Control method of display apparatus and display apparatus

Abstract

The present application provides a display device control method and display device, inhibit due to the generation of domain resulting in coloring. Display device (1) has liquid crystal panel (100R), liquid crystal panel (100G) and liquid crystal panel (100B), based on the emission light from each liquid crystal panel display image. Display control circuit (210) of display device (1) provides R, G and B each color image data to the corresponding liquid crystal panel. Display control circuit (210) will be the lowest transmittance of the 3 panel pixels corresponding to the white side pixel of the domain boundary as the reference panel pixel, by reducing the gray scale of the pixel data provided to the two panel pixels except the reference panel pixel in the 3 panel pixels, inhibit the coloring of the white side pixel.

Description

TECHNICAL FIELD

[0001] The present application relates to a control method of a display device and a display device. BACKGROUND

[0002] In a 3-plate liquid crystal projector, for example, liquid crystal panels are prepared for each of R, G, and B colors, and a color image is generated by synthesizing images generated by the liquid crystal panels. The liquid crystal panel used in the liquid crystal projector is structured such that pixel electrodes are arranged in a matrix shape in one substrate, a common electrode is provided in the other substrate, and a liquid crystal is interposed between the pixel electrodes and the common electrode. When a voltage corresponding to a gray scale is maintained between the pixel electrodes and the common electrode, the orientation state of the liquid crystal molecules is defined, and thus, a transmittance or reflectance corresponding to the voltage is obtained. Therefore, in the above structure, the direction from the pixel electrode toward the common electrode or the opposite direction thereof, that is, the electric field perpendicular to the substrate surface in the electric field acting on the liquid crystal molecules contributes to the control of the transmittance or the like. Hereinafter, the electric field perpendicular to the substrate surface is sometimes referred to as a longitudinal electric field.

[0003] If the gap between the pixel electrodes is narrowed for miniaturization and high definition as in recent years, the influence of the electric field in the direction parallel to the substrate surface, that is, the electric field generated by the pixel electrodes adjacent to each other, cannot be ignored. Hereinafter, the electric field in the direction parallel to the substrate surface is sometimes referred to as a lateral electric field. If the lateral electric field is applied to the longitudinal electric field, the orientation of the liquid crystal becomes poor, that is, a domain is generated, and this is visually recognized as a poor situation on the display. In order to suppress the poor situation on the display caused by the domain, for example, a technique is proposed in which, in the case where the lateral electric field is large, specifically, in the case where the difference between the voltages applied to the adjacent pixel electrodes is assumed to be equal to or greater than a threshold value, correction is performed for each of R, G, and B colors so as to make the difference between the voltages small (for example, refer to Patent Literature 1). In addition, such correction is sometimes referred to as domain correction.

[0004] In Patent Literature 1, it is disclosed that V-T characteristics of each color of R, G, and B are changed identically based on correction values for pixels of a liquid crystal panel of a generation region. In the technology disclosed in Patent Literature 1, for example, in a case where a first difference of a first gray scale level designated for a first sub-pixel corresponding to a first color in a first pixel of each color of R, G, and B and a second gray scale level designated for a second sub-pixel corresponding to the first color in a second pixel adjacent to the first pixel is equal to or more than a threshold value, the first gray scale level is corrected to a first corrected gray scale level close to the second gray scale level by a first correction amount. In addition, in the technology disclosed in Patent Literature 1, a third gray scale level designated for a third sub-pixel corresponding to a second color of each color of R, G, and B in the first pixel is corrected to a second corrected gray scale level which is close to the first corrected gray scale level from the second gray scale level in a direction toward the first gray scale level by a second correction amount based on a second difference of the first corrected gray scale level and the second gray scale level.

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2021-004919

[0006] However, in a case where a range of a voltage used in liquid crystal panels of each color of R, G, and B is different for each color, if correction is performed by the technology disclosed in Patent Literature 1, a relationship of the voltage of each liquid crystal panel is destroyed, and it can be impossible to perform correction correctly. As one example of a case where the range of the voltage used in the liquid crystal panels of each color of R, G, and B is different for each color, a case where color modes are different for each color of R, G, and B can be given. SUMMARY

[0007] In the control method of the display device of one embodiment of the present disclosure, the display device includes a first liquid crystal panel, a second liquid crystal panel, and a third liquid crystal panel, displays an image based on emitted light from the first liquid crystal panel, emitted light from the second liquid crystal panel, and emitted light from the third liquid crystal panel, and includes the steps of providing pixel data of a first color to the first liquid crystal panel, providing pixel data of a second color different from the pixel data of the first color to the second liquid crystal panel, and providing pixel data of a third color different from the pixel data of the first color and the pixel data of the second color to the third liquid crystal panel; and reducing a gray scale level of pixel data provided to a panel pixel other than a reference panel pixel among a first panel pixel of the first liquid crystal panel, a second panel pixel of the second liquid crystal panel, and a third panel pixel of the third liquid crystal panel corresponding to a first display pixel in the image, in a case where a transmittance of the reference panel pixel is the lowest.

[0008] Further, in the control method of a display device of another aspect of the present disclosure, the display device includes a first liquid crystal panel, a second liquid crystal panel, and a third liquid crystal panel, displays an image based on emitted light from the first liquid crystal panel, emitted light from the second liquid crystal panel, and emitted light from the third liquid crystal panel, and includes a correction lookup table in which correction data corresponding to a difference in gray scale level of two adjacent display pixels in the image is stored, the control method of the display device includes: acquiring correction data from the correction lookup table based on pixel data indicating a gray scale level of each color of a first display pixel in the image and pixel data indicating a gray scale level of a second display pixel adjacent to the first display pixel; reducing a gray scale level of pixel data supplied to a panel pixel other than a reference panel pixel among a first panel pixel corresponding to the first display pixel in the first liquid crystal panel, a second panel pixel corresponding to the first display pixel in the second liquid crystal panel, and a third panel pixel corresponding to the first display pixel in the third liquid crystal panel based on the correction data, the reference panel pixel being a panel pixel having the lowest transmittance among the first panel pixel, the second panel pixel, and the third panel pixel; and supplying pixel data in which the gray scale levels of two colors are corrected based on the correction data to the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel for each color.

[0009] Further, another display device of the present disclosure includes: a first liquid crystal panel; a second liquid crystal panel; a third liquid crystal panel; a storage device storing a correction lookup table that stores correction data corresponding to a difference in gray scale level of two adjacent display pixels in an image displayed based on emitted light from the first liquid crystal panel, emitted light from the second liquid crystal panel, and emitted light from the third liquid crystal panel; and a control device that performs the following processing: acquires correction data from the correction lookup table based on pixel data representing a gray scale level of each color of a first display pixel in the image and pixel data representing a gray scale level of a second display pixel adjacent to the first display pixel; lowers a gray scale level of pixel data supplied to a panel pixel other than a reference panel pixel among a first panel pixel corresponding to the first display pixel in the first liquid crystal panel, a second panel pixel corresponding to the first display pixel in the second liquid crystal panel, and a third panel pixel corresponding to the first display pixel in the third liquid crystal panel based on the correction data, with the reference panel pixel being a panel pixel having the lowest transmittance among the first panel pixel, the second panel pixel, and the third panel pixel; and supplies pixel data in which the gray scale levels of two colors are corrected based on the correction data to the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel for each color. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 FIG. 1 is a diagram showing an optical structure example of a display device of Embodiment 1 of the present disclosure.

[0011] Figure 2 FIG. 2 is a block diagram showing an electrical structure example of the display device.

[0012] Figure 3 FIG. 3 is a diagram showing a structure of a liquid crystal panel in the display device.

