities of the radiated lights at predetermined times. For example, an index such as the relaxation time of the radiated light shows a difference in absorption coefficient, and a difference time d is generated.
The impulse response of the radiated light has been described above with reference to fig. 1.
It is considered that the thermal diffusivity of the object is not changed depending on the wavelength of the emitted laser light. Therefore, by measuring the difference time d using a laser light source capable of changing the wavelength, the absorption coefficient and the thermal diffusivity of the object can be obtained.
However, a laser light source capable of changing the wavelength is expensive. Further, in the case of controlling the temperature of the laser light source in order to suppress the variation (variation) in the wavelength and intensity of the laser light as a noise source, there is a possibility that the light source becomes more expensive and large.
Accordingly, the present technology provides a measuring apparatus that can contribute to miniaturization and cost reduction of the apparatus. Specifically, there is provided a measuring apparatus including a light source that irradiates irradiation light to an object, and a light receiving unit that receives radiation light irradiated from the object by irradiation with the irradiation light, wherein the light receiving unit includes a spectroscopic unit that splits the radiation light having a plurality of wavelengths into a plurality of light beams based on wavelengths, and a sensor unit that detects each of the light beams obtained by the spectroscopic of the spectroscopic unit.
A measurement apparatus according to an embodiment of the present technology will be described with reference to fig. 2. Fig. 2 is a block diagram illustrating a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 2, the measuring apparatus 100 includes a light source 1 and a light receiving unit 2.
The light source 1 irradiates the object M with irradiation light. When the object is irradiated with the irradiation light, the light receiving unit 2 receives the irradiation light radiated from the object. The light receiving unit 2 includes a spectroscopic unit 21 and a sensor unit 22.
The sensor unit 22 detects radiation light having a plurality of wavelengths at the same time. Thus, the sensor unit 22 preferably has two or more detection areas. For example, a bolometer array, a pyroelectric sensor array, or the like may be used as the sensor unit 22.
The radiated light includes a plurality of wavelength components, and the behavior of the radiated light varies according to the wavelength components. This will be described with reference to fig. 3. Fig. 3 is a graph showing an example of a temporal change in the intensity of radiated light.
Fig. 3 shows a step response, wherein the horizontal axis represents Time (Time) and the vertical axis represents the relative intensity (or temperature) of the radiated light. The first line L1 represents a temporal change in intensity (radiation) of a wavelength component having a large absorption coefficient among wavelength components included in the radiation light. The second line L2 represents a temporal change in intensity (radiation) of a wavelength component having a small absorption coefficient among wavelength components included in the radiation light. The third line T represents the time variation of the object surface temperature. Note that the surface temperature of the object changes in a step function manner as shown by the third line T, but this change is a schematic representation.
When the object is irradiated with the irradiation light, the vicinity of the surface of the object is strongly heated. At this time, of the wavelength components included in the radiation light generated inside the object, light having a wavelength component strongly absorbed by the object (having a large absorption coefficient) is absorbed by the object before reaching the vicinity of the surface of the object. With this arrangement, wavelength components having a large absorption coefficient emitted from the vicinity of the surface of the object are mainly observed. As described above, as shown by the first line L1, the intensity of the wavelength component having a large absorption coefficient increases immediately after heating the vicinity of the object surface.
When a period of time passes after irradiation with irradiation light, heat diffuses from the vicinity of the object surface to the inside. Then, of the wavelength components included in the radiation light generated inside the object, light having a wavelength component (having a small absorption coefficient) less likely to be absorbed by the object reaches the vicinity of the object surface. At this time, in heat transfer from the vicinity of the object surface to the inside, a time delay corresponding to the thermal conductivity occurs. Therefore, of the wavelength components included in the radiation light generated inside the object, light having a wavelength component with a small absorption coefficient increases with the time delay.
Thus, as shown in fig. 3, a difference time d occurs between the light receiving time t1 before the light having the wavelength component with the large absorption coefficient reaches the predetermined intensity R1 and the light receiving time t2 before the light having the wavelength component with the small absorption coefficient reaches the predetermined intensity R1. By detecting the difference time d, the absorption coefficient of the object can be calculated.
The light splitting unit 21 splits the irradiation light having a plurality of wavelengths into light fluxes having a plurality of wavelength components based on the wavelengths. The sensor unit 22 detects light having each wavelength component obtained by the spectroscopic unit 21 through spectroscopic. With this arrangement, the sensor unit 22 can detect light having each wavelength component contained in the radiation light. As a result, the light source 1 does not need to change the wavelength of the irradiation light. Preferably, the spectroscopic unit 21 blocks the irradiation light and transmits the irradiation light, so that the sensor unit 22 can detect with high accuracy.
The light source 1 and the sensor unit 22 are driven in synchronization with each other. With this arrangement, the sensor unit 22 detects light of each wavelength, and the light source 1 modulates the irradiation light. The sensor unit 22 detects a difference time between an emission time of the irradiation light and a light receiving time of the irradiation light. With this arrangement, the absorption coefficient of the object is obtained.
Note that, in the above configuration example, the difference time between the light receiving time of the wavelength component having a large absorption coefficient and the light receiving time of the wavelength component having a small absorption coefficient is measured. However, in order to perform measurement with higher accuracy, it is preferable to measure a time difference from the light receiving time of the irradiation light with reference to the emission time of the irradiation light.
Conventionally, in order to obtain absorbance spectra of irradiation light of various wavelengths, it is necessary to repeatedly observe the light receiving time of irradiation light while changing the wavelength by using a laser light source capable of changing the wavelength. Therefore, there is a problem in that it takes a lot of time to obtain an absorbance spectrum.
On the other hand, according to the present technology, a plurality of radiation beams having different wavelengths from each other can be received simultaneously without changing the wavelength of the irradiation light. Therefore, the absorbance spectrum can be obtained in a short time.
Further, according to the present technique, since the light splitting unit 21 splits the radiation light based on the wavelength, the light source 1 does not have to be a laser light source having a narrow spectral linewidth. The light source 1 only needs to emit illumination light having a large absorption coefficient for the object. Thus, for example, an LED may be used as the light source 1. With this arrangement, downsizing and cost reduction of the apparatus can be facilitated.
[ (2) Spectroscopic Unit ]
The means for realizing the spectroscopic unit 21 is not particularly limited. For example, a combination of a diffraction grating and a linear sensor, an array sensor using a wavelength selection device such as a band-pass filter, or the like may be used. As an example of the band-pass filter, a linear bubble filter in which the transmission wavelength continuously changes according to the position in the plane, a resonator integrated waveguide mode resonator filter, or the like can be used. Resonator integrated waveguide mode resonator filters are disclosed, for example, in U.S. patent application publication No. 2018/228410, etc.
