JP2022097487A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device capable of reproducing optical characteristics of a print display medium, in particular a display device capable of generating a sense as if the display device is a printing medium such as paper.

SOLUTION: In a display device, with respect to a light flux of external light incident into a specific area in a display panel, a light flux emitted from a pixel in the specific area is controlled in a predetermined diffuse reflection factor, thereby an emission light flux is acquired from a product of the incident light flux and the diffuse reflection factor. Thus, display on the display device can give a sense as if it is a printing medium such as paper.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a display device, and more particularly to a display device that reproduces diffuse reflected light of a print display medium.

Conventionally, display devices such as liquid crystal displays and organic EL display devices have been known. In these display devices, a method of controlling the brightness of the display according to the illuminance of external light is also known.
In conventional display devices such as liquid crystal displays using a backlight, it is common to increase the brightness in order to improve visibility when the surroundings are bright, while lowering the brightness in order to eliminate the glare when the surroundings are dark. Further, in a dark place, it is required to suppress the brightness from the viewpoint of power saving.

On the other hand, reflections that reflect ambient light such as external light, such as electrophoretic displays and reflective liquid crystal displays, that display similar to the optical characteristics of paper print display media such as copy paper, photographs, and calendars. Display development is also underway.

In Patent Document 1, in the display device, the brightness and the color tone are adjusted according to the brightness of the external light, the brightness of the display device is changed for each part, or the illuminance of the external light becomes low due to the shadow of an object. In such a case, a technique for reducing the brightness of the corresponding portion to display the corresponding portion is disclosed.

Japanese Unexamined Patent Publication No. 2011-48196

Although the prior art and the techniques disclosed in Patent Document 1 describe changing the brightness of the display device by adjusting the brightness and the color tone according to the brightness of the external light, they are easy to see and save power. It is only described that the brightness is adjusted from the viewpoint of. Although there is a description in Patent Document 1 that it is possible to provide an atmosphere as if writing characters on real paper, the brightness of the picture element included in the shadow area of the pen is also used for this. By lowering it, it is only shown that the shadow of the pen appears to be reflected, and when the illuminance of the outside light becomes low due to the shadow of an object, the illuminance of the outside light becomes low. There is no change in the point that the brightness of the corresponding part is lowered and displayed according to.

In addition, even in a reflective display that reflects ambient light such as external light and displays it in color, the reflected light is greatly reduced due to light absorption by the color filters of the three primary colors, and the visibility is significantly reduced compared to the print medium. There is a risk of

Therefore, the present invention provides a display device that reproduces the optical characteristics of a print display medium, gives a feeling as if the display device is a print medium such as paper, and is a print medium familiar to the viewer. The purpose is to convey information without discomfort by displaying it as if it were there.

The display device of the present invention includes a display panel and at least one optical sensor, and a luminous flux emitted from a pixel in a specific region in the display panel in order to reproduce diffusely reflected light with respect to external light of a print display medium. However, it is characterized in that it is controlled by a diffuse reflectance of a predetermined ratio.
According to the above configuration, the luminous flux emitted from the pixel is controlled by the diffuse reflectance of a predetermined ratio, so that the display device reproduces the diffuse reflected light of the print display medium, and the display device uses paper. It is possible to give a feeling as if it is a print medium such as.

Further, the diffuse reflectance can be set as a value of 1 or less. Since the amount of emitted light from a print medium such as paper is generally smaller than the amount of emitted light from a display device, the diffuse reflected light can be better controlled by setting the diffuse reflectance value to 1 or less. Can be done.

Further, the optical sensor may be capable of individually detecting the light of the three primary colors, the diffuse reflectance may be determined for each of the three primary colors, and the luminous flux emitted from the pixel may be controlled based on the diffuse reflectance. .. As a result, it is possible to determine the diffuse reflectance of each color in which light diffusion and spectral absorption in various types of paper and other print media are taken into consideration for each of the three primary colors, and control the light beam based on the diffuse reflectance. It is possible to control the diffuse reflected light more finely.

