Disclosure of Invention
The invention provides a backlight module to solve the problem that the brightness of the display product is not uniform at different viewing angles in a sharing mode.
In order to solve the above problems, an aspect of the present invention discloses a backlight module, including:
a first light guide plate;
the first light source is arranged on the light incident side of the first light guide plate;
a second light guide plate disposed on the first light guide plate;
the second light source is arranged on the light incident side of the second light guide plate;
the prism sheet is arranged on one surface, deviating from the first light guide plate, of the second light guide plate;
when the first light source is started, light rays emitted by the first light guide plate are refracted and dispersed by the prism sheet, and the sharing mode of the backlight module is realized; when the first light source is turned off and the second light source is turned on, light rays emitted by the second light guide plate are narrowed through the folding and the contraction of the prism sheet, and the peep-proof mode of the backlight module is realized.
Optionally, the prism sheet includes: a substrate and a plurality of light-transmitting structures; the plurality of light-transmitting structures are arranged on the base material in parallel; the light-transmitting structure is arranged between the substrate and the second light guide plate; the light-transmitting structure is used for adjusting light rays incident to the light-transmitting structure into wide light beam distribution when the first light guide plate works, and narrowing the light rays incident to the light-transmitting structure when the second light guide plate works.
Optionally, a cross-sectional shape of the light-transmitting structure in a direction perpendicular to the substrate includes: acute-angled triangle; the base edge of the acute triangle is positioned on the base material, and the angles of the two base angles of the acute triangle are different.
Optionally, the angles of the two bottom angles are both 40-85 degrees.
Optionally, a second dot structure is disposed on a surface of the second light guide plate facing the first light guide plate; the second dot structure is configured to control the exit angle of the light emitted by the second light guide plate to be 70-85 degrees.
Optionally, the second dot structure includes: the light source comprises a light incident surface, a first bottom surface, a second bottom surface, a first side surface, a second side surface and an upper surface; the light incident surface is used for receiving incident light rays incident to the second dot structure; the first bottom surface and the second bottom surface are used for converging the vertical incident light; the first side surface and the second side surface are used for converging the horizontal incident light, and the light converged by the first bottom surface, the second bottom surface, the first side surface and the second side surface is emitted from the upper surface and is incident to the prism sheet.
Optionally, a first dot structure is disposed on a side of the first light guide plate facing away from the second light guide plate; the first dot structure includes a circular dot or a special-shaped dot.
Optionally, the outer surface of the shaped mesh point comprises: free-form surfaces and flat surfaces; the free-form surface surrounds the periphery of the plane; the free-form surface includes: a convex surface.
Optionally, the shaped dots comprise: a polyhedral structure; the polyhedral structure includes: an upper surface, a lower surface, and a plurality of sides connecting the upper surface and the lower surface.
Optionally, a reflective sheet; the reflector plate is arranged on one side, away from the second light guide plate, of the first light guide plate.
Optionally, the method further comprises: a polymer dispersed liquid crystal layer; the polymer dispersed liquid crystal layer is arranged on one side of the prism sheet, which is far away from the second light guide plate.
Optionally, the method further comprises: a photoresist layer; the light resistance layer is arranged between the polymer dispersed liquid crystal layer and the prism sheet.
Optionally, the first light source and the second light source are located on two opposite sides of the backlight module.
A second aspect of the present invention provides a display device comprising: display panel and backlight module as in any above.
Optionally, one side of the display panel, which is away from the backlight module, is provided with a liquid crystal grating.
The backlight module provided by the embodiment of the invention comprises: a first light guide plate; the first light source is arranged on the light incident side of the first light guide plate; a second light guide plate disposed on the first light guide plate; the second light source is arranged on the light incident side of the second light guide plate; the prism sheet is arranged on one surface, deviating from the first light guide plate, of the second light guide plate; when the first light source is started, light rays emitted by the first light guide plate are refracted and dispersed by the prism sheet, and the sharing mode of the backlight module is realized; when the first light source is turned off and the second light source is turned on, light rays emitted by the second light guide plate are narrowed through the folding and the contraction of the prism sheet, and the peep-proof mode of the backlight module is realized. In the embodiment of the invention, the switching between the sharing mode and the peep-proof mode can be realized by controlling the first light guide plate, the second light guide plate and the prism to deflect the incident light, and the realization mode is simpler. Moreover, the brightness of the backlight module at the main viewing angle and the sub viewing angle in the sharing mode can be more uniform through the folding of the prism sheet.
