JP4353038B2 - Liquid crystal display device and electronic device - Google Patents

Description

  The present invention relates to a liquid crystal display device, a color adjustment method thereof, and an electronic apparatus.

In the field of display devices such as liquid crystal display devices, there are many demands for higher image quality. For example, digitalization of photographs is currently progressing, and at the same time, vivid images can be enjoyed as with conventional photographs without printing. Development of a display device is desired. In addition, when displaying an image, color reproducibility in a liquid crystal display device is also important. For example, Patent Document 1 discloses a liquid crystal display device that performs color adjustment by rewriting a color palette according to the luminance of ambient light. .
Japanese Patent Laid-Open No. 5-11731

  According to the technique described in Patent Document 1, since display according to the state of ambient light is possible, color reproducibility can be improved. However, when the present inventor has examined a liquid crystal display device having a configuration in which a backlight is disposed on the back side of the liquid crystal panel, even a liquid crystal display device having the color adjustment function can be displayed over time. It was found that the hue changed and the color reproducibility deteriorated.

  The present invention has been made in view of the above-mentioned problems of the prior art, and an object thereof is to provide a high-quality liquid crystal display device capable of obtaining good color reproducibility over a long period of time and a color adjustment method thereof. It is said.

In order to solve the above-described problems, the present invention provides a liquid crystal panel including a display region having a plurality of dots by sandwiching a liquid crystal layer between a pair of opposed substrates, and the pair of substrates of the liquid crystal panel . a lighting means disposed on the outer side of one substrate is disposed on the outer side of the other substrate of the pair of substrates, a frame having an opening corresponding to the display area, displays the input image signal signal An image processing means for converting the image data to be supplied to the liquid crystal panel, a spectroscopic means provided on the liquid crystal side of the other substrate, an area outside the display area of the liquid crystal panel, and at least of the display area A light receiving element that is provided on the one substrate along one side edge and that measures the chromaticity of the illumination light of the illuminating means that has passed through the spectroscopic means; a surface of the frame on the liquid crystal panel side; Between Anda light reflecting means for reflecting to the side of said separating means illumination light supplied from the illumination means, the frame is disposed so as to cover the light-receiving element and the spectroscopic means, said light receiving element The spectroscopic means is provided at a position overlapping with the plane, and a display signal supplied from the image processing means to the liquid crystal panel can be changed based on chromaticity information obtained by the light receiving element . Features.
Further, the present invention is the above-described liquid crystal display device, wherein the light reflecting means has a light reflecting property provided on the inner surface or the outer surface of the frame or the other substrate of the liquid crystal panel. It is a metal film .
The present invention is the above-described liquid crystal display device, wherein the light receiving element includes a first light receiving element, a second light receiving element, and a third light receiving element, and the spectroscopic unit corresponds to red. Transmitting a specific frequency component and optically seeing the first color film provided between the illuminating means and the first light receiving element and a specific frequency component corresponding to green and transmitting optically A second color film provided between the illuminating means and the second light receiving element and a specific frequency component corresponding to blue are transmitted, and viewed optically between the illuminating means and the third light receiving element. A third color film provided, and the first light receiving element and the first color film are provided along a first side edge of the display area, and the second light receiving element and The second color film is on a second side edge different from the first side edge of the display area. The third light receiving element and the third color film are provided along a third side edge different from the first side edge and the second side edge of the display region. It is characterized by that.
Further, according to the present invention, the colorimetric means including the light receiving element and the spectroscopic means is stored in the storage means, which holds a reference value of chromaticity information of illumination light output from the illumination means, and is stored in the storage means Color difference deriving means for deriving color difference information from chromaticity information and chromaticity information output from the colorimetric means, and the display signal can be changed based on the color difference information obtained by the color difference deriving means It is characterized by that.
In order to solve the above problems, the present invention provides a liquid crystal panel, illumination means disposed on the back side of the liquid crystal panel, and an image supplied to the liquid crystal panel by converting an input image signal into a display signal. Processing means, and the liquid crystal panel includes color measurement means for measuring chromaticity of illumination light supplied from the illumination means, and a display signal supplied from the image processing means to the liquid crystal panel is provided. A liquid crystal display device characterized in that it can be changed based on chromaticity information obtained by the colorimetric means.
According to this configuration, since the chromaticity information of the illumination light can be easily obtained by the colorimetric means provided in the liquid crystal panel, a change in the chromaticity of the illumination light is detected based on the obtained chromaticity information. can do. Since the display signal output from the image processing means can be changed based on the chromaticity information, an appropriate display state can be obtained in response to the chromaticity change with time of the illumination means, and for a long time. In addition, it is possible to provide a liquid crystal display device capable of obtaining faithful color reproducibility over a wide range.

In the liquid crystal display device of the present invention, the storage means for holding the reference value of the chromaticity information of the illumination light output from the illumination means, the chromaticity information held in the storage means, and the colorimetry means are output. Color difference deriving means for deriving color difference information from chromaticity information, and the display signal can be changed based on the color difference information obtained by the color difference deriving means.
According to this configuration, the color difference information is obtained by a calculation process using the chromaticity information obtained by the color measurement unit and the reference chromaticity information held in the storage unit, and the color difference information is obtained. Since the display signal supplied to the liquid crystal panel is changed based on the display, the chromaticity deviation of the illumination light with respect to the reference value can be obtained easily and with high accuracy, and the chromaticity deviation can be corrected. It can be changed to a signal. Therefore, according to this configuration, it is possible to provide a liquid crystal display device capable of stably maintaining faithful color reproducibility. Examples of the color difference information derived by the color difference deriving unit include a color difference ΔEa ^* b ^* in the CIELAB color space and a color difference ΔEu ^* v ^{* in the} CIEUV color space.

