CN110913152B

Movatterモバイル変換

Info

Publication number: CN110913152B
Application number: CN201911168481.6A
Authority: CN
Inventors: 张海裕
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2022-02-15
Anticipated expiration: 2039-11-25
Also published as: CN110913152A

Abstract

Translated fromChinese

本申请公开了一种图像传感器、摄像头组件和移动终端。图像传感器包括全色像素、彩色像素及模数转换电路。彩色像素具有比全色像素更窄的光谱响应。模数转换电路用于将全色像素输出的模拟信号转换为数字信号，模数转换电路的比较信号的幅值的变化率随时间的增大而增大。本申请的图像传感器、摄像头组件和移动终端采用了比较信号的幅值的变化率随时间的增大而增大的模数转换电路，该模数转换电路既能将不容易饱和像素输出的模拟信号转化为数字信号，还能够将容易饱和的像素输出的模拟信号转化为数字信号，达到抑制过曝现象，从而改善成像质量的目的。

The present application discloses an image sensor, a camera assembly and a mobile terminal. The image sensor includes full-color pixels, color pixels, and analog-to-digital conversion circuits. Color pixels have a narrower spectral response than panchromatic pixels. The analog-to-digital conversion circuit is used to convert the analog signal output by the full-color pixel into a digital signal, and the change rate of the amplitude of the comparison signal of the analog-to-digital conversion circuit increases with time. The image sensor, camera assembly and mobile terminal of the present application employ an analog-to-digital conversion circuit in which the rate of change of the amplitude of the comparison signal increases with time. The signal is converted into a digital signal, and the analog signal output by the pixel that is easy to be saturated can also be converted into a digital signal, so as to suppress the overexposure phenomenon and improve the image quality.

Description

Image sensor, camera assembly and mobile terminal

Technical Field

The present application relates to the field of imaging technologies, and in particular, to an image sensor, a camera assembly, and a mobile terminal.

Background

A camera is often installed in a mobile terminal such as a mobile phone to realize a photographing function. An image sensor is arranged in the camera. In order to realize the acquisition of a color image, color pixels are generally disposed in an image sensor, and the color pixels are arranged in a Bayer (Bayer) array. In order to improve the imaging quality of the image sensor in a low-light environment, white pixels having higher sensitivity than color pixels are added to the image sensor. However, white pixels receive more luminous flux per unit time, are more likely to reach a saturation state, and are likely to be overexposed when some highlight scenes are shot, thereby affecting the imaging quality.

Disclosure of Invention

The embodiment of the application provides an image sensor, a camera assembly and a mobile terminal.

The embodiment of the application provides an image sensor. The image sensor includes panchromatic pixels, color pixels, and analog-to-digital conversion circuitry. The color pixels have a narrower spectral response than the panchromatic pixels. The analog-to-digital conversion circuit is used for converting the analog signals output by the panchromatic pixels into digital signals. The rate of change of the amplitude of the comparison signal of the analog-to-digital conversion circuit increases with time.

In some embodiments, the analog-to-digital conversion circuit includes a comparison signal generator. The comparison signal generator comprises a voltage source, a plurality of switches, a plurality of constant current sources and a resistor. One end of each of the plurality of switches is electrically connected to the voltage source. The plurality of constant current sources correspond to the plurality of switches, one end of one of the constant current sources is electrically connected to the other end of one of the switches, and the magnitudes of currents output by at least two of the constant current sources are different. The resistor is electrically connected to one end of the plurality of constant current sources remote from the switch. As the time increases, the plurality of switches are sequentially closed, and the switches electrically connected to the constant current source that outputs a smaller current are closed first.

In some embodiments, the analog-to-digital conversion circuit includes a comparison signal generator including a voltage source, an adjustable current source, and a resistor. One end of the adjustable current source is electrically connected with the voltage source. The resistor is electrically connected with the other end of the adjustable current source. Along with the increase of the time, the amplitude of the current output by the adjustable current source is gradually increased, and the change rate of the amplitude of the current is gradually increased.

In certain implementations, the panchromatic pixels and the color pixels form a two-dimensional array of pixels. The two-dimensional pixel array includes a minimum repeating unit. In the minimal repeating unit, the panchromatic pixels are arranged on a first diagonal, and the color pixels are arranged in a second diagonal direction, the first diagonal direction being different from the second diagonal direction.

In certain embodiments, a first exposure time of at least two of the panchromatic pixels adjacent in the first diagonal direction is controlled by a first exposure signal, and a second exposure time of at least two of the color pixels adjacent in the second diagonal direction is controlled by a second exposure signal.

In some embodiments, the first exposure time is less than the second exposure time.

In some embodiments, the image sensor further comprises a first exposure control line and a second exposure control line. The first exposure control line is electrically connected with the control ends of the exposure control circuits in at least two of the panchromatic pixels adjacent to the first diagonal direction. The second exposure control line is electrically connected with the control ends of the exposure control circuits in at least two color pixels adjacent to the second diagonal direction. The first exposure signal is transmitted via the first exposure control line, and the second exposure control signal is transmitted via the second exposure control line.

In some embodiments, the first exposure control line is in a W shape and is electrically connected to the control terminals of the exposure control circuits in two adjacent rows of the full-color pixels; the second exposure control line is W-shaped and is electrically connected with the control ends of the exposure control circuits in the two adjacent rows of color pixels.

The embodiment of the application also provides a camera assembly. The camera assembly comprises a lens and the image sensor of any one of the above embodiments, wherein the image sensor is capable of receiving light rays passing through the lens.

The embodiment of the application also provides the mobile terminal. The mobile terminal comprises a shell and a camera assembly, wherein the camera assembly is combined with the shell. The camera assembly comprises a lens and the image sensor of any one of the above embodiments, wherein the image sensor is capable of receiving light rays passing through the lens.

The image sensor, the camera assembly and the mobile terminal adopt the analog-digital conversion circuit which is increased along with the increase of time when the change rate of the amplitude value of the comparison signal is increased, the analog-digital conversion circuit can convert an analog signal output by a pixel which is not easy to saturate into a digital signal, and can convert an analog signal output by a pixel which is easy to saturate into a digital signal, so that the over-exposure phenomenon is inhibited, and the imaging quality is improved.