Example one
Referring to fig. 1, a schematic structural diagram of abacklight module 10 according to a first embodiment of the invention is shown; the backlight module comprises:
a firstlight guide plate 11;
afirst light source 12, wherein thefirst light source 12 is disposed at a light incident side of the firstlight guide plate 11;
a secondlight guide plate 13, the secondlight guide plate 13 being disposed on the firstlight guide plate 11;
asecond light source 14, wherein thesecond light source 14 is disposed at the light incident side of the secondlight guide plate 13;
theprism sheet 15, theprism sheet 15 is arranged on one side of the secondlight guide plate 13 departing from the firstlight guide plate 11;
when thefirst light source 12 is turned on, the light emitted from the firstlight guide plate 11 is refracted and dispersed by theprism sheet 15, so as to realize the sharing mode of the backlight module; when thefirst light source 12 is turned off and thesecond light source 14 is turned on, the light emitted from the secondlight guide plate 13 is narrowed by theprism sheet 15, so as to realize the peep-proof mode of the backlight module.
In the embodiment of the invention, when thefirst light source 12 is turned on and thesecond light source 14 is turned off, thefirst light source 12 is turned on and thesecond light source 14 is turned on, both of which can realize the sharing mode of the backlight module.
When thefirst light source 12 is turned on and thesecond light source 14 is turned off, the central light emitted by the backlight module deflects, so that the brightness of the main viewing angle and the auxiliary viewing angle is uniform, and the viewing experience of the auxiliary viewing angle is not influenced. When thefirst light source 12 is turned on and thesecond light source 14 is turned on, the light emitted by the backlight module has two peak values, one peak value points to the main viewing angle, and the other peak value points to the auxiliary viewing angle, so that the viewing experience of the auxiliary viewing angle can be improved.
In the embodiment of the invention, when thefirst light source 12 is turned on and thesecond light source 14 is turned off, the light is refracted and reflected by the firstlight guide plate 11, passes through the second light guide plate, and is then refracted and dispersed by the prism sheet.
In the embodiment of the present invention, referring to fig. 2, theprism sheet 15 includes: asubstrate 151 and a plurality of light-transmittingstructures 152; the plurality of light-transmittingstructures 152 are arranged on thesubstrate 151 in parallel; the light-transmittingstructure 152 is disposed between thesubstrate 151 and the secondlight guide plate 13; the light-transmittingstructure 152 is configured to adjust light incident to the light-transmitting structure into a wide beam distribution when the first light guide plate operates, referring to fig. 11, and narrow light incident to the light-transmitting structure when the second light guide plate operates, referring to fig. 5.
In the embodiment of the present invention, the material of thesubstrate 151 is different from that of the light-transmittingstructure 152.
Among them, the material of thebase 151 includes: polyethylene terephthalate (PET), and the material of the light-transmittingstructure 152 includes: the light-curable material is formed by irradiating a light-transmittingstructure 152 on a substrate in a roll-to-roll manner with Ultraviolet (UV) light, and curing. The refractive indices of thebase material 151 and the light-transmittingmaterial 152 are close to each other in consideration of the influence of thermal expansion, but the refractive index of the prism may be appropriately adjusted in consideration of the scratch resistance of the prism. In this example, the refractive index of the base PET was 1.5, and the refractive index of the prism structure was 1.57.
In the embodiment of the present invention, theprism sheet 15 is located on a side of the secondlight guide plate 11 away from the firstlight guide plate 11, and has the functions of refracting light and satisfying the narrow viewing angle mode and the wide viewing angle mode, respectively.
In the embodiment of the present invention, the cross-sectional shape of the light-transmittingstructure 152 along the direction perpendicular to the substrate includes: acute-angled triangle; the base edge of the acute triangle is positioned on the base material, and the angles of the two base angles of the acute triangle are different.