In the liquid crystal display device of the present invention, it is preferable that the color difference information derived by the color difference deriving unit is a color difference ΔEa ^* b ^* in the CIELAB color space. The color difference ΔEa ^* b ^* is a distance between two coordinates in the CIELAB space. In this way, if the display signal supplied to the liquid crystal panel is made different based on the value of the color difference ΔEa ^* b ^* , the display signal can be changed based on the objective chromaticity difference independent of the device. The display state can be maintained. In particular, the color difference ΔEa ^* b ^* is preferable because the color difference ΔEa ^* b ^* can be well matched with the result of the visual experiment on the color difference, and the color reproducibility of the liquid crystal display device corresponding to human vision can be maintained.

In the liquid crystal display device of the present invention, it is preferable that the display signal output from the image processing means is changed when the value of the color difference ΔEa ^* b ^* is equal to or greater than a predetermined value. That is, it is preferable that the display signal supplied to the liquid crystal panel is changed when the illumination light output from the illumination unit is illumination light having a predetermined color difference with respect to the reference value. With such a configuration, color adjustment by changing the display signal can be performed based on an objective determination criterion. For example, when the color change of the illumination light is difficult to distinguish, the color adjustment is performed. Therefore, it is possible to prevent the color adjustment operation from affecting the operation speed or the like of the liquid crystal display device.

In the liquid crystal display device of the present invention, it is preferable that the display signal output from the image processing means is changed when the ΔEa ^* b ^* is 3 or more. With such a configuration, the display signal can be corrected before the change in display color becomes significant, and effective color adjustment becomes possible.

In the liquid crystal display device of the present invention, it is preferable that the liquid crystal display device includes a color correction unit that corrects a display signal supplied from the image processing unit to the liquid crystal panel. According to this configuration, the color correction unit that corrects the display signal based on the chromaticity information, the color difference information, or the color difference ΔEa ^* b ^* is provided, so that the chromaticity change of the illumination light can be corrected appropriately and quickly. It is possible to provide a liquid crystal display device that can be used.

  In the liquid crystal display device of the present invention, the image processing means includes a color conversion table for converting the image signal into the display signal, and the color correction means can correct the color conversion table. It can be. With such a configuration, a display signal reflecting color correction based on color difference information can be generated, and once color adjustment is performed, the contents can be held in the color conversion table. Therefore, it is not necessary to correct the display signal, and there is no inconvenience such as a decrease in operation speed of the liquid crystal display device.

In the liquid crystal display device of the present invention, it is preferable that the storage unit is configured to be able to hold chromaticity information obtained by the colorimetric unit. In the liquid crystal display device of the present invention, the color correction unit and the storage unit are configured to be operable in conjunction with each other, and the chromaticity information when the correction process by the color correction unit is executed is stored in the storage unit. Preferably, the configuration is stored in the means.
When adopting a configuration for updating the color conversion table as described above, it is particularly preferable that the chromaticity information in the storage unit be updated in this way. This is because the color conversion table after color adjustment reflects the correction based on the color difference information, and therefore it is necessary to hold the illumination light state corresponding to the color conversion table.

  In the liquid crystal display device according to the aspect of the invention, it is preferable that the color measurement unit includes a light receiving element formed in the liquid crystal panel and a spectroscopic unit provided in a planar region of the liquid crystal panel including the light receiving element. According to this configuration, the color measuring means can be mounted on the panel with a simple configuration, and the configuration is effective in terms of ease of manufacturing and manufacturing cost.

  In the liquid crystal display device of the present invention, it is preferable that the light receiving element is provided outside an effective display area of the liquid crystal panel. There is little merit in providing the color measuring means in the display area, the influence on the display by providing the color measuring means can be eliminated, and the size of the light receiving element and the degree of freedom of the configuration are also outside the display area. It is advantageous.

  In the liquid crystal display device of the present invention, the spectroscopic means may be an optical film that selectively transmits light in a specific wavelength range. According to this configuration, since the spectral means can be prepared separately, it becomes relatively easy to bring the spectral sensitivity of the color measuring means close to the router condition.

  In the liquid crystal display device of the present invention, light reflecting means for covering the light receiving element in a plane is provided on the opposite side of the illumination means with the light receiving element interposed therebetween, and the spectroscopic device is provided between the light receiving element and the light reflecting means. It can also be set as the structure by which the means is provided. Even in such a configuration, the illumination light can be reflected by the light reflecting means, and the reflected light can be incident on the light receiving element after passing through the spectroscopic means. Can be executed smoothly.

In the liquid crystal display device having the above-described configuration, the spectroscopic unit may be a colored member formed on a color filter provided in the liquid crystal panel.
According to this configuration, the spectroscopic means can be formed in the color filter, which is advantageous in terms of alignment accuracy with the light receiving element and manufacturing cost.

  In the liquid crystal display device of the present invention, the light reflecting means may be provided on a frame attached to the liquid crystal panel. Or the said light reflection means may be provided in the outer surface or inner surface of the board | substrate which comprises a liquid crystal panel.