Additional aspects and advantages of embodiments of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic illustration of different color channel exposure saturation times;

FIG. 2 is a schematic diagram of an image sensor according to an embodiment of the present disclosure;

fig. 3 is a schematic diagram of a pixel circuit connected to an analog-to-digital conversion circuit according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of another pixel circuit coupled to an analog-to-digital conversion circuit according to some embodiments of the present application;

FIG. 5 is a graph of a linear comparison signal and a non-linear comparison signal according to certain embodiments of the present application;

FIG. 6 is a schematic diagram of an analog-to-digital conversion circuit according to some embodiments of the present application;

FIG. 7 is a schematic diagram of an analog-to-digital conversion circuit according to some embodiments of the present application;

FIG. 8 is a schematic diagram of a connection between a pixel array and an exposure control line according to an embodiment of the present invention

FIG. 9 is a schematic diagram of a minimum repeating unit pixel arrangement according to an embodiment of the present application;

FIG. 10 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 11 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 12 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 13 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 14 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 15 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 16 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 17 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 18 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 19 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 20 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 21 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 22 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 23 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 24 is a schematic diagram of yet another minimal repeating unit pixel arrangement in an embodiment of the present application;

FIG. 25 is a schematic flow chart diagram illustrating an image capture method according to an embodiment of the present disclosure;

FIG. 26 is a schematic view of a camera assembly according to an embodiment of the present application;

fig. 27 is a schematic diagram of a mobile terminal according to an embodiment of the present application.

Detailed Description

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In a color image sensor, pixels of different colors receive different amounts of exposure per unit time, and some colors are not exposed to a desired state after some colors are saturated. For example, exposure to 60% -90% of the saturated exposure amount may have a relatively good signal-to-noise ratio and accuracy, but embodiments of the present application are not limited thereto.

Fig. 1 illustrates RGBW (red, green, blue, full color) as an example. Referring to fig. 1, in fig. 1, the horizontal axis is exposure time, the vertical axis is exposure amount, Q is saturated exposure amount, LW is exposure curve of full-color pixel W, LG is exposure curve of green pixel G, LR is exposure curve of red pixel R, and LB is exposure curve of blue pixel.

As can be seen from fig. 1, the slope of the exposure curve LW of the panchromatic pixel W is the greatest, i.e., the panchromatic pixel W can obtain more exposure per unit time, and saturation is reached attime t 1. The next to the slope of the exposure curve LG for the green pixel G, the green pixel saturates at time t 2. The slope of the exposure curve LR for the red pixel R is again such that the red pixel is saturated at time t 3. The slope of the exposure curve LB for the blue pixel B is at a minimum and the blue pixel is saturated at time t 4. At time t1, the panchromatic pixel W has saturated and R, G, B three pixel exposures have not reached the ideal state. It should be noted that the exposure curve in fig. 1 is only an example, the slope and the relative relationship of the curve may vary according to the pixel response band, and the application is not limited to the situation shown in fig. 1. For example, when the wavelength band to which the red pixel R responds is narrow, the slope of the exposure curve of the red pixel R may be lower than that of the blue pixel B.

In the related art, the exposure times of the four pixels RGBW are commonly controlled. For example, the exposure time of each row of pixels is the same, and the pixels are connected to the same exposure control line and controlled by the same exposure control signal. For example, with continued reference to fig. 1, during the time period from 0 to t1, all four RGBW pixels can work normally, but in this interval, RGB causes the phenomena of low brightness, low signal-to-noise ratio, and even insufficient vivid color when displaying images due to short exposure time and low exposure amount. In the period from t1 to t4, the W pixel is overexposed due to saturation, and is not operated, and the exposure data cannot truly reflect the target.

For the above reasons, please refer to fig. 2, fig. 4, fig. 5 and fig. 9, which provide animage sensor 10. Theimage sensor 10 includes panchromatic pixels, color pixels and analog-to-digital conversion circuitry 16. Color pixels have a narrower spectral response than panchromatic pixels. The analog-to-digital conversion circuit 16 is configured to convert the analog signal output from the full-color pixel into a digital signal, and the rate of change in the amplitude of the comparison signal of the analog-to-digital conversion circuit 16 increases with time.

Theimage sensor 10 of the present application employs the analog-to-digital conversion circuit 16 in which the rate of change in the amplitude of the comparison signal increases with time, and the analog-to-digital conversion circuit 16 can convert an analog signal output from a pixel (R pixel and/or B pixel) that is not easily saturated into a digital signal, and can also convert an analog signal output from a pixel (W pixel and G pixel) that is easily saturated into a digital signal, thereby achieving the purpose of suppressing an overexposure phenomenon and improving the imaging quality.

Next, the basic structure of theimage sensor 10 will be described. Referring to fig. 2, fig. 2 is a schematic diagram of animage sensor 10 according to an embodiment of the present disclosure. Theimage sensor 10 includes apixel array 11, avertical driving unit 12, a control unit 13, acolumn processing unit 14, and ahorizontal driving unit 15.

For example, theimage sensor 10 may employ a Complementary Metal Oxide Semiconductor (CMOS) photosensitive element or a Charge-coupled Device (CCD) photosensitive element.

For example, thepixel array 11 includes a plurality of pixels two-dimensionally arranged in an array form, each pixel including a photoelectric conversion element (shown in fig. 3). The pixels convert light into electric charges according to the intensity of light incident thereon.

For example, thevertical driving unit 12 includes a shift register and an address decoder. Thevertical driving unit 12 includes a readout scanning and reset scanning functions. The readout scanning refers to sequentially scanning unit pixels row by row, and reading signals from the unit pixels row by row. For example, a signal output from each pixel in the selected and scanned pixel row is transmitted to thecolumn processing unit 14. The reset scan is for resetting charges, and the photocharges of the photoelectric conversion elements are discarded, so that accumulation of new photocharges can be started.

The signal processing performed by thecolumn processing unit 14 is, for example, Correlated Double Sampling (CDS) processing. In the CDS processing, the reset level and the signal level output from each pixel in the selected row are taken out, and a level difference is calculated. Thus, signals of pixels in one row are obtained. Thecolumn processing unit 14 may have an analog-to-digital (a/D) conversion function for converting analog pixel signals into a digital format.