In the embodiment of the invention, the angles of the two bottom angles are 40-85 degrees.
Referring to fig. 2, a first base angle a of the two base angles is smaller than a second base angle B. (ii) a The vertical distance from the top angle to the bottom edge of the light-transmitting structure, i.e. the height h of the light-transmitting structure, is 20-30 μm. The thickness of the base material is 70-80 μm, and the thickness of the whole prism sheet is 90-110 μm. The side corresponding to the bottom angle a corresponds to the light incident on the prism sheet in the privacy mode, and the side corresponding to the bottom angle B corresponds to the light incident on the prism sheet in the sharing mode. The base angle A and the second light source are arranged on the same side of the backlight module, and the base angle B and the first light source are arranged on the same side of the backlight module.
Preferably, the first base angle a is 50 ° and the second base angle B is 56 °.
In the embodiment of the present invention, referring to fig. 3, when thefirst light source 12 is turned on and the secondlight source 14 is turned off, the firstlight guide plate 11 starts to operate, the light emitted from the firstlight guide plate 11 passes through the secondlight guide plate 13, and is deflected by theprism sheet 15, and the area (X area in fig. 3) where the maximum brightness is located between two observers, so as to ensure that the two observers have higher observation brightness, and implement the sharing mode of the backlight module.
In the embodiment of the invention, referring to fig. 4, when thefirst light source 12 is turned off and the secondlight source 14 is turned on, the secondlight guide plate 13 starts to operate, and the light emitted from the secondlight guide plate 13 is refracted by the prism sheet to narrow the light beam incident to the light-transmitting structure, as shown in the Y region in fig. 4, so as to realize the peep-proof mode of the backlight module.
In the embodiment of the present invention, referring to fig. 1, afirst dot structure 111 is disposed on a surface of the firstlight guide plate 11 facing away from the secondlight guide plate 13.
In the embodiment of the present invention, referring to fig. 5, asecond dot structure 131 is disposed on a surface of the secondlight guide plate 13 facing the firstlight guide plate 11; thesecond dot structures 131 are configured to control the exit angle θ 2 of the light ray X emitted from the secondlight guide plate 13 to be 70 ° -85 °.
Wherein, the material of the secondlight guide plate 13 includes: polymethyl methacrylate (PMMA); the refractive index is 1.49, the total reflection angle corresponding to the secondlight guide plate 13 is 42 °, the light ray X is transmitted forward in the secondlight guide plate 13 in a total reflection manner, when encountering thesecond dot structure 131, the total reflection is broken, the light ray X is emitted from the side of the secondlight guide plate 13 facing theprism sheet 15, and n1sin θ 1 — n2sin θ 2 according to the law of refraction; wherein n1 is the refractive index of the secondlight guide plate 13, and is 1.49; when θ 1 is 42 ° in total reflection angle and n2 is 1 in refractive index of air, it can be calculated that θ 2 is 85 ° and the angle formed by the exit angle of the light ray X from the secondlight guide plate 13 and the normal line is 85 °.
In the embodiment of the present invention, the direction of the totally reflected emergent ray X can be adjusted by changing the inclination angle of the bottom oblique side of thesecond dot structure 131, so that the emergent angle of the ray X is controlled to be 70-85 °. The light ray X passes through the two sides of the light-transmittingstructure 152, so that the light ray X can be emitted out of theprism sheet 15 at an angle of 0 ° ± 10 ° in the vertical direction, thereby achieving the anti-peeping mode of the backlight module. The vertical direction is a direction perpendicular to the plane of the secondlight guide plate 13, and the horizontal direction is a direction parallel to the plane of the secondlight guide plate 13.
In the embodiment of the present invention, refer to fig. 6, wherein (b) in fig. 6 is a top view of (a); (c) a left view of (a); (d) a front view of (a); thesecond dot structure 131 includes: alight incident surface 1311, afirst bottom surface 1312, asecond bottom surface 1313, afirst side surface 1314, asecond side surface 1315, and anupper surface 1316; the light incident surface is used for receiving incident light rays incident to the second dot structure; the first bottom surface and the second bottom surface are used for converging the vertical incident light; the first side surface and the second side surface are used for converging the horizontal incident light, and the light converged by the first bottom surface, the second bottom surface, the first side surface and the second side surface is emitted from the upper surface and is incident to the prism sheet.
