Display device

Abstract

To provide a display device in which a color break can be suppressed more.SOLUTION: A display device includes a light source unit including three light sources corresponding to three colors of light, a display unit that reproduces colors according to the data input from the outside using such three colors of light, a storage unit that stores data expressing lighting patterns of the three light sources, and a control unit that controls the lighting patterns of the three light sources. The control unit generates n lighting periods in a display output period of frame images, n is a natural number of 3 or more, the color of light emitted from the light source unit is different in each of the n lighting periods, the data includes information expressing a plurality of kinds of lighting patterns in which the color range that can be reproduced is different in the n lighting periods, and the control unit controls, if the color reproduction by the display unit changes, the lighting patterns of the three light sources in accordance with the difference in lighting pattern for reproducing the color according to the input data before and after the change.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present disclosure relates to a display device. [Background technology]

[0002] 2. Description of the Related Art There is known a display device that performs display output by a so-called field sequential color (FSC) method in which pixels are controlled so that light of multiple colors is output from the same pixel at different timings (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-038544 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the FSC method, the color reproduction of RGB images is generally achieved by outputting the three colors red (R), green (G), and blue (B) at different times. However, when the light sources of primary colors such as red (R), green (G), and blue (B) are controlled to switch between high-intensity on and off states in an extremely short period of time, color breaks are likely to occur.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a display device that can further suppress color breakup. [Means for solving the problem]

[0006] A display device according to one aspect of the present disclosure includes a light source unit having a first light source that emits light of a first color, a second light source that emits light of a second color, and a third light source that emits light of a third color; a display unit that uses light from the light source unit to perform color reproduction according to input data from an outside; a memory unit that stores data indicating lighting patterns of the first light source, the second light source, and the third light source; and a control unit that controls the lighting patterns of the first light source, the second light source, and the third light source based on the input data and the data, and the control unit controls the lighting patterns of the first light source, the second light source, and the third light source based on the input data and the data, wherein n is a natural number of 3 or greater, a color of light emitted from the light source unit in each of the n lighting periods is different, and the data includes information indicating a plurality of types of lighting patterns each having a different color gamut that can be reproduced in the n lighting periods, and when the input data changes to change the color reproduction by the display unit, the control unit controls the lighting patterns of the first light source, the second light source, and the third light source in accordance with the difference between a lighting pattern for color reproduction according to the input data before the change and a lighting pattern for color reproduction according to the input data after the change. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic circuit diagram showing the main configuration of a display device. [Diagram 2] FIG. 2 is a schematic diagram showing a schematic cross section of the display section and the relationship between the display section and the light source device. [Diagram 3] FIG. 3 is a schematic diagram showing the FSC method applied in the first embodiment. [Figure 4] FIG. 4 is a block diagram showing the functional configuration of the image processing circuit. [Diagram 5] FIG. 5 is a block diagram showing a functional configuration of the lighting control unit. [Figure 6] FIG. 6 is a diagram showing the relationship between the two color gamuts and the color patterns. [Figure 7] FIG. 7 is a schematic diagram showing the relationship between the two color gamuts in a more simplified manner than FIG. [Figure 8]FIG. 8 is a table showing the lighting levels of the first light source, the second light source, and the third light source that produce each of the first red color Ra, the first green color Ga, the first blue color Ba, the second red color Rb, the second green color Gb, and the second blue color Bb. [Figure 9] FIG. 9 is a diagram showing the relationship between the two color gamuts and the color pattern in a three-dimensional manner. [Figure 10] FIG. 10 is a schematic diagram showing a three-dimensional relationship between the color gamut and the gradation values ​​indicated by the sampling color gamut CQ based on sampled pixel signals. [Figure 11] FIG. 11 is a diagram showing an example of the relationship between the type of category and the adoption priority. [Figure 12] FIG. 12 is a schematic diagram showing the relationship between the transition of the display output content, the verification of the category, the selection of the target category, and the change in the lighting pattern of the light source unit 11. As shown in FIG. [Figure 13] FIG. 13 is a diagram showing an example of the relationship between the types of categories added in the first modification and the adoption priorities. [Figure 14] FIG. 14 is a schematic diagram showing the FSC method applied in the second embodiment. [Figure 15] FIG. 15 is a diagram showing an example of the relationship between the type of category and the adoption priority in the second embodiment. [Figure 16] FIG. 16 is a diagram showing an example of the relationship between the types of categories added in the second modification and the adoption priorities. [Figure 17] FIG. 17 is a diagram showing an example of category transition in the third modification. [Figure 18] FIG. 18 is a diagram showing an example of category transition in the third modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. Note that the disclosure is merely an example, and those who are skilled in the art can easily come up with appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present disclosure. In addition, in order to make the explanation clearer, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment, but they are merely examples and do not limit the interpretation of the present disclosure. In addition, in this specification and each figure, elements similar to those described above with respect to the previous figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0009] (Embodiment 1) 1 is a schematic circuit diagram showing a main configuration of a display device 100. The display device 100 includes a display panel P and a light source device L.

[0010] The display panel P includes a display unit 7, a signal output circuit 8, a scanning circuit 9, a VCOM drive circuit 10, a timing controller 13, and a power supply circuit 14. Hereinafter, one side of the display panel P facing the display unit 7 will be referred to as the display surface, and the other side will be referred to as the rear surface. Also, when describing a side of the display device 100, it is located in a direction intersecting (for example, perpendicular to) the opposing direction of the display surface and the rear surface with the display device 100 as a reference.

[0011] A plurality of pixels Pix are arranged in a matrix in the display section 7. Each pixel Pix includes a switching element 1 and two electrodes. In Fig. 1 and Fig. 2 described later, a pixel electrode 2 and a common electrode 6 are illustrated as the two electrodes.

[0012] 2 is a schematic diagram showing a schematic cross section of the display unit 7 and the relationship between the display unit 7 and the light source device L. The display unit 7 has two opposing substrates and liquid crystal 3 sealed between the two substrates. Hereinafter, one of the two substrates will be referred to as a first substrate 30, and the other as a second substrate 20.

[0013] The first substrate 30 includes a light-transmitting glass substrate 35, a pixel electrode 2 laminated on the second substrate 20 side of the glass substrate 35, and an insulating layer 55 laminated on the second substrate 20 side so as to cover the pixel electrode 2. The pixel electrode 2 is provided individually for each pixel Pix. The second substrate 20 includes a light-transmitting glass substrate 21, a common electrode 6 laminated on the first substrate 30 side of the glass substrate 21, and an insulating layer 56 laminated on the first substrate 30 side so as to cover the common electrode 6.

[0014] The common electrode 6 shown in FIG. 1 has a plate-like or film-like shape shared by a plurality of pixels Pix aligned in the X direction. The common electrode 6 includes a common electrode Vodd and a common electrode Veven. The common electrode Vodd is the odd-numbered common electrode 6 counting from one end side in the Y direction among the plurality of common electrodes 6 aligned in the Y direction. The common electrode Veven is the even-numbered common electrode 6 counting from one end side in the Y direction. In the configuration example described with reference to FIG. 1 and FIG. 2, the pixel electrode 2 of one pixel Pix of two pixels Pix adjacent to each other in the Y direction faces the common electrode Vodd, and the pixel electrode 2 of the other pixel Pix faces the common electrode Veven.

[0015] The liquid crystal 3 in the first embodiment is a polymer dispersed liquid crystal (PDLC). Specifically, the liquid crystal 3 includes a bulk 51 and fine particles 52. The orientation of the fine particles 52 changes in the bulk 51 according to the potential difference between the pixel electrode 2 and the common electrode 6. The potential of the pixel electrode 2 is individually controlled for each pixel Pix, so that at least the degree of either the light transmission or the dispersion is controlled for each pixel Pix.

[0016] In the embodiment 1 described with reference to Figure 2, the pixel electrode 2 and the common electrode 6 face each other so as to sandwich the liquid crystal 3, but the display unit 7 may also be configured so that the pixel electrode 2 and the common electrode 6 are provided on a single substrate, and the orientation of the liquid crystal 3 is controlled by the electric field generated by the pixel electrode 2 and the common electrode 6.

[0017] Next, a mechanism for controlling the potentials of the pixel electrode 2 and the common electrode 6 will be described. As shown in FIG. 1, the switching element 1 is a switching element using a semiconductor, such as a thin film transistor (TFT). One of the source or drain of the switching element 1 is connected to one of two electrodes (pixel electrode 2). The other of the source or drain of the switching element 1 is connected to a signal line 4. The gate of the switching element 1 is connected to a scanning line 5. The scanning line 5 applies a potential for opening and closing between the source and drain of the switching element 1 under the control of a scanning circuit 9. The scanning circuit 9 controls the potential.

[0018] In the example shown in FIG. 1, multiple signal lines 4 are aligned along one of the arrangement directions of the pixels Pix (row direction). The signal lines 4 extend along the other arrangement direction of the pixels Pix (column direction). The signal lines 4 are shared by the switching elements 1 of multiple pixels Pix aligned in the column direction. Multiple scanning lines 5 are aligned along the column direction. The scanning lines 5 extend along the row direction. The scanning lines 5 are shared by the switching elements 1 of multiple pixels Pix aligned in the row direction.

[0019] In the description of the first embodiment, the extension direction of the scanning lines 5 is the X direction, and the direction in which the multiple scanning lines 5 are arranged is the Y direction. In addition, in Fig. 1, one of the multiple scanning lines 5 arranged at both ends in the Y direction is designated as scanning line 5a, and the other is designated as scanning line 5b.

[0020] The common electrode 6 is connected to a VCOM driving circuit 10. The VCOM driving circuit 10 provides the common electrode 6 with a potential that functions as a common potential. At the timing when the scanning circuit 9 provides the scanning line 5 with a potential that functions as a driving signal, the signal output circuit 8 outputs a pixel signal, which will be described later, to the signal line 4, thereby charging the liquid crystal (particles 52) that is a storage capacitance and a capacitive load formed between the pixel electrode 2 and the common electrode 6. As a result, the voltage between the pixel Pix and the common electrode 6 becomes a voltage corresponding to the pixel signal. After the driving signal is no longer applied, the liquid crystal (particles 52) that is a storage capacitance and a capacitive load holds the pixel signal. The degree of scattering of the liquid crystal (particles 52) is controlled according to the voltage of each pixel Pix and the voltage of the common electrode 6. For example, the liquid crystal 3 may be a polymer-dispersed liquid crystal in which the degree of scattering increases as the voltage between the voltage of each pixel Pix and the common electrode 6 increases, or a polymer-dispersed liquid crystal in which the degree of scattering increases as the voltage between the voltage of each pixel Pix and the common electrode 6 decreases.