The spectroscopic unit 21 may further comprise a wavelength conversion unit for optically up-converting the radiation light. By the light up-conversion, for example, conversion to near-infrared light can be performed, and observation can be performed with high accuracy by using a near-infrared light observation device.
The spectroscopic unit 21 may be configured such that each light beam obtained by the spectroscopic forms interference fringes on the sensor unit 22. For example, monochromatic radiation light is split into two optical paths by using a beam splitter or the like, and one of the light beams is superimposed on the sensor unit 22 by using a mirror or the like by utilizing a phase difference. With this arrangement, sinusoidal interference fringes are formed on the sensor unit 22. The bright-dark interval of the interference fringes depends on the wavelength. The intensity (spectrum) of each radiation beam may be obtained by separating the interference fringes for each wavelength, for example by fourier transformation. This can be achieved using techniques such as those disclosed in International publication No. WO 2016/180551, and the like.
According to the present technique, since the measuring apparatus 100 includes the spectroscopic unit 21, the spectrum of each radiation beam can be collectively acquired. Therefore, the time resolution is high. The configuration according to the present technology is a configuration suitable for the case where the light source 1 and the sensor unit 22 perform light splitting in synchronization with each other.
Note that as a device for splitting infrared light having a wavelength of 6 to 11 μm intended as radiation light, for example, a fourier transform infrared spectrometer (FTIR) using a michelson interferometer is widely used. In this apparatus, a movable mirror is used to change the optical path length of one of two light beams obtained by light splitting. Thus, the time for the mirror to move to obtain one spectrum is created. Therefore, it is difficult to detect a plurality of light beams obtained by light splitting at the same time, which is required in the present technology. In addition, a spectrometer using a fabry-perot interferometer is also used. However, in the case where one of the interference mirrors changes with time, it is difficult to detect a plurality of light beams obtained by the light splitting at the same time. Therefore, application to the present technology is not preferable.
[ (3) Irradiation of light ]
In order to easily detect the emission time of the irradiation light, the light receiving time of the irradiation light, and the difference time d, it is preferable that the temperature gradient from the vicinity of the surface of the object to the inside is large. That is, preferably, the object is irradiated with irradiation light that is unlikely to penetrate into the object.
In order to determine such irradiation light, an object having a predetermined thermal diffusivity was simulated. This will be described with reference to fig. 4. Fig. 4 is a graph showing an example of simulation results of the present technology.
In this simulation, an object having a uniform thermal diffusivity of 0.146[ mm2/s ] was irradiated with irradiation light having various effective absorption coefficients, and a light receiving time difference of the irradiation light was observed. Specifically, as shown in fig. 6, the intensity of the irradiation light varies with time, so that the modulated waveform of the intensity of the irradiation light becomes a sinusoidal waveform. Then, a difference time (phase difference) d between the light receiving time of the wavelength component L1 having a large absorption coefficient and the light receiving time of the wavelength component L2 having a small absorption coefficient is observed. Note that fig. 6 will be described in detail later.
In fig. 4, the horizontal axis represents the absorption coefficient. The vertical axis represents the difference (or "difference") between the light reception time of the radiation light having a wavelength in which the absorption coefficient of the object is large (551 cm-1) and the light reception time of the radiation light having a wavelength in which the absorption coefficient of the object is small (533 cm-1) when the irradiation light having a specific wavelength is emitted. As the absorption coefficient increases, the difference increases.
The graph shows the following. First, light having a wavelength λ0 at which an absorption coefficient of an object to be measured becomes, for example, 530cm-1 is emitted as irradiation light. Then, the object is warmed by the irradiation light, and the radiation light is emitted. At this time, a state of a thick line B extending in the vertical direction in the vicinity of the center is obtained, which indicates that the difference between the light receiving time of the radiation light having the wavelength λ1 and the light receiving time of the radiation light having the wavelength λ2 is 0.3ms, the absorption coefficient of the object is large (551 cm-1) at the wavelength λ1, and the absorption coefficient is small (533 cm-1) at the wavelength λ2.
In the graph to the left of the thick line B, the time difference indicated on the vertical axis is small. For example, when it is desired to detect radiation having an absorption coefficient of about 500cm-1, the radiation is attenuated to 1/e at 1/500 cm=20 μm. In such detection of the radiation light, for example, when heating is performed with the irradiation light having a small absorption coefficient (100 cm-1), the irradiation light reaches 1/100 cm=100 μm, which exceeds 20 μm. Therefore, it is considered that it is difficult to confirm the difference in light receiving time of the radiation light under the difference in absorption coefficient of the irradiation light of 551cm-1 and 533cm-1.
Therefore, it is not necessarily required to irradiate light with a line width as narrow as that of the laser light, but it is preferable that the effective absorption coefficient of the object for the irradiated light is larger than the absorption coefficient of light having the wavelength of the object to be measured included in the radiation light. That is, a graph on the right side of a thick line B extending in the vertical direction near the center of fig. 4 is preferable. At this time, since the spectrum of the irradiation light may be expanded, it is preferable to set the weighted average of the absorption coefficients of the irradiation light as the effective absorption coefficient of the irradiation light.
A specific example of the wavelength of the irradiation light is described with reference to fig. 5. Fig. 5 is a graph showing a measurement example. In this measurement, the absorbance spectrum of the dogwood leaves was obtained with a fourier transform infrared spectrometer (FTIR). The horizontal axis represents wavelength. The vertical axis is absorbance spectrum of dogwood leaves.
Radiation having a wavelength of 6 to 11 μm can be observed, which is believed to be involved in intermolecular bonding of organic substances. The wavelength region of 6 to 11 μm is called a fingerprint region of a molecule because a molecule of an object to be measured can be specified. Further, in this measurement, when the wavelength is about 3 μm, it is confirmed that the absorption by water is large. Therefore, in this case, by irradiating the object with the irradiation light in a range overlapping with the absorbance spectrum of water, the absorbance spectrum of the irradiation light having an absorption coefficient smaller than that of the irradiation light in a range of 6 to 11 μm can be observed.
When the object to be measured is, for example, a human body, since the main component of the human body is water, it is preferable to emit irradiation light in a range overlapping with the absorbance spectrum of water. Specifically, when the peak wavelength of the irradiation light emitted from the light source is in the range of 2.8 μm to 3.3 μm, irradiation light having a wavelength in the range of 6 μm to 11 μm can be observed, which is preferable. As a light source that emits such a wavelength, for example, a light source in which only a desired wavelength is selected using a band-pass filter "L15893-0330M" for LED manufactured by HAMAMATSU PHOTONICS k.k., but the light source is not limited thereto may be used.