In the embodiment of the present invention, the light-transmittingstructure 152 and thesecond dot structure 131 need to be matched with each other to adjust the light-emitting direction, the light-transmittingstructure 152 includes a first base angle a and a second base angle B, the first base angle a is smaller than the second base angle B, the cross section of the second dot structure has a third base angle and a fourth base angle, where the third base angle is an included angle between thefirst side surface 1314 and theupper surface 1316, and the fourth base angle is an included angle between thesecond side surface 1315 and theupper surface 1316; the third base angle is larger than the fourth base angle, and the second base angle and the fourth base angle are positioned on the same side.
In fig. 6(a), thelight incident surface 1311, thefirst bottom surface 1312, and thesecond bottom surface 1313 are regions drawn with lighter lines in the drawing, and thefirst side surface 1314, thesecond side surface 1315, and theupper surface 1316 are regions drawn with darker lines in the drawing.
In the embodiment of the present invention, thefirst side 1314 and thesecond side 1315 re-shrink the light beam in a range of 10 ° to 20 ° based on the light beam shrinkage of the light beam controlled by the second light guide plate in the horizontal direction.
In an embodiment of the present invention, the first dot structure includes: and the circular mesh points enable the central visual angle of the light beam to deflect a specified angle towards a specified direction after the light beam incident to the first light guide plate is emergent through the first light guide plate, the second light guide plate and the prism sheet.
The circular mesh points are used for breaking total reflection in the first light guide plate, light rays are reflected and refracted at the circular mesh points, and the reflected light rays are shared through the second light guide plate and the prism.
In the embodiment of the invention, for example, referring to fig. 7, in order to illustrate the space distance in a conventional small car, the distance L1 between the copilot and the copilot display panel is 0.75 m, the distance between the driver and the copilot is 0.7 m, and the included angle C is 43 °, when the horizontal cut-off angle of the copilot display panel is less than or equal to 43 °, the peep-proof mode is implemented, that is, the driver cannot see the display content of the copilot display panel. If the sharing mode needs to be realized, the central visual angle needs to be deflected to the driver, so that the central visual angle is located between the driver and the copilot, because the distance between the driver and the display panel is farther, in order to enable the screen brightness obtained by the driver and the display panel to meet the brightness requirement, the central visual angle can be selected to be more inclined to the driver, the central visual angle can be selected to be deflected to the driver by about 32 degrees, so that the visual obstacle caused by the brightness when the driver sees the display panel is reduced, and the driving risk is reduced, wherein the deflection range of the central visual angle is greater than or equal to 32 degrees and less than or equal to 43 degrees, and the good picture effect can be obtained by the driver and the copilot in the range.
In the embodiment of the invention, in the peep-proof mode, referring to fig. 4, the half light intensity angle in the horizontal direction is 20-25 degrees, the cut-off angle is about 40 degrees, the driver cannot view the picture of the display panel under the viewing angle, and the picture of the display panel cannot be projected on the window, so that the driving of the driver is not influenced.
In the embodiment of the present invention, thefirst dot structure 12 includes: special-shaped dots; when the first light source and the second light source are simultaneously turned on, the light beam incident to the first light guide plate has brightness peaks in two directions in the angular distribution of the light beam after being emitted through the first light guide plate, the second light guide plate, and the prism sheet.
In the embodiment of the present invention, referring to fig. 8, a three-view of a special-shaped dot is shown, where an outer surface of the special-shaped dot includes: free-form surfaces and flat surfaces; the free-form surface surrounds the periphery of the plane; the free-form surface includes: a convex surface.
In the embodiment of the present invention, refer to fig. 8, wherein (a) is a top view of the halftone dot, (b) is a main view of the halftone dot, and (c) is a side view of the halftone dot. The length L, width W and height H of the special-shaped dots in fig. 8 are respectively: 55 μm, 38 μm and 19 μm. In the embodiment of the present invention, the anisotropic dots may also be other free-form surfaces as long as the prism sheet can make the emergent light have two brightness peaks.