Thehorizontal driving unit 15 includes, for example, a shift register and an address decoder. Thehorizontal driving unit 15 sequentially scans thepixel array 11 column by column. Each pixel column is sequentially processed by thecolumn processing unit 14 by a selection scanning operation performed by thehorizontal driving unit 15, and is sequentially output.

For example, the control unit 13 configures timing signals according to the operation mode, and controls thevertical driving unit 12, thecolumn processing unit 14, and thehorizontal driving unit 15 to cooperatively operate using a variety of timing signals.

Theimage sensor 10 further includes a filter (not shown) disposed on thepixel array 11. The spectral response of each pixel in the pixel array 11 (i.e., the color of light that the pixel is capable of receiving) is determined by the color of the filter corresponding to that pixel. Color pixels and panchromatic pixels throughout this application refer to pixels that are capable of responding to light of the same color as the corresponding filter color.

For example, fig. 3 is a schematic diagram of apixel circuit 200 connected to an analog-to-digital conversion circuit 16 in this embodiment. Thepixel circuit 200 of fig. 3 is applied to each pixel cell of fig. 2. The operation of thepixel circuit 200 is described with reference to fig. 2 and 3.

As shown in fig. 3, thepixel circuit 200 includes a photoelectric conversion element 260 (e.g., a photodiode PD), an exposure control circuit 250 (e.g., a transfer transistor 210), a reset circuit (e.g., a reset transistor 220), an amplification circuit (e.g., an amplification transistor 230), and a selection circuit (e.g., a selection transistor 240). In the embodiment of the present application, thetransfer transistor 210, thereset transistor 220, the amplifyingtransistor 230, and theselection transistor 240 are, for example, MOS transistors, but are not limited thereto.

For example, referring to fig. 2 and 3, the gate TG of thetransfer transistor 210 is connected to thevertical driving unit 12 through an exposure control line (shown in fig. 8); the gate RG of thereset transistor 220 is connected to thevertical driving unit 12 through a reset control line; the gate SEL of theselection transistor 240 is connected to thevertical driving unit 12 through a selection line. For example, the exposure control circuit 250 (e.g., the transfer transistor 210) is electrically connected to the photoelectric conversion element 260 (e.g., the photodiode PD) for transferring the potential accumulated by thephotoelectric conversion element 260 upon illumination. For example, thephotoelectric conversion element 260 includes a photodiode PD, and an anode of the photodiode PD is connected to, for example, ground. The photodiode PD converts the received light into electric charges. The cathode of the photodiode PD is connected to the floating diffusion unit FD via an exposure control circuit 250 (e.g., the transfer transistor 210). The floating diffusion FD is connected to the gate electrode of theamplification transistor 230 and the source of thereset transistor 220.

For example, the exposure control circuit 250 is thetransfer transistor 210, and the control terminal TG of the exposure control circuit 250 is the gate of thetransfer transistor 210. Thetransfer transistor 210 is turned on when a pulse of an effective level (e.g., VPIX level) is transmitted to the gate of thetransfer transistor 210 through an exposure control line (e.g., TX1 or TX 2). Thetransfer transistor 210 transfers the charge photoelectrically converted by the photodiode PD to the floating diffusion unit FD.

For example, the drain of thereset transistor 220 is connected to the pixel power supply VPIX. A source of thereset transistor 220 is connected to the floating diffusion FD. Before the signal charge is transferred from the photodiode PD to the floating diffusion unit FD, a pulse of an active reset level is transmitted to the gate of thereset transistor 220 via the reset line, and thereset transistor 220 is turned on. Thereset transistor 220 resets the floating diffusion unit FD to the pixel power supply VPIX.

For example, the gate of theamplification transistor 230 is connected to the floating diffusion unit FD. The drain of the amplifyingtransistor 230 is connected to the pixel power supply VPIX. After the floating diffusion FD is reset by thereset transistor 220, theamplification transistor 230 outputs a reset level through the output terminal OUT via theselection transistor 240. After the signal charge of the photodiode PD is transferred by thetransfer transistor 210, the amplifyingtransistor 230 outputs a signal level, which is an analog signal, through the output terminal OUT via theselection transistor 240.

For example, the drain of theselection transistor 240 is connected to the source of theamplification transistor 230. The source of theselection transistor 240 is connected to thecolumn processing unit 14 in fig. 2 through the output terminal OUT. When a pulse of an effective level is transmitted to the gate of theselection transistor 240 through the selection line, theselection transistor 240 is turned on. The analog signal output from the amplifyingtransistor 230 is transmitted to thecolumn processing unit 14 through theselection transistor 240.

It should be noted that the pixel structure of thepixel circuit 200 in the embodiment of the present application is not limited to the structure shown in fig. 3. For example, thepixel circuit 200 may have a three-transistor pixel structure in which the functions of the amplifyingtransistor 230 and theselection transistor 240 are performed by one transistor. For example, the exposure control circuit 250 is not limited to thesingle transfer transistor 210, and other electronic devices or structures with a control terminal controlling the on function can be used as the exposure control circuit 250 in the embodiment of the present application, and thesingle transfer transistor 210 is simple, low-cost and easy to control.

The analog-to-digital conversion circuit 16 is provided in thecolumn processing unit 14 of fig. 2 so that thecolumn processing unit 14 has a function of analog-to-digital conversion. The analog-to-digital conversion circuit 16 includes acomparison signal generator 17, acomparator 18, and acounter 19. When the analog-to-digital conversion circuit 16 is operated, the analog signal output from the output terminal OUT of thepixel circuit 200 corresponding to the panchromatic pixel enters the first input terminal of thecomparator 18, and thecomparison signal generator 17 generates the comparison signal and inputs the comparison signal to the second input terminal of thecomparator 18, and at the same time, thecounter 19 starts counting. When the amplitude of the comparison signal rises to be equal to the amplitude of the analog signal, thecomparator 18 is inverted, thecounter 19 stops counting, and at this time, the value counted by thecounter 19 is the digital signal corresponding to the analog signal.