[0021] As shown in FIG. 2, the light source device L is disposed on the side of the display unit 7. The light source device L includes a light source unit 11 and a light source driving circuit 12. The light source unit 11 includes a first light source 11R that emits red (R) light, a second light source 11G that emits green (G) light, and a third light source 11B that emits blue (B) light. The first light source 11R, the second light source 11G, and the third light source 11B each emit light under the control of the light source driving circuit 12. The first light source 11R, the second light source 11G, and the third light source 11B in the first embodiment are light sources using light emitting elements such as light emitting diodes (LEDs), but are not limited thereto and may be any light source whose emission timing can be controlled. The light source driving circuit 12 controls the emission timing of the first light source 11R, the second light source 11G, and the third light source 11B under the control of a timing controller 13. In the first embodiment, red (R) is the first color. In embodiment 1, green (G) is the second color. In embodiment 1, blue (B) is the third color. In each subframe period SF and adjustment subframe period Ad described below, the first light source 11R, the second light source 11G, and the third light source 11B can each emit light independently, and two or three of the first light source 11R, the second light source 11G, and the third light source 11B can emit light simultaneously.

[0022] When light is emitted from the light source unit 11, the display unit 7 is illuminated by the light emitted from one side in the Y direction. Each pixel Pix transmits or scatters the light emitted from one side in the Y direction. The degree of scattering depends on the state of the liquid crystal 3 controlled according to the pixel signal.

[0023] The timing controller 13 is a circuit that controls the operation timing of the signal output circuit 8, the scanning circuit 9, the VCOM driving circuit 10, and the light source driving circuit 12. In the first embodiment, the timing controller 13 operates based on a signal input via the image processing circuit 70. The power supply circuit 14 outputs various electric potentials required for the operation of the display device 100 based on power supplied from the outside.

[0024] The image processing circuit 70 outputs a signal based on frame image data IP from outside the display device 100 to the signal output circuit 8 and the timing controller 13. If data indicating the RGB gradation value assigned to one pixel Pix is ​​defined as pixel data, the frame image data IP input to the image processing circuit 70 to output a frame image is a collection of multiple pixel data for multiple pixels Pix provided in the display unit 7, and functions as input data.

[0025] The display device 100 performs display output using a so-called field sequential color (FSC) method, which controls pixels so that light of multiple colors is transmitted from the same pixel at different timings.

[0026] 3 is a schematic diagram showing the FSC method applied in embodiment 1. In embodiment 1, one frame period FP occurs in response to one input of frame image data IP to the image processing circuit 70. That is, one frame image is displayed in response to one frame image data IP.

[0027] As shown in FIG. 3, the frame period FP includes a subframe period SFP1 and subframe periods SFP2 and SFP3. The subframe period SFP1 includes a writing period WP1 and a lighting period LP1 after the writing period WP1. The subframe period SFP2 includes a writing period WP2 and a lighting period LP2 after the writing period WP2. The subframe period SFP3 includes a writing period WP3 and a lighting period LP3 after the writing period WP3. The writing period WP1 and the writing periods WP2 and WP3 are writing periods. The writing period is a period in which a pixel signal corresponding to a display output signal OP described later is provided to each of the multiple pixels Pix. The lighting period LP1 and the lighting periods LP2 and LP3 are lighting periods. The lighting period is a period in which light is emitted from at least one of the first light source 11R, the second light source 11G, and the third light source 11B by the light source unit 11 controlled according to a pixel signal written in the immediately preceding writing period.

[0028] For example, if a pixel signal corresponding to a red (R) component among the color components of an image to be displayed and output according to frame image data IP is written in a writing period WP1, the first light source 11R is turned on during a lighting period LP1, and the second light source 11G and the third light source 11B are turned off, thereby performing color reproduction according to the red (R) component. If a pixel signal corresponding to a green (G) component among the color components of an image to be displayed and output according to frame image data IP is written in a writing period WP2, the second light source 11G is turned on during a lighting period LP2, and the first light source 11R and the third light source 11B are turned off, thereby performing color reproduction according to the green (G) component. If a pixel signal corresponding to a blue (B) component among the color components of an image to be displayed and output according to frame image data IP is written in a writing period WP3, the third light source 11B is turned on during a lighting period LP3, and the first light source 11R and the second light source 11G are turned off, thereby performing color reproduction according to the blue (B) component.

[0029] Display output control for the red (R) component is performed in subframe period SFP1, display output control for the green (G) component is performed in subframe period SFP2, and display output control for the blue (B) component is performed in subframe period SFP3, thereby reproducing RGB colors when viewed over the entire frame period FP. In this way, the FSC method is a method in which RGB color reproduction is performed when viewed over the entire frame period FP.

[0030] In this way, the image processing circuit 70 generates n lighting periods (for example, lighting period LP1, lighting periods LP2, LP3) during the display output period (frame period FP) of the frame image output by the display panel P. n is a natural number equal to or greater than 3. In the explanation with reference to FIG. 4, n=3.

[0031] The above-mentioned idea of ​​allocating red (R), green (G), and blue (B) to the subframe periods SFP1, SFP2, and SFP3, respectively, is merely the simplest of FSC methods, and is presented for the purpose of explaining the FSC method more clearly. In the first embodiment, control of the light source unit 11 corresponding to the categories described below is applied.

[0032] 4 is a block diagram showing the functional configuration of the image processing circuit 70. The image processing circuit 70 has a lighting control unit 71 and a gradation control unit 72. The lighting control unit 71 generates a light source control signal DP based on the gradation value indicated by the pixel data included in the frame image data IP. The light source control signal DP is a signal for controlling the degree of lighting of the first light source 11R, the second light source 11G, and the third light source 11B. The light source control signal DP is output to the gradation control unit 72 and the timing controller 13.

[0033] The gradation control unit 72 outputs a display output signal OP based on the frame image data IP and the light source control signal DP. The display output signal OP includes a pixel signal for performing a display output corresponding to the frame image data IP. The pixel signal written to the pixel Pix in the above-mentioned writing period is the pixel signal included in the display output signal OP. When the pixel Pix operates in accordance with the display output signal OP, the degree of illumination of the light from the light source unit 11 is controlled in accordance with the light source control signal DP. Therefore, the display output signal OP reflects gradation value control corresponding to the light controlled in this manner.

[0034] For example, assume that the pixel data included in the frame image data IP indicates a gradation value of (R, G, B) = (100, 100, 100) for one pixel Pix. Here, when the first light source 11R, the second light source 11G, and the third light source 11B are turned on at 100% brightness in response to the light source control signal DP, the gradation value indicated by the pixel signal for the pixel Pix in the display output signal OP is (R, G, B) = (100, 100, 100). That is, at this time, the gradation value indicated by the frame image data IP and the gradation value indicated by the display output signal OP are equivalent. On the other hand, in this case, when the first light source 11R, the second light source 11G, and the third light source 11B are turned on at 50% brightness in response to the light source control signal DP, if the gradation value of the pixel data in the frame image data IP is directly reflected in the pixel signal of the display output signal OP, the luminance of the pixel Pix in the display output will be insufficient. Therefore, at this time, in the display output signal OP, the gradation value indicated by the pixel signal for that one pixel Pix is ​​set to (R,G,B)=(200,200,200). This makes it possible to more faithfully reproduce the display output intended by the frame image data IP. In this way, the display output signal OP reflects the pixel signal corresponding to the light from the light source unit 11 generated during the frame period FP.

[0035] 1 and 4, the timing controller 13 transfers a light source control signal DP to the light source drive circuit 12. The light source unit 11 turns on in response to the light source control signal DP under the control of the light source drive circuit 12. The timing controller 13 also outputs a synchronization control signal Sig to the signal output circuit 8. The synchronization control signal Sig is a synchronization signal that is output for the purpose of synchronizing the control of the display unit 7 in response to the display output signal OP and the control of the light source unit 11 in response to the light source control signal DP.

[0036] 5 is a block diagram showing a functional configuration of the lighting control unit 71. The lighting control unit 71 has a color information acquisition unit 711, a category verification unit 712, a usable category extraction unit 713, a target category selection unit 714, an adopted category determination unit 715, and a storage unit 716.

[0037] The color information acquisition unit 711 acquires color information of an image to be displayed according to the frame image data IP. Specifically, the color information acquisition unit 711 acquires the R, G, and B gradation values ​​indicated by the pixel data included in the frame image data IP. In other words, the color information acquisition unit 711 acquires information on the color reproduced according to the gradation values ​​from the gradation values.

[0038] The category verification unit 712 verifies whether or not the color information of the image acquired by the color information acquisition unit 711 can be reproduced for each piece of predetermined category information. The category information here is information indicating the lighting pattern of the light source unit 11. Hereinafter, when simply described as a category, it refers to the lighting pattern of the light source unit 11 unless otherwise specified. The predetermined category information refers to information indicating each of a plurality of categories included in the category information 717 described later, for example.

[0039] Here, matters relating to the relationship between the image displayed and output by the display device 100 and the category will be described with reference to FIG. 6 to FIG.

[0040] FIG. 6 is a diagram showing the relationship between two color gamuts Da, Db and a color pattern CP. FIG. 6 shows this relationship using an xy chromaticity diagram according to the CIE-XYZ color system. The color pattern CP in FIG. 6 includes a plurality of white points, black points, and gray points distributed within the chromaticity diagram. The gray points are circular points with a dot pattern. Each of the white points, black points, and gray points indicates a color reproduced by the gradation value of pixel data included in the frame image data IP. The color pattern CP exemplifies the colors reproduced by each of the pixels constituting an image that is displayed and output according to the frame image data IP.

[0041] The color gamut Da includes all the white points, black points, and gray points included in the color pattern CP. Therefore, when a category in which the light source unit 11 is turned on so that the color gamut reproduced by the display device 100 is the color gamut Da, all of the colors included in the color pattern CP can be reproduced. On the other hand, the color gamut Db includes many of the white points, black points, and gray points included in the color pattern CP, but does not include some of the white points, black points, and gray points included in the color pattern CP. Therefore, when a category in which the light source unit 11 is turned on so that the color gamut reproduced by the display device 100 is the color gamut Db, the colors of the pixels corresponding to the points of the color pattern CP that are not included in the color gamut Db will not be reproduced completely.

[0042] FIG. 7 is a schematic diagram showing the relationship between the two color gamuts in a simplified manner compared to FIG. 6. FIG. 8 is a diagram showing in a table the lighting levels of the first light source 11R, the second light source 11G, and the third light source 11B that establish the first red Ra, the first green Ga, the first blue Ba, the second red Rb, the second green Gb, and the second blue Bb. The column "R" in the table of FIG. 8 indicates the lighting level of the first light source 11R. The column "G" in the table of FIG. 8 indicates the lighting level of the second light source 11G. The column "B" in the table of FIG. 8 indicates the lighting level of the third light source 11B. The numerical values ​​written in the fields of the table of FIG. 8 are numerical values ​​that indicate the lighting level of the light source as a percentage, with 0.0 being the minimum value and 1.0 being the maximum value. For example, when "0.0" is written in a column, the light source is at the lowest brightness (0%), which is equivalent to being turned off. Also, when a column contains "1.0," the light source is turned on at maximum brightness (100%).

[0043] As shown in FIG. 8, in the record of the first red color Ra, the value of the column "R" is 1.0, and the values ​​of the other columns are "0.0". That is, the first red color Ra corresponds to the lighting pattern of the light source unit 11 in which the first light source 11R is turned on at the highest brightness, and the second light source 11G and the third light source 11B are turned off. By checking the records of the first green color Ga and the first blue color Ba in the table of FIG. 8 in the same interpretation as the record of the first red color Ra, the following can be seen. That is, the first green color Ga corresponds to the lighting pattern of the light source unit 11 in which the second light source 11G is turned on at the highest brightness, and the first light source 11R and the third light source 11B are turned off. In addition, the first blue color Ba corresponds to the lighting pattern of the light source unit 11 in which the third light source 11B is turned on at the highest brightness, and the first light source 11R and the second light source 11G are turned off.

