JP7044511B2 - Display device - Google Patents

Description

The present invention relates to a display device.

In a display device illuminated by light from the back side, a configuration is known in which an additional panel capable of controlling the light transmittance is provided between the display panel and the light source for the purpose of suppressing light leakage. (For example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-191053

However, even if an additional panel is provided, if there is a difference in transmittance at a position where the partial regions whose transmittances are individually controlled in the additional panel are adjacent to each other, the difference in the amount of light according to the difference in transmittance is provided. Occurs. Such a difference in the amount of light may be visually recognized as a band-shaped halo along an adjacent position between the partial regions. Such a band-shaped halo causes problems such as a decrease in contrast and a decrease in image quality.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a display device capable of suppressing the generation of a band-shaped halo.

The display device according to one aspect of the present invention includes a display panel having a plurality of pixels, a light guide plate provided on the back side of the display panel, a light source that irradiates light from the side of the light guide plate, and the light guide plate. On the other hand, a dimming panel provided on the display panel side and at least a control unit for controlling the operation of the display panel and the dimming panel are provided, and the dimming panel is provided in the irradiation direction of light from the light source. It has a plurality of dimming regions arranged side by side, and the plurality of dimming regions are provided so that the light transmission rate can be individually changed according to the light intensity required for displaying an image by the display panel, and the control unit. Is a pixel located within a predetermined range from the boundary between the two dimming regions among the pixels in which the dimming region having a low light transmittance is located when the light transmission rate of each of the two adjacent dimming regions is different. Is the target pixel, and the output gradation value of the target pixel is increased.

FIG. 1 is a diagram showing a main configuration example of the display device according to the first embodiment of the present invention. FIG. 2 is a diagram showing an example of the positional relationship between the image display panel, the dimming panel, and the light source device. FIG. 3 is a diagram showing an example in which a polarizing plate is provided on the display surface side of the dimming panel. FIG. 4 is a diagram showing an example of the pixel arrangement of the image display panel. FIG. 5 is a cross-sectional view showing an example of a schematic cross-sectional structure of an image display panel. FIG. 6 is a diagram showing an example of the relationship between the display area and the display division area. FIG. 7 is a diagram showing an example of a main configuration of a light source device. FIG. 8 is a diagram showing another configuration example of the light source device. FIG. 9 is a diagram showing an example of the relationship between the dimming region of the dimming panel and the coordinates in the Y direction. FIG. 10 is a diagram showing an example of the main configuration of the dimming unit. FIG. 11 is a diagram showing another example of the main configuration of the dimming unit. FIG. 12 is a cross-sectional view showing an example of a schematic cross-sectional structure of a dimming panel. FIG. 13 is a diagram showing an example of the luminance distribution (light source luminance distribution) due to the light from the light source. FIG. 14 is a diagram showing an example of the transmittance of an image display panel that outputs an image under the condition that the light source luminance distribution shown in FIG. 13 can be obtained. FIG. 15 is a diagram showing the output luminance of the display device when the image display panel is operated so as to have the transmittance of the image display panel shown in FIG. 14 under the condition that the light source luminance distribution shown in FIG. 13 is obtained. FIG. 16 is an enlarged schematic view of the range A of FIG. 15 when the decrease in brightness due to the dimming panel is not taken into consideration. FIG. 17 is a schematic diagram showing an example of the range in which light reaches from a light source. FIG. 18 is a diagram showing an example of the transmittance of the dimming panel. FIG. 19 shows an enlarged schematic of the output brightness when the transmittance dimming panel shown in FIG. 18 is interposed between the light source device having the light source luminance distribution shown in FIG. 13 and the image display panel having the transmittance shown in FIG. It is a figure. FIG. 20 is a schematic diagram showing an example of a sudden change line of output luminance. FIG. 21 is a diagram showing an example of the transmittance of an image display panel that outputs an image under the condition that the light source luminance distribution shown in FIG. 13 and the transmittance of the dimming panel shown in FIG. 18 can be obtained in the first embodiment. .. FIG. 22 shows an enlarged schematic of the output brightness when the light control panel having the transmittance shown in FIG. 18 is interposed between the light source device having the light source luminance distribution shown in FIG. 13 and the image display panel having the transmittance shown in FIG. It is a figure. FIG. 23 is a block diagram showing an example of the functional configuration of the signal processing unit. FIG. 24 is a flowchart showing the flow of processing by the signal processing unit. FIG. 25 is a diagram schematically showing an example of the processing contents of steps S1 to S5 of the flowchart shown in FIG. 24. FIG. 26 is a flowchart showing the flow of the output gradation value calculation process in FIG. 24. FIG. 27 is a block diagram showing another example of the functional configuration of the signal processing unit in the modified example. FIG. 28 is a flowchart showing a processing flow by the signal processing unit of the modified example. FIG. 29 is a diagram schematically showing an example of the processing contents performed in steps S11 to S15 of the flowchart shown in FIG. 28. FIG. 30 is a diagram schematically showing an example of processing contents performed in steps S16 to S18 of the flowchart shown in FIG. 28. FIG. 31 is a diagram showing an example of the light source device of the second embodiment. FIG. 32 is a diagram showing another example of the light source device of the second embodiment. FIG. 33 is a diagram showing another example of the light source device of the second embodiment. FIG. 34 is a diagram showing a main configuration example of the dimming unit of the second embodiment. FIG. 35 is a schematic diagram showing an example of display output contents. FIG. 36 is a schematic diagram showing an example of a light source luminance distribution corresponding to the display output content shown in FIG. 35. FIG. 37 is a schematic diagram showing a case where a sudden change line of output luminance occurs in the light source luminance distribution shown in FIG. 36. FIG. 38 is a flowchart showing a processing flow by the signal processing unit of the second embodiment. FIG. 39 is a diagram schematically showing an example of the processing contents of steps S21 to S25 of the flowchart shown in FIG. 38. FIG. 40 is a flowchart showing the flow of the output gradation value calculation process in FIG. 38. FIG. 41 is a diagram showing an example of a preprocessing coefficient used for calculating the gradation value of the target pixel in the second embodiment.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention, which are naturally included in the scope of the present invention. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

(Embodiment 1)
FIG. 1 is a diagram showing a main configuration example of the display device 1 according to the first embodiment of the present invention. The display device 1 of the first embodiment includes a signal processing unit 10, a display unit 20, a light source device 50, a light source control circuit 60, and a dimming unit 70. The signal processing unit 10 performs various outputs based on the input signal IP input from the external control device 2, and controls the operations of the display unit 20, the light source device 50, and the dimming unit 70. The input signal IP is a signal that functions as data for displaying and outputting an image on the display device 1, and is, for example, an RGB image signal. The signal processing unit 10 outputs the output image signal OP generated based on the input signal IP to the display unit 20. Further, the signal processing unit 10 outputs the local dimming signal DI generated based on the input signal IP to the dimming unit 70. Further, when the input signal IP is input, the signal processing unit 10 outputs a light source drive signal BL for controlling the lighting amount of each of the light sources 51 (see FIG. 7) of the light source device 50 to the light source control circuit 60. do. The light source control circuit 60 is, for example, a driver circuit for lighting the light source 51 (see FIG. 7) of the light source device 50, and operates the light source device 50 in response to the light source drive signal BL.

The display unit 20 includes an image display panel 30 and an image display panel drive unit 40. The image display panel 30 has a display area OA provided with a plurality of pixels 48. The plurality of pixels 48 are arranged in a matrix, for example. The image display panel 30 of the first embodiment is a liquid crystal image display panel. The image display panel drive unit 40 has a signal output circuit 41 and a scanning circuit 42. The signal output circuit 41 drives a plurality of pixels 48 according to the output image signal OP. The scanning circuit 42 outputs a drive signal for scanning a plurality of pixels 48 arranged in a matrix in units of predetermined rows (for example, one row). The pixel 48 is driven so that the gradation value corresponding to the output image signal OP is output at the timing when the drive signal is output.

The dimming unit 70 adjusts the amount of light emitted from the light source device 50 and output through the display area OA. The dimming unit 70 includes a dimming panel 80 and a circuit unit 90. The dimming panel 80 has a local dimming region DA provided so that the light transmittance can be changed. The local dimming area DA is arranged at a position superimposing on the display area OA when the display area OA is viewed in a plane. The local dimming area DA covers the entire display area OA in plan view. The circuit unit 90 individually controls the transmittance of each of the plurality of dimming region LDs (see FIG. 9) provided in the local dimming region DA according to the local dimming signal DI.

FIG. 2 is a diagram showing an example of the positional relationship between the image display panel 30, the dimming panel 80, and the light source device 50. In the first embodiment, as illustrated in FIG. 2, the image display panel 30, the dimming panel 80, and the light source device 50 are laminated. Specifically, the dimming panel 80 is laminated on the irradiation surface side where the light is output from the light source device 50. Further, the image display panel 30 is laminated on the opposite side of the light source device 50 with the dimming panel 80 interposed therebetween. The light emitted from the light source device 50 illuminates the image display panel 30 by adjusting the amount of light in the local dimming region DA of the dimming panel 80. The image display panel 30 is illuminated from the back side where the light source device 50 is located, and displays and outputs an image on the opposite side (display surface side). In this way, the light source device 50 functions as a backlight that illuminates the display area OA of the image display panel 30 from the back surface. Further, in the first embodiment, the dimming panel 80 is provided between the image display panel 30 and the light source device 50. Hereinafter, the direction in which the image display panel 30, the dimming panel 80, and the light source device 50 are laminated is defined as the Z direction. Further, the two directions orthogonal to the Z direction are defined as the X direction and the Y direction. The X and Y directions are orthogonal. The plurality of pixels 48 are arranged in a matrix along the X direction and the Y direction. In the following description, it is assumed that the number of pixels 48 arranged in the X direction is h and the number of pixels 48 arranged in the Y direction is v. Further, the description (h) shows a case where the coordinate management in the X direction is performed corresponding to the positions of the pixels 48 arranged in the X direction. Further, the description of (v) shows a case where the coordinate management in the Y direction is performed corresponding to the positions of the pixels 48 arranged in the Y direction. Further, the description of (h, v) shows a case where the coordinate management in the X direction and the Y direction is performed corresponding to the positions of the pixels 48 arranged in the X direction and the Y direction.