Further, the optical sensors may be arranged as a two-dimensional array. This makes it possible to appropriately reflect the distribution of the incident luminous flux on the display panel for each region. Further, as the arrangement location, various locations such as the surface of the rear substrate, the surface of the front substrate, the surface of another transparent substrate, and the like can be selected.

Further, a black absorption portion may be formed on the surface of the pixel on which the optical sensor is provided. This makes it possible to block the display light that interferes with the optical sensor that detects external light.

Further, a color filter for the three primary colors may be provided on the light receiving surface of the optical sensor. In this case, it is preferable to use a color filter equivalent to the color filter for the three primary colors of the pixel. This makes it possible to make the sensitivity of the light receiving surface of the optical sensor similar to the sensitivity of the pixel.

Further, the reflection suppression layer and the anti-glare layer may be laminated on the display panel. This makes it possible to suppress the specularly reflected light that does not occur in a print display medium such as paper but occurs in a normal display device.

Furthermore, the angle dependence of the emission light intensity of the pixel becomes a uniform diffusion distribution of the perfect diffuser based on Lambert's cosine law, that is, the brightness has no angle dependence (brightness is isotropic) or the brightness. The half-value angle (angle until the value becomes half of the front luminance) is as wide as 120 ° or more in full angle, and may have a light distribution distribution that gently decreases from the direction perpendicular to the substrate surface. This makes it possible to reproduce the optical characteristics of a print display medium such as paper. Further, when a liquid crystal element is used, the backlight as a light source may have a similar light distribution.

INDUSTRIAL APPLICABILITY The present invention provides a display device that reproduces the optical characteristics of a print display medium, and can give a feeling as if the display device is a print medium such as paper.

It is a block diagram which shows the structure of the liquid crystal display device which concerns on embodiment of this invention. It is a figure which shows the detailed structure of a liquid crystal panel. It is a figure which shows the cross section and the backlight of a liquid crystal panel. It is a figure which shows the relationship between a pixel and an optical sensor. It is a figure which shows the relationship between the intensity of the incident light in a liquid crystal panel, the output signal of an optical sensor, and the intensity of the reflected light of a print display medium. This is a modified example of the structure of the liquid crystal panel. It is an image of a display experiment using a backlight and a liquid crystal element similar to the Lambert light distribution.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a liquid crystal display device according to an embodiment of the present invention. The liquid crystal display device 10 includes a liquid crystal panel 11, an image processing unit 12, an A / D converter 13, a backlight power supply circuit 14, and a backlight 15. The liquid crystal panel 11 includes a panel drive circuit 17 and a display area 18, and the display area 18 includes a plurality of pixel circuits arranged in a two-dimensional manner and a plurality of optical sensors, as will be described later.

The display data D1 and the output control signal OC are input from the outside to the image processing unit 12 of the liquid crystal display device 10, the display data processing is performed in the image processing unit 12, and the display data D2 is output to the liquid crystal panel 11. .. The display data D2 is input to the panel drive circuit 17 of the liquid crystal panel 11, and the panel drive circuit 17 writes to the pixel circuit of the display area 18 based on the display data D2. As a result, the image is displayed in the display area 18.

The backlight 15 is composed of LEDs, and irradiates light as back light from the back surface of the liquid crystal panel 11. The backlight power supply circuit 14 supplies or cuts off power to the backlight 15 based on the control signal output from the image processing unit 12. Further, as will be described later, the drive control of the liquid crystal panel 11 and the control of the backlight 15 are also performed based on the signal from the optical sensor. Although the backlight 15 is composed of white LEDs, it can also be configured by combining red, green, and blue LEDs.