[0044] Hereinafter, the term "first pattern" refers to a lighting pattern of the light source unit 11 in which the first light source 11R is turned on at the highest brightness, and the second light source 11G and the third light source 11B are turned off. In addition, the term "second pattern" refers to a lighting pattern of the light source unit 11 in which the second light source 11G is turned on at the highest brightness, and the first light source 11R and the third light source 11B are turned off. In addition, the term "third pattern" refers to a lighting pattern of the light source unit 11 in which the third light source 11B is turned on at the highest brightness, and the first light source 11R and the second light source 11G are turned off.

[0045] The color gamut reproducible by the display device 100 corresponds to a category, that is, a lighting pattern of the light source unit 11. The color gamut Da shown in Fig. 6 and Fig. 7 is established by adopting a category that is a combination of the first pattern, the second pattern, and the third pattern. This category corresponds to a tenth category Ct0 in Fig. 11 described later.

[0046] As described above, the display device 100 reproduces colors using FSC. Therefore, the color gamut Da is established in the display device 100, which means that the lighting period in which the first pattern is applied, the lighting period in which the second pattern is applied, and the lighting period in which the third pattern is applied occur during the display period of one frame of an image so that they are different periods. In other words, in order to establish the color gamut Da, a period in which only the first light source 11R is turned on at the highest luminance, a period in which only the second light source 11G is turned on at the highest luminance, and a period in which only the third light source 11B is turned on at the highest luminance must occur during one frame period. In this way, when the primary color light source is controlled to switch between a high luminance on state and a low luminance state in an extremely short period of time, a color break is likely to occur. The primary color light source here refers to the first light source 11R, the second light source 11G, and the third light source 11B. Furthermore, unless otherwise specified, high luminance refers to the luminance of the light source when it is turned on at the highest luminance (100%) or a luminance close to it.

[0047] A color break is a state in which multiple colors used to reproduce a certain color can be individually recognized. For example, assume that in order to reproduce the white color of the highest brightness in a certain pixel Pix, the degree of light scattering of the pixel Pix is ​​maximized, and the first light source 11R, the second light source 11G, and the third light source 11B are turned on at the highest brightness. In this case, the scattering of red light occurring during the period when the first light source 11R is turned on, the scattering of green light occurring during the period when the second light source 11G is turned on, and the scattering of blue light occurring during the period when the third light source 11B is turned on overlap in the region of the pixel Pix. As a result, the region of the pixel Pix should be visually recognized as a white region by the user. However, in this case, the light sources of the primary colors (RGB) are controlled to switch between a high-brightness on state and an off state in an extremely short period of time. For this reason, the user may be able to individually recognize the red light, the green light, and the blue light. Such a state in which the user can recognize the individual colors of light is called a color break. Here, color breaks have been explained using the example of reproducing white at maximum brightness, but color breaks can also occur when reproducing other colors if a primary color light source is controlled to switch between a high-brightness on state and an off state in an extremely short period of time.

[0048] For these reasons, when a category that satisfies the color gamut Da is adopted, color breaks are likely to occur. Therefore, in the first embodiment, a mechanism is adopted that allows for preferential use of a category that is more likely to achieve both color reproduction of an image and suppression of color breaks.

[0049] For example, the color gamut Db shown in Fig. 6 and Fig. 7 is established by the second red Rb, the second green Gb, and the second blue Bb. Therefore, when a category in which the color gamut Db is established is adopted, a period of the second red Rb, a period of the second green Gb, and a period of the second blue Bb are generated during one frame period. According to Fig. 8, the second red Rb is a lighting pattern of the light source unit 11 in which the first light source 11R is turned on at 60% brightness (0.6), and the second light source 11G and the third light source 11B are turned on at 20% brightness (0.2). The second green Gb is a lighting pattern of the light source unit 11 in which the second light source 11G is turned on at 60% brightness (0.6), and the first light source 11R and the third light source 11B are turned on at 20% brightness (0.2). The second blue Bb is a lighting pattern of the light source unit 11 in which the third light source 11B is turned on at a luminance of 60% (0.6), and the first light source 11R and the second light source 11G are turned on at a luminance of 20% (0.2). That is, in the color gamut Db, the change in the luminance of the primary color light source occurring when switching between different lighting patterns is within a change between 20% and 60% (±40%). This is significantly smaller than the change in the luminance of the primary color light source (±100%) when the color gamut Da is adopted. In this way, by making the degree of change in the luminance of the primary color light source smaller, it becomes easier to suppress color breaks. Therefore, by adopting a category in which the color gamut Db is established, color breaks can be suppressed more than when a category in which the color gamut Da is established is adopted.

[0050] However, it is undesirable that the color reproduction of the image is significantly impaired as a result of prioritizing only the suppression of color breaks. Therefore, it is desirable to select a category that achieves both the color reproduction of the image and the suppression of color breaks. On the other hand, reproducing the gradation values ​​of all pixel data contained in the frame image data IP places a high processing load on the color information acquisition unit 711 and the category verification unit 712. Therefore, in the first embodiment, for example, pixel data contained in the frame image data IP is sampled, and a category that can contain the gradation value indicated by the sampled pixel data is regarded as a usable category, which will be described later.

[0051] Of course, the gradation values ​​of all pixel data contained in the frame image data IP may be subject to processing by the color information acquisition unit 711 and the category verification unit 712 so that the gradation values ​​of all pixel data contained in the frame image data IP are included within the color gamut. The extent of sampling may be set appropriately depending on the balance between the number of pixels (so-called resolution) contained in the data assumed to be the frame image data IP and the processing capabilities of the color information acquisition unit 711 and the category verification unit 712. As an example, in the first embodiment, in 1920 x 1080 frame image data IP, 90% or more of the pixels with higher luminosity or brightness are sampled.

[0052] FIG. 9 is a diagram showing the relationship between two color gamuts Da, Db and a color pattern CP in a three-dimensional manner. FIG. 9 and FIG. 10, which will be described later, show a three-dimensional space with seven vertices: first red Ra, first green Ga, first blue Ba, yellow Ya, cyan Ca, magenta Ma, and white W. Yellow Ya corresponds to the lighting pattern of the light source unit 11 in which the first light source 11R and the second light source 11G are turned on at the highest brightness and the third light source 11B is turned off. Cyan Ca corresponds to the lighting pattern of the light source unit 11 in which the second light source 11G and the third light source 11B are turned on at the highest brightness and the first light source 11R is turned off. Magenta Ma corresponds to the lighting pattern of the light source unit 11 in which the first light source 11R and the third light source 11B are turned on at the highest brightness and the second light source 11G is turned off. The white color W corresponds to the lighting pattern of the light source unit 11 in which the first light source 11R, the second light source 11G, and the third light source 11B are turned on at the highest brightness. In addition, in Fig. 9, the color pattern CP is shown in a state in which a dot pattern is added within a solid line frame. Note that, when the three-dimensional space is assumed to be a cube, the remaining one of the eight vertices is a point facing the white color W, and corresponds to black.

[0053] In the example shown in Fig. 9, most of the color pattern CP falls within the color gamut Db. According to this relationship between the color gamut Db and the color pattern CP, by adopting a category in which the color gamut Db is established, it is possible to reproduce the colors of most of the image corresponding to the color pattern CP. Therefore, if only a small portion of the pixel data in the color pattern CP is not sampled and is outside the color gamut Db, and degradation in the quality of the reproduced image is within an acceptable range, a category in which the color gamut Db is established can be adopted.

[0054] 10 is a three-dimensional schematic diagram showing the relationship between the color gamut Da and the gradation values ​​indicated by the sampling color gamut CQ of the sampled pixel data. It is assumed that the sampling color gamut CQ indicates a color gamut that covers the gradation values ​​indicated by the pixel data obtained by sampling a portion of all pixel signals included in the frame image data IP. In this case, any category that includes the sampling color gamut CQ can be adopted in the first embodiment. Here, color breaks can be suppressed by giving priority to adopting a category corresponding to a color gamut narrower than the color gamut Da, that is, a category in which a primary color light source is not lit at maximum brightness.

[0055] Fig. 11 is a diagram showing an example of the relationship between the type of category and the adoption priority. Fig. 11 illustrates a first category Ct1, a second category Ct2, a third category Ct3, and a tenth category Ct0 as examples of categories that can be used in the first embodiment.

[0056] The first category Ct1 is established by the occurrence of a first yellow Y1 period, a second yellow Y2 period, and a first blue Ba period during one frame period. The first yellow Y1 period and the second yellow Y2 period are periods during which the first light source 11R and the second light source 11G are turned on and the third light source 11B is turned off. However, the first yellow Y1 and the second yellow Y2 have different luminances of the first light source 11R and the second light source 11G. In the first yellow Y1, the luminance of the second light source 11G is relatively higher than that of the first light source 11R. In the second yellow Y2, the luminance of the first light source 11R is relatively higher than that of the second light source 11G.

[0057] The second category Ct2 is established by the occurrence of a period of the first cyan C1, a period of the second cyan C2, and a period of the first red Ra during one frame period. The period of the first cyan C1 and the period of the second cyan C2 are periods during which the second light source 11G and the third light source 11B are turned on and the first light source 11R is turned off. However, the luminance of the second light source 11G and the luminance of the third light source 11B are different between the first cyan C1 and the second cyan C2. In the first cyan C1, the luminance of the second light source 11G is relatively higher than the luminance of the third light source 11B. In the second cyan C2, the luminance of the third light source 11B is relatively higher than the luminance of the second light source 11G.

[0058] The third category Ct3 is established by the occurrence of a period of the first magenta M1, a period of the second magenta M2, and a period of the first green Ga during one frame period. The period of the first magenta M1 and the period of the second magenta M2 are periods during which the first light source 11R and the third light source 11B are turned on and the second light source 11G is turned off. However, the luminance of the first light source 11R and the luminance of the third light source 11B are different between the first magenta M1 and the second magenta M2. In the first magenta M1, the luminance of the third light source 11B is relatively higher than the luminance of the first light source 11R. In the second magenta M2, the luminance of the first light source 11R is relatively higher than the luminance of the third light source 11B.

[0059] The tenth category Ct0 is equivalent to the above-mentioned color gamut Da. That is, the tenth category Ct0 is established when a period of the first red color Ra, a period of the first green color Ga, and a period of the first blue color Ba occur during one frame period.

[0060] Regardless of which category included in the category information 717 is applied to the control of the light source unit 11, it is desirable to adjust the luminance of the light source for each period included in each category so that the balance of red (R), green (G), blue (B), and white (W) reproduced during one frame period is equal.

[0061] A high or low priority is preset for a plurality of categories such as the first category Ct1, the second category Ct2, the third category Ct3, and the tenth category Ct0. As shown in Fig. 11, in the first embodiment, the first category Ct1 has the highest priority. The second category Ct2 has the second highest priority after the first category Ct1. The third category Ct3 has the third highest priority. The tenth category Ct0 has the lowest priority.