The image display panel 30 has an array substrate 30a and a facing substrate 30b located on the display surface side of the array substrate 30a and facing the array substrate 30a. As will be described later, the liquid crystal layer LC1 is arranged between the array substrate 30a and the facing substrate 30b (see FIG. 5). A polarizing plate 30c is provided on the back surface side of the array substrate 30a. A polarizing plate 30d is provided on the display surface side of the facing substrate 30b. Further, the dimming panel 80 has a first substrate 80a and a second substrate 80b located on the display surface side with respect to the first substrate 80a and facing the first substrate 80a. As will be described later, the liquid crystal layer LC2 is arranged between the first substrate 80a and the second substrate 80b (see FIG. 12). A polarizing plate 80c is provided on the back surface side of the first substrate 80a. The polarizing plate 30c performs both the polarization on the back surface side of the image display panel 30 and the polarization on the display surface side of the dimming panel 80.

FIG. 3 is a diagram showing an example in which the polarizing plate 80d is provided on the display surface side of the dimming panel 80. As shown in FIG. 3, a polarizing plate 80d may be provided on the display surface side of the second substrate 80b.

FIG. 4 is a diagram showing an example of the pixel arrangement of the image display panel 30. As illustrated in FIG. 4, the pixel 48 has, for example, a first sub-pixel 49R, a second sub-pixel 49G, and a third sub-pixel 49B. The first sub-pixel 49R displays the first primary color (for example, red). The second sub-pixel 49G displays a second primary color (for example, green). The third sub-pixel 49B displays a third primary color (for example, blue). In this way, the pixels 48 arranged in a matrix on the image display panel 30 have the first sub-pixel 49R displaying the first color, the second sub-pixel 49G displaying the second color, and the third color. The third sub-pixel 49B to be displayed is included. The first color, the second color, and the third color are not limited to the first primary color, the second primary color, and the third primary color, and may be different colors such as complementary colors. In the following description, when it is not necessary to distinguish between the first sub-pixel 49R, the second sub-pixel 49G, and the third sub-pixel 49B, the sub-pixel 49 is referred to.

The pixel 48 may further have a sub-pixel 49 in addition to the first sub-pixel 49R, the second sub-pixel 49G, and the third sub-pixel 49B. For example, the pixel 48 may have a fourth sub-pixel that displays a fourth color. The fourth sub-pixel displays a fourth color (eg, white). When the fourth sub-pixel is irradiated with the same light source lighting amount, the first sub-pixel 49R displaying the first color, the second sub-pixel 49G displaying the second color, and the third sub-pixel displaying the third color. It is preferably brighter than the 3 sub-pixels 49B.

More specifically, the display device 1 is a transmissive color liquid crystal display device. As illustrated in FIG. 4, the image display panel 30 is a color liquid crystal display panel, and a first color filter for passing the first primary color is arranged between the first sub-pixel 49R and the image observer, and a second color filter is arranged. A second color filter that passes the second primary color is placed between the sub-pixel 49G and the image observer, and a third color filter that passes the third primary color is placed between the third sub-pixel 49B and the image observer. Has been done. The first color filter, the second color filter, and the third color filter are configured to be included in the filter film 26 described later.

When the fourth sub-pixel is provided, the color filter is not arranged between the fourth sub-pixel and the image observer. In this case, a large step will occur in the fourth sub-pixel. Therefore, the fourth sub-pixel may be provided with a transparent resin layer instead of the color filter. As a result, it is possible to suppress the occurrence of a large step in the fourth sub-pixel.

The signal output circuit 41 is electrically connected to the image display panel 30 by a signal line DTL. The image display panel drive unit 40 selects a sub-pixel 49 in the image display panel 30 by the scanning circuit 42, and a switching element for controlling the operation (light transmission rate) of the sub-pixel 49 (for example, a thin film transistor (TFT: Thin)). Film Transistor)) is controlled on (ON) and off (OFF). The scanning circuit 42 is electrically connected to the image display panel 30 by a scanning line SCL. In the first embodiment, the scanning line SCL is along the X direction and the signal line DTL is along the Y direction, but this is an example of the extending direction of the scanning line SCL and the signal line DTL and is limited to this. It can be changed as appropriate.

FIG. 5 is a cross-sectional view showing an example of a schematic cross-sectional structure of the image display panel 30. The array substrate 30a has a filter film 26 provided above a pixel substrate 21 such as a glass substrate, a counter electrode 23 provided above the filter film 26, and an insulating film provided in contact with the counter electrode 23. 24, a pixel electrode 22 on the insulating film 24, and a first alignment film 28 provided on the uppermost surface side of the array substrate 30a. The facing substrate 30b includes a facing pixel substrate 31 such as a glass substrate, a second alignment film 38 provided on the lower surface of the facing pixel substrate 31, and a polarizing plate 35 provided on the upper surface. The array substrate 30a and the facing substrate 30b are fixed via a sealing portion 29. The liquid crystal layer LC1 is sealed in the space surrounded by the array substrate 30a, the facing substrate 30b, and the sealing portion 29. The liquid crystal layer LC1 contains liquid crystal molecules whose orientation direction changes according to the applied electric field. The liquid crystal layer LC1 modulates the light passing through the inside of the liquid crystal layer LC1 according to the state of the electric field. The direction of the liquid crystal molecules of the liquid crystal layer LC1 changes depending on the electric field applied between the pixel electrode 22 and the counter electrode 23, and the amount of light transmitted through the liquid crystal layer LC1 changes. Each of the plurality of sub-pixels 49 has a pixel electrode 22. A plurality of switching elements for individually controlling the operation (light transmittance) of the plurality of sub-pixels 49 are electrically connected to the pixel electrode 22.

FIG. 6 is a diagram showing an example of the relationship between the display area OA and the display division area. The display area OA has a plurality of display division areas PA. The area in which the plurality of display division areas PA are combined is the display area OA. The display area OA shown in FIG. 6 is a total corresponding to the combination of the coordinates of x1, x2, ..., X9 set along the X direction and the coordinates of y1, y2, y3, y4 set along the Y direction. It has a display division area PA individually provided at a position corresponding to each of the 36 coordinates. Hereinafter, the position of the display division area PA or the like may be indicated using the coordinates. For example, "(x1) display division area PA" indicates a display division area PA provided at a position where the coordinates in the X direction are x1. Further, "(y1) display division area PA" indicates a display division area PA provided at a position where the coordinates in the Y direction are y1. Further, the "display division area PA of (x1, y1)" indicates a display division area PA provided at a position where the coordinates in the X direction are x1 and the coordinates in the Y direction are y1. The positions of the light source 51, the light source region GA and the dimming region LD, which will be described later, may be indicated by the same description.

Of the coordinates of the display division area PA possessed by the display area OA, the coordinates in the X direction correspond to the number of the plurality of light sources 51 possessed by the light source device 50 and the positions of the respective light sources 51 in the X direction (see FIG. 7). ). Further, among the coordinates of the display division area PA possessed by the display area OA, the coordinates in the Y direction correspond to the number of a plurality of dimming areas possessed by the dimming panel 80 and the position of each dimming area in the Y direction. (See Fig. 9).

FIG. 7 is a diagram showing an example of the main configuration of the light source device 50. The light source device 50 has, for example, a light guide plate LA and a plurality of light sources 51. The light guide plate LA is provided on the back side of the image display panel 30 at a position corresponding to the display area OA in the XY plan view. The plurality of light sources 51 are arranged along the X direction on one end side in the Y direction. The light source 51 irradiates light from the side of the light guide plate LA. The light source 51 is, for example, a light emitting diode (LED: Light Emitting Diode) that emits white light, but the light source 51 is not limited to this, and can be appropriately changed. The light from the light source 51 is guided by the light guide plate LA and illuminates the entire display area OA from the back side.

In the example shown in FIG. 7, the light sources 51 corresponding to the coordinates (x1, x2, ..., X9) in the X direction are individually arranged. Further, the light guide plate LA has a plurality of light source regions GA provided so as to correspond to each of the coordinates (x1, x2, ..., X9) in the X direction. When light is emitted from the light source 51, the plurality of light source regions GA guide the light so as to illuminate the image display panel 30 from the back surface side of the display division region PA corresponding to the coordinates in each X direction. Each of the plurality of light source regions GA is assumed to guide light from the light source 51 at the coordinates (x1, x2, ..., X9) in the corresponding X direction. In the lighting amount control of the light source 51 described below, it is assumed that the light from the light source 51 having the coordinates (x1, x2, ..., X9) in the X direction corresponding to each of the plurality of light source regions GA is irradiated. ..