[0013] Figure 4 FIG. 4 is a perspective view showing a main part configuration of the liquid crystal panel.

[0014] Figure 5 FIG. 5 is a cross-sectional view showing a configuration of the liquid crystal panel.

[0015] Figure 6 FIG. 6 is a block diagram showing an electrical structure of the liquid crystal panel.

[0016] Figure 7 FIG. 7 is a diagram showing a structure of a pixel circuit in the liquid crystal panel.

[0017] Figure 8 FIG. 8 is a diagram showing an example of a reduction in display quality caused by a domain.

[0018] Figure 9 is a graph showing V-T characteristics of a liquid crystal panel for each wavelength.

[0019] Figure 10 is a graph showing an example of a saved content of a correction LUT.

[0020] Figure 11 is a flowchart showing a processing flow of a control method executed by a display control circuit.

[0021] Figure 12 is a graph showing an example of an operation of a display device.

[0022] Figure 13 is a graph showing an example of a voltage applied to a pixel electrode of each sub-pixel in a conventional domain correction.

[0023] Figure 14 is a graph showing an example of a voltage applied to a pixel electrode of each sub-pixel in the present embodiment.

[0024] Figure 15 is a flowchart showing a processing flow of a control method in the second embodiment.

[0025] Figure 16 is a graph showing an example of an operation of a display device of the second embodiment.

[0026] Figure 17 is an explanatory diagram of a shift of a position of a display pixel based on an optical path shifting element.

[0027] Figure 18 is an explanatory diagram of a reduction in display quality in a display device provided with an optical path shifting element.

[0028] Explanation of Reference Numerals

[0029] 1: display device; 100R, 100G, 100B: liquid crystal panel; 110: sub-pixel circuit; 118: pixel electrode; 120: liquid crystal element; 200: image processing device; 210: display control circuit; 220R, 220B, 220G: processing circuit; 300: storage device. DETAILED DESCRIPTION

[0030] Hereinafter, a display device of one embodiment of the present disclosure will be described with reference to the drawings. Note that in each drawing, the size, the proportion, and the like of each component are not necessarily to scale and are appropriately different from the actual size and proportion. In addition, the embodiments described below are preferred specific examples, and thus various limitations are added to the technology, but the scope of the present disclosure is not limited to these modes as long as the description below does not particularly limit the gist of the present disclosure.

[0031] (A: first embodiment)

[0032] Figure 1 FIG. 1 is a diagram showing an optical structure of a display device 1 according to an embodiment of the present disclosure. The display device 1 is a three-panel type liquid crystal projector provided with a liquid crystal panel 100R, a liquid crystal panel 100G, and a liquid crystal panel 100B. The liquid crystal panel 100R is an example of a first liquid crystal panel in the present disclosure. The liquid crystal panel 100G is an example of a second liquid crystal panel in the present disclosure. The liquid crystal panel 100B is an example of a third liquid crystal panel in the present disclosure.

[0033] A lamp unit 2102 composed of a white light source such as a halogen lamp is provided inside the display device 1. Projection light emitted from the lamp unit 2102 is separated into three primary colors of red (R), green (G), and blue (B) by three mirrors 2106 and two dichroic mirrors 2108 arranged inside. Among them, R light is incident on the liquid crystal panel 100R, G light is incident on the liquid crystal panel 100G, and B light is incident on the liquid crystal panel 100B. In addition, the optical path of B is longer than those of the other colors of red and green. Therefore, in order to prevent loss in the optical path, the light of B is guided to the liquid crystal panel 100B through a relay lens system 2121 composed of an entrance lens 2122, a relay lens 2123, and an exit lens 2124.

[0034] The liquid crystal panel 100R has sub-pixel circuits arranged in a matrix shape, and generates a transmission image of R based on a data signal corresponding to R through light transmitted through liquid crystal elements of the above-described sub-pixel circuits. Similarly, the liquid crystal panel 100G generates a transmission image of G based on a data signal corresponding to G, and the liquid crystal panel 100B generates a transmission image of B based on a data signal corresponding to B.

[0035] The transmission images of each color generated by the liquid crystal panel 100R, the liquid crystal panel 100G, and the liquid crystal panel 100B are incident on a dichroic prism 2112 from three directions. In the dichroic prism 2112, the light of R and B is refracted by 90 degrees, and on the other hand, the light of G is straight. Therefore, after the images of each color are synthesized, a color image is projected onto a screen 2120 by a projection lens 2114. In addition, the transmission images of the liquid crystal panels 100R and 100B are projected after being reflected by the dichroic prism 2112, and in contrast, the transmission image of the liquid crystal panel 100G is projected straight. Therefore, the transmission images of the liquid crystal panels 100R and 100B become in a relationship of being inverted left and right with respect to the transmission image of the liquid crystal panel 100G.

[0036] Figure 2 FIG. 2 is a block diagram showing an electrical structure of the display device 1. As shown in FIG. 2, the display device 1 includes an image processing device 200, a storage device 300, and the above-described liquid crystal panels 100R, 100G, and 100B. Figure 2

[0037] ​The video data Vda and the synchronization signal Sync are supplied from a host device, which is not shown, in synchronization. The video data Vda specifies, for example, the gradation of a pixel in an image to be displayed in 8 bits per RGB. One pixel refers to the smallest unit constituting a color image composed of the liquid crystal panel 100R, the liquid crystal panel 100G, and the liquid crystal panel 100B. One pixel is further divided into three, a red sub-pixel of the liquid crystal panel 100R, a green sub-pixel of the liquid crystal panel 100G, and a blue sub-pixel of the liquid crystal panel 100B. Each of the red, green, and blue sub-pixels is an example of a panel pixel in the present disclosure. The synchronization signal Sync includes a vertical synchronization signal indicating the start of vertical scanning of the pixels arranged in a matrix, a horizontal synchronization signal indicating the start of horizontal scanning of one row in the above arrangement, and a clock signal indicating the timing of the amount of one pixel of the video data.

[0038] The video processing device 200 includes a display control circuit 210, a processing circuit 220R, a processing circuit 220G, and a processing circuit 220B. The display control circuit 210 processes the video data Vda and the synchronization signal Sync, and outputs a control signal Ctr for driving the liquid crystal panel 100R, the liquid crystal panel 100G, and the liquid crystal panel 100B. In addition, the control signal Ctr includes a signal required to scan the sub-pixel circuits arranged in a matrix in the liquid crystal panel 100R, the liquid crystal panel 100G, and the liquid crystal panel 100B. Further, the display control circuit 210 supplies the video data Vda_R corresponding to R to the liquid crystal panel 100R, the video data Vda_G corresponding to G to the liquid crystal panel 100G, and the video data Vda_B corresponding to B to the liquid crystal panel 100B in conjunction with the output of the control signal Ctr. The video data Vda_R is an example of pixel data of a first color. The video data Vda_G is an example of pixel data of a second color. The video data Vda_B is an example of pixel data of a third color.

[0039] Further, the display control circuit 210 performs correction for suppressing coloration caused by a field on the video data Vda_R, the video data Vda_G, and the video data Vda_B, respectively, as necessary. Details of the correction will be described later. The display control circuit 210 is an example of a control device in the present disclosure.

[0040] Processing circuit 220R converts the image data Vda_R provided by display control circuit 210 into an analog voltage data signal Vid_R and provides it to liquid crystal panel 100R. Similarly, processing circuit 220G converts the image data Vda_G provided by display control circuit 210 into an analog voltage data signal Vid_G and provides it to liquid crystal panel 100G. Likewise, processing circuit 220B converts the image data Vda_B provided by display control circuit 210 into an analog voltage data signal Vid_B and provides it to liquid crystal panel 100B.