Here, the intensity of the irradiation light will be described again with reference to fig. 3. As described above, the third line T is a schematic representation. However, in practice, the variation in the intensity of the radiated light is small, and it is difficult to observe the variation in a step function manner with low noise.
Therefore, it is preferable that the light source repeatedly changes the intensity of the irradiation light with the lapse of time. That is, it is preferable to repeatedly change the intensity of the irradiation light, instead of changing the intensity only once. In particular, it is preferable that the modulation waveform of the intensity of the irradiation light is a sinusoidal waveform. This will be described with reference to fig. 6. Fig. 6 is a graph showing an example of a temporal change in the intensity of radiated light.
In fig. 6, the horizontal axis represents time, and the vertical axis represents the intensity (or temperature) of the radiated light. The first line L1 represents a temporal change in the intensity of a wavelength component having a large absorption coefficient among wavelength components included in the radiation light. The second line L2 represents a temporal change in the intensity of a wavelength component having a small absorption coefficient among wavelength components included in the radiation light. The third line T represents the time variation of the object surface temperature.
The light source changes the intensity of the irradiation light with time so that the modulated waveform of the intensity of the irradiation light becomes a sinusoidal waveform. Then, as shown by the third line T, the modulated waveform of the object surface temperature also becomes a sinusoidal waveform. Due to such a change in the surface temperature, as shown by the first line L1 and the second line L2, the modulated waveform of the intensity of the radiation light to be radiated also becomes a sinusoidal waveform. With this arrangement, the difference time (phase difference) d becomes substantially constant without being affected by the measurement timing, so that the measurement becomes easy.
At this time, it is preferable to reduce noise contained in the observation signal. For example, by using a lock-in amplifier or the like, noise mixed into an observation signal can be reduced. Note that the means for reducing noise is not limited thereto.
Further, instead of or in addition to the phase difference, the intensity difference may be measured. The absorption coefficient of the object is also obtained by measuring the intensity difference. Further, by analyzing the intensity difference and the phase difference, the absorption coefficient can be obtained more accurately. That is, it is preferable that the sensor unit 22 detects at least one of a phase difference or an intensity difference between the irradiation light and the radiation light.
The intensity of the irradiation light may be repeatedly changed in time, and the modulation waveform of the intensity of the irradiation light is not limited to a sinusoidal waveform. For example, the light source may repeatedly change the intensity of the irradiation light over time, so that the modulated waveform of the intensity of the irradiation light becomes a rectangular waveform, a triangular waveform, or a sawtooth waveform.
Note that in the case of changing the intensity of the radiated light in a step function manner, it is convenient to manufacture a circuit that generates a drive signal of the light source. Further, when the intensity of the radiated light is changed in a step function manner, the surface temperature of the object is changed rapidly as compared with the case where the surface temperature is changed in a sinusoidal waveform. With this arrangement, it is convenient to observe the change in radiated light. As a result, it is possible to observe the radiated light in a short time. In the case where the noise contained in the irradiation light is small, the light source may change the intensity of the irradiation light with time so that the modulated waveform of the intensity of the irradiation light has a step function shape. In the future, the measurement time may be shortened when the sensitivity of the sensor unit increases and the change may be observed by a step function.
[ (4) Verification ]
It was confirmed that the absorption spectrum of the object was obtained by detecting at least one of the phase difference or the intensity difference between the irradiation light and the irradiation light. First, in order to select a wavelength having a large absorption coefficient and a wavelength having a small absorption coefficient, measurement is performed using an aqueous glucose solution. This measurement will be described with reference to fig. 7. Fig. 7 is a graph showing an example of measurement using fourier transform infrared spectrometer (FTIR). The horizontal axis represents the wavelength of the irradiation light. The vertical axis represents the difference in absorbance spectrum between an aqueous glucose solution having a concentration of 2000mg/dl and pure water.
As shown in FIG. 7, the absorption of glucose is relatively small at a wavelength of about 8.5. Mu.m. On the other hand, when the wavelength is about 9.5 μm, the absorption of glucose is relatively large.
Next, a band-pass filter transmitting only light of these two wavelengths is used to observe a phase difference between the respective wavelengths. The result of the observation will be described with reference to fig. 8. Fig. 8 is a graph showing an example of the verification result of the present technology. The horizontal axis represents the concentration of the glucose aqueous solution. The vertical axis is a phase difference between a wavelength component (9.5 μm) having a large absorption coefficient and a wavelength component (8.5 μm) having a small absorption coefficient among wavelength components included in the radiation light. Note that the phase difference when the object to be measured is pure water is 0ms.
As described above, a wavelength component having a large absorption coefficient can be observed earlier than a wavelength component having a small absorption coefficient. Therefore, a phase difference occurs between the wavelength component (9.5 μm) having a large absorption coefficient and the wavelength component (8.5 μm) having a small absorption coefficient. As shown in fig. 8, the phase difference increases with the increase in the concentration of the aqueous glucose solution.
From the above, it has been confirmed that when irradiation light of a wavelength having a large absorption coefficient is emitted to heat an object, a phase difference changes in proportion to the absorption coefficient, and a plurality of irradiation light beams obtained by wavelength-based spectroscopy are simultaneously detected to detect the phase difference of each of the irradiation light beams. The sensor unit 22 included in the measuring apparatus 100 according to one embodiment of the present technology preferably detects at least one of a phase difference or an intensity difference between the irradiation light and the radiation light. The absorption coefficient of the object is obtained by detecting at least one of a phase difference or an intensity difference between the irradiation light and the irradiation light used as a reference.
Note that in this example, two wavelength components of a wavelength component (9.5 μm) having a large absorption coefficient and a wavelength component (8.5 μm) having a small absorption coefficient are used, but three or more wavelength components may be used. By similarly plotting the phase differences at various wavelengths, an absorbance spectrum is obtained.
The above described contents described for the measuring apparatus according to the first embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[2 ] Second embodiment of the present technology (example 2 of measuring apparatus) ]
The light source 1 included in the measuring device 100 may be, for example, a laser light source having a narrow spectral linewidth or a Light Emitting Diode (LED) having a wide spectral linewidth. Note that since the LED has lower directivity than the laser light source, there is a possibility that the use efficiency of light is lowered. In order to efficiently use the spectroscopic unit 21, the irradiation light from the light source 1 is preferably intensively irradiated to the object.
Therefore, it is preferable to further include an optical system that guides the irradiation light from the light source 1 to the object. This will be described with reference to fig. 9. Fig. 9 is a block diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 9, the measurement apparatus 100 further includes an optical system 3 that guides illumination light from the light source 1 to the object. With this arrangement, a decrease in the use efficiency of the irradiation light can be suppressed.