It should be noted that the light of the light source 51 whose coordinates (x1, x2, ..., X9) in the X direction do not correspond to one light source region GA can also enter. The lighting amount calculation unit 104 (see FIG. 23), which will be described later, is used to obtain the relationship between the brightness distribution of the plurality of light source regions GA and the lighting amount of the light source 51, including the light from the light source 51 having such uncorresponding coordinates. It may have the reference data of. When the reference data is available, the lighting amount calculation unit 104 uses the reference data when calculating the lighting amount of the light source 51.

In the first embodiment, the light source 51 irradiates light from one end side of the light guide plate LA. Specifically, in the first embodiment, for example, as shown in FIG. 7, nine light sources 51 arranged in a row along the X direction on one end side in the Y direction are provided. The example shown in FIG. 7 is an example of the number and arrangement of the light sources 51, and is not limited to this, and can be appropriately changed.

FIG. 8 is a diagram showing another configuration example of the light source device 50. For example, as shown in FIG. 8, a total of 18 light sources 51 arranged in a row along the X direction on each of one end side and the other end side in the Y direction may be arranged. As described above, the display device 1 may have a plurality of light sources 51 provided at positions facing each other across the light guide plate LA.

FIG. 9 is a diagram showing an example of the relationship between the dimming region LD of the dimming panel 80 and the coordinates in the Y direction. The dimming panel 80 has a plurality of dimming region LDs whose light transmittance can be individually controlled. The local dimming area DA is an area including a plurality of dimming areas LD. The light control panel 80 is provided so that the transmittance of light guided by the light guide plate LA to illuminate the entire display area OA from the back side can be individually controlled in each of the plurality of light control area LDs. As described above, the dimming region LD of the first embodiment extends in a direction (for example, the X direction) intersecting the light irradiation direction (for example, the Y direction) from the light source 51 to the light guide plate LA. In the example shown in FIG. 9, four dimming region LDs arranged in the Y direction are provided. The position of each of the four dimming regions LD corresponds to the coordinates (y1, y2, y3, y4) in the Y direction. The number of the plurality of dimming region LDs shown in FIG. 9 is merely an example and is not limited to this, and can be appropriately changed.

In this way, the display division regions PA arranged in the X direction are each illuminated by the light from the light source region GA having the coordinates in the corresponding X direction. Further, each of the display division regions PA arranged in the Y direction is provided so that the degree of irradiation of light from the light source region GA can be dimmed by the dimming region LD having the corresponding coordinates in the Y direction.

FIG. 10 is a diagram showing an example of the main configuration of the dimming unit 70. The dimming panel 80 has a plurality of first electrodes 81 provided in the local dimming region DA. The dimming panel 80 shown in FIG. 10 is, for example, a combination of the coordinates of x1, x2, ..., X9 set along the X direction and the coordinates of y1, y2, y3, y4 set along the Y direction. It has a first electrode 81 individually provided at a position corresponding to each of the corresponding coordinates of a total of 36. Each of the plurality of first electrodes 81 is connected to the circuit unit 90 via the wiring 86.

The circuit unit 90 of the first embodiment controls, for example, to make the potential of the first electrode 81 uniform in coordinate units in the Y direction according to the local dimming signal DI. As a result, the transmittance of the dimming region LD in the longitudinal direction (X direction) becomes uniform. Further, the circuit unit 90 individually controls the potentials of the first electrodes 81 having different coordinates in the Y direction. As a result, the transmittance of each of the plurality of dimming region LDs is individually controlled.

FIG. 11 is a diagram showing another example of the main configuration of the dimming unit. In FIG. 10, the first electrode 81 is provided at a position corresponding to each of the coordinates in the X direction, but this is an example of a specific method of providing the first electrode 81, and the present invention is not limited to this. For example, as shown in FIG. 11, one first electrode 81A may be provided in one dimming region LD. In this case, the length of one first electrode 81A provided in one dimming region LD in the X direction corresponds to the length of the dimming region LD in the X direction.

FIG. 12 is a cross-sectional view showing an example of a schematic cross-sectional structure of the dimming panel 80. The dimming unit 70 has, for example, a switch SW configured by a TFT. The switch SW has a channel 84, a source 85a, a drain 85b, and a gate 85c mounted on the first transparent substrate 83 of the first substrate 80a. The source 85a is given a potential based on the local dimming signal DI, that is, a potential corresponding to the transmittance of each of the plurality of dimming region LDs. The drain 85b is electrically connected to the wiring 86. The switch SW switches whether or not to allow the drain current to flow through the first electrode 81 depending on the presence or absence of a signal for the gate 85c. Note that FIG. 12 schematically illustrates the electrical connection relationship between one switch SW and one first electrode 81, but all the first electrodes 81 are individually connected via individual wiring 86. It may be connected to the drain 85b of the switch SW.

Each of the plurality of dimming region LDs has a first electrode 81 and a second electrode 82 provided at a position facing the first electrode 81 with the liquid crystal layer LC2 interposed therebetween. Specifically, the first substrate 80a includes a first transparent substrate 83, a semiconductor layer 84, a first insulating layer 87a, a second insulating layer 87b laminated on a gate 85c laminated on the first insulating layer 87a, and a source electrode. It has a third insulating layer 87c laminated on the 85a and the drain electrode 85b, and a first electrode 81 laminated on the third insulating layer 87c. Further, the second substrate 80b has a second transparent substrate 88 and a second electrode 82 laminated on the second substrate 80b. The first substrate 80a and the second substrate 80b are arranged so that the surface provided with the first electrode 81 and the surface provided with the second electrode 82 face each other. A liquid crystal layer LC2 is provided between the surface provided with the first electrode 81 and the surface provided with the second electrode 82. Further, a sealing material 89 for sealing the liquid crystal layer LC2 is provided between the first substrate 80a and the second substrate 80b. The first transparent substrate 83 and the second transparent substrate 88 are, for example, glass substrates. The first electrode 81, the second electrode 82, and the wiring 86 are translucent electrodes using, for example, indium tin oxide (ITO).

The second electrode 82 of the first embodiment has a structure shared by a plurality of dimming region LDs. Specifically, the second electrode 82 is a flat film-like electrode provided so as to cross the plurality of dimming region LDs and cover the entire local dimming region DA. By individually controlling the potentials of the first electrodes 81 of each of the plurality of dimming region LDs with respect to the potentials of the second electrodes 82 shared by the plurality of dimming region LDs, the potentials of the plurality of dimming region LDs can be controlled. The degree of twist of the liquid crystal in each is controlled individually. As a result, the light transmittance in each of the plurality of dimming region LDs is individually controlled according to the local dimming signal DI.

The dimming panel 80 of the first embodiment is a twisted nematic (TN: Twisted Nematic) type liquid crystal panel, and transmits light with the highest transmittance when not energized (normally white). This is an example of a specific form of the dimming panel 80, and is not limited to this. The dimming panel 80 may be a liquid crystal panel of another type, or may be normally black. Further, the form of the second electrode 82 described above is merely an example of a specific form of the second electrode 82, and is not limited to this, and can be appropriately changed. For example, the second electrode 82 may be individually provided in each of the plurality of dimming region LDs, similarly to the first electrode 81. In this case, the potentials of the individually provided second electrodes 82 are controlled to be the same potential at the same timing.

The circuit unit 90 that handles the electric signal related to the control of the transmittance of each of the plurality of dimming region LDs is chip-on to, for example, the frame region of the dimming panel 80 in which the local dimming region DA is not located in the dimming unit 70. It is mounted by a method such as glass (COG: Chip On Glass), and is connected to each of a plurality of first electrodes 81 via a wiring 86. In this way, by providing a circuit for individually controlling the transmittance of each of the plurality of dimming region LDs outside the local dimming region DA, it becomes easier to increase the maximum transmittance of light in the local dimming region DA. ..

FIG. 13 is a diagram showing an example of the luminance distribution (light source luminance distribution) due to the light from the light source. FIG. 14 is a diagram showing an example of the transmittance of the image display panel 30 that outputs an image under the condition that the light source luminance distribution shown in FIG. 13 can be obtained. FIG. 15 is a diagram showing the output luminance of the display device 1 when the image display panel 30 is operated so as to have the transmittance of the image display panel 30 shown in FIG. 14 under the condition that the light source luminance distribution shown in FIG. 13 is obtained. Is. For example, as shown in FIG. 15, the output luminance corresponds to a gradation value of 100 [%] in one or more colors in a part of the display division area PA closest to the light source 51 in the coordinates in the Y direction (y1). Imagine the case. In this case, it is assumed that an image in which black ((R, G, B) = (0,0,0)) is displayed except for the part thereof. In this case, the luminance of 100 [%] or more is required in the display division area PA of (y1). In the display division area PA of (y2), (y3), and (y4), the gradation values of the pixels 48 included in the input signal IP are all (R, G, B) = (0,0,0). Yes, the light from the light source 51 is unnecessary. In this case, as shown in FIG. 13, if the luminance of 100 [%] is secured at the boundary between the display division area PA of (y1) and the display division area PA of (y2), the display division of (y1) is performed. The output brightness of the region PA can be sufficiently secured. Since the light source 51 at the time of lighting illuminates a closer position brighter, the output luminance of the display division area PA of (y1) is the boundary between the display division area PA of (y1) and the display division area PA of (y2). It will be higher than the brightness.