For example, fig. 4 is a schematic diagram of anotherpixel circuit 200 connected to the analog-to-digital conversion circuit 16 in this embodiment. Unlike fig. 3, the output terminal OUT of thepixel circuit 200 is not directly connected to the analog-to-digital conversion circuit 16, and thepixel circuit 200 and the analog-to-digital conversion circuit 16 are connected through a Correlated Double Sampling (CDS)circuit 300. Correlateddouble sampling circuit 300 includes acapacitor 310, aswitch 320, aramp signal generator 330, and acomparator 340. The correlateddouble sampling circuit 300 can eliminate the interference of reset noise. Specifically, during the reset period, theswitch 320 in the correlateddouble sampling circuit 300 is closed to sample the reset level for the first time, resulting in the reset level. During the signal output period, theswitch 320 in the correlateddouble sampling circuit 300 is turned off to perform the second sampling, and the signal level is obtained. The time interval between two times of sampling is far less than a time constant, so that the noise voltage between two times of sampling is almost the same, and the interference of reset noise can be basically eliminated by subtracting the reset level and the signal level from each other, so as to obtain the actual effective amplitude of the signal level. In the embodiment of the present application, by providing the correlateddouble sampling circuit 300, the interference of reset noise can be eliminated, the signal-to-noise ratio can be significantly improved, and the signal detection precision can be improved.

Referring to fig. 2, 3, 4 and 9, the two-dimensional pixel array of theimage sensor 10 of the present application includes a plurality of color pixels (a pixels, B pixels, C pixels) and a plurality of panchromatic pixels (W pixels), wherein the color pixels have a narrower spectral response than the panchromatic pixels. When thepixel circuit 200 of fig. 3 is applied to a full-color pixel, the output terminal OUT is connected to the analog-to-digital conversion circuit 16 for converting an analog signal output from the full-color pixel into a digital signal. Here, the rate of change of the amplitude of the comparison signal of the analog-to-digital conversion circuit 16 (the comparison signal is a voltage signal, and the amplitude refers to the amplitude of the voltage signal) increases with time.

Fig. 5 is a graph of the amplitude of a linear comparison signal with time in the related art and a graph of the amplitude of a non-linear comparison signal with time in the embodiment of the present application. As shown in fig. 5, the amplitude of the linear comparison signal gradually increases with time, but the rate of change in the amplitude of the linear comparison signal (i.e., the slope of the straight line in fig. 5) does not change. As shown in fig. 5, the nonlinear comparison signal is approximated to an exponential curve, the amplitude of the nonlinear comparison signal gradually increases with time, and the rate of change in the amplitude of the nonlinear comparison signal (i.e., the slope of the curve in fig. 5) also gradually increases.

It will be appreciated that more light per unit time can be received by a panchromatic pixel and, therefore, the analog signal output by the panchromatic pixel will have a greater amplitude. When the linear comparison signal is used, if the input analog signal is large, it takes a long time for the amplitude of the linear comparison signal to rise to be equal to the amplitude of the analog signal, and at this time, the counter 19 (shown in fig. 4) has a long counting time, which easily causes overflow of thecounter 19. However, when the nonlinear comparison signal shown in fig. 5 is used, if the input analog signal is large, the time required for the amplitude of the nonlinear comparison signal to rise to be equal to the amplitude of the analog signal is less than the time required for the amplitude of the linear comparison signal to rise to be equal to the amplitude of the analog signal, and at this time, the counting time of thecounter 19 is short, so that the problem of overflow of thecounter 19 can be avoided. In other words, when the linear comparison signal is used, the conversion rate of the analog signal into the digital signal is always constant, and when the input analog signal is large, the digital signal into which the analog signal is converted is also large, and at this time, thecounter 19 is likely to overflow. With the nonlinear comparison signal shown in fig. 5, the conversion rate of the analog signal into the digital signal decreases as the analog signal increases. When the input analog signal is large, the digital signal converted by the nonlinear comparison signal is small compared with the digital signal converted by the linear comparison signal, and thecounter 19 is not easy to overflow. Therefore, the analog signals output by the panchromatic pixels can be accurately converted into corresponding digital signals, and the problem that the data output by the panchromatic pixels cannot truly reflect the target is solved.

Fig. 6 is a schematic circuit diagram of acomparison signal generator 17 according to an embodiment of the present application. Thecomparison signal generator 17 may generate a non-linear comparison signal as shown in fig. 5 in which the rate of change of the amplitude increases with time. Specifically, thecomparison signal generator 17 includes a voltage source 171 (i.e., VDDA), a plurality ofswitches 172, a plurality of constantcurrent sources 173, and a resistor 174 (i.e., R). One end of each of the plurality ofswitches 172 is electrically connected to thevoltage source 171. A plurality of constantcurrent sources 173 correspond to the plurality ofswitches 172, and one end of each constantcurrent source 173 is electrically connected to the other end of thecorresponding switch 172. The magnitude of the current output by the at least two constantcurrent sources 173 is different. The other end of each constantcurrent source 173 is connected to the second input terminal of thecomparator 18, one end of theresistor 174 is connected between the constantcurrent source 173 and the second input terminal of thecomparator 18, and the other end of theresistor 174 is grounded. That is, one end of theresistor 174 is connected to one end of each constantcurrent source 173, and the other end of theresistor 177 is grounded. As time increases, the plurality ofswitches 172 are sequentially closed, and theswitch 172 electrically connected to the constantcurrent source 173 that outputs a smaller current is closed earlier.

Specifically, the number of constantcurrent sources 173 is equal to the number ofswitches 172. The number of the constantcurrent sources 173 and the number of theswitches 172 may be 5, 6, 7, 8, 10, 20, etc., and are not limited herein. In the embodiment of the present application, 8switches 172 and 8 constantcurrent sources 173 are used as an example for description. For example, the 8switches 172 are respectively aswitch 1721, aswitch 1722, aswitch 1723, aswitch 1724, aswitch 1725, aswitch 1726, aswitch 1727, and aswitch 1728, and the 8 constantcurrent sources 173 electrically connected to theswitch 1721, theswitch 1722, theswitch 1723, theswitch 1724, theswitch 1725, theswitch 1726, theswitch 1727, and theswitch 1728 are respectively a constantcurrent source 1731, a constantcurrent source 1732, a constantcurrent source 1733, a constantcurrent source 1734, a constantcurrent source 1735, a constantcurrent source 1736, a constantcurrent source 1737, and a constantcurrent source 1738. Of the 8 constantcurrent sources 173, at least two constantcurrent sources 173 output currents having different magnitudes. For example, in fig. 6, the constantcurrent source 1731 and the constantcurrent source 1732 each output a current of i, the constantcurrent source 1733 and the constantcurrent source 1734 each output a current of 2i, the constantcurrent source 1735 and the constantcurrent source 1736 each output a current of 4i, and the constantcurrent source 1737 and the constantcurrent source 1738 each output a current of 6 i. Of course, in other embodiments, the magnitude of the current output by each constantcurrent source 173 may also be: the constantcurrent source 1731, the constantcurrent source 1732, and the constantcurrent source 1733 output the same current i, the constantcurrent source 1734, the constantcurrent source 1735, and the constantcurrent source 1736 output the same current 2i, and the constantcurrent source 1737 and the constantcurrent source 1738 output the same current 4 i; alternatively, the magnitude of the current output by each constantcurrent source 173 may be: the constantcurrent source 1731 outputs a current of i, the constantcurrent source 1732 outputs a current of 2i, the constantcurrent source 1733 outputs a current of 3i, and so on, and the constantcurrent source 1738 outputs a current of 8i and so on. The current outputted by each constantcurrent source 173 may have other values as long as the current outputted by at least two constantcurrent sources 173 is different in magnitude, which is not described herein.