[0062] It is preferable that the relative priority between categories is set so that the one that is less likely to cause a color break is set to have a higher priority. In the example shown in Fig. 11, the highest priority is set to the first category Ct1, which does not generate a period in which the first light source 11R and the second light source 11G, whose luminance change is more easily recognized by the user than the third light source 11B, among the first light source 11R, the second light source 11G, and the third light source 11B, are turned on at the highest luminance. In addition, the second category Ct2, which does not generate a period in which the second light source 11G, whose luminance change is most easily recognized by the user, among the first light source 11R, the second light source 11G, and the third light source 11B, is turned on at the highest luminance, is set to have a higher priority than the third category Ct3 and the tenth category Ct0.

[0063] 5 stores category information 717, priority order information 718, goal information 719, and transition information 720. The storage unit 716 is a non-volatile storage circuit that can store data in a rewritable manner. However, the goal information 719 and the transition information 720 are initialized when the display device 100 starts operating.

[0064] The category information 717 includes information indicating each of a plurality of categories. Specifically, the category information 717 includes information indicating each of the first category Ct1, the second category Ct2, the third category Ct3, and the tenth category Ct0 shown in FIG. 11, for example. That is, the category verification unit 712 can specify what kind of lighting pattern of the light source unit 11 occurs and what color gamut can be reproduced when a certain category is adopted by referring to the category information 717. One category includes data indicating n types of periods. In the first embodiment, corresponding to the above-mentioned n=3, three periods for establishing the category are set in the information of each category. For example, the information of the above-mentioned tenth category Ct0 includes information indicating the period of the first red color Ra, the period of the first green color Ga, and the period of the first blue color Ba.

[0065] The category verification unit 712 verifies whether or not it is possible to reproduce the color information of the image acquired by the color information acquisition unit 711, for each of the category information 717 except for the tenth category Ct0. In other words, the category verification unit 712 performs processing to individually verify for each category whether or not it is possible to perform color reproduction corresponding to the color information acquired by the color information acquisition unit 711 based on the frame image data IP.

[0066] The reason why the 10th category Ct0 is not subject to verification is that if color reproduction cannot be performed with any category other than the 10th category Ct0, the 10th category Ct0, which has the widest color gamut of all the categories, is adopted by a process of elimination.

[0067] Also, in the first embodiment, the category verification unit 712 verifies color information based on sampled pixel data among the color information reproduced by the gradation values ​​indicated by each of the multiple pixel data included in the image, which is acquired by the color information acquisition unit 711 based on the frame image data IP.

[0068] 5 extracts, from among the categories included in category information 717, categories that can perform color reproduction corresponding to the color information acquired by color information acquisition unit 711 based on frame image data IP, based on the processing performed by category verification unit 712. When performing this extraction, available category extraction unit 713 adds information obtained by referring to priority order information 718.

[0069] Specifically, the usable category extraction unit 713 extracts, as usable categories, categories verified by the category verification unit 712 that color information based on the pixel data sampled falls within the color gamut, and generates information indicating the categories extracted as usable categories. In other words, categories in which color information based on the pixel data sampled by the category verification unit 712 is outside the color gamut are not extracted as usable categories.

[0070] The priority order information 718 includes information indicating the priority order of a plurality of categories included in the category information 717. Specifically, the priority order information 718 includes information indicating the relative order of priority of the first category Ct1, the second category Ct2, the third category Ct3, and the tenth category Ct0 shown in Fig. 11. The usable category extraction unit 713 refers to the priority order information 718 and adds information indicating the priority order of the usable category to information indicating the category extracted as the usable category.

[0071] The target category selection unit 714 selects, as a target category, a category with the highest priority among the categories extracted as available categories by the available category extraction unit 713. The target category selection unit 714 stores information indicating the target category as target information 719 in the storage unit 716.

[0072] However, when the display output content of the display device 100 is colorless Bak, which will be described later, the tenth category Ct0 may be set as the target category regardless of the level of priority.

[0073] The adopted category determination unit 715 generates and outputs the light source control signal DP with reference to the goal information 719 and the transition information 720. Hereinafter, a mechanism for generating the light source control signal DP by the adopted category determination unit 715 will be described with reference to FIG.

[0074] FIG. 12 is a schematic diagram showing the relationship between the transition of the display output contents, the verification of the category, the selection of the target category, and the change of the lighting pattern of the light source unit 11. FIG. 12 illustrates an example in which the display output contents are switched at timing Ta between the periods Ti1 and Ti2, and timing Tb between the periods Ti2 and Ti3. The period Ti1 is a period after the operation of the display device 100 starts, and is a period until the frame image data IP is input at timing Ta. The period Ti2 is a display output period corresponding to the frame image data IP after the frame image data IP is input at timing Ta, and is a period until the frame image data IP is input at timing Tb. The period Ti3 is a display output period corresponding to the frame image data IP after the frame image data IP is input at timing Tb. The timings Ta and Tb each indicate a timing at which frame image data IP different from that before is input. That is, the timings Ta and Tb are timings for updating the display output contents.

[0075] First, in period Ti1, the display output content of the display device 100 according to the frame image data IP becomes colorless Bak. The display unit 7 controlled according to colorless Bak has the lowest degree of light scattering for all pixels. Colorless Bak is established, for example, when all pixel data included in the frame image data IP is (R, G, B) = (0, 0, 0). Note that a mechanism may be adopted in which colorless Bak is achieved when the frame image data IP has not yet been input after the display device 100 starts operating.

[0076] In the first embodiment, during the period Ti1 in which the display output content is colorless Bak, the target category and lighting pattern are set to the 10th category Ct0. This is in consideration of the ease of transition to a category according to the display output content after the transition when the display output content transitions from colorless Bak to another display output content other than colorless Bak. Details will be described later.

[0077] In Fig. 12, at the time point Ta, the display output content transitions from colorless Bak to the first image CP1. The first image CP1 includes a yellow region DpY, a blue region DpB, and a white region DpW. The yellow region DpY is reproduced by scattering high-luminance red light and high-luminance green light. The blue region DpB is reproduced by scattering high-luminance blue light. The white region DpW is reproduced by scattering high-luminance red light, high-luminance green light, and high-luminance blue light.

[0078] At timing Ta, the color information acquisition unit 711 acquires color information of the first image CP1. The category verification unit 712 samples the color information of the first image CP1 and verifies whether the colors of the first image CP1 can be reproduced in each of the first category Ct1, the second category Ct2, and the third category Ct3. Here, it is assumed that the color information of the yellow area DpY, the blue area DpB, and the white area DpW is all included in the sampling.

[0079] In the first category Ct1, the yellow area DpY, the blue area DpB, and the white area DpW can be reproduced. On the other hand, in the second category Ct2 and the third category Ct3, the yellow area DpY cannot be reproduced. Therefore, the available category extraction unit 713 extracts the first category Ct1 as an available category. As described above, information indicating priority is also added to the information indicating the available category, but in the example of the timing Ta, only the first category Ct1 is an available category, so the target category selection unit 714 automatically selects the first category Ct1 as the target category. Therefore, during the period Ti2, the target information 719 becomes information indicating the first category Ct1. In FIG. 12, the target category from the timing Ta to the timing Tb is the first category Ct1.

[0080] Here, in the first embodiment, a mechanism capable of further suppressing color break is adopted. Specifically, as shown in the "Lighting Pattern" column in Fig. 12, in the process of changing the lighting pattern of the light source unit 11 from the tenth category Ct0 before the timing Ta to the first category Ct1, which is the target category after the timing Ta, a control is applied that generates an intermediate category between the tenth category Ct0 and the first category Ct1.

[0081] In FIG. 12, category Ct01 is illustrated as an intermediate category between the tenth category Ct0 and the first category Ct1. Category Ct01 is established when a third yellow Y3 period, a fourth yellow Y4 period, and a first blue Ba period occur during one frame period. The third yellow Y3 period and the fourth yellow Y4 period are periods during which the first light source 11R and the second light source 11G are turned on and the third light source 11B is turned off. However, the third yellow Y3 and the fourth yellow Y4 have different luminances of the first light source 11R and the second light source 11G. In the third yellow Y3, the luminance of the second light source 11G is relatively higher than the luminance of the first light source 11R. In the fourth yellow Y4, the luminance of the first light source 11R is relatively higher than the luminance of the second light source 11G. Furthermore, in the third yellow Y3, the luminance of the second light source 11G is relatively high and the luminance of the first light source 11R is relatively low compared to the first yellow Y1. In addition, in the fourth yellow Y4, the luminance of the first light source 11R is relatively high and the luminance of the second light source 11G is relatively low compared to the second yellow Y2.

[0082] The tenth category Ct0, the category Ct01, and the first category Ct1 are common in that a period of the first blue color Ba occurs. Therefore, there is no change in the period Ti2 in that the third light source 11B is turned on at high luminance during the period of the first blue color Ba. On the other hand, the tenth category Ct0 and the first category Ct1 are different in that a period of the first red color Ra and a period of the first green color Ga occur in the tenth category Ct0, whereas a period of the first yellow color Y1 and a period of the second yellow color Y2 occur in the first category Ct1. Here, if the lighting pattern of the light source unit 11 is suddenly changed from the tenth category Ct0 to the first category Ct1, the period of the first red color Ra is suddenly replaced with a period of the first yellow color Y1, and the period of the first green color Ga is suddenly replaced with a period of the second yellow color Y2. Such a sudden change in the luminance distribution of the light source unit 11 due to the sudden replacement may trigger the user to recognize a color break.

[0083] Therefore, in the first embodiment, an intermediate category between the tenth category Ct0 and the first category Ct1, such as category Ct01, is generated during the transition period from the tenth category Ct0 to the first category Ct1. As a result, the period of the first red Ra in the tenth category Ct0 transitions to the period of the first yellow Y1 in the first category Ct1 via the period of the third yellow Y3 in the category Ct01. Here, the luminance of the first light source 11R is successively lowered as the period of the first red Ra, the period of the third yellow Y3, and the period of the first yellow Y1 are successively reduced. In addition, the luminance of the second light source 11G is successively higher as the period of the first red Ra, the period of the third yellow Y3, and the period of the first yellow Y1 are successively reduced. In addition, the period of the first green Ga in the tenth category Ct0 transitions to the period of the second yellow Y2 in the first category Ct1 via the period of the fourth yellow Y4 in the category Ct01. Here, the luminance of the second light source 11G decreases successively as the period of the first green Ga, the period of the fourth yellow Y4, and the period of the second yellow Y2 are sequentially decreased. Also, the luminance of the first light source 11R increases successively as the period of the first green Ga, the period of the fourth yellow Y4, and the period of the second yellow Y2 are sequentially decreased.

[0084] In this way, when a category is switched due to a transition in the display output content, the possibility of a color break occurring due to a sudden change in the color of the light from the light source unit 11 becoming apparent can be further reduced by generating an intermediate category. Therefore, by generating an intermediate category, it is possible to further reduce a color break. At timing Ta in FIG. 12, the tenth category Ct0 is the category before the switch, the first category Ct1 is the category after the switch, and the category Ct01 is the intermediate category.