In FIG. 13, the light source 51 is turned on with an intensity of, for example, 120 [%] in order to secure a luminance of 100 [%] in the entire display division region PA of (y1). Further, FIG. 13 shows that the brightness of the light becomes lower as the coordinates are separated from each other, such as (y1), y2, y3, and y4. FIG. 13 shows an example in which the brightness becomes 60 [%] on the other end side of the display division region PA farthest from the light source 51 (y4). Considering that the brightness of the light changes according to the distance from the light source 51 in this way, the transmittance of the image display panel 30 is gained based on the reciprocal of the brightness (the reciprocal of the brightness gainpix (h, v) described later). To multiply. Specifically, the gain is multiplied by the output gradation value of each pixel of the image display panel 30. In FIG. 14, the gain is applied so that the transmittance of the image display panel 30 increases from one end side to the other end side according to the brightness that decreases from one end side to the other end side in FIG. Is. By combining the brightness of the light from the light source 51 (see FIG. 13) and the gained transmittance (see FIG. 14), the output brightness is 100 in the display division region PA of (y1) as shown in FIG. Can be [%].

As shown in FIG. 14, for example, the image display panel 30 is provided so that the transmittance can be changed within a range in which the maximum transmittance (DP_max) is the upper limit and the minimum transmittance (DP_min) is the lower limit. When each gradation value of (R, G, B) is represented by a predetermined number of bits (for example, 8 bits: 0 to 255), the transmittance corresponding to the highest (255) gradation value in the number of bits is transparent. The rate is the highest transmittance (DP_max). Further, the transmittance corresponding to the lowest (0) gradation value in the number of bits is the minimum transmittance (DP_min). Hereinafter, the value relating to the ratio of the maximum transmittance (DP_max) and the minimum transmittance (DP_min) of the image display panel 30 is referred to as "first contrast (DP_c: see FIG. 21)". The first contrast represents, for example, "contrast of the image display panel 30", for example, DP_c = DP_max / DP_min. When DP_c = 1000, the minimum transmittance (DP_min) of the image display panel 30 is 1/1000 of the maximum transmittance (DP_max). In other words, even with the lowest transmittance (DP_min), the light transmittance of the image display panel 30 is not zero.

FIG. 16 is an enlarged schematic view of the range A of FIG. 15 when the contrast control by the dimming panel 80 is not taken into consideration. As described above, the light transmittance of the image display panel 30 is not 0 even at the minimum transmittance (DP_min). Therefore, when there is no dimming panel 80, even the pixel 48 controlled to have the minimum transmittance (DP_min) corresponding to (R, G, B) = 0 is completely free of light (Fig.). Black floating U corresponding to the gap between 0 [%]) in the graph of 16 and the output luminance of the lowest transmittance (DP_min) is generated. To give a specific example, the output brightness of the image display panel 30 having a first contrast of 1000 due to the black floating U is about 0.1 [%].

FIG. 17 is a schematic diagram showing an example of the range in which light reaches from the light source 51. FIG. 17 and the like show the boundary line LDL between adjacent dimming regions. As described with reference to FIG. 13, the brightness of the light from the light source 51 decreases as the distance from the light source 51 increases. Therefore, the degree of black floating U also changes depending on the distance from the light source 51, as shown in the graph of FIG. 16 and the schematic diagram of FIG. Such a black floating U is known as a so-called halo (halo) effect.

FIG. 18 is a diagram showing an example of the transmittance of the dimming panel 80. The light control panel 80 is provided so that the transmittance can be changed within a range in which the maximum transmittance (BL_max) is the upper limit and the minimum transmittance (BL_min) is the lower limit. Hereinafter, the value relating to the ratio of the maximum transmittance (BL_max) and the minimum transmittance (BL_min) of the dimming panel 80 is referred to as “second contrast (BL_c: see FIG. 21)”. The second contrast represents "contrast of the dimming panel 80". For example, BL_c = BL_max / BL_min. When BL_c = 500, the minimum transmittance (BL_min) of the dimming panel 80 is 1/500 of the maximum transmittance (BL_max).

FIG. 19 shows the output brightness when the light control panel 80 having the transmittance shown in FIG. 18 is interposed between the light source device having the light source luminance distribution shown in FIG. 13 and the image display panel 30 having the transmittance shown in FIG. It is an enlarged schematic diagram. When it is desired to obtain the output luminance as shown in FIG. 15, light is not required in the display divided region PAs of (y2), (y3), and (y4). Therefore, as shown in FIG. 18, by operating the dimming panel 80 so that the dimming region LD of (y2), (y3), and (y4) has the minimum transmittance (BL_min), (y2), The output luminance in (y3) and (y4) can be made lower. Specifically, as shown in FIG. 19, the output luminance of the display division region PA of (y2), (y3), and (y4) is set to the minimum transmittance (DP_min) of the image display panel 30 and the dimming panel 80. The output luminance can be reduced to the product of the lowest transmittance (BL_min). For example, by setting the light control panel 80 having a second contrast of 500 to the minimum transmittance (BL_min), the reduction rate of light can be reduced to about 0.2 [%]. In this case, depending on the combination of the image display panel 30 having a first contrast of 1000 and the dimming panel 80 having a second contrast of 500, the output luminance of the display division regions PA of (y2), (y3), and (y4) Can be 0.0002 [%]. In this way, by using the dimming panel 80, it is possible to suppress the black floating U as shown in FIG.

On the other hand, since the output brightness of 100 [%] is required in (y1), the dimming region LD in (y1) is set to the maximum transmittance (BL_max). Therefore, as shown in FIG. 19, in the display division area PA of (y1), in the area other than the area where the output luminance is 100 [%], (y2), (y3), and (y4) are displayed. Unlike the divided region PA, the dimming panel 80 does not suppress the black floating U. As a result, the sudden change line ST1 of the output luminance is generated at the boundary between the display division area PA of (y1) and the display division area PA of (y2).

FIG. 20 is a schematic diagram showing an example of the sudden change line ST1 of the output luminance. When the sudden change line ST1 of the output luminance occurs, as shown in FIG. 20, the range in which the black floating U is suppressed by the dimming panel 80 and the black floating U with the boundary line LDL between adjacent dimming region LDs as a boundary. The brightness difference from the unsuppressed range may be visually recognized as a band-shaped halo along the X direction.

Therefore, when the light transmittances of the two adjacent dimming region LDs are different, the signal processing unit 10 of the first embodiment has a predetermined number of pixels near the boundary between the two dimming region LDs (for example, from the boundary). In the range of x_pix)), it functions as a control unit for increasing the output gradation value of the pixel located in the dimming region where the light transmittance is low. This makes it possible to suppress the occurrence of the sudden change line ST1 in the output luminance.

FIG. 21 is a diagram showing an example of image data output to the image display panel 30 under the conditions of the light source luminance distribution shown in FIG. 13 and the transmittance of the dimming panel 80 shown in FIG. 18 in the first embodiment. As shown in FIG. 21, for example, the signal processing unit 10 has a position (position) closest to the boundary between the display division area PA of (y1) and the display division area PA of (y2) in the display division area PA of (y2). The pixel 48 of P1) is set as one end, and the pixel 48 located within the range of a predetermined number of pixels (x_pix) from one end side to the other end side is set as a target pixel. The predetermined number of pixels (x_pix) is a number equal to or less than the number of pixels in the Y direction possessed by one display division region PA. In the example shown in FIG. 21, the width of the display division area PA in (y2) in the Y direction, that is, the number of pixels in the Y direction of one display division area PA and the predetermined number of pixels (x_pix) match. However, this is an example and is not limited to this.

The signal processing unit 10 raises the output gradation value of the target pixel closer to the boundary between the two dimming regions LD. Specifically, the signal processing unit 10 (see FIG. 23) sets the gradation value of the pixel 48 at the position P1 of the target pixels to a value corresponding to the ratio (k) of the first contrast and the second contrast. do. Specifically, for example, k = BL_c / DP_c. For example, when BL_c = 500 and DP_c = 1000, k = 0.5 (= 50 [%]). In this case, the signal processing unit 10 raises the gradation value of the pixel 48 at the position P1 to the gradation value at which the transmittance of the image display panel 30 becomes 50 [%]. To give a specific example, since the display output content of the display division area PA of (y2) is black in all pixels 48, the gradation value before increasing is (R, G, B) = (0,0, 0). The signal processing unit 10 raises the gradation value of the pixel 48 at the position P1 to the gradation value corresponding to gray of 50 [%]. When the gradation value is 8 bits, the gray color of 50 [%] is (R, G, B) = (127,127,127). Further, the signal processing unit 10 corrects the gradation value of each of the target pixels other than the pixel 48 at the position P1 to be higher than (R, G, B) = (0, 0, 0). Specifically, the signal processing unit 10 determines the degree of correction so that the corrected gradation value of the target pixel gradually decreases from one end side to the other end side. In FIG. 21, as shown by the straight line L1, the corrected gradation value of the target pixel gradually decreases linearly from one end side to the other end side, but this is the position of the target pixel in the Y direction. This is an example of the relationship between the degree of correction of the gradation value, and is not limited to this. The relationship between the position of the target pixel in the Y direction and the degree of correction of the gradation value may be, for example, a quadratic or higher curve.

FIG. 22 shows the output brightness when the light control panel 80 having the transmittance shown in FIG. 18 is interposed between the light source device having the light source luminance distribution shown in FIG. 13 and the image display panel 30 having the transmittance shown in FIG. It is an enlarged schematic diagram. By increasing the gradation value of the target pixel by the signal processing unit 10, as shown in FIG. 22, the output luminance in the display division region PA of (y2) gradually decreases from one end side to the other end side. .. As a result, it is possible to suppress the occurrence of the sudden change line ST1 of the output luminance as described with reference to FIGS. 19 and 20. Therefore, it is possible to make it more difficult to visually recognize the difference in brightness due to the difference in transmittance between the two adjacent dimming region LDs. Therefore, it is possible to suppress the generation of band-shaped halo, and it is possible to improve the image quality and the contrast feeling by suppressing the black floating U.