  In the liquid crystal display device of the present invention, a light shielding portion having at least a metal film and a metal oxide film is provided outside the effective display area of the liquid crystal panel, and a part of the metal film of the light shielding portion is the light. It can also be set as the structure which forms the reflection means. That is, the back surface side of the light shielding portion in which the metal oxide film and the metal film are laminated as viewed from the display surface side of the liquid crystal panel can be used as the light reflecting means. The light-shielding part having such a structure appears black due to the interference of the metal oxide film when viewed from the display surface side, but has a metallic luster when viewed from the back side of the liquid crystal panel, so that the light output from the illumination means Then, it can be reflected by the back surface of the light-shielding portion having the metallic luster and incident on the light receiving element. In this way, by using the light-shielding portion provided in the liquid crystal panel, it can be easily manufactured and is advantageous in terms of cost.

  In the liquid crystal display device of the present invention, the color measuring means is provided according to the number of colors of the color filter provided in the liquid crystal panel, and the spectroscopic means has spectral characteristics corresponding to the respective colors of the color filter. It is preferable to have a configuration. That is, it is preferable that the spectroscopic unit has a color gamut corresponding to the color gamut of the color filter. According to this configuration, the chromaticity information obtained by the colorimetric means and the chromaticity information of the color light output through the color filter can be easily matched, and the color adjustment of the liquid crystal display device can be performed with higher accuracy. Will be able to do.

The color adjustment method for a liquid crystal display device according to the present invention includes a liquid crystal panel, illumination means disposed on the back side of the liquid crystal panel, and an image supplied to the liquid crystal panel by converting an input image signal into a display signal. A color adjustment method for a liquid crystal display device comprising a processing means, and a colorimetric means for measuring the chromaticity of illumination light output from the illumination means on the liquid crystal panel, the colorimetric means measuring Detecting a temporal change of the illumination light by calculating color difference information from the chromaticity information obtained and the chromaticity information of the illumination light accumulated in advance, and when the temporal change is detected, the display Applying correction signal processing based on the color difference information to the signal.
According to this color adjustment method, the chromaticity of the illumination light output from the illumination unit can be measured by the liquid crystal panel, and the display on the liquid crystal panel can be corrected based on the measurement result. In spite of the color change with time, the liquid crystal display device can reproduce the color faithfully.

  A color adjustment program for a liquid crystal display device according to the present invention converts a liquid crystal panel, illumination means disposed on the back side of the liquid crystal panel, and an input image signal into a display signal and supplies the display signal to the liquid crystal panel. And a program applicable to color adjustment of a liquid crystal display device provided with color measurement means for measuring the chromaticity of illumination light output from the illumination means on the liquid crystal panel. Calculating color difference information from the chromaticity information measured by the color means and the chromaticity information of the illumination light accumulated in advance, and determining whether or not color correction processing is necessary for the display signal based on the color difference information And a step of executing the color correction process.

  An electronic apparatus according to the present invention includes the liquid crystal display device according to the present invention described above. According to this configuration, an electronic apparatus including a display unit that can faithfully reproduce an input image signal and can maintain such reproducibility well over a long period of time is provided.

(First embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a plan configuration diagram of a liquid crystal display device according to an embodiment of the present invention, FIG. 2 is a cross-sectional configuration diagram taken along line AA ′ in FIG. 1, and FIG. 3 is a diagram of the liquid crystal display device. It is a plane block diagram which shows 1 pixel area | region.

  The liquid crystal display device 100 is an active matrix transmissive color liquid crystal display device, and is mainly composed of a liquid crystal panel 110 and a backlight (illuminating means) 120 as shown in FIG. The liquid crystal panel 110 includes a pair of substrates 111 and 112 arranged to face each other, and a liquid crystal layer 114 sandwiched between the substrates 111 and 112 and sealed with a sealing material 113.

  Although not shown, a polarizing plate and a retardation plate are provided on the outer surface side (the side opposite to the liquid crystal layer) of the substrates 111 and 112, respectively. For example, when the liquid crystal layer 114 is made of a vertically aligned liquid crystal, a λ / 4 retardation plate and a polarizing plate are laminated on the outer surface side of each of the substrates 111 and 112 to form a circular polarizing plate. Configuration is adopted. In addition, a reflective polarizing plate may be provided to increase the use efficiency of the illumination light of the backlight 120.

  A color filter 115 is provided on the inner surface (side surface of the liquid crystal layer 114) side of the substrate 111 on the front side (upper side in FIG. 2), and a circuit layer 116 is formed on the inner surface side of the substrate 112. As shown in FIG. 1, the liquid crystal panel 110 includes a substrate 111 and a substrate 112 having different planar dimensions, which are bonded to each other, and a scanning line is formed in a region (circuit layer 116) on the substrate 111 protruding outward from the substrate 112. The drive circuit 130 and the data line drive circuit 140 are disposed along the side edge of the substrate.

  A display area 110A is formed in a planar area where the substrates 111 and 112 overlap, and color sensors 180R, 180G, and 180B are provided in areas outside the display area 110A. The color sensors 180R, 180G, and 180B are arranged in a distributed manner at three edge portions of the display area 110A. Each of the color sensors 180R, 180G, and 180B includes light receiving elements 160R, 160G, and 160B and color films 170R, 170G, and 170B provided in correspondence thereto, and the light receiving elements 160R, 160G, and 160B are illustrated in FIG. As described above, the color films 170R, 170G, and 170B are provided at positions that overlap the light receiving elements 160R, 160G, and 160B on the outer surface side of the substrate 112 in a plane.