The closing process of theswitch 172 is: as time increases, the plurality ofswitches 172 are sequentially closed, and theswitch 172 electrically connected to the constantcurrent source 173 that outputs a smaller current is closed earlier. When there is a plurality of constantcurrent sources 173 whose output currents are equal in magnitude, theswitch 172 electrically connected to any one of the plurality of constantcurrent sources 173 is selected to be closed at random, theswitch 172 electrically connected to the remaining one of the plurality of constantcurrent sources 173 is closed again, and so on until theswitches 172 electrically connected to the plurality of constantcurrent sources 173 outputting the same current are closed, and then theswitch 172 electrically connected to the constantcurrent source 173 outputting a larger current starts to be closed. Taking 8switches 172 and 8 constantcurrent sources 173 shown in fig. 6 as an example, the closing sequence of the 8 switches 172 may be that theswitch 1721, theswitch 1722, theswitch 1723, theswitch 1724, theswitch 1725, theswitch 1726, theswitch 1727, and theswitch 1728 are closed in sequence, and theswitch 1722, theswitch 1721, theswitch 1724, theswitch 1723, theswitch 1726, theswitch 1725, theswitch 1728, and theswitch 1727 are closed in sequence. The interval between the closing moments of any two successivelyclosed switches 172 may be equal or unequal. For example, the interval between the closing time of theswitch 1721 and the closing time of theswitch 1722 may be t1, the interval between the closing time of theswitch 1722 and the closing time of theswitch 1723 may be t2, t1 may be equal to t2, or t1 may be different from t2, which is not limited herein.

The amplitude V of the comparison signal satisfies the formula: v is n × i × R, where n × i represents the magnitude of the current that can be supplied by the plurality ofcurrent sources 173 with the correspondingswitches 172 closed, and R is the resistance value of theresistor 174. Taking fig. 6 as an example, when only theswitch 1721 is closed, V ═ iR; when theswitch 1721 and theswitch 1722 are closed, V ═ 2 iR; when theswitch 1721, theswitch 1722, and theswitch 1723 are closed, V ═ 4 iR; by analogy, when all 8switches 172 are closed, V ═ 26 iR. As such, the number of the constantcurrent sources 173 that supply current for generation of the comparison signal can be gradually increased by the closing control of theswitch 172, so that a continuous increase in the amplitude of the comparison signal can be achieved. Further, since the closing sequence of theswitch 172 is such that theswitch 172 electrically connected to the constantcurrent source 173 outputting a smaller current is closed earlier, the newly added constantcurrent source 173 can supply a larger current as time increases, thereby allowing the rate of change in the amplitude of the comparison signal to gradually increase as time increases.

Fig. 7 is a schematic circuit diagram of anothercomparison signal generator 17 according to the embodiment of the present application. Thecomparison signal generator 17 may generate a comparison signal with an increasing rate of change of amplitude over time as shown in fig. 5. Thecomparison signal generator 17 includes avoltage source 175, an adjustablecurrent source 176, and aresistor 177. One terminal of the adjustablecurrent source 176 is electrically connected to one terminal of thevoltage source 175, and the other terminal of thevoltage source 175 is connected to a second input terminal of thecomparator 18. One terminal of theresistor 177 is connected between the adjustablecurrent source 176 and the second input terminal of thecomparator 18, and the other terminal of theresistor 177 is connected to ground. That is, one end of theresistor 177 is connected to one end of the adjustablecurrent source 176, and the other end of theresistor 177 is grounded. As time increases, the magnitude of the current output by the adjustablecurrent source 176 gradually increases, and the rate of change of the magnitude of the current gradually increases.

Specifically, the comparison signal of the analog-to-digital conversion circuit 16 satisfies the formula: v is the amplitude of the comparison signal, R is the resistance of theresistor 177, and I represents the amount of current that the adjustablecurrent source 176 can supply. As time increases, the rate of change of the amplitude of the current I output by the adjustablecurrent source 176 gradually increases, for example, when t is t1, I1 is I, and V is IR; when t is t2, I2 is 5I, then V is 5 IR; when t is t3, I3 is 12I, then V is 12 IR; when t is t4, I4 is 21I, V is 21IR, and so on. In this manner, a continuous increase in the magnitude of the comparison signal may be achieved through control of the current output by the adjustablecurrent source 176. Further, since the rate of change in the amplitude of the current output by the adjustablecurrent source 176 gradually increases, the increasing current of the adjustablecurrent source 176 increases with increasing time, thereby allowing the rate of change in the amplitude of the comparison signal to gradually increase with increasing time.

It is noted that the sensitivities in the color pixels and panchromatic pixels are ordered from strong to weak as: w > G > R > B, wherein the sensitivity represents the exposure of a pixel per unit time, and a pixel with a greater exposure per unit time has a higher sensitivity. As can be seen from the difference in the sensitivity levels of the R pixel, the G pixel, and the B pixel, the sensitivity of the G pixel is higher than that of the R pixel and higher than that of the B pixel, and the G pixel may be overexposed. Therefore, the analog signal output by the G pixel can also be analog-to-digital converted by the analog-to-digital conversion circuit 16, so that the problem of overexposure of the G pixel is avoided, and the imaging quality is improved.