In FIG. 22, the gradual decrease of the output luminance in the display division region PA of (y2) is illustrated by the straight line L2, but the straight line L2 only shows the gradual decrease of the output luminance corresponding to the straight line L1 shown in FIG. Not limited. The tapering pattern of the output luminance due to the correction of the gradation value of the target pixel is a pattern corresponding to the relationship between the position of the target pixel in the Y direction and the degree of correction of the gradation value.

FIG. 23 is a block diagram showing an example of the functional configuration of the signal processing unit 10. The signal processing unit 10 of the first embodiment is an integrated circuit such as an FPGA (Field-Programmable Gate Array). As shown in FIG. 23, for example, the signal processing unit 10 includes a required luminance information acquisition unit 101, a dimming gradation calculation unit 102, an image correction coefficient generation unit 103, a lighting amount calculation unit 104, a brightness distribution generation unit 105, and a brightness inverse number. It has a generation unit 106, an image processing unit 107, and the like.

The required luminance information acquisition unit 101 acquires the luminance of the light source 51 required in each display division region PA in order to perform the display output corresponding to the input signal IP. Specifically, the required luminance information acquisition unit 101 specifies the gradation value of the sub-pixel 49 in which the highest gradation value is set in each display division region PA. More specifically, the required luminance information acquisition unit 101 divides the gradation value of each sub-pixel 49 indicated by the input signal IP into each display division region PA. The required luminance information acquisition unit 101 specifies the gradation value of the sub-pixel 49 in which the highest gradation value is set among the gradation values of the sub-pixel 49 included in one display division area PA. The required luminance information acquisition unit 101 specifies the luminance of the light source 51 required to obtain the output luminance corresponding to the luminance value of the sub-pixel 49 in which the highest luminance value is set in each display division region PA. For example, when the gradation value of the sub-pixel 49 is 8 bits (0 to 255), the brightness of the light source 51 required to obtain the output brightness corresponding to the gradation value of 255 is 100 [%]. On the other hand, the brightness of the light source 51 required to obtain the output brightness corresponding to the gradation value of 0 is 0 [%]. The required luminance information acquisition unit 101 performs the process of specifying the luminance of the light source 51 in this way for each display division region PA. The required luminance information acquisition unit 101 acquires information indicating the luminance of the light source 51 of each specified display division region PA as the required luminance information. Further, the required brightness is calculated in consideration of the attenuation of the light intensity according to the distance from the light source 51.

The dimming gradation calculation unit 102 calculates the gradation value of each dimming region LD. Specifically, the dimming gradation calculation unit 102 divides each display division area PA by the coordinate unit in the Y direction (for example, (y1), (y2), (y3), (y4)). The dimming gradation calculation unit 102 refers to the required luminance information acquired by the required luminance information acquisition unit 101, and calculates the transmittance of the dimming region LD of (y1). The dimming gradation calculation unit 102 of the first embodiment is, for example, when the required brightness of all the display division region PAs whose coordinates in the Y direction are (y1) is 0 [%], the dimming region LD of (y1). The transmittance is calculated as the minimum transmittance (BL_min), and if not, the transmittance of the dimming region LD of (y1) is calculated as the maximum transmittance (BL_max). The dimming gradation calculation unit 102 has a gradation value (for example, 0) of the dimming region LD having a minimum transmittance (BL_min) and a dimming region LD having a maximum transmittance (BL_max). The gradation value is calculated so as to be distinguishable from the gradation value (for example, 1) of. The dimming gradation calculation unit 102 calculates the transmittance and the gradation value for the dimming region LD of (y2), (y3), and (y4) in the same manner as in the dimming region LD of (y1). The dimming gradation calculation unit 102 outputs a signal including information indicating the calculated gradation value of each dimming region LD as a local dimming signal DI.

In the first embodiment, the dimming region LD is controlled to have the minimum transmittance (BL_min) according to the gradation value (for example, 0) of the dimming region LD whose transmittance is the minimum transmittance (BL_min). To. Further, the dimming region LD is controlled to have the maximum transmittance (BL_max) according to the gradation value (for example, 1) of the dimming region LD having the maximum transmittance (BL_max).

The image correction coefficient generation unit 103 calculates an image correction coefficient (kpix (v)) used for correction for increasing the output gradation value of the target pixel. Specifically, the image correction coefficient generation unit 103 is, for example, the floor of two adjacent dimming region LDs among the gradation values of each of the plurality of dimming region LDs calculated by the dimming gradation calculation unit 102. When the toning values are different, the target pixel is set in the dimming area LD in which the gradation value corresponding to the one having the lower transmission rate is calculated. The image correction coefficient generation unit 103 calculates a correction value for correcting each output gradation value of the target pixel by the mechanism described with reference to FIG. 21. Further, the image correction coefficient generation unit 103 calculates the correction value other than the target pixel as 0. The image correction coefficient generation unit 103 has a function (for example, a linear function) in which the calculated correction value corresponds to the arrangement of the pixels 48 arranged from one end side to the other end side (or from the other end side to one end side) in the Y direction. ) Is calculated as an image correction coefficient (kpix (v)). In the first embodiment, the correction values of the pixels 48 arranged from one end side to the other end side in the Y direction can be obtained by sequentially reading out the image correction coefficient (kpix (v)). As described above, the image correction coefficient (kpix (v)) includes information for associating the position of the target pixel in which the correction value for increasing the gradation value is set with the correction value. Further, as for the image correction coefficient (kpix (v)), by setting the correction value of the pixel 48 that is not the target pixel to 0, the pixel 48 whose gradation value is increased by the correction can be limited to the target pixel.

The lighting amount calculation unit 104 calculates the lighting amount of each of the plurality of light sources 51 based on the required luminance information. Specifically, as described with reference to FIGS. 13 and 14, the lighting amount calculation unit 104 can sufficiently obtain the required brightness of each display division area PA on the other end side of each display division area PA. , The lighting amount of each of the plurality of light sources 51 is calculated. Information indicating the relationship between the lighting amount of the light source 51 and the brightness on the other end side of each display division region PA may be included in the reference data, for example, or data prepared separately from the reference data and lit. It may be included in the data included in the quantity calculation unit 104. The lighting amount calculation unit 104 outputs a signal including information indicating the lighting amount of each of the calculated light sources 51 as a light source drive signal BL.

The brightness distribution generation unit 105 generates information indicating the brightness distribution obtained by the lighting amounts of the plurality of light sources 51 calculated by the lighting amount calculation unit 104. Specifically, the brightness distribution generation unit 105 determines the brightness distribution in the Y direction at each position of the pixels 48 arranged in the X direction based on the lighting amount of each of the plurality of light sources 51 calculated by the lighting amount calculation unit 104. Generates information that indicates. More specifically, the luminance distribution generation unit 105 has data showing the relationship between the lighting amount of the plurality of light sources 51 and the luminance distribution, which are measured in advance in consideration of the influence of light from the plurality of light sources 51, for example. The luminance distribution generation unit 105 refers to the data and generates information indicating the luminance distribution in the Y direction (v) at each position (h) of the pixels 48 arranged in the X direction. That is, from the information indicating the luminance distribution generated by the luminance distribution generation unit 105, the luminance of the light from the light source device 50 at the position of the pixel 48 of (h, v) can be specified.

The luminance reciprocal generation unit 106 generates a luminance reciprocal (luminance reciprocal gainpix (h, v)) corresponding to the position of the pixel 48 of (h, v) based on the luminance distribution generated by the luminance distribution generation unit 105. do. Specifically, the luminance reciprocal generation unit 106 is a value obtained through, for example, a process of correcting the luminance distribution of the percentage ([%]) generated by the luminance distribution generation unit 105 to a decimal number (a process of dividing by 100). The reciprocal is the luminance reciprocal gainpix (h, v) corresponding to the position of the pixel 48 of (h, v). For example, in the case of the pixel 48 to which the luminance of 120 [%] is associated with the information indicating the luminance distribution, the luminance reciprocal gainpix (h, v) is about 0.83. Further, in the case of the pixel 48 to which the luminance of 60 [%] is associated with the information indicating the luminance distribution, the luminance reciprocal gainpix (h, v) is about 1.67.

The image processing unit 107 includes the gradation value of each pixel 48 included in the input signal IP, the luminance inverse number gainpix (h, v) generated by the luminance inverse numeral generation unit 106, and the image correction calculated by the image correction coefficient generation unit 103. Based on the coefficient (kpix (v)), the output gradation value of each pixel 48 that functions as the output image signal OP is calculated. Specifically, the image processing unit 107 applies a gain to the gradation value of each pixel 48 included in the input signal IP. More specifically, the reciprocal luminance gainpix (h, v) is multiplied by each gradation value of R, G, and B included in the gradation value of the pixel 48 of (h, v). As a result, gain is applied to each gradation value of R, G, and B. However, no gain is applied to the black gradation value (R, G, B) = (0, 0, 0). The image processing unit 107 may not apply a gain to the black gradation value (R, G, B) = (0, 0, 0). Further, the image processing unit 107 adds an image correction coefficient (kpix (v)) to the black gradation value among the gradation values of each pixel 48 included in the input signal IP. More specifically, for each gradation value of R, G, B included in the gradation value of the pixel 48 of (v) where (R, G, B) = (0,0,0). , The image correction coefficient (kpix (v)) is added. As a result, among the pixels 48 of (v) where (R, G, B) = (0,0,0), the gradation value of the target pixel can be increased. The image processing unit 107 outputs the output image signal OP.