  The light receiving elements 160R, 160G, and 160B are configured by photodiodes, phototransistors, or the like. The color films 170R (red), 170G (green), and 170B (blue) provided between the light receiving elements 160R, 160G, and 160B and the backlight 120 function as a spectroscopic unit that transmits only a specific wavelength component of incident light. For example, a film colored with a dye or a pigment or a dichroic film can be used. Under such a configuration, the light receiving elements 160R, 160G, and 160B function as colorimetric means for measuring the color of illumination light incident from the backlight 120, and the liquid crystal display device 100 includes the light receiving elements 160R, 160G, and 160B. The liquid crystal display device is capable of adjusting the display color based on the chromaticity information output from.

For the substrates 111 and 112, a light-transmitting substrate such as glass, quartz, or plastic is used. The liquid crystal forming the liquid crystal layer 114 is not particularly limited as long as it can form a predetermined alignment state, and typically nematic liquid crystal is used. Also, the initial alignment mode of the liquid crystal is not limited to the TN mode, and a vertical alignment mode can also be applied.
In the color filter 115, colored portions 115R, 115G, and 115B of three colors (R, G, and B) are periodically arranged in a plane, and although not illustrated, the color filter 115 is provided on the side surface of the liquid crystal layer 114. Are provided with an electrode as means for applying a voltage to the liquid crystal layer and an alignment film for controlling the initial alignment state of the liquid crystal. On the other hand, the circuit layer 116 on the substrate 112 side includes at least an electrode for applying an electric field to the liquid crystal layer 114 together with the electrode on the substrate 111 side. In this embodiment, a pixel switching element made of a TFT (thin film transistor) is provided. .

  Looking at the schematic planar configuration of the pixel shown in FIG. 3, a plurality of data lines 116d and a plurality of scanning lines 116g extending in directions intersecting each other are formed in the circuit layer 116 of the liquid crystal panel 110. A rectangular area surrounded by 116d and the scanning line 116g forms one dot 118. The circuit layer 116 in the dot 118 is provided with a pixel electrode 116e and a TFT 116s, and the pixel electrode 116e is connected to the data line 116d and the scanning line 116g through the TFT 116s. On the other hand, on the substrate 112 in the dot region, one of the colored portions 115R, 115G, and 115B is disposed so as to overlap the pixel electrode 116e of the circuit layer 116 in a plan view. Three dots including the set of colored portions 115R, 115G, and 115B constitute one pixel of the liquid crystal display device 100.

  As shown in FIG. 2, the backlight 120 is mainly composed of a light guide plate 121 and a light source 122 disposed on a side end surface (left end in the drawing) of the light guide plate 121. Then, the light emitted from the light source 122 is introduced into the light guide plate through the side end surface of the light guide plate 121, propagated inside, and emitted from the upper surface of the light guide plate 121 to the liquid crystal panel 110 side. . A light emitting element such as a cold cathode tube or LED (light emitting diode) can be used for the light source 122, and a light-transmitting acrylic resin or the like can be used for the light guide plate 121.

  4 is a diagram illustrating an electrical configuration of the liquid crystal display device 100, and FIG. 5 is a diagram illustrating an electrical configuration of the image processing unit 210 illustrated in FIG. As shown in FIG. 4, the liquid crystal display device 100 mainly includes a liquid crystal panel 110, a backlight 120, a control unit 200, and an image processing unit (image processing unit) 210, and further includes a chromaticity detection unit 220, A color difference calculation unit (color difference deriving unit) 230 and a memory (storage unit) 240 are provided.

  As described above, the liquid crystal panel 110 includes the plurality of scanning lines 116g and the plurality of data lines 116d, the plurality of dots 118 provided corresponding to the intersections thereof, and the drive connected to these dots 118. A circuit 150 and a light receiving element 160 are provided. The driving circuit 150 includes a scanning line driving circuit 130 conductively connected to the scanning lines 116g, and a data line driving circuit 140 conductively connected to the data lines 116d.

  The control unit 200 functions as a timing signal generation unit in the liquid crystal display device of the present embodiment, and performs various types according to a vertical scanning signal Vsync, a horizontal scanning signal Hsync, a dot clock signal dCLK, a clock CLK, and the like supplied from a host device (not shown). Are generated and output to the drive circuit 150 of the liquid crystal panel 110. DY and CLY shown in FIG. 4 are a start pulse and a clock signal, respectively, and are input to the scanning line driving circuit. LP and CLX are a latch pulse and a clock signal, respectively, and are input to the data line driving circuit.

  The image processing unit 210 converts an image signal DATA input from a host device (not shown) into a display signal Ds in a form that can be appropriately displayed on the liquid crystal panel 110, and outputs an analog signal as shown in FIG. A / D converter 211 that converts a formatted image signal into a digital signal, a color converter 212 that applies a color conversion table 214 to each RGB image signal and performs predetermined color conversion, and an analog display of the digital signal A D / A conversion unit 213 that converts the signal Ds and outputs the signal Ds, and a table generation unit (color correction unit) 215 that corrects the color conversion table 214 based on the color difference information output from the color difference calculation unit 230 are configured. ing.

  The color conversion table 214 is an LUT (lookup table) that holds a correspondence table between input values and output values, and in this embodiment, holds an input / output profile (input / output characteristics unique to the panel) of the liquid crystal panel 110. It is a thing. Based on the color conversion table 214, the color conversion unit 212 converts the input RGB digital signal (image signal) into an RGB digital signal (display signal) for liquid crystal panel output. In some cases, the color conversion unit 212 may include a gamma correction table for performing gamma correction on the image signal. The table generation unit 215 updates the color conversion table 214 based on the color difference information input from the color difference calculation unit 230.