[0041] The storage device 300 is, for example, a non-volatile memory such as flash memory ROM (Read Only Memory). In the storage device 300, a lookup table for correction is pre-stored for each color (R, G, and B). Furthermore, in... Figure 2 In this document, the lookup table is referred to as "LUT", and will be used in the same way throughout this specification. The correction LUT stores correction data, which represents the correction values ​​for the gray levels of each color when correcting image data Vda_R, image data Vda_G, and image data Vda_B respectively to suppress coloration caused by the domain, as will be described in detail later.

[0042] Next, LCD panels 100R, 100G, and 100B will be described. LCD panels 100R, 100G, and 100B differ only in the color of the incident light, i.e., the wavelength; they are structurally identical. Therefore, for LCD panels 100R, 100G, and 100B, the reference numeral will be 100, and they will be described generally without specifying a color.

[0043] Figure 3 This is a diagram showing the structure of the LCD panel 100. Figure 4 This diagram shows the main parts of the LCD panel 100. Figure 5 It is along Figure 4 A cross-sectional view cut by the Hh line. (See figure.) Figure 3 As shown, the liquid crystal panel 100 is housed in a frame-shaped housing 72 with an opening in the display area. An FPC substrate 74 is connected to one end of the liquid crystal panel 100. FPC is short for Flexible Printed Circuits. Multiple terminals 76 are provided at the other end of the FPC substrate 74 for connection to the image processing device 200.

[0044] like Figure 4 and Figure 5As shown, the liquid crystal panel 100 is configured such that an element substrate 100a provided with pixel electrodes 118 and a counter substrate 100b provided with a common electrode 108 are adhered with their electrode formation surfaces facing each other with a gap in which a liquid crystal 105 is held being kept fixed by a seal 90 including spacers, which are not shown.

[0045] As the element substrate 100a and the counter substrate 100b, a substrate having light transmittance such as glass, quartz, or the like is used for each. As shown in FIG. 1, the element substrate 100a and the counter substrate 100b are adhered to each other with a gap in which the liquid crystal 105 is held being kept fixed by the seal 90 including the spacers, which are not shown. Figure 4 As shown, one side of the element substrate 100a protrudes from the counter substrate 100b. In the region that protrudes, a plurality of terminals 106 are provided along the X direction. The plurality of terminals 106 are connected to one end of the FPC substrate 74 shown, and are supplied with various signals and the like described above. Figure 3

[0046] On the surface of the element substrate 100a facing the counter substrate 100b, the pixel electrodes 118 are formed, for example, by patterning of a conductive layer having transparency such as ITO or the like. ITO is an abbreviation of Indium Tin Oxide. In addition, on the opposing surface of the element substrate 100a and the opposing surface of the counter substrate 100b, various elements are provided in addition to the electrodes, but in the present embodiment, they are omitted. Figure 3

[0047] Figure 6 is a block diagram showing the electrical structure of the liquid crystal panel 100. In the liquid crystal panel 100, a scan line drive circuit 130 and a data line drive circuit 140 are provided on the periphery of a display region 10.

[0048] In the display region 10 of the liquid crystal panel 100, sub-pixel circuits 110 corresponding to sub-pixels of an image to be displayed are arranged in a matrix shape. In detail, in the display region 10, a plurality of scan lines 12 are provided extending in the X direction in the drawing, and in addition, a plurality of data lines 14 are provided extending in the Y direction while being kept electrically insulated from the scan lines 12. Further, the sub-pixel circuits 110 are provided in a matrix shape corresponding to the intersections of the plurality of scan lines 12 and the plurality of data lines 14.

[0049] In a case where the number of the scan lines 12 is m and the number of the data lines 14 is n, the sub-pixel circuits 110 are arranged in a matrix shape in m rows by n columns. m and n are each an integer of 2 or more. In the scan lines 12 and the sub-pixel circuits 110, in order to distinguish the rows of the matrix, they are sometimes referred to as 1, 2, 3, …, (m-1), m rows in order from the top in the drawing. Similarly, in the data lines 14 and the sub-pixel circuits 110, in order to distinguish the columns of the matrix, they are sometimes referred to as 1, 2, 3, …, (n-1), n columns in order from the left in the drawing.

[0050] ​​The scan line drive circuit 130 selects the scan line 12 one by one in the order of the 1st, 2nd, 3rd,..., mth row, for example, under the control of the display control circuit 210, and sets the scan signal to the selected scan line 12 to the H level. In addition, the scan line drive circuit 130 sets the scan signal to the scan lines 12 other than the selected scan line 12 to the L level.

[0051] The data line drive circuit 140 latches the data signal provided from the circuit of the corresponding color among the processing circuit 220R, the processing circuit 220G, or the processing circuit 220B for one row, and outputs to the sub-pixel circuit 110 located at the scan line 12 via the data line 14 during the period in which the scan signal to the scan line 12 becomes the H level.

[0052] Figure 7 is a diagram showing an equivalent circuit of 2 rows and 2 columns of a total of 4 sub-pixel circuits 110 corresponding to the intersection of the adjacent 2 scan lines 12 and the adjacent 2 data lines 14. As shown in Figure 7 The sub-pixel circuit 110 includes a transistor 116 and a liquid crystal element 120, for example. The transistor 116 is a thin film transistor of the n-channel type, for example. In the sub-pixel circuit 110, the gate node of the transistor 116 is connected to the scan line 12, and on the other hand, the source node is connected to the data line 14, and the drain node is connected to the pixel electrode 118 which has a substantially square shape in plan view.

[0053] The common electrode 108 is provided in common to all pixels in a manner opposed to the pixel electrode 118. A voltage LCcom is applied to the common electrode 108. Also, the liquid crystal 105 is held between the pixel electrode 118 and the common electrode 108 as described above. Thus, the liquid crystal element 120 is constituted by the pixel electrode 118 and the common electrode 108 holding the liquid crystal 105 in the sub-pixel circuit 110. Further, the storage capacitor 109 is provided in parallel to the liquid crystal element 120. In the storage capacitor 109, one end is connected to the pixel electrode 118, and the other end is connected to the capacitor line 107. The capacitor line 107 is applied with a voltage which is constant in time, for example, the same voltage LCcom as the applied voltage to the common electrode 108. The sub-pixel circuits 110 are arranged in a matrix shape in the extension direction of the scan line 12, that is, the X direction, and in the extension direction of the data line 14, that is, the Y direction, and thus the pixel electrodes 118 included in the sub-pixel circuits 110 are also arranged in the Y direction and the X direction.

[0054] In the scan line 12 in which the scan signal becomes the H level, the transistor 116 of the sub-pixel circuit 110 provided corresponding to the scan line 12 is turned on. By the turning on of the transistor 116, the data line 14 and the pixel electrode 118 become in the state of being electrically connected, and thus the data signal supplied to the data line 14 reaches the pixel electrode 118 via the turned-on transistor 116. When the scan line 12 becomes the L level, the transistor 116 is turned off, but the voltage of the data signal reaching the pixel electrode 118 is held by the capacitive and storage capacitances 109 of the liquid crystal element 120.

[0055] As is well known, in the liquid crystal element 120, the orientation of the liquid crystal molecules changes according to the electric field generated by the pixel electrode 118 and the common electrode 108. Thus, the liquid crystal element 120 becomes the transmittance corresponding to the effective value of the applied voltage. In the present embodiment, as the applied voltage to the liquid crystal element 120 becomes higher, the transmittance becomes higher.