[0085] In this way, when the color reproduction by the display panel P changes, the image processing circuit 70 controls the lighting patterns of the first light source 11R, the second light source 11G, and the second light source 11G according to the difference between the lighting pattern for color reproduction according to the frame image data IP before the change and the lighting pattern for color reproduction according to the frame image data IP after the change. The above-mentioned category before the change corresponds to the lighting pattern for color reproduction according to the frame image data IP before the change. Also, the above-mentioned category after the change corresponds to the lighting pattern for color reproduction according to the frame image data IP after the change. Also, the "case where the color reproduction by the display panel P changes" here includes, for example, a case where the state changes from a state where the frame image data IP has not been input to a state where the input of the frame image data IP starts. In that case, the "frame image data IP before the change" is treated as the frame image data IP in which all the gradation values ​​of all the pixel data are 0.

[0086] Furthermore, the image processing circuit 70 generates a transition period in which a lighting pattern different from both the first timing and the second timing is applied between a first timing in which a lighting pattern for color reproduction according to the frame image data IP before the change is applied and a second timing in which a lighting pattern for color reproduction according to the frame image data IP after the change is applied. In the example shown in FIG. 12, for example, a timing before the timing Ta corresponds to the first timing. Furthermore, a timing after the timing Ta in which the category after the change (the first category Ct1) is applied corresponds to the second timing. Furthermore, a period in which an intermediate category is applied corresponds to the transition period. Here, the difference between the color of the light emitted from the light source unit 11 during the transition period and the color of the light emitted from the light source unit 11 at the first timing, and the difference between the color of the light emitted from the light source unit 11 during the transition period and the color of the light emitted from the light source unit 11 at the second timing are smaller than the difference between the color of the light emitted from the light source unit 11 at the first timing and the color of the light emitted from the light source unit 11 at the second timing. That is, the difference in light color between the tenth category Ct0 and category Ct01 and between the category Ct01 and the first category Ct1 is smaller than the difference in light color between the tenth category Ct0 and the first category Ct1 before and after the switching. More specifically, the difference in light color between the tenth category Ct0 and category Ct01 and between the category Ct01 and the first category Ct1 is smaller than the difference between the tenth category Ct0 and the first category Ct1 in terms of the difference in red (R) luminance and green (G) luminance in two of the three lighting periods occurring in one frame period.

[0087] 10 stores information indicating a category corresponding to the light source control signal DP that was applied to the control of the light source unit 11 immediately before the timing when information indicating a newly selected category is stored in the target information 719. That is, before the timing Ta, information indicating the tenth category Ct0 is stored in the transition information 720. Note that, in a state in which there is no content in the target information 719 and the transition information 720, such as immediately after the start-up of the display device 100, control may be applied that regards the information of the tenth category Ct0 as having been stored.

[0088] The adopted category determination unit 715 refers to the target information 719 and the transition information 720, and when the contents of the target information 719 and the transition information 720 match, generates a light source control signal DP for applying to the light source unit 11 control corresponding to the category stored in the target information 719 and the transition information 720. The light source control signal DP generated by the adopted category determination unit 715 is output to the gradation control unit 72 and the timing controller 13, as described with reference to FIG.

[0089] After the timing Ta, when the available category extraction unit 713 extracts the first category Ct1, the target category selection unit 714 stores information indicating the first category Ct1 in the target information 719. At the time when the information indicating the first category Ct1 is stored in the target information 719, the transition information 720 still stores information on the tenth category Ct0.

[0090] The adopted category determination unit 715 refers to the target information 719 and the transition information 720, and when the contents of the target information 719 and the transition information 720 become different, performs processing to transition the control applied to the light source unit 11 to the category indicated by the information stored in the transition information 720 over a predetermined time from the timing when the contents of the target information 719 and the transition information 720 become different. Specifically, for example, as described above, a light source control signal DP is generated to apply to the light source unit 11 a category (e.g., category Ct01) intermediate between the tenth category Ct0 and the first category Ct1. After the predetermined time has elapsed, a light source control signal DP is generated to apply to the light source unit 11 a control corresponding to the category (e.g., the first category Ct1) indicated by the information stored in the transition information 720.

[0091] The number of intermediate categories is not limited to one, and multiple stages may be provided in order to make the change in the lighting pattern of the light source before and after the change more gradual. For example, at least one intermediate category between the 10th category Ct0 and the category Ct01 in FIG. 12 and one intermediate category between the category Ct01 and the first category Ct1 may be further applied. The predetermined time is an arbitrary time, but is preferably short enough that the transition time between the categories before and after the change is not recognized by the user. For example, in the display device 100 in which the display output contents are updated at 60 frames per second, it is preferable to set the predetermined time to about 10 frame periods (1 / 6 seconds).

[0092] As described above, the gradation control unit 72 reflects in the display output signal OP the gradation value control for performing display output corresponding to the frame image data IP with light from the light source unit 11, the degree of illumination of which is controlled in accordance with the light source control signal DP. Therefore, when the category reflected in the light source control signal DP changes, such as during the above-mentioned predetermined time, the gradation value reflected in the display output signal OP may also change in accordance with this change.

[0093] Note that the transition information 720 may be controlled to hold information indicating the category before switching until the category switching is completed, or every time an intermediate category is applied, information indicating the intermediate category may be written to the transition information 720. In any case, it is sufficient that the control of the light source unit 11 before and after switching is established as described with reference to the target information 719 and the transition information 720 and with reference to FIG. 12 from the viewpoint of suppressing color breakup.

[0094] During the period Ti2 after timing Ta in FIG. 12, after the first category Ct1 is applied to the lighting pattern of the light source unit 11, the light source control signal DP corresponding to the first category Ct1 continues to be output until timing Tb when the display output content changes again.

[0095] In Fig. 12, at the time Tb, the display output content transitions from the first image CP1 to the second image CP2. The second image CP2 includes a red region DpR, a cyan region DpC, and a white region DpW. The red region DpR is reproduced by scattering high-luminance red light. The cyan region DpC is reproduced by scattering high-luminance green light and high-luminance blue light. The white region DpW is reproduced by scattering high-luminance red light, high-luminance green light, and high-luminance blue light, as in the case of the first image CP1.

[0096] At timing Tb, the color information acquisition unit 711 acquires color information of the second image CP2. The category verification unit 712 samples the color information of the second image CP2 and verifies whether the colors of the second image CP2 can be reproduced in each of the first category Ct1, the second category Ct2, and the third category Ct3. Here, it is assumed that the color information of the red area DpR, the cyan area DpC, and the white area DpW is all included in the sampling.

[0097] In the second category Ct2, the red area DpR, the cyan area DpC, and the white area DpW can be reproduced. On the other hand, in the first category Ct1 and the third category Ct3, the red area DpR cannot be reproduced. Therefore, the available category extraction unit 713 extracts the second category Ct2 as an available category. As described above, information indicating priority is also added to the information indicating the available category, but since only the second category Ct2 is an available category in the example of the timing Tb, the target category selection unit 714 automatically selects the second category Ct2 as the target category. Therefore, during the period Ti3, the target information 719 becomes information indicating the second category Ct2. In FIG. 12, the target category after the timing Tb is the second category Ct2. If the first category Ct1 is also an available category, the first category Ct1 will be selected because the first category Ct1 has a higher priority than the second category Ct2.

[0098] After timing Tb, an intermediate category between before and after the category change is applied, as in the above-described case after timing Ta. In other words, in the first embodiment, when a category change occurs, an intermediate category between before and after the category change is applied, so that color breaks can be further suppressed.

[0099] 12, the category before timing Tb is the first category Ct1, and the category after timing Tb is the second category Ct2. Therefore, unlike the category transition starting from timing Ta, the category before the switch is not the tenth category Ct0. Therefore, in the first embodiment, if the category before the switch is not the tenth category Ct0, the tenth category Ct0 may be generated as an intermediate category.

[0100] 12, the lighting pattern after timing Tb transitions in the order of category Ct01, tenth category Ct0, category Ct02, and second category Ct2. Therefore, from the first category Ct1 before timing Tb to the tenth category Ct0 after timing Tb, the lighting pattern of the light source unit 11 transitions in the reverse order to that before and after the change at timing Ta, thereby further suppressing color breakup.

[0101] The category Ct02 is established by the occurrence of a period of the third cyan C3, a period of the fourth cyan C4, and a period of the first red Ra during one frame period. The period of the third cyan C3 and the period of the fourth cyan C4 are periods during which the second light source 11G and the third light source 11B are turned on and the first light source 11R is turned off. However, the third cyan C3 and the fourth cyan C4 have different luminances of the second light source 11G and the third light source 11B. In the third cyan C3, the luminance of the second light source 11G is relatively higher than that of the third light source 11B. In the fourth cyan C4, the luminance of the third light source 11B is relatively higher than that of the second light source 11G. Furthermore, in the third cyan C3, the luminance of the second light source 11G is relatively higher than that of the first cyan C1, and the luminance of the third light source 11B is relatively lower. Moreover, in the fourth cyan C4, the luminance of the third light source 11B is relatively high and the luminance of the second light source 11G is relatively low compared to the second cyan C2.

[0102] The tenth category Ct0, the category Ct02, and the second category Ct2 are common in that a period of the first red Ra occurs. Therefore, there is no change in the point that the first light source 11R is turned on at high brightness during the period of the first red Ra during the transition period of these categories. On the other hand, the tenth category Ct0 and the second category Ct2 are different in that a period of the first green Ga and a period of the first blue Ba occur in the tenth category Ct0, whereas a period of the first cyan C1 and a period of the second cyan C2 occur in the second category Ct2. Here, the category Ct02 functions as an intermediate category between the tenth category Ct0 and the second category Ct2, and acts to make the change in the brightness of the second light source 11G and the third light source 11B during the transition period more gradual. This makes it possible to further suppress color breaks.

[0103] In this way, during the transition period before and after the switching, a timing may occur in which the control of the light source unit 11 corresponding to the tenth category Ct0 is applied. That is, a timing may occur in which a lighting pattern that generates a lighting period in which the first light source 11R is turned on at the highest brightness and the second light source 11G and the third light source 11B are turned off, a lighting period in which the second light source 11G is turned on at the highest brightness and the first light source 11R and the third light source 11B are turned off, and a lighting period in which the third light source 11B is turned on at the highest brightness and the first light source 11R and the second light source 11G are turned off may be applied. Note that the fact that the target category and lighting pattern are the tenth category Ct0 during the period Ti1 in which the display output content is colorless Bak is based on a similar idea. That is, since it is easier to make the change in brightness more gradual when transitioning from the tenth category Ct0 to another category, the purpose is to be able to respond to any category by adopting the tenth category Ct0 at the time when it is not clear which category is appropriate after the period Ti1.

[0104] The intermediate category does not necessarily have to include the tenth category Ct0. For example, as shown by AnP in FIG. 12, another category different from the tenth category Ct0 may be applied as an intermediate category between the first category Ct1 and the second category Ct2. In FIG. 12, category Ct8 is illustrated as the other category. Category Ct8 is established when a period of color mixing BC2, a period of color mixing RY2, and a period of color mixing GW2 occur during one frame period (see the eighth category in FIG. 13).