The panel drive circuit 17 performs an operation of writing a voltage to the pixel circuit of the liquid crystal panel 11. At the same time, an operation of reading a voltage according to the amount of received light from the optical sensor 2 (not shown in FIG. 1) of the liquid crystal panel 11 is also performed. The signal SS output from the optical sensor is output to the outside of the liquid crystal panel 11 and input to the A / D converter 13. The A / D converter 13 converts the analog output signal from the optical sensor 2 into a digital signal. The image processing unit 12 controls the drive of the liquid crystal panel 11 and the backlight 15 by the control described later based on the digital signal output from the A / D converter 13.

FIG. 2 is a diagram showing a detailed configuration of the liquid crystal panel 11. The pixel array of the display area 18 includes m scanning signal lines G1 to Gm and 3n data signal lines Sr1 to Srn, Sg1 to Sgn, and Sb1 to Sbn at the intersection of the scanning signal lines and the data signal lines. An m × 3n pixel circuit is formed. Further, the pixel array of the display area 18 includes an optical sensor 2 corresponding to each pixel circuit, sensor reading lines Rw1 to Rwm, and sensor lines Srw1 to Srwn, Sgw1 to Sgwn, and Sbw1 to Sbwn.

The scanning signal lines G1 to Gm are arranged in parallel. The data signal lines Sr1 to Srn, Sg1 to Sgn, and Sb1 to Sbn are all arranged in parallel so as to be orthogonal to the scanning signal lines G1 to Gm, and the scanning signal lines G1 to Gm and the data signal lines Sr1 to Srn are arranged in parallel. A pixel circuit 1 is provided at the intersection of Sg1 to Sgn and Sb1 to Sbn. The pixel circuits 1 are provided in m pieces in a direction parallel to the scanning signal line and 3n pieces in a direction parallel to the data signal line, and are arranged two-dimensionally. Red, green, and blue color filters are provided in order in the direction parallel to the data signal line, and the R (red) pixel circuit 1r, the G (green) pixel circuit 1g, and the B (blue) pixel circuit 1b are configured in order. One pixel is composed of three types of pixel circuits.

The pixel circuit 1 includes a TFT 3 and a liquid crystal capacity 4. The gate terminal of the TFT 3 is connected to the scanning signal line, and the source terminal is connected to any of the data signal lines. Further, the drain terminal is connected to the electrode of the liquid crystal capacity. Further, a common voltage is applied to an electrode different from the electrode to which the drain terminal is connected.

A scanning signal line drive circuit 31, a data signal line drive circuit 32, a sensor line drive circuit 33, a sensor row drive circuit 34, switches (35, 36), and the like are provided around the display area 18. The scanning signal line drive circuit 31, the data signal line drive circuit 32, the sensor line drive circuit 33, and the sensor row drive circuit 34 correspond to the panel drive circuit 17 in FIG.
The data signal line drive circuit 32 has 3n output terminals corresponding to 3n data signal lines. A switch is provided between the data signal line drive circuit 32 and the data line, respectively.

The brightness of the pixel circuit 1 is determined by the voltage written in the pixel circuit 1. To write the voltage to the pixel circuit 1, a high level voltage for turning on the TFT 3 is applied to the scanning signal line Gi (i is an integer from 1 to m), and the data signal line Sxj (x is r, g, A voltage to be written may be applied to any of b. J is an integer from 1 to n). By writing the voltage corresponding to the display data D2 to the pixel circuit 1, it is possible to set the brightness of each pixel to a desired level.