[0056] By performing the operation of supplying the data signal to the pixel electrode 118 of the liquid crystal element 120 in the order of the 1st, 2nd, 3rd,..., mth rows, the voltage corresponding to the data signal is held in the liquid crystal element 120 of the sub-pixel circuit 110 arranged in m rows and n columns, respectively. By the holding of such a voltage, each liquid crystal element 120 becomes the target transmittance, generating an image composed of pixels arranged in m rows and n columns.

[0057] Further, the pixel electrode 118 is provided to the sub-pixel circuit 110, and is provided for the purpose of expressing an arbitrary color sub-pixel, and thus should be strictly called a sub-pixel electrode. However, in the present embodiment, the 3 colors of sub-pixels are synthesized to express one pixel, and from the shape of one pixel, it is in a relationship approximately equal to the shape when the pixel electrode 118 is viewed from above, and thus is called a pixel electrode.

[0058] Further, in Figure 6 In the present embodiment, two scan line drive circuits 130 are provided, and the structure in which the scan signal is supplied to the scan line 12 from both ends is adopted. The reason for adopting such a structure is to suppress the influence of the delay of the scan signal on the display compared to the case where the scan signal is supplied from only one end. In addition, in the case of driving the liquid crystal element 120, in order to prevent the deterioration of the liquid crystal 105, it is necessary to perform the AC drive, and thus the positive polarity voltage on the high side and the negative polarity voltage on the low side with respect to the amplitude center are alternately switched and applied to the pixel electrode 118. In such an AC drive, in the present embodiment, the surface inversion mode in which the writing polarity of each liquid crystal element 120 is made all the same in the vertical scanning of the sub-pixel circuit 110 is adopted. In addition, the voltage with respect to the amplitude center mentioned here can be considered as a voltage approximately the same as the voltage LCcom applied to the common electrode 108.

[0059] Furthermore, if the pixel pitch is narrowed for the purpose of miniaturization and high precision, a domain is generated due to the lateral electric field produced by the adjacent pixel electrodes, which is visually perceived as a display defect.

[0060] Figure 8 This is a diagram showing the pixel count of the displayed image magnified from a top-down view, used to illustrate the degradation in display quality caused by domain limitations. Figure 8 In this context, a square represents one pixel. For example, when displaying white text against a black background, if the pixels constituting the background and the pixels constituting the white text are enlarged, the result should be... Figure 8 The display is as shown in (1). In addition, the white color mentioned here refers to the state in which the three sub-pixels R, G and B are combined at the highest gray level, that is, at the maximum transmittance. Figure 8 The hollow squares in the image represent white pixels. Black refers to the state where the R, G, and B sub-pixels are combined at their lowest gray levels, i.e., with the lowest transmittance. Figure 8 In the image, a shaded box with a diagonal line represents a black pixel. Hereinafter, in the displayed image, the pixel formed by combining the R, G, and B sub-pixels with maximum transmittance among two adjacent pixels is called the white-side pixel, and the pixel formed by combining the R, G, and B sub-pixels with minimum transmittance is called the black-side pixel. Furthermore, white-side pixels are not limited to pixels formed by combining the R, G, and B sub-pixels with maximum transmittance, and black-side pixels are not limited to pixels formed by combining the R, G, and B sub-pixels with minimum transmittance. A white-side pixel is any pixel with a higher grayscale level than a black-side pixel. Hereinafter, the sub-pixel corresponding to a white-side pixel is sometimes referred to as a white-side sub-pixel, and the sub-pixel corresponding to a black-side pixel is sometimes referred to as a black-side sub-pixel.

[0061] In this state, when focusing on a certain color, such as G, the sub-pixel corresponding to the white-side pixel, specifically... Figure 8 In (1), the voltage of the pixel electrode 118 corresponding to the sub-pixel on the right and the sub-pixel corresponding to the black side pixel, specifically, are Figure 8 In (1), the voltage difference between the pixel electrode 118 corresponding to the sub-pixel on the left increases, thus generating a lateral electric field. Due to this lateral electric field, such as Figure 8 As shown in (2), a domain Ds is generated near the boundary Edg between the white-side sub-pixels and the black-side sub-pixels, resulting in a decrease in display quality. If... Figure 8 If domain Ds is generated as shown in (2), the transmittance of the white-side sub-pixels decreases, resulting in reduced display quality. Specifically, the transmittance of the sub-pixels of G corresponding to the white-side pixels is less than the maximum transmittance, such as... Figure 8 As shown in (3), the white-side pixel is colored magenta. Figure 8 In the image, the square with dotted shadows represents pixels colored magenta.

[0062] In the conventional domain correction for suppressing a decrease in display quality caused by a domain, by lowering the voltage applied to the pixel electrode 118 of each color sub-pixel corresponding to a white-side pixel for each color, the voltage difference between the black-side sub-pixel adjacent to the white-side sub-pixel and the white-side sub-pixel is reduced in the liquid crystal panel 100, and the generation of a domain is suppressed. In contrast, in the present embodiment, the display control circuit 210 corrects the voltage of the data signal in such a manner that the transmittances of the three white-side sub-pixels are made uniform.

[0063] Specifically, the display control circuit 210 lowers the voltage of the data signal to the pixel electrode 118 corresponding to the two sub-pixels in such a manner that the transmittance of the sub-pixel of the color having the lowest transmittance among the three white-side sub-pixels, that is, the sub-pixel of the darkest color, is left unchanged, and the transmittances of the sub-pixels of the remaining two colors are each lowered. The white-side pixel is an example of the first display pixel in the present disclosure. The white-side sub-pixels of the R, G, and B colors corresponding to the white-side pixel are examples of the first panel pixel, the second panel pixel, and the third panel pixel in the present disclosure. The white-side sub-pixel having the lowest transmittance among the three white-side sub-pixels is referred to as a reference panel pixel, and the color of the reference panel pixel is referred to as a reference color.

[0064] The reason why the transmittance of the reference panel pixel is left unchanged and the transmittances of the white-side sub-pixels of the remaining two colors are lowered is as follows. This is because, by increasing the transmittance of the reference panel pixel and leaving the transmittances of the white-side sub-pixels of the remaining two colors as they are, it seems that the same effect can be achieved, but the reference panel pixel is a white-side sub-pixel, and sometimes it is not possible to further increase the transmittance.

[0065] In the liquid crystal panel 100, it is known that the characteristics of the transmittance with respect to the voltage applied to the liquid crystal element 120 differ depending on the wavelength of incident light. Figure 9 is a graph showing the applied voltage-transmittance characteristics (V-T characteristics) for the liquid crystal panels 100R, 100G, and 100B. In Figure 9 , the single-dot chain curve represents the V-T characteristics of the liquid crystal panel 100R, the broken curve represents the V-T characteristics of the liquid crystal panel 100G, and the solid curve represents the V-T characteristics of the liquid crystal panel 100B. As Figure 9 indicated in

[0066] As described above, in conventional domain correction, to suppress domain distortion, the voltage applied to the pixel electrode 118 of each color sub-pixel on the white side is reduced for each color. However, if the VT characteristics of the wavelength of each incident light are different, the following problem arises. That is, by reducing the voltage applied to the pixel electrode 118 of each color sub-pixel on the white side for each color, the voltage difference with the adjacent black side sub-pixel decreases, and the domain distortion is improved. However, if the voltage applied to the pixel electrode 118 of each color sub-pixel on the white side is reduced for each color, the deviation in the transmittance of each of the R, G, and B colors increases. Ideally, the transmittance of each of the R, G, and B colors in the white side pixels is 1:1:1, but if the deviation in the transmittance of each of the R, G, and B colors increases, shading occurs in the white side pixels.