[0105] The period of the color mixture BC2 is a period in which the second light source 11G and the third light source 11B are turned on, and the first light source 11R is turned off. In the color mixture BC2, the luminance of the third light source 11B is relatively higher than that of the second light source 11G. In the period of the color mixture RY2, the first light source 11R and the second light source 11G are turned on, and the third light source 11B is turned off. In the color mixture RY2, the luminance of the first light source 11R is relatively higher than that of the second light source 11G. In the period of the color mixture GW2, the first light source 11R, the second light source 11G, and the third light source 11B are turned on. In the color mixture GW2, the luminance of the second light source 11G is relatively higher than that of the first light source 11R and the third light source 11B. In the color mixture GW2, the luminance of the first light source 11R and the luminance of the third light source 11B are equivalent.

[0106] In addition, after the transition of the display output content, i.e., after the category is switched and the category is the 10th category Ct0, the lighting pattern can be switched, for example, like the transition from the first category Ct1 through category Ct01 to the 10th category Ct0 from timing Tb onwards.

[0107] Moreover, the type of category to be the intermediate category is determined in advance depending on the categories before and after the switch. A program or the like relating to the method of determining the intermediate category may be pre-implemented in the adopted category determination unit 715, or may be stored in a storage device or storage circuit (not shown) and provided so as to be referable to by the adopted category determination unit 715.

[0108] The transition direction of the hue of the color of the light source occurring during one frame period is common to the categories before and after the switching and the intermediate category. For example, assume that a rule is set in advance such that the first light source 11R is relatively the most luminous in the lighting period LP1 described with reference to FIG. 4, the second light source 11G is relatively the most luminous in the lighting period LP2, and the third light source 11B is relatively the most luminous in the lighting period LP3. In this case, the categories included in the category information 717 satisfy the rule. In addition, intermediate categories that can be reflected in the light source control signal DP by the adopted category determination unit 715 are also generated by the adopted category determination unit 715 so as to satisfy the rule. The relationship between each of the lighting periods LP1, LP2, and LP3 and the color of the most luminous light source in the rule can be changed as appropriate.

[0109] As described above, according to the first embodiment, the present invention includes a light source unit (e.g., light source unit 11) having a first light source (e.g., first light source 11R) that emits light of a first color, a second light source (e.g., second light source 11G) that emits light of a second color, and a third light source (e.g., third light source 11B) that emits light of a third color, a display unit (e.g., a display panel P, particularly a display unit 7 provided with pixels Pix) that uses light from the light source unit to perform color reproduction according to input data (e.g., frame image data IP) from the outside, a storage unit (e.g., storage unit 716) that stores data (e.g., category information 717) indicating lighting patterns of the first light source, the second light source, and the third light source, and a control unit (e.g., image processing circuit 70 having a lighting control unit 71) that controls the lighting patterns of the first light source, the second light source, and the third light source based on the input data and the data. The control unit generates n lighting periods (e.g., lighting period LP1, lighting periods LP2, LP3) during a display output period of a frame image output by the display unit. n is a natural number equal to or greater than 3 (e.g., n=3). The color of light emitted from the light source unit in each of the n lighting periods is different. The data includes information indicating a plurality of types of lighting patterns (e.g., a first category Ct1, a second category Ct2, a third category Ct3, and a tenth category Ct0) each having a different color gamut that can be reproduced in the n lighting periods. When color reproduction by the display unit changes, the control unit controls the lighting patterns of the first light source, the second light source, and the third light source according to the difference between a lighting pattern for color reproduction according to the input data before the change and a lighting pattern for color reproduction according to the input data after the change.

[0110] This allows the control of a light source unit (e.g., light source unit 11) to be applied with any of a plurality of lighting patterns each having a different reproducible color gamut. Furthermore, the control of the light source unit can reflect the difference in lighting patterns for color reproduction according to input data (e.g., frame image data IP) before and after the change. Therefore, by applying a lighting pattern that is less likely to cause color breaks to at least one of the before and after the change, color breaks can be further suppressed.

[0111] Furthermore, the control unit (image processing circuit 70) can further suppress color break by generating a transition period in which a lighting pattern different from either the first timing or the second timing is applied between a first timing in which a lighting pattern for color reproduction according to input data before the change (for example, frame image data IP before the change or a state in which frame image data IP is not input) is applied and a second timing in which a lighting pattern for color reproduction according to input data after the change (for example, frame image data IP before the change) is applied. Here, the difference between the color of light emitted from the light source unit (for example, light source unit 11) during the transition period and the color of light emitted from the light source unit at the first timing, and the difference between the color of light emitted from the light source unit during the transition period and the color of light emitted from the light source unit at the second timing are smaller than the difference between the color of light emitted from the light source unit at the first timing and the color of light emitted from the light source unit at the second timing, so that the degree of manifestation of the difference in light between the first timing and the second timing can be further suppressed compared to the case in which there is no transition period. Therefore, color breaks can be further suppressed.

[0112] In addition, by generating a timing during the transition period in which a lighting pattern that generates a lighting period in which the first light source (e.g., the first light source 11R) is turned on at the highest brightness and the second light source (e.g., the second light source 11G) and the third light source (e.g., the third light source 11B) are turned off, a lighting period in which the second light source is turned on at the highest brightness and the first light source and the third light source are turned off, and a lighting period in which the third light source is turned on at the highest brightness and the first light source and the second light source are turned off, the degree of light manifestation of the lighting pattern of the first timing and the lighting pattern of the second timing described above can be further suppressed. Therefore, color break can be further suppressed.

[0113] Furthermore, the data (e.g., category information 717) includes information indicating a lighting pattern that generates a lighting period during which any one of the first light source (e.g., first light source 11R), the second light source (e.g., second light source 11G), and the third light source (e.g., third light source 11B) is turned on at the highest brightness and the other two are turned off. For example, in the description with reference to FIG. 11, the first category Ct1, the second category Ct2, the third category Ct3, and the tenth category Ct0 all correspond to such a lighting pattern. According to such a lighting pattern, it is possible to more reliably reproduce colors corresponding to the colors of the light emitted from a light source turned on at the highest brightness.

[0114] The data (e.g., category information 717) also includes information indicating a lighting pattern in which two lighting periods are generated in which two of the first light source (e.g., the first light source 11R), the second light source (e.g., the second light source 11G), and the third light source (e.g., the third light source 11B) are turned on and the other is turned off, and the luminance ratio of the two lighting periods among the first light source, the second light source, and the third light source is different between one and the other of the two lighting periods. For example, in the description with reference to FIG. 11, the first category Ct1, the second category Ct2, and the third category Ct3 correspond to the lighting patterns. According to such a lighting pattern, the degree of the difference in light between the two lighting periods can be further suppressed. Therefore, color break can be further suppressed.

[0115] Furthermore, a predetermined priority is set for each of the multiple types of lighting patterns included in the data (e.g., category information 717). The control unit (e.g., image processing circuit 70) applies the lighting pattern with the highest priority among the lighting patterns capable of reproducing colors reproduced according to the gradation values ​​indicated by the pixel data included in the input data (e.g., frame image data IP) to the control of the light source unit (e.g., light source unit 11). This makes it easier to suppress color breakup by setting a higher priority for a lighting pattern that can further suppress color breakup.

[0116] Furthermore, one of the first color, second color, and third color (for example, the first color) is red (R). Furthermore, one of the first color, second color, and third color that is not red (R) is green (G). Furthermore, one of the first color, second color, and third color that is neither red nor green is blue (B). This allows for sufficient color reproduction.

[0117] Moreover, the display unit (for example, the display panel P) is a liquid crystal panel in which polymer-dispersed liquid crystal is sealed in. This makes it possible to further suppress color breakup in a liquid crystal panel that can switch between transmitting and scattering light.

[0118] (Variation 1) Next, Modification 1, which is a modification of the first embodiment, will be described with reference to Fig. 13. In the description of Modification 1, the same items as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

[0119] Fig. 13 is a diagram showing an example of the relationship between the type of category added in Modification 1 and the adoption priority. In Modification 1, in addition to the first category Ct1, the second category Ct2, the third category Ct3, and the tenth category Ct0 described with reference to Fig. 11 in the description of the first embodiment, the category information 717 may further include information indicating the fourth category, the fifth category, the sixth category, the seventh category, the eighth category, and the ninth category shown in Fig. 13.

[0120] The fourth category is established by the occurrence of a period of color mixing RW, a period of color mixing GW, and a period of color mixing BW during one frame period. The period of color mixing RW, the period of color mixing GW, and the period of color mixing BW are periods during which the first light source 11R, the second light source 11G, and the third light source 11B are turned on. In the color mixing RW, the luminance of the first light source 11R is relatively higher than the luminance of the second light source 11G and the luminance of the third light source 11B. In the color mixing RW, the luminance of the second light source 11G is relatively higher than the luminance of the first light source 11R and the luminance of the third light source 11B. In the color mixing GW, the luminance of the second light source 11G is relatively higher than the luminance of the first light source 11R and the luminance of the third light source 11B. In the color mixing GW, the luminance of the first light source 11R is relatively higher than the luminance of the first light source 11R and the luminance of the third light source 11B. In the mixed color BW, the luminance of the third light source 11B is relatively higher than the luminance of the first light source 11R and the luminance of the second light source 11G. In the mixed color BW, the luminance of the first light source 11R and the luminance of the second light source 11G are equivalent.

[0121] The fifth category is established by the occurrence of a period of color mixture BC, a period of color mixture GY, and a period of color mixture RM during one frame period. The period of color mixture BC is a period during which the second light source 11G and the third light source 11B are turned on, and the first light source 11R is turned off. During the period of color mixture BC, the luminance of the third light source 11B is relatively higher than that of the second light source 11G. During the period of color mixture GY, the first light source 11R and the second light source 11G are turned on, and the third light source 11B is turned off. During the period of color mixture GY, the luminance of the second light source 11G is relatively higher than that of the first light source 11R. During the period of color mixture RM, the first light source 11R and the third light source 11B are turned on, and the second light source 11G is turned off. During the period of color mixture RM, the luminance of the first light source 11R is relatively higher than that of the third light source 11B.

[0122] The sixth category is established by the occurrence of a period of color mixing GC, a period of color mixing RY, and a period of color mixing BM during one frame period. The period of color mixing GC is a period during which the second light source 11G and the third light source 11B are turned on, and the first light source 11R is turned off. In the period of color mixing GC, the luminance of the second light source 11G is relatively higher than that of the third light source 11B. In the period of color mixing RY, the first light source 11R and the second light source 11G are turned on, and the third light source 11B is turned off. In the period of color mixing RY, the luminance of the first light source 11R is relatively higher than that of the second light source 11G. In the period of color mixing BM, the first light source 11R and the third light source 11B are turned on, and the second light source 11G is turned off. In the period of color mixing BM, the luminance of the third light source 11B is relatively higher than that of the first light source 11R.