On the basis of setting the analog-to-digital conversion circuit of the panchromatic pixel as the analog-to-digital conversion circuit 16, the exposure of the panchromatic pixel and the color pixel can be further balanced by independently controlling the exposure time of the panchromatic pixel and the exposure time of the color pixel, so that the problem of overexposure of the panchromatic pixel is avoided.

Fig. 8 is a schematic diagram illustrating a connection manner between a pixel array and an exposure control line in the embodiment of the present application. Referring to fig. 8, a part of pixels in thepixel array 11 is taken as an example for explanation, and the pixels are arranged as follows:

for convenience of illustration, fig. 8 shows only some of the pixels in thepixel array 11, and other pixels and lines in the periphery are replaced with an ellipsis "… …".

As shown in fig. 8,

pixels

201, 203, 206, 208, 209, 211, 214, 216 are full-color pixels W,

pixels

202, 205 are first-color pixels a (e.g., red pixels R),

pixels

204, 207, 210, 213 are second-color pixels B (e.g., green pixels G), and

pixels

212, 215 are third-color pixels C (e.g., blue pixels Bu). As can be seen from fig. 8, the control terminal TG of the exposure control circuit in the full-color pixel W (

pixels

201, 203, 206, and 208) is connected to one first exposure control line TX1, and the control terminal TG of the exposure control circuit in the full-color pixel W (

pixels

209, 211, 214, and 216) is connected to another first exposurecontrol line TX 1; the control terminal TG of the exposure control circuit in the first color pixel a (pixels 202 and 205), the control terminal TG of the exposure control circuit in the second color pixel B (pixels 204 and 207), the control terminal TG of the exposure control circuit in the second color pixel B (pixels 210 and 213), and the control terminal TG of the exposure control circuit in the third color pixel C (pixels 212 and 215) are connected to one second exposure control line TX2, and the other second exposure control line TX 2. Each of the first exposure control lines TX1 may control the exposure time period of the full-color pixels by a first exposure control signal; each of the second exposure control lines TX2 may control an exposure time period of color pixels (e.g., the first and second color pixels a and B, the second color pixel B, and the third color pixel C) by a second exposure control signal. Thereby realizing independent control of exposure time of the panchromatic pixel and the color pixel. For example, it can be realized that at the end of the exposure of the panchromatic pixels, the exposure of the color pixels is continued to achieve the desired imaging effect.

It should be noted that the terms "first", "second", etc. herein and in the context are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features.

For example, referring to fig. 2 and 8, the first exposure control line TX1 and the second exposure control line TX2 are connected to thevertical driving unit 12 in fig. 2, and transmit respective exposure control signals in thevertical driving unit 12 to the control terminal TG of the pixel cell exposure control circuit in thepixel array 11.

It is to be understood that, since there are a plurality of rows in thepixel array 11, thevertical driving unit 12 is connected to the plurality of first exposure control lines TX1 and the plurality of second exposure control lines TX 2. The plurality of first exposure control lines TX1 and the plurality of second exposure control lines TX2 correspond to respective pixel row groups.

For example, a first exposure control line TX1 corresponds to panchromatic pixels in a first row and a second row; the second first exposure control line TX1 corresponds to the panchromatic pixels in the third and fourth rows, and so on, and will not be described again. The timing of signals transmitted by different first exposure control lines TX1, which are configured by thevertical driving unit 12, may also be different.

For example, the first second exposure control line TX2 corresponds to color pixels in the first and second rows; the second exposure control line TX2 corresponds to the color pixels in the third and fourth rows, and so on, and will not be described again. The timing of signals transmitted by different second exposure control lines TX2, which are also configured by thevertical driving unit 12, may also be different.

For example, fig. 9-24 show examples of pixel arrangements invarious image sensors 10, see fig. 9-24. Theimage sensor 10 includes a two-dimensional pixel array composed of a plurality of color pixels (e.g., a plurality of first color pixels a, a plurality of second color pixels B, and a plurality of third color pixels C) and a plurality of panchromatic pixels W. For example, color pixels have a narrower spectral response than panchromatic pixels. The response spectrum of a color pixel is, for example, part of the response spectrum of a panchromatic pixel W. The two-dimensional pixel array includes a minimal repeating unit (fig. 9-24 show various examples of pixel minimal repeating units in theimage sensor 10 of fig. 2). In the minimum repeating unit, the panchromatic pixels W are arranged in a first diagonal direction D1, and the color pixels are arranged in a second diagonal direction D2, the first diagonal direction being different from the second diagonal direction. The first exposure time of at least two panchromatic pixels adjacent to the first diagonal direction D1 is controlled by a first exposure signal, and the second exposure time of at least two color pixels adjacent to the second diagonal direction D2 is controlled by a second exposure signal, thereby achieving independent control of the panchromatic pixel exposure time and the color pixel exposure time.

For example, the minimum repeating unit row and column have equal numbers of pixels. For example, the minimal repeating unit includes, but is not limited to, 4 rows and 4 columns, 6 rows and 6 columns, 8 rows and 8 columns, and 10 rows and 10 columns. The arrangement is helpful for balancing the resolution of the image in the row direction and the column direction and balancing the color expression, thereby improving the display effect.

For example, fig. 9 is a schematic diagram of a pixel arrangement of a minimalrepeating unit 510 in an embodiment of the present application; the minimum repeating unit is 4 rows, 4 columns and 16 pixels, and the arrangement mode is as follows:

w denotes a panchromatic pixel; a denotes a first color pixel of the plurality of color pixels; b denotes a second color pixel of the plurality of color pixels; c denotes a third color pixel of the plurality of color pixels.

It should be noted that the first diagonal direction D1 and the second diagonal direction D2 are not limited to diagonal lines, and include directions parallel to diagonal lines. The "direction" herein is not a single direction, and is understood as a concept of "straight line" indicating arrangement, and there may be a bidirectional direction of both ends of the straight line.

It is to be understood that the terms "upper", "lower", "left", "right", and the like herein and hereinafter are used in the appended drawings to indicate orientations and positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated in a particular orientation, and thus should not be construed as limiting the present application.