FIG. 24 is a flowchart showing a processing flow by the signal processing unit 10. The signal processing unit 10 acquires the required luminance information (step S1), calculates the transmittance of the dimming region LD (step S2), generates the image correction coefficient (step S3), calculates the lighting amount (step S4), and reciprocals the luminance. (Step S5) and calculation of the output gradation value (step S6). Of the processes from step S1 to step S6, the processes from step S2 to step S3 and the processes from step S4 to step S5 may be executed in parallel after the process of step S1. After the processing of step S3 and step S5, the processing of step S6 is performed.

FIG. 25 is a diagram schematically showing an example of the processing contents of steps S1 to S5 of the flowchart shown in FIG. 24. In the acquisition of the required luminance information (step S1), the required luminance information acquisition unit 101 acquires the luminance of the light source 51 required in each display division region PA. In FIG. 25, in step S1, the required luminances of the display division region PAs of (x1, y1), (x1, y3), (x3, y1), and (x3, y3) are 40 [%] and 10 [%, respectively. ], 100 [%], 20 [%], and the case where the required luminance of the other display division area PA is 0 [%] is illustrated.

In the transmittance calculation of the dimming region LD (step S2), the dimming gradation calculation unit 102 calculates the gradation value according to the transmittance and the transmittance of each dimming region LD. In FIG. 25, in step S2, the transmittance of the dimming region LD of (y1) and (y3) is the maximum transmittance (BL_max) (100 [%] notation in FIG. 25), and (y2) and (y4). ) Is illustrated when the transmittance of the dimming region LD is the minimum transmittance (BL_min) (in FIG. 25, it is expressed as 0 [%]).

In the generation of the image correction coefficient (step S3), the image correction coefficient generation unit 103 calculates the image correction coefficient (kpix (v)). In FIG. 25, in step S3, the target pixel is set in the display division area PA of (y2) and (y4), and the gradation value of the target pixel is (R, G, B) = (0,0,0). An example of calculating a correction value for increasing the gradation value in a certain case is shown. More specifically, in FIG. 25, among the pixels 48 included in the display division area PA of (y2), the position closest to the boundary between the display division area PA of (y1) and the display division area PA of (y2). Pixel 48 is set as one end, and pixel 48 located within a predetermined number of pixels (x_pix) from one end side to the other end side is set as a target pixel. Further, among the pixels 48 included in the display division area PA of (y2), the pixel 48 at the position closest to the boundary between the display division area PA of (y2) and the display division area PA of (y3) is set as the other end. The target pixel is the pixel 48 located within the range of a predetermined number of pixels (x_pix) from the other end side to the one end side. In this way, the predetermined number of pixels (x_pix) is determined in consideration of the case where the pixel 48 located within the range of the predetermined number of pixels (x_pix) from one end side and the other end side in one display division area PA is set as the target pixel. You may do so. For example, the predetermined number of pixels (x_pix) may be ½ or less of the number of pixels in the Y direction of one display division area PA. Further, in FIG. 25, among the pixels 48 included in the display division area PA of (y4), the pixel 48 at the position closest to the boundary between the display division area PA of (y3) and the display division area PA of (y4) is shown. The target pixel is a pixel 48 located within a predetermined number of pixels (x_pix) from one end side to the other end side.

In the calculation of the lighting amount (step S4), the lighting amount calculation unit 104 calculates the lighting amount of each of the plurality of light sources 51. In FIG. 25, in step S4, the light sources 51 of (x1) and (x3) are lit so that the brightness on one end side of the display division region PA of (y1) can be set to 42 [%] and 120 [%], respectively. The case where the lighting amount is calculated so as to light by the amount is illustrated.

In the generation of the reciprocal brightness (step S5), the brightness distribution generation unit 105 generates information indicating the brightness distribution obtained by the lighting amount of the plurality of light sources 51 calculated by the lighting amount calculation unit 104. After that, the luminance reciprocal generation unit 106 generates the luminance reciprocal gainpix (h, v) corresponding to the position of the pixel 48 of (h, v) based on the luminance distribution generated by the luminance distribution generation unit 105. In FIG. 25, in step S5, the luminance distribution and the reciprocal luminance gainpix (h, v) corresponding to the light source 51 of (x3) are illustrated.

FIG. 26 is a flowchart showing the flow of the output gradation value calculation process in FIG. 24. In the calculation of the output gradation value (step S6), the image processing unit 107 calculates the output gradation value of each pixel 48 that functions as the output image signal OP. Specifically, the image processing unit 107 determines whether or not the gradation value of one pixel 48 included in the input signal IP is (R, G, B) = (0,0,0) (step). S61). More specifically, the image processing unit 107 checks whether or not the gradation value is 0 for each sub-pixel 49 of one pixel 48, for example, as shown in step S61. That is, the image processing unit 107 has a gradation value (Rin (h, v)) of one first sub-pixel 49R included in the input signal IP, and a gradation value (Gin (h, v)) of one second sub-pixel 49G. v)) and the gradation value (Bin (h, v)) of one third sub-pixel 49B are individually checked to see if they are 0.

When the gradation value of one target pixel included in the input signal IP is (R, G, B) = (0,0,0) (step S61: Yes), the image processing unit 107 determines that the target pixel is the target pixel. An image correction coefficient (kpix (v)) is added to each gradation value of the sub-pixel 49 of the one pixel 48 (step S62). Specifically, the image processing unit 107 includes a gradation value (Rin (h, v)) of one first sub-pixel 49R included in the input signal IP, and a gradation value (Gin) of one second sub-pixel 49G. (H, v)) and the image correction coefficient (kpix (v)) are added to each of the gradation values (Bin (h, v)) of one third sub-pixel 49B. As a result, the image processing unit 107 has a gradation value (Rout (h, v)) of one first sub-pixel 49R that functions as an output image signal OP, and a gradation value (Gout (Gout)) of one second sub-pixel 49G. h, v)) and the gradation value (Bout (h, v)) of one third sub-pixel 49B are calculated.

On the other hand, when the gradation value of one pixel 48 included in the input signal IP is not (R, G, B) = (0,0,0) (step S61: No), the image processing unit 107 is determined. Multiply each gradation value of the sub-pixel 49 of one pixel 48 by the reciprocal brightness gainpix (h, v) (step S63). Specifically, the image processing unit 107 has a gradation value (Rin (h, v)) of one first sub-pixel 49R included in the input signal IP, and a gradation value (Gin) of one second sub-pixel 49G. (H, v)) and each of the gradation values (Bin (h, v)) of one third sub-pixel 49B are multiplied by the reciprocal brightness gainpix (h, v). As a result, the image processing unit 107 has a gradation value (Rout (h, v)) of one first sub-pixel 49R that functions as an output image signal OP, and a gradation value (Gout (Gout)) of one second sub-pixel 49G. h, v)) and the gradation value (Bout (h, v)) of one third sub-pixel 49B are calculated.

As described above, according to the first embodiment, when the light transmittances of the two adjacent dimming region LDs are different, the two of the pixels located in the dimming region LD having the low light transmittance. Pixels 48 located near the boundary between the two dimming regions LD are set as target pixels, and the output gradation value of the target pixels is increased. As a result, it is possible to suppress the generation of band-shaped halo, and it is possible to improve the image quality and the contrast feeling by suppressing the black floating U.

Further, the output gradation value of the target pixel closer to the boundary between the two dimming regions LD is made higher. As a result, the output brightness of the display device 1 tends to be gradually reduced as the distance from the vicinity of the boundary between the two dimming regions LD increases. Therefore, the generation of band-shaped halo can be suppressed more reliably.

(Modification example)
Hereinafter, a modified example of the first embodiment will be described with reference to FIGS. 27 to 30. In the description of the modified example, the same reference numerals may be given to the same configurations as those of the first embodiment described with reference to FIGS. 1 to 26, and the description thereof may be omitted.

FIG. 27 is a block diagram showing another example of the functional configuration of the signal processing unit 10A in the modified example. The display device according to the modified example includes a signal processing unit 10A as a configuration in place of the signal processing unit 10 of the first embodiment. The signal processing unit 10A of the modification has, in addition to each configuration of the signal processing unit 10 of the first embodiment, a required luminance correction coefficient generation unit 111, a required luminance correction unit 112, and a luminance reciprocal correction unit 113. Further, the signal processing unit 10A of the modified example replaces the dimming gradation calculation unit 102, the image correction coefficient generation unit 103, and the image processing unit 107 of the first embodiment with the dimming gradation calculation unit 102A and the image correction coefficient generation. It has a unit 103A and an image processing unit 107A.