  The chromaticity detection unit 220 drives the color sensor 180 (color sensors 180R, 180G, and 180B shown in FIG. 1), reads out the outputs thereof, and outputs chromaticity information to the color difference calculation unit 230. The color difference calculation unit 230 compares the input chromaticity information with the chromaticity information stored in advance in the memory 240 and detects a color change with time of the illumination light.

Hereinafter, the color adjustment method of the liquid crystal display device 100 according to the present embodiment will be described with reference to the flowchart shown in FIG.
In order to perform color adjustment of the liquid crystal display device by the method according to the present invention, first, color measurement of illumination light supplied from the backlight 120 is performed by the color sensor 180 provided in the liquid crystal panel 110 (step S1). The chromaticity information read out by the chromaticity detection unit 220 is output to the color difference calculation unit 230 through a color space conversion process performed as necessary. In the case of this embodiment, since color measurement is performed by three light receiving elements via color films having different spectral characteristics, a device-dependent color signal (RGB value) output from the color sensor 180 is converted into a device-independent color signal (RGB value). Tristimulus values XYZ) and output to the color difference calculator 230 as chromaticity information.

  When converting the color signal from the RGB value to the XYZ value, linear conversion as shown in the following (Equation 1) can be used. In (Expression 1), M is a 3 × 3 RGB → XYZ conversion matrix, and indicates the color characteristics of the color sensor 180. Further, (α, β, γ) is a correction term, and is a term added when the spectral characteristics of the color films 170R, 170G, and 170B are out of the router condition. The correction terms (α, β, γ) are obtained by measuring the spectral sensitivities of the light receiving elements 160R, 160G, and 160B and the spectral sensitivities of the color films 170R, 170G, and 170B in advance, and obtaining the difference from the CIE color matching function. Can be calculated. The above color signal conversion function may be implemented in the chromaticity detection unit 220 as an arithmetic circuit that executes the calculation of (Equation 1), and an LUT (lookup table) that can be referred to from the chromaticity detection unit 220 is prepared. The arithmetic circuit may be mounted as an arithmetic circuit that performs interpolation calculation while referring to the LUT. This arithmetic circuit may be mounted on the chromaticity arithmetic unit 230.

Next, the color difference calculation unit 230 performs color difference ΔEa ^* b ^* (color difference information) through calculation processing based on the chromaticity information input from the chromaticity detection unit 220 and the chromaticity information held in the memory (storage unit) 240. ) And is output to the table generation unit 215 of the image processing unit 210 (step S2). Specifically, first, the color signal (X, Y, Z) input from the chromaticity detection unit 220 is converted into the CIELAB color space using the following (Equation 2). In (Expression 2), (Xn, Yn, Zn) represents X, Y, Z of white light, and is a value obtained by normalizing Xn, Zn with Yn = 100.

The values (L ^* ₁ , a ^* ₁ , b ^* ₁ ) held in the memory 240 in advance and the values (L ^* ₂ , a ^* ₂ , b ^* ₂ ) obtained based on (Equation ₂ ) Is used to determine the color difference ΔEa ^* b ^* by the equation shown in (Formula 3) below. The values (L ^* ₁ , a ^* ₁ , b ^* ₁ ) held in the memory 240 are chromaticity information obtained by measuring the illumination light of the backlight 120 by the color sensor 180 when the liquid crystal display device 100 is manufactured. Or chromaticity information obtained by performing the color measurement of the above procedure after that.

Next, based on the value of the obtained color difference ΔEa ^* b ^* , execution of the color correction operation in the image processing unit 210 is selected (step S3). That is, when the color difference ΔEa ^* b ^* is a predetermined value (for example, 3) or more, color difference information (ΔEa ^* b ^* ) for updating the color conversion table 214 from the color difference calculation unit 230 to the image processing unit 210. Is output, and the image processing unit 210 updates the color conversion table 214 (step S4).

The chrominance calculation unit 230 has a function of recording the chromaticity information input from the chromaticity detection unit 220 in the memory 240. When the output of the chromaticity information is selected, the chrominance information is stored in the memory 240. The held chromaticity information is updated to chromaticity information (L ^* ₂ , a ^* ₂ , b ^* ₂ ) obtained by colorimetry. If the color difference ΔEa ^* b ^* is less than the predetermined value, it is determined that the color shift of the illumination light is within the allowable range, and the process is terminated without updating the color conversion table 214 (END).

The predetermined value related to the color difference ΔEa ^* b ^* is preferably about 3. With such a range, a value that makes the color deviation of the illumination light with respect to the reference value recognizable to humans can be used as a reference value for color adjustment, and color adjustment can be performed efficiently. become.
If the color difference ΔEa ^* b ^* is 2.5 or less, the two colors related to the comparison can be recognized as almost the same color when observed at a distance (see the following reference). Therefore, it is preferable that the predetermined value as the reference value for color adjustment is larger than 2.5. Further, since the color difference ΔEa ^* b ^* color differences become clear in 3.2 above (ΔEa ^* b ^* in a range that can be handled in the same color range of 3.2 to 6.5 is at the impression level), the default value If the range is less than 3.2, color adjustment can be performed before a significant change in display color appears, which is effective.