FIG. 3 is a diagram showing a cross section of the liquid crystal panel 11 and a backlight 15. The liquid crystal panel 11 has a structure in which a liquid crystal layer 42 is sandwiched between two glass substrates 41a and 41b. The glass substrate 41a is provided with three color filters 43r, 43g, 43b, a black absorption unit 44, and a counter electrode 45. Further, the glass substrate 41b is provided with a pixel electrode 46 and a data signal line 47. Further, in this example, the optical sensor 2 is also provided on the glass substrate 41b. The photodiode 6 in the optical sensor 2 is provided in the vicinity of the pixel electrode 46. An alignment film 48 is provided on the surfaces of the glass substrates (41a, 41b) facing each other, and a polarizing plate 49 is provided on the surface opposite to the alignment film 48. In FIG. 3, the surface on the glass substrate 41a side is the front surface, and the surface on the glass substrate 41b side is the back surface. A backlight 15 is provided on the back side and on the glass substrate 41b side. Although the optical sensor 2 is provided in the vicinity of the pixel electrode 46 on the glass substrate 41b side in FIG. 3, it can also be provided on the surface of the glass substrate 41a side facing the glass substrate 41b or the glass substrate. It may be provided on the side surface portion of the 41a or the glass substrate 41b.

In the example shown in FIG. 2, one optical sensor 2 is provided for one pixel circuit and includes a photodiode 6. A sensor readout wire Rwi is connected to the anode electrode of the photodiode 6, and a sensor wire (Srwj, Sgwj, Sbwj (j is an integer from 1 to n)) is connected to the cathode electrode of the photodiode 6. When a reverse bias voltage is applied to the photodiode 6 from the sensor train drive circuit 14 to the sensor wires (Srwj, Sgwj, Sbwj (j is an integer from 1 to n)), the current corresponding to the amount of incident light is applied to the photodiode 6. The voltage of the cathode terminal of the photodiode 6 is reduced by that amount. This makes it possible to obtain the amount of light detected by the optical sensor 2.

Further, in the example shown in FIG. 2, the matrix circuit portion has a simple configuration in which a photodiode is connected to a wiring intersection, but a field effect transistor for line selection, an amplification transistor, and a reset transistor are used. A transfer transistor may be provided at the intersection, and a photodiode may be connected to the output of the transistor. With such a connection configuration, it is possible to obtain a clear photodetection signal such as a current or voltage with less electrical noise from each photodiode. As the semiconductor used for the field effect transistor, it is possible to use a semiconductor such as amorphous or polycrystalline Si or a metal oxide used for an existing thin film transistor.

In the liquid crystal panel 11, the emitted light is directly emitted by the backlight 15 arranged on the back side, and the brightness is controlled by the control in the pixel circuit 1. On the other hand, since a print display medium such as paper does not have a light emitting light source such as a backlight in a liquid crystal panel, light incident from the outside is reflected on the surface of the paper and is reflected by the observer as diffusely reflected light. Will enter. Therefore, in general, the amount of emitted light is smaller than that of direct emitted light from a backlight or the like in a liquid crystal panel, and the amount of light emitted is also lower than the amount of light incident from the outside.

In the present invention, paying attention to the difference in the emitted light between the liquid crystal panel and the print display medium such as paper, the direct emitted light by the backlight or the like in the liquid crystal panel becomes equivalent to the diffused reflected light in the paper. It is characterized in that it is displayed so as to look like printing on paper, even though the display is performed by the liquid crystal panel.

FIG. 5A is a graph showing the relationship between the light intensity indicating the intensity of light incident on a unit area and the voltage signal output from the optical sensor 2 in the liquid crystal panel 11. As shown in this graph, the light intensity and the voltage signal are generally in a proportional relationship, although an offset voltage (Vs) exists. Based on this relationship, parameters can be obtained by actual measurement, and the light intensity with respect to the voltage signal can be calculated based on the obtained parameters.

FIG. 5B is a graph showing the relationship between the light intensity indicating the intensity of light incident on a unit area and the intensity of a print display medium such as paper at that time. As shown in this graph, the relationship between the light intensity and the intensity of the reflected light is generally proportional. Based on this relationship, it is possible to obtain parameters by actual measurement and calculate the intensity of reflected light with respect to the light intensity based on the obtained parameters. This proportionality constant is a numerical value of about 1 or less as described above.