A configuration example of the optical system 3 will be described with reference to fig. 10. Fig. 10 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 10, the measurement apparatus 100 includes a light source 1, a light receiving unit 2, and an optical system 3.
The optical system 3 includes a parabolic mirror 300, a first lens 301, a second lens 302, a third lens 303, and a fourth lens 304.
The irradiation light emitted from the light source 1 is sequentially transmitted through the first lens 301 and the second lens 302, and is emitted toward the object M. The radiation light radiated from the object M passes through the third lens 303 and the fourth lens 304 in this order, and is incident on the light receiving unit 2.
The parabolic mirror 300 and the first lens 301 are arranged with the light source 1 interposed therebetween. The parabolic mirror 300 is arranged around the light source 1. With this arrangement, illumination light emitted from opposite sides of the first lens 301 is reflected by the parabolic mirror 300 and guided to the first lens 301. With this arrangement, the use efficiency of the irradiation light can be improved.
Note that there is a limitation in capturing the irradiation light with the first lens 301. Further, in the case where the irradiation light is efficiently condensed, there is a possibility that an aspherical lens must be used as the first lens 301 or the like, which results in an expensive configuration. Further, in the case where the irradiation light is emitted from the side surface, an optical path for guiding the irradiation light is required. With this optical path, the third lens 303 is arranged at a position away from the object M. As a result, there is a possibility that the use efficiency of the radiated light is lowered.
Another configuration example of the optical system 3 will be described with reference to fig. 11. Fig. 11 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 11, the measurement apparatus 100 includes a light source 1, a light receiving unit 2, and an optical system 3.
The optical system 3 includes a parabolic mirror 310, a first lens 311, a second lens 312, a third lens 313, and a dichroic mirror 314.
The irradiation light emitted from the light source 1 passes through the first lens 311, is reflected by the dichroic mirror 314, and is emitted toward the object M. The radiation light radiated from the object M passes through the second lens 312, the dichroic mirror 314, and the third lens 313 in this order, and is incident on the light receiving unit 2.
In this configuration example, since the second lens 312 can be close to the object M, the use efficiency of light is improved.
Note that in the configuration example shown in fig. 11, it is difficult to adjust the optical path of the irradiation light and the optical path of the radiation light in the arrangement of the dichroic mirror 314. Further, since a space for installing the dichroic mirror 314 is required, there is a possibility that the apparatus becomes large.
Therefore, it is more preferable that the optical system 3 has a light guide path that totally reflects the irradiation light internally and guides the irradiation light to the object. This will be described with reference to fig. 12. Fig. 12 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 12, the measuring apparatus 100 includes a light source 1, a light receiving unit 2, an optical system 3, and a deflection unit 32.
The optical system 3 has a light guide path 30 that totally reflects the irradiation light inside and guides the irradiation light to the object M. The light guide path 30 is formed inside a light guide plate as an example of the optical system 3. Hereinafter, for simplicity of explanation, the light guide path and the light guide plate are treated as synonyms for each other. Note that the light guide path 30 is not necessarily formed inside the plate-like object as shown in the figure, but may be formed inside an object of another shape.
The light source 1 is arranged at one side end of the light guide path 30 in the traveling direction (Y-axis direction) of the irradiation light. The refractive index of the light guide plate 30 is different from that of the air layer around the light guide plate 30. With this arrangement, the illumination light is totally reflected within the light guide plate 30 and guided to the object M. Since the object M is intensively irradiated with the irradiation light from the light source 1, the use efficiency of the irradiation light is improved.
As described above, when the peak wavelength of the irradiation light emitted from the light source 1 is in the range of 2.8 μm to 3.3 μm, this is preferable because the irradiation light having a wavelength in the range of 6 μm to 11 μm can be observed. Therefore, the light guide plate 30 is preferably a material that transmits light having a wavelength in the range of 2.8 μm to 3.3 μm and light having a wavelength in the range of 6 μm to 11 μm. For example, zinc selenide, zinc sulfide, silicon, germanium, chalcogenide glass, or the like may be used as the material of the light guide plate 30.
The light receiving unit 2 is preferably arranged on the opposite side of the light guiding path 30 to the side facing the object M. With this arrangement, the radiation light is incident substantially perpendicularly to the surface of the spectroscopic unit 21. In general, the light splitting unit 21 is designed to have an optimal resolution when light is incident substantially perpendicular to the surface. Therefore, the radiation light is split with high accuracy.
When the light guide plate 30 and the object M are in close contact with each other, there is a possibility that total reflection of the irradiated light is blocked. Therefore, it is preferable to form an air layer AL between the light guide path 30 and the object M.
The deflection unit 32 deflects the irradiation light guided in the light guide path 30, and irradiates the irradiation light to the object M via the irradiation unit 31. In order to extract the irradiation light efficiently, it is preferable that the number of times of irradiation light reflected by the deflection unit 32 is large. Therefore, it is preferable that the length in the thickness direction (Z-axis direction) of the light guide plate 30 at the position where the irradiation unit 31 is formed is short. In particular, it is preferable that the length is, for example, about 0.6mm.
On the other hand, it is preferable that the size of the surface facing the light source 1 is substantially twice the size of the light source 1 among the plurality of surfaces of the light guide plate 30. With this arrangement, the illumination light from the light source 1 is efficiently incident on the light guide path 30. Therefore, as shown in the figure, it is preferable that the length in the thickness direction (Z-axis direction) of the light guide path 30 becomes longer toward the light source 1. With this arrangement, the irradiation light from the light source 1 efficiently propagates and is easily extracted from the irradiation unit 31.
Note that, in the case where the inclination angle θ of the light guide plate 30 is excessively large, there is a possibility that the irradiation light does not totally reflect within the light guide plate 30 and the irradiation light leaks from the light guide path in the middle of the light guide plate. Therefore, it is preferable that the inclination angle θ is a predetermined value or less.
Specifically, the length in the thickness direction (Z-axis direction) of the surface facing the light source 1 among the plurality of surfaces of the light guide plate 30 is set to h, the distance from the surface to the position where the inclination angle θ becomes 0 degrees is set to x, and the critical angle is set to α. At this time, it is preferable that the following expression (1) is satisfied.
[ Mathematical expression 1]
Note that, when the refractive index of the light guide plate 30 is assumed to be n, the critical angle α is derived from the following expression (2).
[ Mathematical expression 2]
n·sin(α)=1... (2)
In order to increase the utilization efficiency of the irradiation light, it is preferable that the length in the direction (X-axis direction) orthogonal to the traveling direction (Y-axis direction) of the irradiation light on the light guide path 30 and the thickness direction (Z-axis direction) of the light guide path 30 is made shorter as the light source 1 is positioned closer. This is described with reference to fig. 13. Fig. 13 is a perspective view showing a configuration example of the light guide plate 30 according to one embodiment of the present technology.