  References: “New Color Science Handbook 2nd Edition” The Color Society of Japan The University of Tokyo Press

  The color difference information output from the color difference calculation unit 230 is input to the table generation unit 215 of the image processing unit 210 as shown in FIG. The table generation unit 215 updates the color conversion table 214 based on the input color difference information. At this time, a new color conversion table may be generated and replaced by the table generation unit 215, or a part of the color conversion table 214 may be overwritten with a correction value. Then, by applying the updated color conversion table 214 in the color conversion unit 212, the display signal Ds that can correct the color change of the illumination light is supplied to the liquid crystal panel 110.

  As described above, according to the liquid crystal display device 100 of the present embodiment, the color change of the backlight 120 over time can be corrected, the color of the input image can be faithfully reproduced, and the reproducibility can be maintained over a long period of time. It can be kept stable.

  In the present embodiment, the color sensors 180R, 180G, and 180B are arranged at positions along different side edges of the display area 110A. With such an arrangement, the positional accuracy when the color films 170R, 170G, and 170B are provided on the back surface of the panel can be relaxed and the liquid crystal display device can be easily manufactured. However, the color sensors 180R and 180G , 180B is not limited to the form shown in the drawing, and the color sensor can be arranged at an arbitrary position as long as it is an area outside the display area 110A and an irradiation area of the backlight 120. For example, the three color sensors 180R, 180G, and 180B may be arranged along one edge of the display area 110A.

  In this embodiment, the transmissive liquid crystal display device has been described. However, a transflective type in which a reflective layer is partially provided in the dot region of the liquid crystal panel so that both reflective display and transmissive display are possible. The present invention can be applied to a liquid crystal display device without any problem.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 7 is a plan configuration diagram of the liquid crystal display device 300 of the present embodiment, and FIG. 8 is a sectional configuration diagram taken along the line BB ′ of FIG. This embodiment is a modification of the first embodiment. Therefore, among the components shown in FIGS. 7 and 8, the same components as those in FIG. 1 or FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The liquid crystal display device 300 shown in FIGS. 7 and 8 is mainly composed of a liquid crystal panel 310 and a backlight 120 arranged on the back side thereof. The liquid crystal display device 300 has the same electrical configuration as the liquid crystal display device of the first embodiment shown in FIGS.

  The liquid crystal panel 310 has a configuration in which a liquid crystal layer 114 is sandwiched between substrates 111 and 112 that are arranged to face each other with a sealant 113 interposed therebetween. On the inner surface side (liquid crystal layer side) of the substrate 111, a light shielding layer 119 provided with a light shielding portion 119a having a predetermined planar shape, a color filter 315, and electrodes and an alignment film (not shown) are provided. A circuit layer 116 is provided on the inner surface side of the substrate 112, and an alignment film (not shown) is provided on the circuit layer 116. The circuit layer 116 includes a TFT as a pixel switching element, a pixel electrode, a driving circuit 150, light receiving elements 160R, 160G, and 160B.

  As shown in FIG. 7, the liquid crystal panel 310 has a display region 110A in a region where the substrates 111 and 112 overlap in a plane, and light receiving elements 160R, 160G, and outside the three edges of the display region 110A, respectively. 160B is disposed. In addition, the color filter 315 has a configuration in which the colored portions 115R, 115G, and 115B of three colors (R, G, and B) are periodically arranged in the display region 110A, and outside the display region 110A. Sensor filters 315R, 315G, and 315B are provided at positions that overlap the light receiving elements 160R, 160G, and 160B, respectively. These sensor filters 315R, 315G, and 315B have the same configuration as the colored portions 115R, 115G, and 115B, respectively. Further, the light shielding portion 119a of the light shielding layer 119 extends so as to overlap the boundary region of the colored portions 115R, 115G, and 115B in a plan view. The light shielding portion 119a extends to the outside of the display area 110A and constitutes a so-called “peripheral parting” of the liquid crystal panel 310, but is not formed around the formation area of the sensor filters 315R, 315G, and 315B. In addition, the illumination light incident from the liquid crystal layer 114 side can be transmitted.

  In addition, a frame 330 having a rectangular opening 330a corresponding to the display area 110A is displayed on the liquid crystal panel 310 from the front side. The frame 330 is disposed so as to cover the light receiving elements 160R, 160G, and 160B and the sensor filters 315R, 315G, and 315B in a plan view. And it has the light reflection area | region to which light reflectivity was provided in the back surface 331 of the flame | frame facing sensor filter 315R, 315G, 315B. With this configuration, the illumination light output from the backlight 120 and transmitted through the liquid crystal panel 310 is reflected by the light reflection region, and the color light for each sensor 315R, 315G, and 315B, which is a spectroscopic unit, is dispersed and corresponding to each color light. The light is incident on the light receiving elements 160R, 160G, and 160B. Therefore, the liquid crystal display device 300 of the present embodiment has the same configuration as the color sensors 180R, 180G, and 180B shown in FIGS. 1 to 4 by the light receiving elements 160R, 160G, and 160B and the sensor filters 315R, 315G, and 315B. Is realized.

  Since the liquid crystal display device 300 has the electrical configuration shown in FIGS. 4 and 5, the backlight 120 is formed by a color sensor including light receiving elements 160R, 160G, and 160B and sensor filters 315R, 315G, and 315B. It is possible to measure the chromaticity of the illumination light and detect the change of the illumination light with time from the chromaticity information. Then, based on the color difference information obtained from the chromaticity information of the illumination light and the chromaticity information stored in the memory, the image signal supplied to the liquid crystal panel 310 is appropriately color-corrected to compensate for the temporal change of the backlight 120. Thus, the input image can be faithfully reproduced and displayed.