In detecting the incident amount of external light, the average value of the outputs of the optical sensors provided for each pixel is taken when driving the pixels in the liquid crystal panel, but from each optical sensor. It is also possible to use the output to multiply each pixel by the diffuse reflectance.

Further, as shown in FIG. 4, the optical sensor 2 has been described as an example provided for each pixel circuit, but one optical sensor 2 may be provided for each pixel, or one optical sensor 2 may be provided for each more pixel. It may be provided. Further, it is also possible to provide one optical sensor for the entire liquid crystal panel or to provide a plurality of optical sensors in the peripheral portion of the liquid crystal panel. As shown in FIG. 4, when an optical sensor is provided for each of the red, green, and blue sub-pixels, red is used for each optical sensor using the same color filter provided for the pixel. , Green, and blue can be individually detected with the same sensitivity as that of the pixel. In such a configuration, for each of the three primary colors, the print display medium such as paper is diffuse-reflected by actually irradiating the print display medium with light according to the type of the print display medium. Find it based on the value of light.

Further, it is generally known that the diffuse reflectance (total light reflectance) is 85 to 91% for white paper used for copy paper and 40 to 50% for newspaper paper, and the diffuse reflectance of these papers is known to be 40 to 50%. By using the value, the difference in paper quality can be easily expressed. It is also useful to store a plurality of these diffuse reflectance values and switch them as appropriate. Furthermore, even if the white color is the same, the diffuse reflectance of the white cloth is 60 to 70%, and the diffuse reflectance of the white tile is 70 to 80%. Therefore, by using the values of the diffuse reflectance, the surface other than the paper can be reproduced. It is possible. Further, in the present invention, if it is composed of a color sensor of three primary colors and display pixels, it is necessary to obtain and use the diffuse reflectance for each of the three primary colors on paper. As a result, not only the brightness of the paper but also the hue can be easily reproduced.

Also, on the liquid crystal panel side, the relationship between the incident amount of external light and the output of the optical sensor, and the relationship between the driving state of the pixel and the amount of light emitted from the pixel are obtained in advance for each of the three primary colors. Then, for each of the three primary colors, the amount of light emitted from the pixels in the liquid crystal panel is the diffuse reflectance obtained by multiplying the amount of external light incident detected by the optical sensor by the diffuse reflectance of a specific print display medium. The pixels in the liquid crystal panel are driven so as to be the amount of light emitted.

An example of a specific pre-adjustment / calibration and driving method for a liquid crystal panel will be described below. Irradiate the standard white illumination that is supposed to be used with the maximum illuminance, and set the maximum value of the input and output of the optical sensor at that time. The output value of the optical sensor is proportional to the optical intensity of the optical sensor. As the standard white light, a D50 light source or a D65 light source, which is a white standard light source defined by the International Commission on Illumination, may be used. Under the illuminance of these light sources, the diffuse reflectance of a commercially available standard diffuse white plate is set to the ideal 100%, and then the brightness is calculated as brightness = illuminance / π, or the brightness of the standard diffuse white plate is obtained. Is obtained by measurement with a luminance meter. Then, the three primary color drive signals are adjusted so that the luminance value thus obtained and the luminance of the display match. The drive signals of the three primary colors at this time are associated with each other as the maximum value of each color.

Further, the drive signal of the display is set so as to change in proportion to the output signal of the optical sensor. By these adjustments, the balance of the three primary color lights, that is, the chromaticity, the color temperature, and the hue, is maintained even on the display even if the intensity of the illumination light changes. In adjusting the brightness of the display, the drive signal may be adjusted while keeping the balance of the three primary color lights constant, but the light source (LED or the like) of the backlight may be adjusted to save power.