As shown in fig. 13, the length in the direction (X-axis direction) orthogonal to the traveling direction (Y-axis direction) of the irradiation light on the light guide path 30 and the thickness direction (Z-axis direction) of the light guide path 30 becomes shorter as the light source 1 is closer. With this arrangement, even in the light source 1 having low directivity, the irradiation light can be efficiently guided to the irradiation unit 31. Moreover, by reducing the volume of the light guide path 30, space savings are achieved.
In order to obtain the amount of irradiation light required for observing the irradiation light, two or more light sources 1 may be arranged for one light guide plate 30. This will be described with reference to fig. 14 and 15. Fig. 14 and 15 are perspective views showing configuration examples of the light guide plate 30 according to one embodiment of the present technology. As shown in fig. 14, for example, two light sources 1 may be arranged with respect to one light guide plate 30. As shown in fig. 15, for example, four light sources 1 may be arranged for one light guide plate 30. Note that the number of light sources 1 is not particularly limited.
In order to obtain the light quantity of the irradiation light required for observing the irradiation light, two or more light sources 1 may be arranged for one side surface end portion of one light guide plate 30. This will be described with reference to fig. 16. Fig. 16 is a perspective view showing a configuration example of the light guide plate 30 according to one embodiment of the present technology. As shown in fig. 16, for example, two light sources 1 may be arranged on one side surface end of one light guide plate 30.
The above described matters described for the measuring apparatus according to the second embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[ 3] Third embodiment of the present technology (example 3 of measurement apparatus) ]
The material and shape of the deflection unit 32 are not particularly limited as long as the traveling direction of the irradiation light can be changed. For example, by forming a periodic structure on the surface of the deflection unit 32, the periodic structure can change the traveling direction of the irradiation light.
An example of the shape of the periodic structure will be described with reference to fig. 17 to 21. Fig. 17 to 21 are perspective views showing configuration examples of the deflection unit 32 according to one embodiment of the present technology. As shown in fig. 17 to 21, the shape of the periodic structure of the deflection unit 32 may be hemispherical, cylindrical, conical or lattice-shaped. As shown in fig. 17, the shape of the periodic structure may be hemispherical. As shown in fig. 18, the periodic structure may be cylindrical in shape. Note that in this figure, the shape of the periodic structure is a cylinder as a kind of column, but may be, for example, a prism. As shown in fig. 19, the shape of the periodic structure may be tapered. Note that in this figure, the shape of the periodic structure is a pyramid as one of the cone shapes, but may be, for example, a cone. As shown in fig. 20 and 21, the shape of the periodic structure may be a lattice shape. In the configuration example shown in fig. 20, the shape of the periodic structure is a prismatic shape that is a lattice shape. In the configuration example shown in fig. 21, the cross-sectional shape of the periodic structure is an asymmetric triangle.
In order to scatter the illuminating light, it is preferable that the size or spacing of the periodic structures of the deflection unit 32 or both are larger than the wavelength of the illuminating light. Pitch is the spacing between periodic structures. Taking the configuration shown in fig. 17 as an example, it is preferable that the diameter r of the hemispheres or the spacing between hemispheres or both be greater than the wavelength of the illumination light. Note that in the case where the diameter r of the hemispheres or the spacing between hemispheres or both are much larger than the wavelength, the irradiation light is unlikely to be emitted uniformly, and thus it is preferable to design appropriately. Furthermore, when the periodic structures are arranged at equal intervals, interference may be generated with the array-shaped sensor units 22. Thus, the size or spacing of the periodic structures, or both, may be random. Or the pitch of the periodic structure may be designed according to the pitch of the array-shaped sensor units 22. The specific value of the pitch of the periodic structure depends on the pitch, manufacturability, etc. of the array-shaped sensor units 22, and is preferably, for example, about 100 μm or less.
The shapes shown in fig. 17 to 21 are preferable because mass production can be performed at low cost by manufacturing a mold. The deflection unit 32 may be manufactured by other methods as long as the traveling direction of the irradiation light can be changed. For example, a particulate bead transmitting irradiation light and radiation light may be applied. As examples of the beads, polyethylene beads or the like can be used. Or, for example, metamaterials may be used. Metamaterials are artificial substances that include structures that are smaller than the wavelength of light and that can impart predetermined characteristics to the light.
Meanwhile, when the irradiation light is introduced into the light guide plate 30, the optical density of the side closer to the light source 1 is higher than that of the side farther from the light source 1, and thus, a large amount of light is easily extracted from the light guide plate 30.
In order to improve uniformity of light, it is preferable that the irradiation light is not extracted from the side close to the light source 1, but extracted from the irradiation unit 31 arranged at the side far from the light source 1. A configuration example of the deflection unit 32 in this case is described with reference to fig. 22. Fig. 22 is a schematic plan view showing an example of the configuration of the deflection unit 32 according to one embodiment of the present technology. As shown in fig. 22, the pitch of the periodic structure of the deflection unit 32 becomes longer as approaching the light source 1. In this configuration, the closer to the light source 1, the lower the density of the periodic structure, and the further from the light source 1, the higher the density of the periodic structure.
An example of this density distribution is described with reference to fig. 23. Fig. 23 is a diagram showing an example of density distribution of a periodic structure of the deflection unit 32 according to one embodiment of the present technology. The horizontal axis represents the distance from the light source 1. The vertical axis represents the density of periodic structures. As shown in fig. 23, the closer to the light source 1, the density of the periodic structure is lower, and the farther from the light source 1, the higher the density of the periodic structure is. With this arrangement, the irradiation light is less likely to be extracted from the side close to the light source 1, thereby improving the uniformity of the irradiation light. Note that the density distribution depends on the shape and design of the entire light guide plate 30 including the light source 1.
Note that, as another example in which the irradiation light is unlikely to be extracted from the side close to the light source 1, the shape of the periodic structure may be different depending on the position.
In order to improve the use efficiency of light, a reflection suppressing film that suppresses light reflection may be formed on the surface of the deflection unit 32. The reflection suppressing film can suppress reflection of the irradiation light or can suppress reflection of the irradiation light. Or the reflection of light having a wavelength between the wavelength of the irradiation light and the wavelength of the radiation light may be suppressed. As an example of a method of forming the reflection suppressing film, a metamaterial may be used, or a moth-eye structure may be applied. Or a material having a lower refractive index than the light guide plate 30 may be applied to the surface of the deflection unit 32.
As shown in fig. 12, the deflection unit 32 is disposed on one surface of the light guide path 30. Specifically, the deflection unit 32 is disposed on the upper surface (surface on the opposite side to the surface facing the object M) of the light guide plate 30.