  In the liquid crystal display device 300 of the present embodiment, sensor filters 315R, 315G, and 315B, which are spectroscopic means, are provided in the color filter 315, and are formed with the same positional accuracy as the colored portions 115R, 115G, and 115B. Therefore, the sensor filter can be accurately aligned with respect to the light receiving elements 160R, 160G, and 160B. Accordingly, the light receiving elements 160R, 160G, and 160B are disposed outside the three sides of the display area 110A as shown in FIG. 7, and the light receiving elements 160R, 160G, and 160B are arranged along one side of the display area 110A. A form in which is arranged can be easily applied. Furthermore, since the sensor filters 315R, 315G, and 315B can be formed together with the colored portion in the process of forming the color filter 315, the sensor filter 315R, 315G, and 315B has an advantageous configuration in terms of manufacturing cost as compared with the first embodiment using a color film. .

  In the present embodiment, a light reflecting area is provided on the back surface 331 of the frame 330 so that the illumination light is reflected by the light reflecting area and is incident on the color sensor. It may be provided. That is, a light-reflective metal film made of aluminum, silver, or the like may be provided on the inner surface or outer surface of the substrate 111 at a position overlapping the sensor filters 315R, 315G, and 315B in a plane.

  Further, in the liquid crystal panel 310 according to the present embodiment, the light shielding layer 119 is provided in a position overlapping the boundary regions of the color portions 115R, 115G, and 115B of the color filter 315 and the peripheral portions of the sensor filters 315R, 315G, and 315B. It has been. The light shielding portion 119a provided in the light shielding layer 119 has a structure in which, for example, a metal film made of Cr or Ti and a metal oxide film made of the oxide are laminated, and the display surface side (the substrate 111 side) ) And a metal oxide film and a metal film are stacked in order. When the light-shielding portion 119a having such a configuration is viewed from the display surface side, it is visually recognized as black due to the interference of the metal oxide film, and is reflected by the wiring extending to the peripheral portion of the dot 118, and the light outside the display region is reflected. Transmission is prevented. On the other hand, when the light-shielding portion 119a is viewed from the back side (the liquid crystal layer 114 side), the metal oxide film is not provided, so that light can be reflected on the surface. Therefore, if the light shielding portion 119a is extended to the formation region of the sensor filters 315R, 315G, and 315B, the illumination light output from the backlight 120 is reflected by the metal film of the light shielding portion 119a, and the sensor filters 315R, The light can be incident on 315G and 315B. As a result, a configuration in which the same function as that of the frame 330 is incorporated in the liquid crystal panel 310 can be realized, which is advantageous in terms of manufacturing cost and the like.

(Electronics)
Hereinafter, embodiments in which the present invention is applied to a mobile phone will be described in detail with reference to the drawings. As shown in FIG. 9, the mobile phone according to the present invention includes a display unit 1012 that includes the liquid crystal display device of the previous embodiment and a lower end of a main body unit 1001 that includes an operation unit 1013 in which a plurality of operation keys are arranged. The lid portion 1002 is connected to the body via a hinge mechanism, and the lid portion 1002 is openable and closable with respect to the main body portion 1001.

  A lid sensor for detecting the open / closed state of the lid portion 1002 is provided in the vicinity of the connecting portion between the main body portion 1001 and the lid portion 1002, and the top portion of the main body portion 1001 is connected to the main body portion 1001. An antenna 1019 that can be moved back and forth is provided. A receiving unit (speaker) 1020 is provided above the display unit 1012, and a transmitting unit (microphone) 1014 is provided at the tip of the lid 1002, so that a call can be made with the lid 1002 opened. ing.

  FIG. 10 is a diagram showing an electrical configuration of the mobile phone 1000. As shown in the figure, a receiving circuit 1018 and a transmitting circuit 1016 are connected in parallel to a transmission / reception duplexer (duplexer) 1017. During a call, a signal received by the antenna 1019 is transmitted to the receiving circuit 1018 side by the duplexer 1017. Then, the reception signal demodulated by the reception circuit 1018 is supplied to the reception unit 1020 through the control circuit 1010 and emitted. The voice input to the transmitter 1014 is transmitted from the control circuit 1010 to the transmitter circuit 1016 as a transmission signal and modulated. The modulated transmission signal is transmitted from antenna 1019 via transmission / reception duplexer 1017. A memory 1011, a display unit 1012, an operation unit 1013, a transmission unit 1014, a lid sensor 1015, a transmission circuit 1016, a reception circuit 1018, and a reception unit 1020 are connected to the control unit 1010.

  Since the mobile phone of this embodiment having the above-described configuration includes the liquid crystal display device of the previous embodiment, it is possible to faithfully reproduce the input image even when the backlight deteriorates with time. Therefore, a high-quality display can be obtained over a long period of time. In addition, since the color adjustment function provided in the liquid crystal display device according to the embodiment can be operated manually or automatically, for example, the color is adjusted from the control unit 1010 in conjunction with the timer function normally provided in the mobile phone. An adjustment command can be transmitted to the display unit 1012, and the color adjustment command can be transmitted from the control unit 1010 by a key input from the operation unit 1013. Alternatively, the color adjustment command can be linked to a lid opening / closing signal input from the lid sensor 1015 or an incoming signal input from the receiving circuit 1018.