On the other hand, measure the three primary color reflectances of the paper to be simulated. The reflectance of paper may be roughly considered as the rate of decrease in brightness when paper is used instead of the standard diffused white plate. If the reflectance of each of the three primary colors of paper is known, the drive signal of the display is calculated by multiplying the reflectance ratio (1 or less) by the maximum drive signal when the standard diffused white plate is used. be able to. For example, in the case of reproducing the reflected light of white copy paper having a reflectance of the three primary colors equal to 80%, the signal to be actually driven can be obtained by multiplying the drive signals of the three primary colors by 80%. .. If the reflected light of the white copy paper is assumed to be the Lambert light distribution, the brightness of the white copy paper can be roughly approximated from the formula of luminance = reflectance × illuminance / π.

As a result, even if the lighting environment of the usage environment changes, the brightness of the three primary colors of the display can be automatically determined and controlled. For example, if the light is switched from standard white light to illumination light with different brightness and color temperature, the three primary color display of the display is linked according to the change of the three primary color output of the optical sensor, so that the white paper can also be displayed on the display. Brightness and hue can be reproduced at the same time. Furthermore, when reproducing the reflected light of paper other than white copy paper (white dull paper, colored paper, etc.) on the display, the reflectance of the three primary colors of each paper is determined in advance. Alternatively, the luminance can be measured to obtain a value, and the diffuse reflectance thereof can be multiplied by the maximum drive level of the display of the three primary colors to obtain the drive level for each of the three primary colors. As a result, the reflected light of paper having various diffuse reflectances can be reproduced as the display light of the display.

FIG. 6 is a modified example of the structure of the liquid crystal panel in FIG. In the example of FIG. 6, an anti-glare layer for suppressing specular reflected light is provided on the outer surface of the polarizing plate 49. Unlike liquid crystal panels, print display media such as paper do not have positively reflected light on the surface. Therefore, by providing an anti-glare layer on the surface of the liquid crystal panel to suppress the positively reflected light, the display can be made more like paper. It is possible to bring it closer to the print display medium. Further, in the example of FIG. 6, the anti-glare layer is provided on the outer surface of the polarizing plate 49, but it is also possible to provide a reflection suppression layer instead of the anti-glare layer.

Some papers and cloths have a pattern on the surface. In such a case, the diffuse reflectance of the surface may differ depending on the presence or absence of a pattern, the shape of the pattern, and the like. In such a case, the diffuse reflectance for each region on paper or cloth is obtained in advance according to the pattern, and when displaying on the liquid crystal panel, the diffuse reflectance for each region is multiplied according to the pattern. It is possible to display the pattern by changing the brightness while reproducing the texture of paper or cloth.

In the description of these embodiments, a display device using a liquid crystal display has been described, but these are not limited to the liquid crystal display device, and are also applied to a self-luminous display device such as an organic EL. It is possible. In the case of a self-luminous display device as well, as in the case of a liquid crystal display device, the luminous flux to be emitted may be obtained by the product of the incident luminous flux of external light and the diffuse reflectance and driven.

The ideal light distribution of the display device is Lambert light distribution, but when the half-value angle of the brightness of white copy paper is measured, it is approximately 160 °, and the light distribution gradually decreases from the vertical direction of the display surface. Had. Therefore, we made a prototype backlight box (half-value angle of brightness is 160 °) in which LED light is diffused so that the brightness is close to the isotropic Lambert light distribution, and conducted a display experiment by stacking it with a commercially available liquid crystal element. rice field. As a result, it was confirmed that a high-quality display image that is indistinguishable from color printing paper can be obtained even when viewed from the front or diagonally. FIG. 7 shows the results of observing the prototype device and the printed image in comparison with each other under indoor lighting.

It has also been confirmed that even if a strong diffuser plate is laminated on the existing light guide plate backlight, a light distribution distribution close to the Lambert distribution (half-value angle of brightness is 160 °) can be obtained. In this case, the stronger the diffusing effect of the diffusing plate, the closer to the Lambert light distribution, but the lower the brightness may be. Furthermore, in the laminated relationship with polarizing plates, liquid crystal panels, light diffusion films, etc., if an air layer exists between them, Frenel reflection occurs, and the tilted light with a large incident angle is totally reflected and displayed without being emitted to the outside. In this case as well, the brightness may decrease and the light may become dark because it does not contribute to the light for the purpose. In order to prevent this, it is preferable to have a close contact structure such as bonding or injection of matching oil in laminating various optical members. As a result, it is possible to prevent a decrease in the intensity of the obliquely emitted light, and it is possible to significantly suppress a decrease in the half-value angle of the brightness due to Fresnel reflection.