[0123] The seventh category is established by the occurrence of a period of color mixing BM2, a period of color mixing GY2, and a period of color mixing RW2 during one frame period. The period of color mixing BM2 is a period during which the first light source 11R and the third light source 11B are turned on, and the second light source 11G is turned off. During the period of color mixing BM2, the luminance of the third light source 11B is relatively higher than the luminance of the first light source 11R. During the period of color mixing GY2, the first light source 11R and the second light source 11G are turned on, and the third light source 11B is turned off. During the period of color mixing GY2, the luminance of the second light source 11G is relatively higher than the luminance of the first light source 11R. During the period of color mixing RW2, the first light source 11R, the second light source 11G, and the third light source 11B are turned on. In the mixed color RW2, the luminance of the first light source 11R is relatively higher than the luminance of the second light source 11G and the luminance of the third light source 11B. In the mixed color RW2, the luminance of the second light source 11G and the luminance of the third light source 11B are equivalent.

[0124] The eighth category is similar to the category Ct8 described with reference to FIG.

[0125] The ninth category is established by the occurrence of a period of color mixing RM2, a period of color mixing GC2, and a period of color mixing BW2 during one frame period. The period of color mixing RM2 is a period during which the first light source 11R and the third light source 11B are turned on, and the second light source 11G is turned off. During the period of color mixing RM2, the luminance of the first light source 11R is relatively higher than that of the third light source 11B. During the period of color mixing GC2, the second light source 11G and the third light source 11B are turned on, and the first light source 11R is turned off. During the period of color mixing GC2, the luminance of the second light source 11G is relatively higher than that of the third light source 11B. During the period of color mixing BW2, the first light source 11R, the second light source 11G, and the third light source 11B are turned on. In the mixed color BW2, the luminance of the third light source 11B is relatively higher than the luminance of the first light source 11R and the luminance of the second light source 11G. In the mixed color BW2, the luminance of the first light source 11R and the luminance of the second light source 11G are equivalent.

[0126] The categories shown in Fig. 13 are arranged in order of decreasing priority as follows: fourth category, fifth category, sixth category, seventh category, eighth category, and ninth category. The fourth category has a lower priority than the third category Ct3. The ninth category has a higher priority than the tenth category Ct0. Therefore, by applying Fig. 13 between the two boundary lines BL1 and BL2 between the third category Ct3 and the tenth category Ct0 shown in Fig. 11, the priority of the categories in Modification 1 can be shown.

[0127] As described above, except for the matters noted above, the first modification is the same as the first embodiment. According to the first modification, the data (e.g., category information 717) includes information indicating a lighting pattern that generates a lighting period in which the first light source (e.g., the first light source 11R) and the second light source (e.g., the second light source 11G) are turned on and the third light source (e.g., the third light source 11B) is turned off, a lighting period in which the second light source and the third light source are turned on and the first light source is turned off, and a lighting period in which the first light source and the third light source are turned on and the second light source is turned off. In the description with reference to FIG. 13, the fifth and sixth categories correspond to the lighting patterns. According to such a lighting pattern, the degree of the difference in light between the lighting periods can be more suppressed than in a lighting pattern in which the first light source, the second light source, and the third light source are turned on at the highest brightness. Therefore, color break can be more suppressed.

[0128] Moreover, the data (e.g., category information 717) generates three lighting periods in which the first light source (e.g., first light source 11R), the second light source (e.g., second light source 11G), and the third light source (e.g., third light source 11B) are turned on, and each of the three lighting periods includes information indicating a lighting pattern in which the luminance ratios of the first light source, the second light source, and the third light source are different. In the description with reference to FIG. 13, the lighting pattern corresponds to the fourth category. According to such a lighting pattern, the degree of the manifestation of the difference in light between the lighting periods can be further suppressed compared to a lighting pattern in which the first light source, the second light source, and the third light source are turned on at the highest luminance. Therefore, color break can be further suppressed.

[0129] (Embodiment 2) Next, a second embodiment, which is partially different from the first embodiment, will be described with reference to Figures 14 and 15. In the description of the second embodiment, the same items as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

[0130] FIG. 14 is a schematic diagram showing the FSC method applied in the second embodiment. The frame period FP in the second embodiment includes a subframe period SFP4 in addition to the subframe periods SFP1, SFP2, and SFP3 described with reference to FIG. 3. The subframe period SFP4 includes a writing period WP4 and a lighting period LP4 following the writing period WP4. The writing period WP4 is a writing period. The lighting period LP4 is a lighting period. That is, in the second embodiment, n=4. Therefore, in the second embodiment, four periods are set in the information indicating the category included in the category information 717. Hereinafter, the categories in the second embodiment will be described with reference to FIG. 15.

[0131] Fig. 15 is a diagram showing an example of the relationship between the type of category and the adoption priority in embodiment 2. Fig. 15 illustrates an 11th category, a 12th category, a 13th category, and a 20th category as examples of categories that can be used in embodiment 2.

[0132] The eleventh category is established when a period of a first yellow Y1, a period of a second yellow Y2, a period of a first blue Ba, and a period of a first white W1 occur during one frame period.

[0133] The twelfth category is established when a period of the first cyan C1, a period of the second cyan C2, a period of the first red Ra, and a period of the first white W1 occur during one frame period.

[0134] The thirteenth category is established when a period of the first magenta M1, a period of the second magenta M2, a period of the first green Ga, and a period of the first white W1 occur during one frame period.

[0135] The twentieth category is established when a period of the first red color Ra, a period of the first green color Ga, a period of the first blue color Ba, and a period of the first white color W1 occur during one frame period.

[0136] The first white light W1 is a period during which the first light source 11R, the second light source 11G, and the third light source 11B are turned on. In the first white light W1, the luminance ratio of the first light source 11R to the luminance of the second light source 11G to the luminance of the third light source 11B is equal.

[0137] The categories that can be adopted in the second embodiment are set to have a higher luminance component of white (W) in one frame period as compared with the categories that can be adopted in the first embodiment. Specifically, in the case of the eleventh, twelfth, thirteenth, and twentieth categories shown in FIG. 15, the luminance component of white (W) becomes equivalent to that of the tenth category Ct0 of the first embodiment in three periods excluding the first white W1. In this case, the luminance component of white (W) increases compared to the tenth category Ct0 by further reproducing the color of white (W) by the first white W1. More specifically, the first white W1 is a lighting pattern of the light source unit 11 in which the first light source 11R, the second light source 11G, and the third light source 11B are turned on at a luminance of 20% (0.2). In other words, the ratio of the luminance of the first light source 11R, the second light source 11G, and the third light source 11B in the first white W1 is the ratio of the luminance component of white (W) that is increased in the category of embodiment 2 compared to the category of embodiment 1. This ratio is not limited to 20% (0.2) and can be changed as appropriate.

[0138] In the second embodiment, the first category Ct1 in the first embodiment is replaced with the eleventh category. In the second embodiment, the second category Ct2 in the first embodiment is replaced with the twelfth category. In the second embodiment, the third category Ct3 in the first embodiment is replaced with the thirteenth category. In the second embodiment, the tenth category Ct0 in the first embodiment is replaced with the twentieth category.

[0139] Furthermore, in the second embodiment, categories assuming that n=4 are applied to the intermediate categories described with reference to Fig. 12. For example, the categories applied in the second embodiment can be explained by adding a period of the first white color W1 to each category described with reference to Fig. 12.

[0140] Except for the above-mentioned points, the second embodiment is the same as the first embodiment. According to the second embodiment, n, which indicates the number of lighting periods (for example, lighting period LP1, lighting periods LP2, LP3, LP4), is 4 or more (for example, n=4). In addition, the data (for example, category information 717) includes information indicating a lighting pattern that generates a lighting period in which the first light source (for example, the first light source 11R), the second light source (for example, the second light source 11G), and the third light source (for example, the third light source 11B) are lit. In the description with reference to FIG. 15, the eleventh category, the twelfth category, the thirteenth category, and the twentieth category all correspond to the lighting pattern. The lighting period in which the first light source (for example, the first light source 11R), the second light source (for example, the second light source 11G), and the third light source (for example, the third light source 11B) are lit is, for example, the period of the first white color W1 described above. This makes it easier to increase the brightness of the image to be displayed and output.

[0141] (Variation 2) Next, Modification 2, which is a modification of the second embodiment, will be described with reference to Fig. 16. In the description of Modification 2, the same items as those in the second embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

[0142] Fig. 16 is a diagram showing an example of the relationship between the type of category added in Modification 2 and the adoption priority. In Modification 2, in addition to the 11th category, 12th category, 13th category, and 20th category described with reference to Fig. 15, category information 717 may further include information indicating the 14th category and the 15th category shown in Fig. 16.

[0143] The 14th category is established by the occurrence of a period of color mixing RW, a period of color mixing GW, a period of color mixing BW, and a period of second white W2 during one frame period. The second white W2 may be equivalent to the first white W1, or the luminance of the first light source 11R, the second light source 11G, and the third light source 11B may be different from that of the first white W1. However, it is desirable that the luminance of white (W) when viewed as a whole over the period of color mixing RW, the period of color mixing GW, the period of color mixing BW, and the period of second white W2 is adjusted to be equivalent to that of the other categories.

[0144] The 15th category is established by the occurrence of a period of third red Rc, a period of third green Gc, a period of third blue Bc, and a period of third white W3 during one frame period. The third red Rc is a lighting pattern of the light source unit 11 in which the first light source 11R is turned on at a lower luminance than the first red Ra, and the second light source 11G and the third light source 11B are turned off. The third green Gc is a lighting pattern of the light source unit 11 in which the second light source 11G is turned on at a lower luminance than the first green Ga, and the first light source 11R and the third light source 11B are turned off. The third blue Bc is a lighting pattern of the light source unit 11 in which the third light source 11B is turned on at a lower luminance than the first blue Ba, and the second light source 11G and the third light source 11B are turned off. The third white W3 is a lighting pattern of the light source unit 11 in which the first light source 11R, the second light source 11G, and the third light source 11B are turned on with a higher luminance than the first white W1. In the fifteenth category, it is desirable that the luminance of the white (W) when viewed as a whole over the period of the third red Rc, the period of the third green Gc, the period of the third blue Bc, and the period of the third white W3 is adjusted to be equivalent to that of the other categories.

[0145] The 14th category has a lower priority than the 13th category (see FIG. 15), but a higher priority than the 15th category. The 15th category has a higher priority than the 20th category (see FIG. 15). Therefore, by applying FIG. 16 between the two boundary lines BL3 and BL4 between the 13th category and the 20th category shown in FIG. 15, the priority of the categories in the second modification can be shown.

[0146] Except for the points noted above, Modification 2 is the same as Embodiment 2. According to Modification 2, similar to Modification 1 described above, color breaks can be further suppressed.

[0147] (Variation 3) Next, Modification 3, which is a modification of the second embodiment, will be described with reference to Fig. 17 and Fig. 18. In the description of Modification 3, the same items as those in the second embodiment are denoted by the same reference numerals and the description thereof will be omitted. In addition, both Modification 2 and Modification 3 may be applied to the second embodiment.

[0148] Figures 17 and 18 are diagrams showing an example of category transition in Modification 3. Figures 17 and 18 show an example of category transition when the 20th category described with reference to Figure 15 is the category before switching.

[0149] For example, assuming that category Ct23 shown in FIG. 17 is the category after switching, color breaks can be further suppressed by sequentially generating categories Ct21 and Ct22 between the 20th category and category Ct23.