  The liquid crystal display device according to the present invention is not limited to the above mobile phone, but is an electronic book, personal computer, digital still camera, viewfinder type or monitor direct view type video tape recorder, car navigation device, pager, electronic notebook, calculator. It can be suitably used as a display unit for a word processor, a workstation, a video phone, a POS terminal, a device equipped with a touch panel, and the like.

FIG. 1 is a plan configuration diagram of the liquid crystal display device according to the first embodiment. FIG. 2 is a cross-sectional configuration diagram taken along the line A-A ′ of FIG. 1. FIG. 3 is a plan configuration diagram showing one pixel region. FIG. 4 is a diagram showing an electrical configuration of the same. FIG. 5 is a diagram illustrating an electrical configuration of the image processing unit illustrated in FIG. 4. FIG. 6 is a flowchart illustrating a color adjustment method according to the embodiment. FIG. 7 is a plan configuration diagram of the liquid crystal display device according to the second embodiment. FIG. 8 is a cross-sectional configuration diagram taken along line B-B ′ of FIG. 7. FIG. 9 is a perspective view illustrating a mobile phone as an example of an electronic apparatus. FIG. 10 is a diagram showing an electrical configuration of the same.

Explanation of symbols

  100,300 Liquid crystal display device, 110,310 Liquid crystal panel, 120 Backlight (illuminating means), 160R, 160G, 160B Light receiving element, 170R, 170G, 170B Color film (spectral means), 180, 180R, 180G, 180B Color sensor (Color measurement means), 115, 315 color filter, 119 light shielding layer (light shielding part), 130, 140, 150 drive circuit, 200 control part, 210 image processing part (image processing means), 220 chromaticity detection part (color measurement) Means), 230 color difference calculation unit (color difference deriving means), 240 memory (storage means), 214 color conversion table, 330 frames

Claims (11)

A liquid crystal panel provided with a display region having a plurality of dots by sandwiching a liquid crystal layer between a pair of opposed substrates ;
And disposed illumination means outside side of one substrate of the pair of substrates of the liquid crystal panel,
A frame disposed outside the other substrate of the pair of substrates and having an opening corresponding to the display area;
Image processing means for converting an input image signal into a display signal and supplying the converted signal to the liquid crystal panel;
Spectral means provided on the liquid crystal side of the other substrate;
The chromaticity of the illumination light of the illumination means that is provided on the one substrate along the at least one side edge of the display area and is outside the display area of the liquid crystal panel and transmitted through the spectroscopic means is measured. A light receiving element;
A light reflecting means provided between a surface of the frame on the liquid crystal panel side and the spectroscopic means, and reflecting illumination light supplied from the illuminating means to the spectroscopic means side;
The frame is arranged to cover the light receiving element and the spectroscopic means ,
The spectroscopic means is provided at a position overlapping the light receiving element in a plane,
A liquid crystal display device, wherein a display signal supplied from the image processing means to the liquid crystal panel can be changed based on chromaticity information obtained by the light receiving element . 2. The light reflecting means according to claim 1, wherein the light reflecting means is a light reflecting metal film provided on the inner surface or the outer surface of the frame or the other substrate of the liquid crystal panel . Liquid crystal display device. The light receiving element includes a first light receiving element, a second light receiving element, and a third light receiving element,
The spectroscopic means transmits a specific frequency component corresponding to red, and when viewed optically, a first color film provided between the illumination means and the first light receiving element, and a specific frequency component corresponding to green And the second color film provided between the illumination unit and the second light receiving element as viewed optically and the specific frequency component corresponding to blue are transmitted and the illumination unit as viewed optically. And a third color film provided between the third light receiving elements,
The first light receiving element and the first color film are provided along a first side edge of the display area,
The second light receiving element and the second color film are provided along a second side edge different from the first side edge of the display region,
The third light receiving element and the third color film are provided along a third side edge different from the first side edge and the second side edge of the display region. 3. A liquid crystal display device according to 1 or 2. Colorimetric means including the light receiving element and the spectroscopic means ,
Storage means for holding a reference value of chromaticity information of illumination light output from the illumination means;
Color difference deriving means for deriving color difference information from chromaticity information held in the storage means and chromaticity information output from the colorimetric means,
4. The liquid crystal display device according to claim 1, wherein the display signal can be changed based on color difference information obtained by the color difference deriving unit. 5. 5. The liquid crystal display device according to claim 4, wherein the color difference information derived by the color difference deriving unit is a color difference ΔEa ^* b ^* in the CIELAB color space. 6. The liquid crystal display device according to claim 5, wherein when the value of the color difference ΔEa ^* b ^* is greater than or equal to a predetermined value, a display signal output from the image processing means is changed.   7. The liquid crystal display device according to claim 1, further comprising color correction means for correcting a display signal supplied from the image processing means to the liquid crystal panel.   The image processing means includes a color conversion table for converting the image signal into the display signal, and the color correction means can correct the color conversion table. The liquid crystal display device described.   9. The liquid crystal display device according to claim 4, wherein the storage unit is capable of holding chromaticity information obtained by the colorimetry unit.   The color correction unit and the storage unit are configured to be operable in conjunction with each other, and the chromaticity information when the correction process by the color correction unit is executed is recorded in the storage unit. The liquid crystal display device according to claim 9.   An electronic apparatus comprising the liquid crystal display device according to claim 1.

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