In the embodiment of the present invention, referring to fig. 9, the special-shaped dots include: a polyhedral structure; the polyhedral structure includes: an upper surface, a lower surface, and a plurality of sides connecting the upper surface and the lower surface.
In the embodiment of the invention, referring to fig. 10, when thefirst dot structure 111 is a special-shaped dot and the first light source and the second light source are both turned on, the angular distribution of the light beam emitted after being refracted by the prism sheet has brightness peaks in two directions. Such as the Z region and the W region in fig. 10. For example, if the Z-region points to the co-driver and the W-region points to the driver, then a sufficiently high brightness level for both observers is also achieved.
In the embodiment of the invention, when only the second light source is turned on and the secondlight guide plate 13 is operated, the light ray diagram is shown in fig. 5, which is a peep-proof mode. When the first light source is turned on and the firstlight guide plate 11 is operated, the light ray diagram is in the sharing mode with reference to fig. 11.
In the conventional sharing mode, the brightness is very low at the secondary viewing angle position (driver position), which is not favorable for observing the display picture, and especially for outdoor vehicle-mounted display products, the requirement on the brightness is very high.
In the embodiment of the invention, the light emitted from the first light guide plate is deflected to a large angle through the second light guide plate and the second light guide dots, namely, the brightness of the auxiliary visual angle position is improved, and a driver is ensured to have good observation conditions.
And in the sharing mode, the light emitted by the light guide plate is deflected through the prism lens, so that the brightness of the large visual angle is improved.
In the embodiment of the present invention, the first dot structure may also adopt the same dot structure as the second dot structure. Referring to fig. 11, when the first dot structure and the second dot structure are the same, the base angle of the first dot structure is opposite to the base angle of the second dot structure.
For example, the viewing angle range for copilot (primary observer) is 0 ° ± 10 °; the viewing angle range of the driver (secondary observer) is 50 ° ± 10 °; the range of deflection angles between the primary and secondary viewers is 25 ° ± 10 °. Wherein ± 10 ° is an angle generated by the driver or the passenger car in a spatial range of the left-right sway, and each of the left and right sides is about 10 °.
In the embodiment of the present invention, the shape of thesecond dot structure 131 is designed mainly in relation to the range of the outgoing light, so that the range of the outgoing light is 70 ° -85 °, the modulation effect of the second dot structure on the outgoing light of the firstlight guide plate 11 is small, and the deflection angle of the first light guide plate is mainly adjusted by the prism sheet. The side edge corresponding to the first bottom angle A of the light-transmitting structure mainly adjusts light rays emitted by the first light guide plate and controls the light rays to be emitted towards the vertical direction; the side edge corresponding to the second base angle B mainly adjusts the light rays emitted by the second light guide plate, and deflects the emitted light rays to the range of 25 degrees +/-10 degrees.
In the embodiment of the present invention, the method further includes: areflective sheet 16; thereflective sheet 16 is disposed on a side of the firstlight guide plate 11 facing away from the secondlight guide plate 13.
In the embodiment of the invention, the reflector plate is used for reflecting the light rays incident to the reflector plate, so that the loss of the light rays is avoided.
In the embodiment of the present invention, the method further includes: a polymer dispersedliquid crystal layer 17; the polymer dispersed liquid crystal layer is arranged on one side of the prism sheet, which is far away from the second light guide plate.
Wherein, in order to prevent that under the sharing mode, the visual angle is not enough, and the light beam angle undersize can not guarantee that two observers can both see clear picture effect, set up polymer dispersedliquid crystal layer 17 and can increase the light beam angle. In the privacy mode, an alternating current driving voltage of 12V-36V is applied to a polymer dispersed liquid Crystal layer (PDLC), wherein the specific voltage value is determined according to the use area and optical parameters of the polymer dispersed liquid Crystal layer, such as light transmittance, haze, selection of liquid Crystal and polymer, and the like, and the polymer dispersed liquid Crystal layer is in a transparent state and does not affect the vision of the backlight module. And in the sharing mode, the polymer dispersed liquid crystal layer is closed, and the polymer dispersed liquid crystal layer has a diffusion effect on the light beams, so that the visual angle of the backlight module is increased. The switchable backlight module for increasing PDLC has the advantage of beam expanding effect in a sharing mode, and ensures that two observers can see clear picture content.