[0067] In contrast, in this embodiment, such as Figure 9 As shown, the display control circuit 210 reduces the voltage supplied to the pixel electrodes 118 of the two sub-pixels (i.e., G and B) to the voltage represented by the correction data stored in the correction LUT corresponding to the reference color, so that the transmittance of the sub-pixel of R, which serves as the reference panel pixel, remains constant, while the transmittance of the sub-pixels of the other two white-side sub-pixels is consistent with the transmittance of the reference panel pixel. This process of reducing the voltage supplied to the pixel electrodes 118 of the two white-side sub-pixels other than the reference panel pixel is called the first correction process. Figure 9 The blackened circles, triangles, and quadrilaterals in the image represent the transmittance of the R, G, and B sub-pixels corresponding to the white-side pixels, respectively. Figure 9 The hollow triangles and quadrilaterals in the diagram represent the transmittance of each color sub-pixel of G and B after correction based on the first correction process, respectively. In this embodiment, as... Figure 9 As shown, the transmittance of the three sub-pixels corresponding to the white-side pixel is roughly the same, approximately 1:1:1, thus improving the coloring of the white-side pixel.

[0068] Even if the gray scales of the two sub-pixels on the white side other than the reference panel pixel, that is, the voltage applied to the pixel electrode 118, are corrected, in a case where a predetermined condition that the coloring of the white side pixel can be confirmed by visual observation or the like is satisfied, the user of the display device 1 can instruct execution of the second correction process by operation of an operation section not shown. In a case where execution of the second correction process is instructed, the display control circuit 210 executes the second correction process. In the second correction process, the voltage supplied to the pixel electrode 118 of the sub-pixel adjacent to the reference panel pixel among the three sub-pixels corresponding to the black side pixel adjacent to the reference panel pixel is increased to the voltage indicated by the correction data stored in the correction LUT. By increasing the voltage supplied to the pixel electrode 118 of the sub-pixel adjacent to the reference panel pixel, the lateral electric field between the reference panel pixel and the sub-pixel adjacent to the reference panel pixel becomes small, and the domain is suppressed. As a result of the domain being suppressed, the transmittance of the reference panel pixel becomes high, and the coloring of the white side pixel is suppressed.

[0069] Next, the correction LUT will be described. Since the data structure of the correction LUT corresponding to each color of R, G, and B is the same, the following will describe the storage content of the correction LUT using the correction LUT corresponding to R as an example. Figure 10 is a view showing an example of the storage content of the correction LUT corresponding to R. As shown in Figure 10 , in the correction LUT, the correction data indicating the correction values of the voltages of the sub-pixels of each color of B and G in the first correction process and the correction data indicating the correction values of the voltages of the sub-pixels of R in the second correction process are stored in correspondence with the gray scales of the sub-pixels of R on the black side and the gray scales of the sub-pixels of R on the white side. In a case where the reference color is R, in the first correction process, the display control circuit 210 reads out the correction data indicating the correction values of the voltages of the sub-pixels of each color of B and G stored in the correction LUT of R in correspondence with the gray scale of the sub-pixel of R adjacent to the reference panel pixel in the liquid crystal panel 100R, and executes the first correction process using the correction data. Similarly, in the second correction process, the display control circuit 210 reads out the correction data indicating the correction values of the voltages of the sub-pixels of R stored in the correction LUT of R in correspondence with the gray scale of the sub-pixel of R adjacent to the reference panel pixel in the liquid crystal panel 100R, and executes the second correction process using the correction data.

[0070] The contents of the correction LUT to be held can be set in accordance with the V-T characteristic. The V-T characteristic is determined, for example, by measuring the transmittance of a sub-image of each color of R, G, and B in a state in which a pattern image in which each pixel of white, gray, and black is arranged is displayed on the display device 1. The determination of the V-T characteristic is performed, for example, once for each model of the display device 1, that is, for one model, and the setting of the contents of the correction LUT based on the V-T characteristic is performed at the time of factory shipment of the display device 1 or the like. In addition, in order to perform fine adjustment corresponding to individual differences of the display device 1 or the like, the correction amount in the first correction process and the second correction process can also be adjusted by multiplying the correction data held in the correction LUT by a coefficient. In addition, by setting the coefficient in accordance with a function having elapsed time from the time of factory shipment of the display device 1 as an argument, the first correction process and the second correction process that take into account deterioration over time can be performed.

[0071] Figure 11 is a flowchart showing the processing flow in the control method performed by the display control circuit 210. As shown in Figure 11 , the control method includes a decision process SA110, a first correction process SA120, a first determination process SA130, and a second correction process SA140.

[0072] In the decision process SA110, the display control circuit 210 decides the reference color and the reference panel pixel by analyzing the image data Vda_R, the image data Vda_G, and the image data Vda_B, respectively. In the present embodiment, the display control circuit 210 takes the sub-pixel having the lowest transmittance among the three sub-pixels corresponding to the white-side pixel adjacent to the black-side pixel as the reference panel pixel, and takes the color corresponding to the reference panel pixel as the reference color. The portion where the black-side pixel and the white-side pixel are adjacent to each other is sometimes referred to as a domain boundary. Furthermore, the transmittance of the three sub-pixels corresponding to the white-side pixel of the domain boundary can be calculated, for example, based on the gradation levels indicated by the image data Vda_R, the image data Vda_G, and the image data Vda_B, respectively, and the V-T characteristic described above.

[0073] In the first correction process SA120 after the decision process SA110, the display control circuit 210 refers to the contents of the correction LUT corresponding to the reference color, and reduces the gradation levels indicated by the image data corresponding to the two sub-pixels other than the reference panel pixel among the three sub-pixels corresponding to the white-side pixel at the domain boundary. For example, as shown in Figure 12 , the transmittance of G among the respective colors of R, G, and B corresponding to the white-side pixel of the domain boundary is lower than the other two. In Figure 12 , the hatched diagonal line indicates black, the hatched vertical line indicates R, the hatched checkered pattern indicates G, and the hatched horizontal line indicates B. In addition, in Figure 12In this case, the transmittance of each sub-pixel is represented by the density of the lines constituting the shade. Specifically, the higher the density of the lines constituting the shade, the lower the transmittance. In this case, the display control circuit 210 sets the reference color to G, as in Figure 12 As shown in (2) of the same drawing, the display control circuit 210 lowers the transmittance of the sub-pixels of each of the colors B and R corresponding to the white-side pixel. The display control circuit 210 supplies the image data Vda_B after correction of the gradation of the sub-pixel of B corresponding to the white-side pixel of the domain boundary to the processing circuit 220B, and supplies the image data Vda_R after correction of the gradation of the sub-pixel of R corresponding to the white-side pixel to the processing circuit 220R. In addition, the display control circuit 210 supplies the uncorrected image data Vda_G to the processing circuit 220G.

[0074] In the first decision process SA130 after the first correction process SA120, the display control circuit 210 decides whether or not the execution of the second correction process is instructed. In the case where the display control circuit 210 receives an operation signal instructing the execution of the second correction process from the operation section, the decision result of the first decision process SA130 is "Yes". In contrast, in the case where the display control circuit 210 receives another operation signal, for example, an operation signal instructing the end of the present control method, from the operation section, the decision result of the first decision process SA130 is "No". In the case where the decision result of the first decision process SA130 is "No", the display control circuit 210 ends the execution of the present control method. In contrast, in the case where the decision result of the first decision process SA130 is "Yes", the display control circuit 210 executes the second correction process SA140.