In order to improve the utilization efficiency of the light transmitted through the deflection unit 32, the deflection unit 32 may be disposed on both surfaces of the light guide path 30. This point will be described with reference to fig. 24. Fig. 24 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 24, deflection units 32 (32-1, 32-2) may be disposed on both surfaces of the light guide path 30. Specifically, the deflection unit 32-1 may be disposed on an upper surface (a surface on a side opposite to a surface facing the object M) of the light guide plate 30, and the deflection unit 32-2 may be disposed on a lower surface (a surface facing the object M) of the light guide plate 30.
The effect of arranging the deflection units 32 (32-1, 32-2) on both surfaces of the light guide path 30 is described with reference to fig. 25. Fig. 25 is a simplified cross-sectional view showing a configuration example of the light guide plate 30 according to one embodiment of the present technology.
In fig. 25A, the deflection unit 32 is arranged on one surface of the light guide path 30. Specifically, the deflection unit 32 is disposed on the upper surface (surface on the opposite side to the surface facing the object M) of the light guide plate 30. The deflection unit 32 is formed in a prism shape having a substantially 90-degree apex angle. When the radiation light is incident on the deflection unit 32 from below, total reflection occurs twice on the inner surface of the deflection unit 32, and the light can be returned to one side of the object M. Light returned to the object M is absorbed without returning. Therefore, the use efficiency of light is lowered.
On the other hand, in fig. 25B, deflection units 32 (32-1, 32-2) are arranged on both surfaces of the light guide path 30. Specifically, the deflection unit 32-1 is disposed on the upper surface (surface on the opposite side from the surface facing the object M) of the light guide plate 30, and the deflection unit 32-2 is disposed on the lower surface (surface facing the object M) of the light guide plate 30. Therefore, when the radiation light is incident on the deflection units 32-1 and 32-2 from below, the deflection unit 32-2 refracts the radiation light so that the radiation light is less likely to return to the object M side, and thus, the use efficiency of the light is improved.
The above described contents described for the measuring apparatus according to the third embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[ 4] Fourth embodiment of the present technology (example 4 of measurement apparatus) ]
As shown in fig. 12 and the like, it is preferable to arrange the light receiving unit 2 on the side opposite to the side of the light guide path 30 facing the object M. With this configuration, the radiation light is incident substantially perpendicularly with respect to the surface of the spectroscopic unit 21. In general, the spectroscopic unit 21 is designed to have an optimal resolution when light is incident substantially perpendicularly to the surface. Therefore, the radiation light is split with high accuracy.
Note that, since the radiation light is natural light, the radiation light may not be incident substantially perpendicularly with respect to the surface of the spectroscopic unit 21. Accordingly, the measuring device 100 preferably further comprises a radiation light guiding unit guiding the radiation light radiated from the object M to the light receiving unit 2. This will be described with reference to fig. 26. Fig. 26 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 26, the measuring device 100 further comprises a radiation light guiding unit 4. The radiation light guiding unit 4 is arranged on the optical path of the radiation light, and guides the radiation light radiated from the object M to the light receiving unit 2.
The irradiation light guide unit 4 can be realized by, for example, a louver film arranged in a lattice shape, a lens or a lens array that converts incident light into parallel light, or the like.
The above-described contents described for the measuring apparatus according to the fourth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[5 ] Fifth embodiment of the present technology (example 5 of measuring apparatus) ]
As described above, when the air layer AL is formed between the light guide path 30 and the object M, the irradiation light is totally reflected within the light guide path 30, and therefore, it is preferable to prevent close contact between the light guide path 30 and the object M. A configuration example in this case will be described with reference to fig. 27. Fig. 27 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 27, the measuring apparatus 100 further includes a close contact preventing unit 5 disposed at a side of the light guide path 30 facing the object M. With this arrangement, an air layer AL is formed between the light guide path 30 and the object M.
Preferably, the close contact preventing unit 5 transmits the irradiation light and the radiation light. With this arrangement, the use efficiency of light is improved. For example, a polyethylene film or the like transmitting light having a wavelength of 3 to 11 μm may be used for the close contact preventing unit 5.
In addition, it is preferable that the concave-convex portion is formed on the surface of the close contact preventing unit 5. This point will be described with reference to fig. 28. Fig. 28 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 28, the concave-convex portion 51 is formed on the surface of the close contact preventing unit 5. With this arrangement, an air layer AL is formed between the light guide path 30 and the object M. For example, the concave-convex 51 may be formed by spraying polyethylene beads.
Although not shown, it is preferable that the close contact preventing unit 5 is not disposed between the light receiving unit 2 and the object M in order to reduce light loss. For example, in the close contact preventing unit 5, a hole may be formed in a portion facing the light receiving unit 2.
Also, in order to reduce the loss of light, it is preferable that the close contact preventing unit 5 is not disposed between the irradiation unit 31 and the object M. For example, in the close contact preventing unit 5, a hole may be formed in a portion facing the irradiation unit 31.
The above-described contents described for the measuring apparatus according to the fifth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[ 6] Sixth embodiment of the present technology (example 6 of measuring apparatus) ]
Other configuration examples of preventing close contact between the light guide path 30 and the object M are described with reference to fig. 29. Fig. 29 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 29, the measuring device 100 further includes a housing 6 covering the periphery of the light guide path 30. A portion 61 of the housing 6 is arranged between the light-guiding path 30 and the object M. With this arrangement, an air layer AL is formed between the light guide path 30 and the object M.
In addition, it is preferable that a reflection unit 62 that reflects the irradiation light is formed on the inner surface (surface facing the light guide path 30) of the housing 6. With this arrangement, light leaking from the light guide path 30 can be reflected back to the light guide path 30. As a result, the light use efficiency is improved.
The above-described contents described for the measuring apparatus according to the sixth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[7 ] Seventh embodiment of the present technology (example 7 of measurement apparatus) ]
As described above, when the air layer AL is formed between the light guide path 30 and the object M, the irradiation light is totally reflected within the light guide path 30. That is, in the case where the light guide path 30 and the object M are in close contact with each other without forming the air layer AL, the irradiation light is extracted from the light guide path 30 without being totally reflected. Accordingly, in order to intentionally extract the irradiation light from the light guide path 30, the light guide path 30 and the object M may be brought into close contact with each other.
A configuration example in this case will be described with reference to fig. 30. Fig. 30 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 30, in the measuring apparatus 100, the light guide path 30 has a protrusion 33 in which a surface to be in close contact with the object M protrudes. The surface of the protruding portion 33 (the irradiation unit 31) is brought into close contact with the object M, so that irradiation light is extracted from the surface. Such a configuration is preferable in the case where the object is, for example, a liquid, a gel, or the like. In this configuration, since it is not necessary to include the deflection unit 32, the measurement apparatus 100 can be manufactured at low cost.