The dimming gradation calculation unit 102A of the modified example refers to the required luminance information acquired by the required luminance information acquisition unit 101, and calculates the transmittance of the dimming region LD of (y1). For example, when the required brightness of all the display division region PAs whose coordinates in the Y direction are (y1) is 0 [%], the dimming gradation calculation unit 102A determines the transmittance of the dimming region LD of (y1). Calculated as the lowest transmittance (BL_min). Further, in the dimming gradation calculation unit 102A, the maximum required brightness of the required brightness of the display division region PA whose coordinates in the Y direction is (y1) exceeds 0 [%] and is 25 [%] or less. If this is the case, the transmittance of the dimming region LD of (y1) is set as the first intermediate transmittance. The dimming gradation calculation unit 102A calculates, for example, 25 [%] as the first intermediate transmittance. Further, the dimming gradation calculation unit 102A determines (y1) when the maximum required brightness of the display division region PA of (y1) exceeds 25 [%] and is 50 [%] or less. ), The transmittance of the dimming region LD is defined as the second intermediate transmittance. The dimming gradation calculation unit 102A calculates, for example, 50 [%] as the second intermediate transmittance. When none of these is applicable, the dimming gradation calculation unit 102A calculates the transmittance of the dimming region LD of (y1) as the maximum transmittance (BL_max). The dimming gradation calculation unit 102A has a gradation value (for example, 0) of the dimming region LD having a minimum transmittance (BL_min) and a dimming region LD having a first intermediate transmittance. Gradation value (for example, 1), gradation value (for example, 2) of the dimming region LD whose transmittance is the second intermediate transmittance, and dimming whose transmittance is the maximum transmittance (BL_max). The gradation value is calculated so as to be distinguishable from the gradation value (for example, 3) of the region LD. The dimming gradation calculation unit 102A calculates the transmittance and the gradation value for the dimming region LD of (y2), (y3), and (y4) in the same manner as the dimming region LD of (y1). The dimming gradation calculation unit 102A outputs a signal including information indicating the calculated gradation value of each dimming region LD as a local dimming signal DI in the modified example.

In the modified example, the dimming region LD is controlled to have the minimum transmittance (BL_min) according to the gradation value (for example, 0) of the dimming region LD whose transmittance is the minimum transmittance (BL_min). .. Further, the dimming region LD is controlled to have a transmittance of 25 [%] according to the gradation value (for example, 1) of the dimming region LD whose transmittance is the first intermediate transmittance. Further, the dimming region LD is controlled to have a transmittance of 50 [%] according to the gradation value (for example, 2) of the dimming region LD whose transmittance is the second intermediate transmittance. Further, the dimming region LD is controlled to have the maximum transmittance (BL_max) according to the gradation value (for example, 3) of the dimming region LD having the maximum transmittance (BL_max). As described above, the dimming region LD of the modified example sets the light transmittance between the minimum transmittance (BL_min), the maximum transmittance (BL_max) or the minimum transmittance (BL_min) and the maximum transmittance (BL_max). It is provided so as to be changeable to any one or more kinds of intermediate transmittances which are the transmittances. The intermediate transmittance may be one type, three or more types, or an arbitrary transmittance between 0% and 100%.

The required brightness correction coefficient generation unit 111 generates the required brightness correction coefficient based on the gradation value calculated by the dimming gradation calculation unit 102A. The required luminance correction coefficient is a coefficient for correcting the required luminance indicated by the required luminance information acquired by the required luminance information acquisition unit 101. Specifically, the required luminance correction coefficient generation unit 111 sets the required luminance correction coefficient of the dimming region LD, for which the gradation value is 0 or 3, to 1.0, for example, when the dimming value is set to 4 tones. That is, the required luminance correction coefficient generation unit 111 sets the required luminance correction coefficient of the dimming region LD whose transmittance is the minimum transmittance (BL_min) or the maximum transmittance (BL_max) to 1.0. Further, the required luminance correction coefficient generation unit 111 sets the required luminance correction coefficient of the dimming region LD having a gradation value of 1 to 4.0. That is, the required luminance correction coefficient generation unit 111 sets the required luminance correction coefficient of the dimming region LD having a transmittance of 25 [%] to 4.0. Further, the required luminance correction coefficient generation unit 111 sets the required luminance correction coefficient of the dimming region LD having a gradation value of 2 to 2.0. That is, the required luminance correction coefficient generation unit 111 sets the required luminance correction coefficient of the dimming region LD having a transmittance of 50 [%] to 2.0.

The required brightness correction unit 112 corrects the required brightness information acquired by the required brightness information acquisition unit 101 based on the required brightness correction coefficient generated by the required brightness correction coefficient generation unit 111. Specifically, the required luminance correction unit 112 multiplies the required luminance of each display division region PA by the required luminance correction coefficient of the dimming region LD located at the coordinates in the corresponding Y direction. The lighting amount calculation unit 104 of the modification calculates the lighting amount of each of the plurality of light sources 51 based on the required brightness information corrected by the required brightness correction unit 112.

The image correction coefficient generation unit 103A of the modified example is not the minimum transmittance when the light transmittance in the dimming region where the light transmittance is low among the two adjacent dimming region LDs is the minimum transmittance (BL_min). The output gradation value of the target pixel is made higher than in the case. Specifically, when the image correction coefficient generation unit 103A has the lowest transmittance (BL_min) in the dimming region where the light transmittance is low among the two adjacent dimming region LDs, FIG. 21 The same processing as that of the image correction coefficient generation unit 103 described with reference to the above is performed. Specifically, the image correction coefficient generation unit 103A has, for example, a value corresponding to the ratio (k) of the first contrast and the second contrast (for example, k =) of the gradation value of the pixel 48 at the position P1 of the target pixels. Set to 0.5 (= 50 [%])).

On the other hand, when the light transmittance in the light transmittance region LD, which has the lowest light transmittance among the two adjacent dimming regions, is not the minimum transmittance (BL_min), the image correction coefficient generation unit 103A is the pixel 48 at the position P1. The correction value (ka) for the gradation value of is calculated based on the following equation (1). B (PY) in the formula (1) is the luminance ([%]) from the light source 51 at the boundary between the two adjacent dimming regions LD. Further, BL_high is the light transmittance ([%]) in the dimming region LD, which has the highest light transmittance among the two adjacent dimming regions. Further, BL_low is the light transmittance ([%]) in the dimming region LD having the lower light transmittance among the two adjacent dimming region LDs.
ka = (B (PY) / DP_con) × (BP_con / DP_con) / (BL_high / BL_low) ... (1)

For example, when B (PY) = 120 [%], DP_con = 1000, BP_con = 500, BL_high = 100 [%], BL_low = 25 [%], ka = 0.24 [%]. As for the various values constituting the equation (1) and the relationship between the values, ka is always a value lower than the ratio (k) of the first contrast and the second contrast.

Further, in the image correction coefficient generation unit 103A, similarly to the image correction coefficient generation unit 103, the gradation value after correction of the target pixel is from one end side to the other end side (when the position P1 is the other end side, the other end side). The degree of correction is determined for each pixel so as to gradually decrease toward one end side). The image correction coefficient generation unit 103A calculates the calculated correction value as an image correction coefficient (kpix (h, v)). In the modified example, the X direction is added to the coordinate management of the image correction coefficient because the brightness ([%]) from the light source 51 at the boundary between the two adjacent dimming regions LD may differ depending on the position in the X direction. be. In other words, in the modified example, an individual image correction coefficient is calculated for each pixel 48 not only in the Y direction but also in the X direction.

The luminance reciprocal correction unit 113 corrects the luminance reciprocal gainpix (h, v) generated by the luminance reciprocal generation unit 106 based on the required luminance correction coefficient generated by the required luminance correction coefficient generation unit 111. Specifically, the luminance reciprocal correction unit 113 multiplies the luminance reciprocal gainpix (h, v) by the required luminance correction coefficient of the dimming region LD located at the corresponding Y-direction coordinate. The luminance reciprocal correction unit 113 sets the corrected luminance reciprocal gainpix (h, v) as the luminance reciprocal Egainpix (h, v).

The image processing unit 107A of the modified example uses the reciprocal brightness Egainpix (h, v) corrected by the reciprocal brightness correction unit 113 to apply a gain to the gradation value of the pixel 48 included in the input signal IP, and then inputs the input. The image correction coefficient (kpix (h, v)) is added regardless of whether or not the gradation value of the pixel 48 included in the signal IP is the gradation value corresponding to black. The image processing unit 107A of the modified example has the same configuration as the image processing unit 107 of the first embodiment, except for the processing for the gradation value of the pixel 48 included in the input signal IP.

FIG. 28 is a flowchart showing a processing flow by the signal processing unit 10A of the modified example. The signal processing unit 10A acquires the required luminance information (step S11), calculates the transmittance of the dimming region LD (step S12), generates the required luminance correction coefficient (step S13), corrects the required luminance (step S14), and lights up. The amount is calculated (step S15), the luminance reciprocal is generated (step S16), the luminance reciprocal is corrected (step S17), the image correction coefficient is generated (step S18), and the output gradation value is calculated (step S19).

FIG. 29 is a diagram schematically showing an example of the processing contents performed in steps S11 to S15 of the flowchart shown in FIG. 28. In the acquisition of the required luminance information (step S11), the required luminance information acquisition unit 101 acquires the luminance of the light source 51 required in each display division region PA. In FIG. 29, in step S11, the required brightness of the display division region PAs of (x1, y1), (x1, y3), (x3, y1), (x3, y2), and (x3, y3) is 40 [, respectively. %], 10 [%], 100 [%], 20 [%], 40 [%], and the case where the required brightness of the other display division region PA is 0 [%] is illustrated.

In the transmittance calculation of the dimming region (step S12), the dimming gradation calculation unit 102A calculates the gradation value according to the transmittance and the transmittance of each dimming region LD. In FIG. 29, in step S12, the transmittance of the dimming region LD of (y1) is the maximum transmittance (BL_max) (indicated by 100 [%] in FIG. 29), and the transmittance of the dimming region LD of (y2) is shown. The rate is the first intermediate transmittance (25 [%]), the transmittance of the dimming region LD of (y3) is the first intermediate transmittance (50 [%]), and the dimming of (y4). The case where the transmittance of the region LD is the lowest transmittance (BL_min) (0 [%] notation in FIG. 29) is illustrated.