[0075] In the second correction process SA140, the display control circuit 210 refers to the saved content of the correction LUT corresponding to the reference color, and raises the gradation shown by the image data corresponding to the sub-pixel adjacent to the reference panel pixel among the three sub-pixels corresponding to the black-side pixel at the domain boundary. As described above, the reference panel pixel in the present action example is the sub-pixel of the color G on the white side, and therefore, by executing the second correction process SA140, as shown in (3) of the same drawing, the transmittance of the sub-pixel of the color G corresponding to the black-side pixel is raised. The display control circuit 210 supplies the image data Vda_G after correction of the gradation of the sub-pixel of G corresponding to the black-side pixel of the domain boundary to the processing circuit 220G, and supplies the image data Vda_R and the image data Vda_B which have been corrected in the first correction process SA120 to the processing circuit 220R and the processing circuit 220B, respectively. Figure 12

[0076] ​As explained above, according to the display device 1 of the first embodiment, the gradation levels of the pixel data supplied to the two sub-pixels other than the reference panel pixel among the sub-pixels of each color of R, G, and B corresponding to the white-side pixel at the domain boundary are lowered. Therefore, the difference between the transmittance of the reference panel pixel and the transmittance of each of the two sub-pixels becomes small, and the coloring of the white-side pixel caused by the deviation of the transmittance can be suppressed. Further, according to the display device 1 of the first embodiment, in a case where the second correction processing SA140 is executed, the lateral electric field between the reference panel pixel and the sub-pixel adjacent to the reference panel pixel becomes small, and the domain is suppressed. As a result of the domain being suppressed, the transmittance of the reference panel pixel becomes high, and the coloring of the white-side pixel is suppressed. In this way, according to the display device 1 of the present embodiment, the coloring of the white-side pixel at the domain boundary can be suppressed.

[0077] In the existing domain correction, as shown in Figure 13 , the voltage applied to the pixel electrode is changed from the voltage in a state where no domain is generated for all the sub-pixels located at the domain boundary. In contrast, according to the display device 1 of the first embodiment, as shown in Figure 14 , in a case where the sub-pixel of, for example, the G color on the white side among the sub-pixels located at the domain boundary is the reference panel pixel, the voltage applied to the pixel electrode is not changed from the voltage in a state where no domain is generated for the reference panel pixel and the sub-pixels of each of the R and B colors on the black side.

[0078] The first determination processing SA130 in the present embodiment is not a necessary process, and can be omitted. In a manner in which the first determination processing SA130 is omitted, the second correction processing SA140 is executed after the first correction processing SA120. In addition, the second correction processing SA140 is also not a necessary process, and can be omitted. That is, the control method of the present embodiment can also be constituted by the decision processing SA110 and the first correction processing SA120.

[0079] (B: Second Embodiment)

[0080] The display control circuit 210 can also execute the control method shown in Figure 15 instead of the control method shown in Figure 11 . In Figure 11 and Figure 15 , the same processing is denoted by the same reference numerals. In comparison with Figure 11 and Figure 15As can be seen, the control method in this embodiment differs from the control method in the first embodiment in that it includes a second determination process SA150, a third correction process SA160, a third determination process SA170, and a fourth correction process SA180. Furthermore, in this embodiment, the correction LUT stores correction data from the third and fourth correction processes in addition to the correction data from the first and second correction processes. For example, in the case of the correction LUT corresponding to R, the correction data in the third correction process can include data representing the correction values ​​of the grayscale levels of the image data corresponding to the reference panel pixels. Similarly, the correction data in the fourth correction process can include data representing the correction values ​​of the grayscale levels of the image data of the two sub-pixels (excluding the sub-pixel adjacent to the reference panel pixel) out of the three sub-pixels corresponding to the black-side pixels.

[0081] like Figure 15 As shown, the second determination process SA150 is executed after the second correction process SA140. In the second determination process SA150, the display control circuit 210 determines whether the execution of the third correction process has been instructed. If the display control circuit 210 receives an operation signal from the operation unit instructing the execution of the third correction process, the determination result of the second determination process SA150 is "yes". Conversely, if the display control circuit 210 receives other operation signals from the operation unit, such as an operation signal indicating the end of this control method, the determination result of the second determination process SA150 is "no". If the determination result of the second determination process SA150 is "no", the display control circuit 210 ends the execution of this control method. Conversely, if the determination result of the second determination process SA150 is "yes", the display control circuit 210 executes the third correction process SA160.

[0082] In the third correction process SA160, the display control circuit 210 refers to the stored contents of the correction LUT corresponding to the reference color and increases the grayscale level of the image data corresponding to the reference panel pixel. Assuming that the reference panel pixel in this example is the same as in the example of the first embodiment, and is a white-side G-color sub-pixel, at the moment the third correction process SA160 begins execution, the transmittance of the R, G, and B-color sub-pixels corresponding to the white-side pixel is... Figure 16 The state shown in (1).

[0083] exist Figure 16 In, with Figure 12 Similarly, diagonal shading represents black, vertical shading represents R, grid-like shading represents G, and horizontal shading represents B. Additionally, in Figure 16 In, with Figure 12Similarly, the transmittance of each sub-pixel is represented by the density of the lines that constitute the shadow. In this case, by performing the third correction process SA160, such as... Figure 16 As shown in (2), the transmittance of the G-color sub-pixel corresponding to the white-side pixel increases. The display control circuit 210 provides the image data Vda_G, after correcting the grayscale levels of the G sub-pixels corresponding to the black-side pixels and white-side pixels at the domain boundary, to the processing circuit 220G, and provides the image data Vda_R and image data Vda_B, which were corrected in the first correction process SA120, to the processing circuit 220R and processing circuit 220B, respectively. When the third correction process SA160 is performed, the difference between the transmittance of the reference panel pixel and the transmittance of the other two white-side sub-pixels further decreases, suppressing the coloring of the white-side pixel caused by the transmittance deviation.

[0084] In the third determination process SA170 following the third correction process SA160, the display control circuit 210 determines whether the execution of the fourth correction process has been instructed. If the display control circuit 210 receives an operation signal from the operation unit instructing the execution of the fourth correction process, the determination result of the third determination process SA170 is "yes". Conversely, if the display control circuit 210 receives other operation signals from the operation unit, such as an operation signal indicating the end of this control method, the determination result of the third determination process SA170 is "no". If the determination result of the third determination process SA170 is "no", the display control circuit 210 terminates the execution of this control method. Conversely, if the determination result of the third determination process SA170 is "yes", the display control circuit 210 executes the fourth correction process SA180.

[0085] In the fourth correction process SA180, the display control circuit 210, referring to the stored contents of the correction LUT corresponding to the reference color, reduces the grayscale level of the image data corresponding to the sub-pixels of the three sub-pixels corresponding to the black-side pixels at the domain boundary, excluding the sub-pixels adjacent to the reference panel pixel. As described above, the reference panel pixel in this example is a sub-pixel of the white-side G color; therefore, by executing the fourth correction process SA180, as... Figure 16As shown in (3), the transmittance of the R and B sub-pixels corresponding to the black-side pixels decreases. The display control circuit 210 provides the image data Vda_G, after correcting the gray level of the G sub-pixel corresponding to the black-side pixel at the domain boundary, to the processing circuit 220G, and provides the image data Vda_R and image data Vda_B, which were corrected in the first correction process SA120, to the processing circuit 220R and processing circuit 220B, respectively. When the fourth correction process SA180 is performed, for each color of R and B, by increasing the gray level of the black-side sub-pixels, the transverse electric field at the domain boundary is enhanced, and the transmittance of each color of R and B sub-pixels decreases. As a result, the deviation of the transmittance of each color of R, G, and B sub-pixels corresponding to the white-side pixels is further reduced, and the coloring of the white-side pixels is further suppressed.