[0150] Category Ct21 is established when a period of the first red color Ra, a period of the first blue color Ba, a period of the fourth green color Gd, and a period of the mixed color GW2 occur during one frame period. The fourth green color Gd is a lighting pattern of the light source unit 11 in which the second light source 11G is turned on with a lower luminance than the first green color Ga, and the first light source 11R and the third light source 11B are turned off.

[0151] Category Ct22 is established when a period of first red Ra, a period of first blue Ba, a period of color mixture GC3, and a period of color mixture GY3 occur during one frame period. Color mixture GC3 is a lighting pattern of the light source unit 11 in which the second light source 11G and the third light source 11B are turned on and the first light source 11R is turned off. Color mixture GY3 is a lighting pattern of the light source unit 11 in which the first light source 11R and the second light source 11G are turned on and the third light source 11B is turned off. In color mixture GC3 and color mixture GY3, the luminance of the second light source 11G is relatively high compared to the luminance of the light sources of other colors that are turned on.

[0152] The category Ct23 is established by the occurrence of a period of the first red Ra, a period of the first blue Ba, a period of the mixed color GC4, and a period of the mixed color GY4 during one frame period. The mixed color GC4 is a lighting pattern of the light source unit 11 in which the second light source 11G and the third light source 11B are turned on and the first light source 11R is turned off. The mixed color GY4 is a lighting pattern of the light source unit 11 in which the first light source 11R and the second light source 11G are turned on and the third light source 11B is turned off. In the mixed color GC4 and the mixed color GY4, the luminance of the second light source 11G is relatively high compared to the luminance of the light source of the other color that is turned on. In addition, in the mixed color GC4 and the mixed color GY4, the luminance of the second light source 11G is relatively low compared to the mixed color GC3 and the mixed color GY3, and the luminance of the light source of the other color that is turned on is relatively high.

[0153] In category Ct23, it is desirable to adjust the luminance of the second light source 11G in the mixed color GC4 and the luminance of the second light source 11G in the mixed color GY4 so that the sum of the luminance of the second light source 11G in the mixed color GC4 and the luminance of the second light source 11G in the mixed color GY4 produces color reproduction equivalent to the luminance of the first green color Ga.

[0154] Moreover, assuming that the category Ct32 shown in FIG. 18 is the category after switching, the color break can be further suppressed by creating the category Ct31 between the twentieth category and the category Ct32.

[0155] The category Ct31 is established by the occurrence of a period of the first blue Ba, a period of the mixed color GC5, a period of the mixed color RM5, and a period of the fifth yellow Y5 during one frame period. The mixed color GC5 is a lighting pattern of the light source unit 11 in which the second light source 11G and the third light source 11B are turned on and the first light source 11R is turned off. In the mixed color GC5, the luminance of the second light source 11G is relatively higher than the luminance of the third light source 11B. The mixed color RM5 is a lighting pattern of the light source unit 11 in which the first light source 11R and the third light source 11B are turned on and the second light source 11G is turned off. In the mixed color RM5, the luminance of the first light source 11R is relatively higher than the luminance of the third light source 11B. The fifth yellow Y5 is a lighting pattern of the light source unit 11 in which the first light source 11R and the second light source 11G are turned on and the third light source 11B is turned off.

[0156] The category Ct32 is established by the occurrence of a period of the first blue Ba, a period of the mixed color GC6, a period of the mixed color RM6, and a period of the sixth yellow Y6 during one frame period. The mixed color GC6 is a lighting pattern of the light source unit 11 in which the second light source 11G and the third light source 11B are turned on, and the first light source 11R is turned off. In the mixed color GC6, the luminance of the second light source 11G is relatively high compared to the luminance of the third light source 11B. In the mixed color GC6, the luminance of the second light source 11G is relatively low compared to the mixed color GC5. The mixed color RM6 is a lighting pattern of the light source unit 11 in which the first light source 11R and the third light source 11B are turned on, and the second light source 11G is turned off. In the mixed color RM6, the luminance of the first light source 11R is relatively high compared to the luminance of the third light source 11B. In the mixed color RM6, the luminance of the first light source 11R is relatively low compared to the mixed color RM5. The sixth yellow Y6 is a lighting pattern of the light source unit 11 in which the first light source 11R and the second light source 11G are turned on and the third light source 11B is turned off. In the sixth yellow Y6, the luminance of the first light source 11R and the luminance of the second light source 11G are relatively high compared to the fifth yellow Y5.

[0157] In category Ct32, it is desirable to adjust the luminance of the second light source 11G in the sixth yellow Y6 and the luminance of the second light source 11G in the mixed color GC6 so that the sum of the luminance of the second light source 11G in the sixth yellow Y6 and the luminance of the second light source 11G in the mixed color GC6 reproduces a color equivalent to the luminance of the first green Ga. Also, in category Ct32, it is desirable to adjust the luminance of the first light source 11R in the sixth yellow Y6 and the luminance of the second light source 11G in the mixed color RM6 so that the sum of the luminance of the first light source 11R in the sixth yellow Y6 and the luminance of the second light source 11G in the mixed color RM6 reproduces a color equivalent to the luminance of the first red Ra.

[0158] In the third modification, data indicating lighting patterns such as category Ct23 shown in Fig. 17 and category Ct32 shown in Fig. 18 are included in the category information 717. Note that data indicating lighting patterns such as category Ct21, category Ct22, and category Ct31 may also be included in the category information 717, but it is desirable to adjust the luminance of the light source for each period included in each category so that the balance of red (R), green (G), blue (B), and white (W) reproduced during one frame period is equivalent to that of the other categories.

[0159] As described above, except for the matters noted above, the third modification is the same as the second embodiment. According to the third modification, the data (e.g., category information 717) includes information indicating a lighting pattern in which two of the first light source (e.g., the first light source 11R), the second light source (e.g., the second light source 11G), and the third light source (e.g., the third light source 11B) are turned on and the other is turned off, and in which the luminance ratio of the two of the first light source, the second light source, and the third light source that are turned on is different between one and the other of the two lighting periods. In the description with reference to Figs. 17 and 18, for example, the category Ct32 corresponds to the lighting pattern. According to such a lighting pattern, the degree of the difference in light between the lighting periods can be more suppressed than in a lighting pattern in which the first light source, the second light source, and the third light source are turned on at the highest luminance. Therefore, color break can be more suppressed.

[0160] Note that the above-described embodiments and their modified examples are merely examples and do not limit the specific form of the present disclosure. For example, n may be 5 or more. In that case, a period corresponding to n, a natural number of 5 or more, is appropriately set for each category.

[0161] Furthermore, the specific embodiment of a display unit having pixels Pix such as display unit 7 is not limited to an embodiment using PDLC, and other panels having a plurality of pixels capable of reflecting light may be adopted.

[0162] Furthermore, other advantageous effects brought about by the aspects described in the embodiments, etc. that are obvious from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present disclosure. [Explanation of symbols]

[0163] 3. Liquid crystal 7 Display section 11 Light source section 11R 1st light source 11G 2nd light source 11B Third light source 70 Image processing circuit 71 Lighting control unit 100 display device 716 Storage section LP1, LP2, LP3, LP4 lighting period P Display Panel Pix

Claims

1. a light source unit including a first light source that emits light of a first color, a second light source that emits light of a second color, and a third light source that emits light of a third color; a display unit that uses the light from the light source unit to perform color reproduction according to input data from an external source; a storage unit that stores data indicating a lighting pattern of the first light source, the second light source, and the third light source; a control unit that controls a lighting pattern of the first light source, the second light source, and the third light source based on the input data and the data, the control unit generates n lighting periods during a display output period of a frame image output by the display unit, n is a natural number equal to or greater than 3, a color of light emitted from the light source unit in each of the n lighting periods is different, the data includes information indicating a plurality of types of lighting patterns each having a different color gamut that can be reproduced in the n lighting periods, when the color reproduction by the display unit changes, the control unit controls the lighting patterns of the first light source, the second light source, and the third light source according to a difference between a lighting pattern for color reproduction according to the input data before the change and a lighting pattern for color reproduction according to the input data after the change. Display device.

2. the control unit generates a transition period between a first timing at which a lighting pattern for color reproduction according to the input data before the change is applied and a second timing at which a lighting pattern for color reproduction according to the input data after the change is applied, during which a lighting pattern different from both the first timing and the second timing is applied; a difference between a color of light emitted from the light source unit during the transition period and a color of light emitted from the light source unit at the first timing; And, The difference between the color of the light emitted from the light source unit during the transition period and the color of the light emitted from the light source unit at the second timing is a difference between the color of the light emitted from the light source unit at the first timing and the color of the light emitted from the light source unit at the second timing is smaller than the difference between the color of the light emitted from the light source unit at the first timing and the color of the light emitted from the light source unit at the second timing; The display device according to claim 1 .

3. During the transition period: a lighting period during which the first light source is turned on at the highest luminance and the second light source and the third light source are turned off; a lighting period during which the second light source is turned on at the highest luminance and the first light source and the third light source are turned off; a lighting period during which the third light source is turned on at the highest luminance and the first light source and the second light source are turned off; A timing occurs when a lighting pattern that causes The display device according to claim 2 .

4. the data includes information indicating a lighting pattern that generates a lighting period during which any one of the first light source, the second light source, and the third light source is turned on at the highest luminance and the other two light sources are turned off; The display device according to claim 1 .

5. the data includes information indicating a lighting pattern in which two lighting periods are generated in which two of the first light source, the second light source, and the third light source are turned on and the remaining one is turned off, and a luminance ratio of two of the first light source, the second light source, and the third light source that are turned on is different between one of the two lighting periods and the other. The display device according to claim 4.

6. The data is a lighting period during which the first light source and the second light source are turned on and the third light source is turned off; a lighting period during which the second light source and the third light source are turned on and the first light source is turned off; a lighting period during which the first light source and the third light source are turned on and the second light source is turned off, The display device according to claim 1 .

7. The data is generating three lighting periods in which the first light source, the second light source, and the third light source are turned on, each of the three lighting periods including information indicating a lighting pattern having a different luminance ratio between the first light source, the second light source, and the third light source; The display device according to claim 1 .

8. n is 4 or more; The data is The information includes information indicating a lighting pattern that generates a lighting period during which the first light source, the second light source, and the third light source are turned on. The display device according to claim 1 .

9. The data is two lighting periods are generated in which two of the first light source, the second light source, and the third light source are turned on and the remaining one is turned off, and the lighting period includes information indicating a lighting pattern in which the luminance ratio of two of the first light source, the second light source, and the third light source that are turned on is different between one and the other of the two lighting periods; The display device according to claim 8.

10. a predetermined priority is set for each of the plurality of types of lighting patterns included in the data; the control unit applies to the control of the light source unit a lighting pattern with a highest priority among lighting patterns capable of reproducing a color reproduced according to a gradation value indicated by pixel data included in the input data. The display device according to claim 1 .

11. one of the first color, the second color, and the third color is red; one of the first color, the second color, and the third color that is not red is green; one of the first color, the second color, and the third color that is neither red nor green is blue; The display device according to claim 1 .

12. The display unit is a liquid crystal panel in which a polymer dispersed liquid crystal is enclosed. The display device according to claim 1 .

Images