For example, as shown in fig. 9, the panchromatic pixels of the first and second rows are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (a and B) of the first and second rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels in the third and fourth rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the third and fourth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. For example, a first exposure signal is transmitted via the first exposure control line TX1, and a second exposure signal is transmitted via the second exposure control line TX 2. For example, the first exposure control line TX1 is in a "W" shape and is electrically connected to the control terminals of the exposure control circuits in the full-color pixels of two adjacent rows; the second exposure control line TX2 is in a "W" shape and is electrically connected to the control terminals of the exposure control circuits in the color pixels in two adjacent rows. The specific connection manner can be seen from the description of the connection and the pixel circuit in the relevant part of fig. 3 and fig. 8.

It should be noted that the first exposure control line TX1 and the second exposure control line TX2 are "W" type, which does not mean that the physical wiring must be strictly set up according to "W" type, and only the connection mode is required to correspond to the arrangement of the panchromatic pixels and the color pixels. For example, the setting of the W-shaped exposure control line corresponds to the W-shaped pixel arrangement mode, the wiring of the arrangement mode is simple, the resolving power and the color of the pixel arrangement have good effects, and the independent control of the exposure time of full-color pixels and the exposure time of color pixels is realized at low cost.

For example, fig. 10 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 520 in the embodiment of the present application. The minimum repeating unit is 4 rows, 4 columns and 16 pixels, and the arrangement mode is as follows:

For example, as shown in fig. 10, the panchromatic pixels W are arranged in a first diagonal direction D1 (i.e., the direction in which the upper right corner and the lower left corner in fig. 10 are connected), and the color pixels are arranged in a second diagonal direction D2 (e.g., the direction in which the upper left corner and the lower right corner in fig. 10 are connected). For example, the first diagonal and the second diagonal are perpendicular. A first exposure time of two panchromatic pixels W adjacent in the first diagonal direction D1 (for example, two panchromatic pixels of the first row and the second column from the upper left and the second row and the first column) is controlled by a first exposure signal, and a second exposure time of at least two color pixels adjacent in the second diagonal direction (for example, two color pixels a of the first row and the first column from the upper left and the second row and the second column) is controlled by a second exposure signal.

For example, as shown in fig. 10, the panchromatic pixels of the first and second rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (a and B) of the first and second rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels in the third and fourth rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the third and fourth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time.

For example, fig. 11 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 530 in this embodiment. Fig. 12 is a schematic diagram of a pixel arrangement of aminimum repeating unit 540 according to an embodiment of the present application. In the embodiment of fig. 11 and 12, corresponding to the arrangement of fig. 9 and 10, the first color pixel a is a red pixel R; the second color pixel B is a green pixel G; the third color pixel C is a blue pixel Bu.

It is noted that in some embodiments, the response band of the panchromatic pixel W is the visible band (e.g., 400nm-760 nm). For example, an infrared filter is disposed on the panchromatic pixel W to filter infrared light. In some embodiments, the response bands of the panchromatic pixels W are in the visible and near infrared (e.g., 400nm-1000nm) bands, matching the response bands of the photodiodes PD (described in FIG. 3) in the image sensor 10 (shown in FIG. 2). For example, the panchromatic pixel W may be provided without a filter, and the response band of the panchromatic pixel W is determined by the response band of the photodiode PD, that is, matched. Embodiments of the present application include, but are not limited to, the above-described band ranges.

For example, fig. 13 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 550 in this embodiment. Fig. 14 is a schematic diagram of a pixel arrangement of aminimum repeating unit 560 according to an embodiment of the present application. In the embodiment of fig. 13 and 14, corresponding to the arrangement of fig. 9 and 10, the first color pixel a is a red pixel R; the second color pixel B is a yellow pixel Y; the third color pixel C is a blue pixel Bu.

For example, fig. 15 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 570 in this embodiment mode. Fig. 16 is a schematic diagram of a pixel arrangement of aminimum repeating unit 580 according to an embodiment of the present application. In the embodiment of fig. 15 and 16, the first color pixel a is a magenta color pixel M corresponding to the arrangement of fig. 9 and 10; the second color pixel B is a cyan color pixel Cy; the third color pixel C is a yellow pixel Y.

For example, fig. 17 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 610 in this embodiment mode. The minimum repeating unit is 6 rows, 6 columns and 36 pixels, and the arrangement mode is as follows:

For example, as shown in fig. 17, the full-color pixels of the first and second rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the full-color pixels. The color pixels (a and B) of the first and second rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels in the third and fourth rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (A, B and C) of the third and fourth rows are connected together by a second exposure control line TX2 in the shape of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels of the fifth row and the sixth row are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the fifth and sixth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time.

For example, fig. 18 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 620 in this embodiment mode. The minimum repeating unit is 6 rows, 6 columns and 36 pixels, and the arrangement mode is as follows:

For example, as shown in fig. 18, the full-color pixels of the first and second rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the full-color pixels. The color pixels (a and B) of the first and second rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels in the third and fourth rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (A, B and C) of the third and fourth rows are connected together by a second exposure control line TX2 in the shape of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels of the fifth row and the sixth row are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the fifth and sixth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time.

For example, fig. 19 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 630 in this embodiment mode. Fig. 20 is a schematic diagram of a pixel arrangement of aminimum repeating unit 640 according to an embodiment of the present disclosure. In the embodiment of fig. 19 and 20, corresponding to the arrangement of fig. 17 and 18, respectively, the first color pixel a is a red color pixel R; the second color pixel B is a green pixel G; the third color pixel C is a blue pixel Bu.

For example, in other embodiments, the first color pixel a is a red pixel R; the second color pixel B is a yellow pixel Y; the third color pixel C is a blue pixel Bu. For example, the first color pixel a is a magenta color pixel M; the second color pixel B is a cyan color pixel Cy; the third color pixel C is a yellow pixel Y. Embodiments of the present application include, but are not limited to, the following. The specific connection manner of the circuit is described above, and is not described herein again.

For example, fig. 21 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 710 in this embodiment. The minimum repeating unit is 8 rows, 8 columns and 64 pixels, and the arrangement mode is as follows:

For example, as shown in fig. 21, the full-color pixels of the first and second rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the full-color pixels. The color pixels (a and B) of the first and second rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels in the third and fourth rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (a and B) of the third and fourth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels of the fifth row and the sixth row are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the fifth and sixth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels of the seventh and eighth rows are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the seventh and eighth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time.