The above-described contents described for the measuring apparatus according to the seventh embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[8 ] Eighth embodiment of the present technology (example 8 of measurement apparatus) ]
In order to improve the utilization efficiency of light, the measurement apparatus 100 may further include a wavelength selection unit that selects light having a predetermined wavelength from the irradiation light and guides the light to the optical system 3. This will be described with reference to fig. 31. Fig. 31 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology.
As shown in fig. 31, the measurement apparatus 100 further includes a wavelength selection unit 7 that selects light having a predetermined wavelength from the irradiation light and guides the light to the optical system 3. In order to make the irradiation light from the light source 1 incident on the light guide path 30 without being reflected, the wavelength selection unit 7 may have a function of preventing reflection of the irradiation light, for example. Or the wavelength selection unit 7 may be, for example, a band-pass filter that removes light having a predetermined wavelength included in the radiation light from the light source 1. Or the wavelength selective unit 7 may have a function of reflecting the radiation light, for example. With this arrangement, the use efficiency of light can be improved.
Note that the wavelength selection unit 7 may be integrally formed with the optical system 3, or may be disposed separately from the optical system 3.
The above-described contents described for the measuring apparatus according to the eighth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[9 ] Ninth embodiment of the present technology (example 9 of measuring apparatus) ]
In order to improve the light utilization efficiency, the measurement apparatus 100 may further include a first reflection unit that reflects the irradiation light emitted from the light source 1 toward the optical system 3. This will be described with reference to fig. 32. Fig. 32 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology.
As shown in fig. 32, the measurement apparatus 100 further includes a first reflection unit 8 that reflects the irradiation light emitted from the light source 1 toward the optical system 3. The first reflection unit 8 and the optical system 3 are arranged sandwiching the light source 1. With this arrangement, the first reflection unit 8 reflects the irradiation light emitted from the light source 1 toward the optical system 3. As a result, the light use efficiency is improved.
Although not shown, the first reflection unit 8 may be disposed on a side surface to cover a gap between the optical system 3 and the light source 1. With this arrangement, the first reflection unit 8 reflects the light leaked from the optical system 3 toward the optical system 3. As a result, the light use efficiency is improved.
It is preferable that the first reflection unit 8 has a high reflectance for the irradiation light and the radiation light. As a material of the first reflecting unit 8, for example, aluminum, gold, or the like is preferable.
Note that the first reflection unit 8 may be integrally formed with the optical system 3, or may be disposed separately from the optical system 3.
The above-described contents described for the measuring apparatus according to the ninth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[10 ] Tenth embodiment of the present technology (example 10 of measurement apparatus) ]
A portion of the irradiation light propagating within the light guide path 30 is not extracted from the irradiation unit 31, and the portion of the irradiation light may reach an end of the light guide path 30. Accordingly, the measurement apparatus 100 may further include a second reflection unit that reflects the illumination light guided by being totally reflected within the light guide path 30 toward the light guide path 30. This will be described with reference to fig. 33. Fig. 33 is a schematic diagram showing a configuration example of the measurement apparatus 100 according to one embodiment of the present technology.
As shown in fig. 33, the measurement apparatus 100 further includes a second reflection unit 9 that reflects the illumination light guided by being totally reflected within the light guide path 30 toward the light guide path 30. The second reflecting unit 9 and the light source 1 are arranged sandwiching the light guide path 30. With this arrangement, the second reflection unit 9 reflects the illumination light guided by being totally reflected within the light guide path 30 toward the light guide path 30. As a result, the light use efficiency is improved.
In particular, it is preferable that the second reflection unit 9 is arranged around the light guide path 30. For example, the inner surface of the housing 6 shown in fig. 29 may be the second reflecting unit 9.
Preferably, the second reflection unit 9 has a high reflectivity for the irradiation light and the radiation light. As a material of the second reflecting unit 9, for example, aluminum, gold, or the like is preferable.
Note that the second reflection unit 9 may be integrally formed with the optical system 3, or may be disposed separately from the optical system 3.
The above-described contents described for the measuring apparatus according to the tenth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[11 ] An eleventh embodiment of the present technology (example 11 of a measurement apparatus) ]
Another configuration example of the measurement apparatus 100 according to one embodiment of the present technology will be described with reference to fig. 34. Fig. 34 is a schematic diagram illustrating a configuration example of the measurement apparatus 100 according to one embodiment of the present technology. As shown in fig. 34, the optical system 3 may include a lens 10. The radiation light from the object M is incident on the light receiving unit 2 via the lens 10.
The beam splitting unit 21 splits the radiation light having passed through the slit into a plurality of light beams by, for example, a diffraction grating. The sensor unit 22 receives each of the light beams obtained by the light splitting. This configuration is preferable in the case where higher spectroscopic performance is required. With such a configuration, it is possible to observe radiation light of a plurality of wavelengths at the same time when modulating the radiation light from the light source 1.
The above described contents described for the measuring apparatus according to the eleventh embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
[12 ] Twelfth embodiment of the present technology (example of bioinformation measurement apparatus) ]
The present technology provides a biological information measuring apparatus including the measuring apparatus of any one of the first to eleventh embodiments. The living body may be, for example, a human, an animal, or the like. A configuration example of the biological information measuring apparatus is described using fig. 35. Fig. 35 is a block diagram showing a configuration example of the biological information measuring apparatus 1000 according to one embodiment of the present technology. As shown in fig. 35, the biological information measuring apparatus 1000 includes at least the measuring apparatus 100, the memory 101, the storage unit 102, and the calculation unit 103 of any one of the first to eleventh embodiments. Each component may be connected by, for example, a bus as a data transmission path.
The memory 101 temporarily stores, for example, a program or the like executed by the calculation unit 103. The memory 101 may be implemented using, for example, a Random Access Memory (RAM) or the like.
The storage unit 102 stores programs read by the calculation unit 103, control data such as calculation parameters, and the like. The storage unit 102 may be implemented by using, for example, a Hard Disk Drive (HDD), a Solid State Drive (SSD), or the like.
The calculation unit 103 performs processing by reading a program, and controls the operation of each component. The computing unit 103 may be implemented by using, for example, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), or the like.
The calculation unit 103 measures biological information based on the value measured by the measurement device 100 and the information stored in the storage unit 102. For example, when the phase difference of the radiation light has a predetermined value or more, the calculation unit 103 measures that a hazard occurs in the living body.