[0086] As explained above, the control method of the second embodiment can further suppress the coloring of white-side pixels at the domain boundary compared to the first embodiment.

[0087] (C. Deformation)

[0088] The first and second embodiments of this disclosure have been described above, but these embodiments may also be modified as follows.

[0089] (C-1: Variation Example 1)

[0090] In the first and second embodiments described above, a normally black mode was used, but a normally white mode can also be used. Furthermore, the liquid crystal panels 100R, 100G, and 100B are described as transmissive, but they can also be described as reflective.

[0091] (C-2: Variation Example 2)

[0092] The display device 1 may also include an optical path shifting element that shifts the position of display pixels formed by light emitted from liquid crystal panels 100R, 100G, and 100B by each unit period contained in a frame, thereby achieving high resolution by shifting the position of the display pixels by each unit period. For example, by dividing a frame into four unit periods, the optical path shifting element is used to shift the display position of display pixel B1 as follows: Figure 17 The pixels are shifted as shown to positions P1, P2, P3, and P4, thereby achieving a resolution four times higher than that of the liquid crystal panel 100. According to this method, in a display device that achieves high resolution by shifting the position of the display pixels in each unit period, it is possible to suppress color distortion of the displayed image caused by differences in the transmittance of the reference panel pixel and the transmittance of the two panel pixels other than the reference panel pixel.

[0093] (C-3: Variation Example 3)

[0094] The correction LUT in the above embodiments is a two-dimensional lookup table that stores correction values ​​for the black-side R sub-pixels and correction values ​​for each color of the white-side G and B sub-pixels, corresponding to the gray levels of the black-side R sub-pixels and the white-side R sub-pixels. However, the correction LUT of this disclosure can be a one-dimensional lookup table that stores correction values ​​for the black-side R sub-pixels and correction values ​​for each color of the white-side G and B sub-pixels, corresponding to the difference between the gray levels of the black-side R sub-pixels and the white-side R sub-pixels.

[0095] In addition, in such Figure 18 As shown in (1), in the case of a display device that achieves high resolution by moving the position of the display pixel in each unit period, such as Figure 18 As shown in (2), when pixel B2 is a white-side pixel and pixel B1 is a black-side pixel in one frame, color deviation caused by the domain occurs at positions P5 and P6. Additionally, in Figure 18 In the diagram, W represents the white-side pixel, and K represents the black-side pixel. On the other hand, suppose... Figure 18 As shown in (3), although pixel B2 is displayed as a white-side pixel in one frame, pixel B1 switches from a black-side pixel to a white-side pixel. In this case, a decrease in display quality due to liquid crystal response occurs at positions P3 and P4, and a color deviation due to domain occurs at positions P5 and P6. Even in the case of a combination of a decrease in display quality due to liquid crystal response and a color deviation due to domain, the display device according to this disclosure can suppress the aforementioned decrease in display quality caused by the combination by setting the stored contents of the correction LUT in a manner that makes the transmittance of each sub-pixel in each of the white-side pixels displayed at positions P3 to P8 consistent.

[0096] (D. Summary of this disclosure)

[0097] This disclosure is not limited to the embodiments and variations described above, and can be implemented in various ways without departing from its spirit. For example, this disclosure can also be implemented in the following ways. In order to solve part or all of the problems of this disclosure, or to achieve part or all of the effects of this disclosure, the technical features in the above embodiments corresponding to the technical features in the various methods described below can be appropriately replaced or combined. In addition, if a technical feature is not described as an essential feature in this specification, it can be appropriately deleted.

[0098] The following is a summary published in this note.

[0099] (Postscript 1)

[0100] The control method of the display device of one embodiment of the present disclosure includes: providing pixel data of a first color to the first liquid crystal panel, providing pixel data of a second color different from the pixel data of the first color to the second liquid crystal panel, and providing pixel data of a third color different from the pixel data of the first color and the pixel data of the second color to the third liquid crystal panel; and reducing the gradation of the pixel data provided to the panel pixels other than the reference panel pixel among the first panel pixel of the first liquid crystal panel, the second panel pixel of the second liquid crystal panel, and the third panel pixel of the third liquid crystal panel corresponding to the first display pixel in the image.

[0101] According to the control method of (Addenda 1), since the gradation of the pixel data provided to the panel pixels other than the reference panel pixel among the first panel pixel, the second panel pixel, and the third panel pixel is reduced, the difference between the transmittance of the reference panel pixel and the transmittance of each of the two panel pixels other than the reference panel pixel among the first panel pixel, the second panel pixel, and the third panel pixel is small, and the coloring of the displayed image caused by the difference in transmittance is suppressed.

[0102] (Addenda 2)

[0103] The control method of (Addenda 2) is the control method of (Addenda 1), in which the display device includes an optical path shifting element that shifts the position of a display pixel formed by the emission light from each of the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel by each unit period included in one frame.

[0104] According to the control method of (Addenda 2), in the display device in which high resolution is achieved by shifting the position of a display pixel by each unit period, the coloring of a displayed image caused by the difference between the transmittance of the reference panel pixel and the transmittance of each of the two panel pixels other than the reference panel pixel can be suppressed.

[0105] (Addenda 3)

[0106] The control method according to (Pare 3) is the control method according to (Pare 1) or (Pare 2), further comprising increasing a gradation level of pixel data supplied to a panel pixel adjacent to the reference panel pixel among a fourth panel pixel of the first liquid crystal panel corresponding to a second display pixel adjacent to the first display pixel in the image, a fifth panel pixel of the second liquid crystal panel corresponding to the second display pixel, and a sixth panel pixel of the third liquid crystal panel corresponding to the second display pixel.

[0107] According to the control method according to (Pare 3), by increasing the gradation level of the pixel data supplied to the panel pixel adjacent to the reference panel pixel among the fourth panel pixel, the fifth panel pixel, and the sixth panel pixel, a lateral electric field between the reference panel pixel and the panel pixel adjacent to the reference panel pixel is reduced, and a domain is suppressed. As a result of the domain being suppressed, the transmittance of the reference panel pixel is increased, and coloring is suppressed.

[0108] (Pare 4)

[0109] The control method according to (Pare 4) is the control method according to (Pare 3), further comprising increasing a gradation level of pixel data supplied to the reference panel pixel.

[0110] According to the control method according to (Pare 4), the transmittance of the reference panel pixel is increased as the gradation level of the pixel data supplied to the reference panel pixel is increased, and thus a difference between the transmittance of the reference panel pixel and the transmittance of each of the two panel pixels other than the reference panel pixel among the first panel pixel, the second panel pixel, and the third panel pixel is further reduced, and coloring of a displayed image caused by a difference in transmittance can be suppressed.

[0111] (Pare 5)

[0112] The control method according to (Pare 5) is the control method according to (Pare 4), further comprising decreasing a gradation level of pixel data supplied to a panel pixel other than the panel pixel adjacent to the reference panel pixel among the fourth panel pixel, the fifth panel pixel, and the sixth panel pixel.

[0113] According to the control method according to (Pare 5), by decreasing the gradation level of the pixel data supplied to the panel pixel other than the panel pixel adjacent to the reference panel pixel, a lateral electric field at a domain boundary is enhanced, and the transmittance of the panel pixel other than the panel pixel adjacent to the reference panel pixel among the fourth panel pixel, the fifth panel pixel, and the sixth panel pixel is decreased. As a result, a difference in transmittance is further reduced.

[0114] (Pare 6)

[0115] The control method according to (Pare 6) is the control method according to any one of (Pare 1), (Pare 2), (Pare 3), (Pare 5), in which the gray scale of the first display pixel is higher than the gray scale of the second display pixel.