On the other hand, in order to bring the backlight closer to the Lambert light distribution, the problem that the front luminance decreases as the light diffusion effect is increased and the light distribution distribution is widened arises. Therefore, from a practical point of view, it is desirable that the half-value angle of the brightness of the display device or the backlight is 120 ° or more. For the liquid crystal element laminated on the backlight, it is desirable to use a display operation method that can obtain wide viewing angle characteristics such as an in-plane switching liquid crystal method (IPS) and a vertically oriented liquid crystal method (VA).

1 pixel circuit 2 optical sensor 6 photodiode 10 liquid crystal display 11 liquid crystal panel 12 image processing unit 13 A / D converter 14 backlight power supply circuit 15 backlight 17 panel drive circuit 18 display area 31 scanning signal line drive circuit 32 data signal Line drive circuit 33 Sensor row drive circuit 34 Sensor row drive circuit 41 Glass substrate 42 Liquid crystal layer 43 Color filter 44 Black absorber 45 Opposite electrode 46 Pixel electrode 48 Alignment film 49 Plate plate

Claims (11)

A display panel with two-dimensionally arranged pixels to emit display light,
Equipped with at least one optical sensor to detect outside light,
In order to reproduce diffusely reflected light with respect to external light of the print display medium,
In the specific region in the display panel, the luminous flux emitted from the pixels in the specific region is the light flux emitted from the pixels in the specific region with respect to the luminous flux of the external light incident on the specific region of the display panel from the outside, which is detected by the optical sensor. A display device characterized by being controlled by the product of a diffuse reflectance of a predetermined ratio and a luminous flux of external light incident on the specific region. The display device according to claim 1, wherein the diffuse reflectance is a value of 1 or less. The optical sensor can detect light of the three primary colors individually.
The diffuse reflectance is determined for each of the three primary colors of light.
The display device according to claim 1 or 2, wherein the luminous flux emitted from the pixels in the specific region is controlled based on the diffuse reflectance determined for each of the three primary colors. The display device according to any one of claims 1 to 3, wherein the optical sensor is arranged as a two-dimensional array. The optical sensor is provided on any of the surface of the rear substrate on which the thin film transistor for driving the pixel is formed, the inner surface or the outer surface of the front substrate, and the surface of the transparent substrate to be laminated. The display device according to any one of claims 1 to 4. The display device according to claim 5, wherein a black absorber is formed on a surface of the pixel on which the optical sensor is provided. The display device according to any one of claims 3 to 6, wherein a color filter for three primary colors is provided on the light receiving surface of the optical sensor. The display device according to any one of claims 1 to 7, wherein the pixel is composed of a liquid crystal element or an organic EL element that is voltage-driven by a thin film transistor. The display device according to any one of claims 1 to 8, wherein a reflection suppression layer and an anti-glare layer are laminated on the display panel. Based on Lambert's cosine law, the angle dependence of the synchrotron radiation intensity of the pixel becomes a uniform diffusion distribution of the perfect diffuser, or the half-value angle of the brightness is 120 ° or more, and it gradually decreases from the vertical direction of the substrate surface. The display device according to any one of claims 1 to 9, wherein the display device has a light distribution. Claim 1 is characterized in that the orientation characteristic of the backlight used in the liquid crystal element has a uniform diffusion distribution of a complete diffusion plate, or the half-value image of the luminance is 40 ° or more and the degree of gradual decrease from the direction perpendicular to the substrate surface. The display device according to any one of 10.

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