The above described contents described for the biological information measuring apparatus according to the twelfth embodiment of the present technology can be applied to another embodiment of the present technology as long as there is no technical contradiction.
Note that the embodiments according to the present technology are not limited to the above-described respective embodiments, and various modifications may be made without departing from the gist of the present technology. The specific values, shapes, materials (including compositions), and the like described in the respective embodiments are merely examples, and are not limited thereto.
In addition, the present technology can also employ the following configuration.
[1] A measurement device, comprising:
A light source for irradiating the object with irradiation light, and
A light receiving unit that receives radiation light radiated from the object by being irradiated with the radiation light,
Wherein the light receiving unit comprises
A light splitting unit that splits radiation light having a plurality of wavelengths into a plurality of light beams based on the wavelengths, an
And a sensor unit that detects each of the light beams obtained by the light splitting unit.
[2] The measuring apparatus according to [1], wherein
The light source and the sensor unit are driven in synchronization with each other.
[3] The measuring apparatus according to [1] or [2], wherein
The sensor unit detects at least one of a phase difference or an intensity difference between the irradiation light and the radiation light.
[4] The measuring apparatus according to any one of [1] to [3], wherein
The light source repeatedly modulates the intensity of the illumination light over time.
[5] The measuring apparatus according to any one of [1] to [4], wherein
The modulated waveform of the intensity of the illumination light includes a sinusoidal waveform.
[6] The measuring apparatus according to any one of [1] to [5], wherein
The effective absorption coefficient of the object for the irradiation light is larger than the absorption coefficient of the light having the wavelength to be measured included in the irradiation light.
[7] The measuring apparatus according to any one of [1] to [6], wherein
The wavelength of the irradiation light is included in the range of 2.8 μm to 3.3 μm.
[8] The measuring apparatus according to any one of [1] to [7], wherein
The light-splitting unit blocks the irradiation light and transmits the irradiation light.
[9] The measuring apparatus according to any one of [1] to [8], wherein,
In the spectroscopic unit, the transmission wavelength of the radiation light is continuously changed according to the position in the plane.
[10] The measuring apparatus according to any one of [1] to [9], wherein
The spectroscopic unit is configured such that each light beam obtained by spectroscopic forms interference fringes on the sensor unit.
[11] The measuring apparatus according to any one of [1] to [10], further comprising
An optical system guides the irradiation light from the light source to the object.
[12] The measuring apparatus according to [11], wherein
The optical system includes a light guide path that totally reflects the irradiation light internally and guides the irradiation light to the object.
[13] The measuring apparatus according to [12], wherein
The light receiving unit is arranged on the opposite side of the light guiding path to the object facing side.
[14] The measuring apparatus according to [12] or [13], wherein
The length of the light guide path in the thickness direction becomes longer as approaching the light source.
[15] The measuring apparatus according to any one of [12] to [14], further comprising
And a deflection unit for deflecting the irradiation light guided in the light guide path and irradiating the object with the irradiation light.
The measurement device of claim 12.
[16] The measuring apparatus according to [15], wherein
The pitch of the periodic structure of the deflection unit becomes longer as it gets closer to the light source.
[17] The measuring apparatus according to any one of [1] to [16], further comprising a radiation light guiding unit that guides radiation light radiated from the object to the light receiving unit.
[18] The measuring apparatus according to any one of [12] to [17], wherein
An air layer is formed between the light guide path and the object.
[19] The measuring apparatus according to any one of [12] to [18], further comprising
A close contact preventing unit disposed at a side of the light guide path facing the object.
[20] The measuring apparatus according to any one of [1] to [19], wherein
The modulated waveform of the intensity of the irradiation light has a rectangular waveform.
[21] The measuring apparatus according to any one of [1] to [20], wherein
The light splitting unit further comprises a wavelength converting unit for optically up-converting the radiation light.
[22] The measuring apparatus according to any one of [12] to [21], wherein
The light source is arranged at one side end of the light guide path in the traveling direction of the irradiation light.
[23] The measuring apparatus according to any one of [12] to [22], wherein
The length in the direction orthogonal to the traveling direction of the irradiation light in the light guide path and the thickness direction of the light guide path becomes shorter as approaching the light source.
[24] The measurement apparatus according to any one of [15] to [23], wherein
The shape of the periodic structure of the deflection unit is hemispherical, cylindrical, conical or lattice-shaped.
[25] The measurement apparatus according to any one of [15] to [24], wherein
The size or spacing of the periodic structures of the deflection unit or both the size and spacing of the periodic structures is greater than the wavelength of the illuminating light.
[26] The measurement apparatus according to any one of [15] to [25], wherein
The deflection unit includes an anti-reflection unit that prevents reflection of light.
[27] The measurement apparatus according to any one of [15] to [26], wherein
The deflection unit is disposed on one surface of the light guide path.
[28] The measurement apparatus according to any one of [15] to [27], wherein
The deflection units are arranged on both surfaces of the light guide path.
[29] The measurement apparatus according to any one of [19] to [28], wherein
The close contact preventing unit transmits the irradiation light and the radiation light.
[30] The measurement apparatus according to any one of [19] to [29], wherein
Concave-convex portions are formed on the surface of the close contact preventing unit.
[31] The measuring apparatus according to any one of [12] to [30], wherein
The light guide path has a protruding portion in which a surface in close contact with the object protrudes.
[32] The measuring apparatus according to any one of [12] to [31], further comprising
A housing covering the periphery of the light guide path,
Wherein a portion of the housing is disposed between the light guide path and the object.
[33] The measuring apparatus according to [32], wherein
A reflection unit that reflects the irradiation light is formed on an inner surface of the housing.
[34] The measuring apparatus according to any one of [1] to [33], further comprising
And a wavelength selection unit that selects light having a predetermined wavelength from the irradiation light and guides the light to the optical system.
[35] The measuring apparatus according to any one of [1] to [34], further comprising
And a first reflection unit that reflects the irradiation light emitted from the light source toward the optical system.
[36] The measuring apparatus according to any one of [12] to [35], further comprising
And a second reflection unit that reflects the irradiation light guided by being totally internally reflected in the light guide path toward the light guide path.
[37] A biological information measuring apparatus comprising the measuring apparatus according to any one of [1] to [36 ].
List of reference numerals
100. Measuring device
1. Light source
2. Light receiving unit
21. Light splitting unit
22. Sensor unit
3. Optical system
30. Light guide path (light guide plate)
31. Irradiation unit
32. Deflection unit
33. Protruding portion
4. Radiation light guide unit
5. Close contact preventing unit
6. Outer casing
62. Reflection unit
7. Wavelength selection unit
8. First reflecting unit
9. Second reflecting unit
10. Lens
1000. Biological information measuring apparatus
M object
AL air layer