For example, fig. 22 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 720 in this embodiment mode. The minimum repeating unit is 8 rows, 8 columns and 64 pixels, and the arrangement mode is as follows:

For example, as shown in fig. 22, the full-color pixels of the first and second rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the full-color pixels. The color pixels (a and B) of the first and second rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels in the third and fourth rows are connected together by a first exposure control line TX1 in the form of a "W" to achieve individual control of the exposure time of the panchromatic pixels. The color pixels (a and B) of the third and fourth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels of the fifth row and the sixth row are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the fifth and sixth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time. The panchromatic pixels of the seventh and eighth rows are connected together by a first exposure control line TX1 in the form of a "W" to enable individual control of the exposure time of the panchromatic pixels. The color pixels (B and C) of the seventh and eighth rows are connected together by a second exposure control line TX2 in the form of a "W" to enable individual control of the color pixel exposure time.

For example, fig. 23 is a schematic diagram of a pixel arrangement of anotherminimum repeating unit 730 in the embodiment of the present application. Fig. 24 is a schematic diagram of a pixel arrangement of aminimum repeating unit 740 in an embodiment of the present application. In the embodiment of fig. 23 and 24, corresponding to the arrangement of fig. 21 and 22, respectively, the first color pixel a is a red pixel R; the second color pixel B is a green pixel G; the third color pixel C is a blue pixel Bu.

As can be seen from the above-described embodiments, theimage sensor 10 includes a plurality of color pixels and a plurality of panchromatic pixels W arranged in a matrix, the color pixels and the panchromatic pixels being arranged at intervals in the row and column directions, as shown in fig. 9 to 24.

For example, panchromatic pixels, color pixels … … are alternately arranged in this order in the row direction

For example, panchromatic pixels, color pixels … … are alternately arranged in the column direction in this order

The first exposure control line TX1 is electrically connected to the control terminal TG (e.g., the gate of the transfer transistor 210) of the exposure control circuit 250 (shown in fig. 3) in the full-color pixels W in the 2n-1 th and 2 n-th rows; a second exposure control line TX2 electrically connected to the control terminal TG (e.g., the gate of the transfer transistor 210) of the exposure control circuit 250 in the color pixels of the 2n-1 th and 2 n-th rows; n is a natural number of 1 or more.

For example, when n is 1, the first exposure control line TX1 is electrically connected to the control terminal of the exposure control circuit 250 in the full-color pixels W in the 1 st and 2 nd rows; the second exposure control line TX2 is electrically connected to the control terminals of the exposure control circuits 250 in the color pixels in the 1 st and 2 nd rows. When n is 2, the first exposure control line TX1 is electrically connected to the control terminal of the exposure control circuit 250 in the full-color pixels W in the 3 rd and 4 th rows; the second exposure control line TX2 is electrically connected to the control terminals of the exposure control circuits 250 in the color pixels in the 3 rd and 4 th rows. And so on, and will not be described herein.

In some embodiments, the first exposure time is less than the second exposure time. In some embodiments, the ratio of the first exposure time to the second exposure time is 1: 2,1: 3 or 1: 4. For example, in an environment with dark light, the color pixels are more likely to be underexposed, and the ratio of the first exposure time to the second exposure time can be adjusted to be 1: 2,1: 3 or 1: 4. for example, in the case where the exposure ratio is the above-described integer ratio or a ratio close to the integer ratio, setting and control of the setting signal of the timing are facilitated.

For example, fig. 25 is a flowchart illustrating an image capturing method according to an embodiment of the present disclosure. As shown in fig. 25, the method includes:

step 810, obtaining ambient brightness;

step 820, judging whether the ambient brightness is less than a brightness threshold value;

step 830, if yes, controlling the first exposure time to be equal to the second exposure time;

instep 840, if not, the first exposure time is controlled to be less than the second exposure time.

For example, in the above method, a first exposure time for the 2n-1 th and 2n th row panchromatic pixels is controlled with a first exposure signal; controlling a second exposure time of the 2n-1 th row and the 2n th row of color pixels by using a second exposure signal; the color pixels and the panchromatic pixels are arranged at intervals in the directions of rows and columns; the first exposure time is less than or equal to the second exposure time; n is a natural number of 1 or more.

For example, fig. 26 is a schematic view of acamera head assembly 20 according to an embodiment of the present disclosure. Thecamera assembly 20 includes animage sensor 10, alens 21, and acircuit component 22 of any embodiment of the present application. Thelens 21 is used for imaging onto theimage sensor 10, for example, light of a subject is imaged onto theimage sensor 10 through thelens 21, and theimage sensor 10 is disposed on a focal plane of thelens 21. Thecircuit component 22 is used for obtaining power and transmitting data to the outside, for example, the circuit component can be connected with a power supply of our department to obtain power, and can also be connected with a memory and a processor to transmit image data or control data.

For example, thecamera assembly 20 may be provided on the back of a cell phone as a rear camera. It will be appreciated that thecamera assembly 20 may also be provided on the front of the handset as a front facing camera.

For example, fig. 27 is a schematic diagram of amobile terminal 900 according to an embodiment of the present application. Themobile terminal 900 includes acamera assembly 20 according to any embodiment of the present application.

For example,mobile terminal 900 further includes:display component 50,memory 60,processor 70, andstructure 80. Thecamera assembly 20 is disposed on astructural member 80, for example, thestructural member 80 includes a center frame and a back plate, and thecamera assembly 20 is fixedly disposed on the center frame or the back plate.

For example,memory 60 is used to store images acquired bycamera assembly 20. For example,processor 70 is used to process images acquired bycamera assembly 20. For example, thememory 60 stores a computer program, and theprocessor 70 implements the image capturing method according to the embodiment of the present application when executing the computer program. For example, thedisplay unit 50 is used to display an image captured by thecamera assembly 20.

For example, themobile terminal 900 may be a mobile phone, a tablet computer, a notebook computer, a smart band, a smart watch, a smart helmet, smart glasses, and the like. In the embodiment of the present application, a mobile phone is taken as an example for description. It is understood that the specific form of the mobile terminal may be other, and is not limited herein.

The above embodiments are merely examples and are not intended to limit the scope of the present disclosure, and all modifications, equivalents, and flow charts using the contents of the specification and drawings of the present disclosure or those directly or indirectly applied to other related technical fields are intended to be included in the scope of the present disclosure.