In the embodiment of the present invention, the method further includes: aphotoresist layer 18; the light resistance layer is arranged between the polymer dispersed liquid crystal layer and the prism sheet. The light resistance layer can absorb light rays with large visual angle, the peep-proof effect is better, and the wide visual angle state in the sharing mode cannot be influenced due to the combined use of the light resistance layer and the polymer dispersed liquid crystal layer.
Wherein, the material of the light resistance layer is acrylic glue mixed with black particles or carbon black particles, or other black optical grade plastics or black particles.
In the embodiment of the invention, the first light source and the second light source are positioned at two opposite sides of the backlight module.
The backlight module provided by the embodiment of the invention comprises: a first light guide plate; the first light source is arranged on the light incident side of the first light guide plate; a second light guide plate disposed on the first light guide plate; the second light source is arranged on the light incident side of the second light guide plate; the prism sheet is arranged on one surface, deviating from the first light guide plate, of the second light guide plate; when the first light source is started, light rays emitted by the first light guide plate are refracted and dispersed by the prism sheet, and the sharing mode of the backlight module is realized; when the first light source is turned off and the second light source is turned on, light rays emitted by the second light guide plate are narrowed through the folding and the contraction of the prism sheet, and the peep-proof mode of the backlight module is realized. In the embodiment of the invention, the switching between the sharing mode and the peep-proof mode can be realized by controlling the first light guide plate, the second light guide plate and the prism to deflect the incident light, and the realization mode is simpler. Moreover, the light emitted by the backlight module in the sharing mode can be more uniform through the folding of the prism sheet.
Example two
Referring to fig. 12, a schematic structural diagram of a display device according to an embodiment of the present invention is shown.
Wherein, display device includes: adisplay panel 20 and abacklight module 10 as described above.
In the embodiment of the present invention, a liquid crystal grating 30 is disposed on a side of thedisplay panel 20 away from thebacklight module 10.
In the sharing mode, the liquid crystal grating is opened, so that different display contents can be displayed at the main visual angle and the auxiliary visual angle, namely, the double-vision effect in the sharing mode is realized, and the display contents at the main visual angle and the auxiliary visual angle are the same when the liquid crystal grating is closed.
The working principle of the liquid crystal grating is as follows: when the liquid crystal grating is turned on, the first light source is turned on, and the second light source is turned off, the liquid crystal grating has a light resistance effect. The light resistance area of the grating is about two pixels in size, the light transmission area is about one pixel in size, and the distance between the liquid crystal grating and the display panel is about 0.8 pixel. In this case, the different display screens are visible for the copilot and the main driver.
The liquid crystal grating comprises a first substrate, a second substrate and a liquid crystal layer positioned between the first substrate and the second substrate. The surface of the first substrate close to the liquid crystal layer is provided with a plurality of strip electrodes, and the second substrate is provided with a common electrode. The opening and closing of the liquid crystal grating are controlled by controlling the opening and closing of the strip-shaped electrode on the first substrate; the liquid crystal grating is positioned above the liquid crystal box, and the second substrate of the liquid crystal grating is shared with the upper substrate of the liquid crystal box, or can be separately manufactured and then pasted on the liquid crystal layer.
The display device provided by the embodiment of the invention comprises: the display device comprises a display panel and a backlight module according to the first embodiment, wherein a liquid crystal grating is arranged on one side of the display panel, which is far away from the backlight module. A dual view effect in the sharing mode can be achieved.
While, for purposes of simplicity of explanation, the foregoing method embodiments have been described as a series of acts or combination of acts, it will be appreciated by those skilled in the art that the present invention is not limited by the illustrated ordering of acts, as some steps may occur in other orders or concurrently with other steps in accordance with the invention. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required by the invention.
The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The backlight module and the display device provided by the invention are described in detail, and the principle and the implementation mode of the invention are explained by applying specific examples, and the description of the examples is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.