[0116] According to the control method according to (Pare 6), it is possible to suppress a decrease in display quality caused by a difference between the gray scale of the first display pixel and the gray scale of the second display pixel.

[0117] (Pare 7)

[0118] The control method of the display device according to another aspect of the present disclosure includes: acquiring correction data from the correction look-up table based on pixel data representing a gray scale of each color of a first display pixel in the image and pixel data representing a gray scale of a second display pixel adjacent to the first display pixel; reducing a gray scale of pixel data supplied to panel pixels other than a reference panel pixel among the first panel pixel, the second panel pixel, and the third panel pixel based on the correction data, the reference panel pixel being a panel pixel having the lowest transmittance among the first panel pixel corresponding to the first display pixel, the second panel pixel corresponding to the first display pixel, and the third panel pixel corresponding to the first display pixel in the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel; and supplying pixel data in which a gray scale of each color is corrected based on the correction data to the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel for each color.

[0119] According to the control method according to (Pare 7), a gray scale of pixel data supplied to panel pixels other than a reference panel pixel among the first panel pixel, the second panel pixel, and the third panel pixel is reduced based on correction data stored in the correction look-up table. Therefore, a difference between a transmittance of the reference panel pixel and a transmittance of each of the two panel pixels other than the reference panel pixel among the first panel pixel, the second panel pixel, and the third panel pixel becomes small, and it is possible to suppress coloring of a display image caused by a deviation in transmittance.

[0120] (Pare 8)

[0121] A display device according to one aspect of this disclosure includes: a first liquid crystal panel; a second liquid crystal panel; a third liquid crystal panel; a storage device storing a calibration lookup table, the calibration lookup table storing calibration data corresponding to the difference in gray levels of two adjacent display pixels in an image displayed based on emitted light from the first liquid crystal panel, emitted light from the second liquid crystal panel, and emitted light from the third liquid crystal panel; and a control device that performs the following processing: obtaining calibration data from the calibration lookup table based on pixel data representing the gray levels of each color of the first display pixel in the image and pixel data representing the gray levels of the second display pixels adjacent to the first display pixel. The panel pixel with the lowest transmittance among the first panel pixel in the first liquid crystal panel corresponding to the first display pixel, the second panel pixel in the second liquid crystal panel corresponding to the first display pixel, and the third panel pixel in the third liquid crystal panel corresponding to the first display pixel is used as the reference panel pixel. Based on the correction data, the gray level of the pixel data provided to the panel pixels other than the reference panel pixel in the first panel pixel, the second panel pixel, and the third panel pixel is reduced. The pixel data after the gray level of the two colors has been corrected based on the correction data is provided to the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel for each color.

[0122] In the display device described in (Appendix 8), the grayscale level of the pixel data provided to the panel pixels other than the reference panel pixel in the first panel pixel, second panel pixel, and third panel pixel is reduced based on the correction data stored in the correction lookup table. Therefore, the difference between the transmittance of the reference panel pixel and the transmittance of each of the two panel pixels other than the reference panel pixel in the first panel pixel, second panel pixel, and third panel pixel becomes smaller, and the coloring of the displayed image caused by the deviation in transmittance can be suppressed.

Claims

1. A control method of a display device that has a first liquid crystal panel, a second liquid crystal panel, and a third liquid crystal panel, displays an image based on emergent light from the first liquid crystal panel, emergent light from the second liquid crystal panel, and emergent light from the third liquid crystal panel, the control method of the display device comprising: providing pixel data of a first color to the first liquid crystal panel, providing pixel data of a second color different from the pixel data of the first color to the second liquid crystal panel, and providing pixel data of a third color different from the pixel data of the first color and the pixel data of the second color to the third liquid crystal panel; and decreasing a gradation level of pixel data provided to a panel pixel other than a reference panel pixel among a first panel pixel of the first liquid crystal panel corresponding to a first display pixel in the image, a second panel pixel of the second liquid crystal panel corresponding to the first display pixel, and a third panel pixel of the third liquid crystal panel corresponding to the first display pixel, based on a transmittance of the reference panel pixel being the lowest among the first panel pixel, the second panel pixel, and the third panel pixel.

2. The control method of the display device according to claim 1, wherein the display device has an optical path shifting element that shifts a position of a display pixel formed by the emergent light from each of the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel per unit period included in one frame.

3. The control method of the display device according to claim 1, wherein the control method of the display device further comprises increasing a gradation level of pixel data provided to a panel pixel adjacent to the reference panel pixel among a fourth panel pixel of the first liquid crystal panel corresponding to a second display pixel adjacent to the first display pixel in the image, a fifth panel pixel of the second liquid crystal panel corresponding to the second display pixel, and a sixth panel pixel of the third liquid crystal panel corresponding to the second display pixel.

4. The control method of the display device according to claim 3, wherein the control method of the display device further comprises increasing a gradation level of pixel data provided to the reference panel pixel.

5. The control method of the display device according to claim 4, wherein the control method of the display device further comprises decreasing a gradation level of pixel data provided to a panel pixel other than the panel pixel adjacent to the reference panel pixel among the fourth panel pixel, the fifth panel pixel, and the sixth panel pixel.

6. The control method of the display device according to claim 3, wherein a gradation level of the first display pixel is higher than a gradation level of the second display pixel.

7. A control method of a display device that has a first liquid crystal panel, a second liquid crystal panel, and a third liquid crystal panel, displays an image based on outgoing light from the first liquid crystal panel, outgoing light from the second liquid crystal panel, and outgoing light from the third liquid crystal panel, and has a correction lookup table in which correction data corresponding to a difference in gray scale level of two display pixels adjacent in the image is stored, the control method comprising: acquiring correction data from the correction lookup table based on pixel data representing a gray scale level of each color of a first display pixel in the image and pixel data representing a gray scale level of a second display pixel adjacent to the first display pixel; decreasing a gray scale level of pixel data supplied to a panel pixel other than a reference panel pixel among a first panel pixel corresponding to the first display pixel in the first liquid crystal panel, a second panel pixel corresponding to the first display pixel in the second liquid crystal panel, and a third panel pixel corresponding to the first display pixel in the third liquid crystal panel, based on the correction data, the reference panel pixel being a panel pixel having the lowest transmittance among the first panel pixel, the second panel pixel, and the third panel pixel; and supplying pixel data in which the gray scale levels of two colors are corrected based on the correction data to the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel for each color.

8. A display device comprising: a first liquid crystal panel; a second liquid crystal panel; a third liquid crystal panel; a storage device in which a correction lookup table is stored, the correction lookup table storing correction data corresponding to a difference in gray scale level of two display pixels adjacent in an image displayed based on outgoing light from the first liquid crystal panel, outgoing light from the second liquid crystal panel, and outgoing light from the third liquid crystal panel; and a control device, the control device performing the following processing: acquiring correction data from the correction lookup table based on pixel data representing a gray scale level of each color of a first display pixel in the image and pixel data representing a gray scale level of a second display pixel adjacent to the first display pixel; decreasing a gray scale level of pixel data supplied to a panel pixel other than a reference panel pixel among a first panel pixel corresponding to the first display pixel in the first liquid crystal panel, a second panel pixel corresponding to the first display pixel in the second liquid crystal panel, and a third panel pixel corresponding to the first display pixel in the third liquid crystal panel, based on the correction data, the reference panel pixel being a panel pixel having the lowest transmittance among the first panel pixel, the second panel pixel, and the third panel pixel; and supplying pixel data in which the gray scale levels of two colors are corrected based on the correction data to the first liquid crystal panel, the second liquid crystal panel, and the third liquid crystal panel for each color.

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