In the generation of the required luminance correction coefficient (step S13), the required luminance correction coefficient generation unit 111 generates the required luminance correction coefficient. In FIG. 29, in step S13, the required brightness correction coefficient of the dimming region LD of (y1) and (y4) is 1.0, and the required brightness correction coefficient of the dimming region LD of (y2) is 4.0. Yes, the case where the required luminance correction coefficient of the dimming region LD of (y3) is 2.0 is illustrated.

In the required luminance correction (step S14), the required luminance correction unit 112 corrects the required luminance information based on the required luminance correction coefficient. In FIG. 29, in step S14, the required brightness (10 [%], 40 [%]) of the display division region PA of (x1, y3) and (x3, y3) is combined with the required brightness of the dimming region LD of (y3). By multiplying by the correction coefficient (2.0), the required luminance of the display division area PA of (x1, y3) and (x3, y3) is corrected to 20 [%] and 80 [%], respectively. .. Further, the required luminance (20 [%]) of the display division region PA of (x3, y2) is multiplied by the required luminance correction coefficient (4.0) of the dimming region LD of (y2), so that (x3, y2). The required brightness of the display division area PA in y2) is corrected to 80 [%].

In the calculation of the lighting amount (step S15), the lighting amount calculation unit 104 of the modified example calculates the lighting amount of each of the plurality of light sources 51. In FIG. 29, in step S15, the light sources 51 of (x1) and (x3) are lit so that the brightness on one end side of the display division region PA of (y1) can be set to 48 [%] and 140 [%], respectively. The case where the lighting amount is calculated so as to light by the amount is illustrated.

FIG. 30 is a diagram schematically showing an example of processing contents performed in steps S16 to S18 of the flowchart shown in FIG. 28. In the generation of the reciprocal brightness (step S16), the brightness distribution generation unit 105 generates information indicating the brightness distribution obtained by the lighting amount of the plurality of light sources 51 calculated by the lighting amount calculation unit 104. After that, the luminance reciprocal generation unit 106 generates the luminance reciprocal gainpix (h, v) corresponding to the position of the pixel 48 of (h, v) based on the luminance distribution generated by the luminance distribution generation unit 105. In FIG. 30, in step S16, the luminance distribution and the reciprocal luminance gainpix (h, v) corresponding to the light source 51 of (x3) are illustrated. In the luminance distribution corresponding to the light source 51 of (x3), the luminance P3 from the light source 51 at the boundary position between the display division region PA of (y1) and the display division region PA of (y2), and the display division region PA of (y2). The brightness P4 from the light source 51 at the boundary position between (y3) and the display divided area PA, and the luminance P5 from the light source 51 at the boundary position between the display divided area PA (y3) and the display divided area PA (y4). Shows. Of these, the luminance P5 corresponds to the required luminance (80 [%]) of the corrected (x3, y3) display division region PA.

In the correction of the reciprocal of luminance (step S17), the reciprocal of luminance correction unit 113 corrects the reciprocal of luminance gainpix (h, v). FIG. 30 illustrates the correction of the reciprocal luminance corresponding to the light source 51 of (x3) in step S17. Specifically, the reciprocal luminance gainpix (h, v) of (y2) is multiplied by the required luminance correction coefficient (4.0) of the dimming region LD of (y2). Further, the reciprocal luminance gainpix (h, v) of (y3) is multiplied by the required luminance correction coefficient (2.0) of the dimming region LD of (y3). The luminance reciprocal correction unit 113 sets the corrected luminance reciprocal gainpix (h, v) as the luminance reciprocal Egainpix (h, v).

In the generation of the image correction coefficient (step S18), the image correction coefficient generation unit 103A calculates the image correction coefficient (kpix (h, v)). In FIG. 30, in step S18, the image correction coefficient (kpix (h, v)) of the coordinate (h) in the X direction corresponding to the light source 51 of (x3) is illustrated. In the image correction coefficient (kpix (h, v)), an example in which a target pixel is set in the display division area PA of (y2) and (y4) and a correction value for increasing the gradation value is calculated. Shows. More specifically, in FIG. 30, among the pixels 48 included in the display division area PA of (y2), the position closest to the boundary between the display division area PA of (y1) and the display division area PA of (y2). Pixel 48 is set as one end, and pixel 48 located within a predetermined number of pixels (x_pix) from one end side to the other end side is set as a target pixel. Further, among the pixels 48 included in the display division area PA of (y2), the pixel 48 at the position closest to the boundary between the display division area PA of (y2) and the display division area PA of (y3) is set as the other end. The target pixel is the pixel 48 located within the range of a predetermined number of pixels (x_pix) from the other end side to the one end side. Further, among the pixels 48 included in the display division area PA of (y4), the pixel 48 at the position closest to the boundary between the display division area PA of (y3) and the display division area PA of (y4) is set as one end. The target pixel is the pixel 48 located within the range of a predetermined number of pixels (x_pix) from the side to the other end side. K1 and k2 in the image correction coefficient (kpix (h, v)) are examples of specific values of ka calculated by the above equation (1). k1 is the value of ka (0.24 [%]) when B (P3) = 120 [%], DP_con = 1000, BP_con = 500, BL_high = 100 [%], BL_low = 25 [%]. be. k2 is the value of ka (0.10 [%]) when B (P3) = 100 [%], DP_con = 1000, BP_con = 500, BL_high = 50 [%], BL_low = 25 [%]. be.

In the calculation of the output gradation value (step S19), the image processing unit 107A of the modified example gains the gradation value of the pixel 48 included in the input signal IP by using the reciprocal luminance Egainpix (h, v). After that, the image correction coefficient (kpix (h, v)) is added. Specifically, the image processing unit 107A of the modified example functions as an output image signal OP as shown in the following equations (2), (3), and (4), as shown in FIG. 28, for example. The gradation value of one first sub-pixel 49R (Rout (h, v)), the gradation value of one second sub-pixel 49G (Gout (h, v)), and the floor of one third sub-pixel 49B. The metering price (Bout (h, v)) is calculated.
Rout (h, v) = Egainpix (h, v) x Rin (h, v) + kpix (h, v) ... (2)
Gout (h, v) = Egainpix (h, v) x Gin (h, v) + kpix (h, v) ... (3)
Bout (h, v) = Egainpix (h, v) x Bin (h, v) + kpix (h, v) ... (4)

As described above, according to the modified example, even when the intermediate transmittance is included as the transmittance of the dimming region LD, the generation of the band-shaped halo can be more reliably suppressed.

(Embodiment 2)
FIG. 31 is a diagram showing an example of the light source device 50A of the second embodiment. The light source device 50A of the second embodiment functions as a light source unit having a plurality of light emitting regions arranged in two intersecting directions. Specifically, for example, as shown in FIG. 31, the light source device 50A of the second embodiment has a plurality of light sources 51A arranged in the X direction and the Y direction.

In the description of the second embodiment such as FIG. 31, the case where the coordinates in the Y direction are managed by the five coordinates y1, y2, ..., Y5 is illustrated, but this is only an example and is limited to this. Not a thing. Further, in the description of the second embodiment, as in the description of the first embodiment, a case where the coordinates in the X direction are managed by nine coordinates of x1, x2, ..., X9 is illustrated, but this is only an example. It is not limited to this. In both the first embodiment and the second embodiment, the number of coordinates can be changed as appropriate.

The light source device 50A is a light source 51A provided in units of coordinates ((x1, y1), (x2, y1), ..., (X8, y5), (x9, y5)) of the display division region PA in the second embodiment. It has a light guide plate LAA separated by a groove or the like so as to guide light in these coordinate units. This is only a configuration example for realizing a plurality of light emitting regions arranged in two intersecting directions, and is not limited to this. For example, a light guide plate may be provided individually for each of these coordinates.

32 and 33 are views showing another example of the light source device of the second embodiment. As shown in FIGS. 32 and 33, the light source device 50B has a plurality of emitting portions (for example, emitting portions G1b, G2b, G3b, G4b, of the light guide plates G1, G2, G3, G4, G5) arranged in two intersecting directions. It may have a G5b) and a guide portion (for example, a light guide plate G1, G2, G3, G4, G5) that guides light to each of the plurality of emission portions. The light guide plate G1 reflects light by a surface of the bottom surface portion G1a on the exit portion G1b side and a side surface portion that separates adjacent emission portions at the position of the boundary LDL, and emits light from the emission portion G1b. The light of the light source 51B provided at one end of the light guide plate G1 is guided to (y1). The light guide plate G2 reflects light by the back surface of the bottom surface portion G1a of the light guide plate G1 and the surface of the bottom surface portion G2a on the exit portion G2b side and the side surface portion that separates the adjacent emission portions at the position of the boundary LDL. By emitting light from G2b, the light of the light source 51B provided at one end of the light guide plate G2 is guided to (y2). The light guide plate G3 reflects light by the back surface of the bottom surface portion G2a of the light guide plate G2, the surface of the bottom surface portion G3a on the exit portion G3b side, and the side surface portion that separates the adjacent emission portions at the position of the boundary LDL. By emitting light from G3b, the light of the light source 51B provided at one end of the light guide plate G3 is guided to (y3). The light guide plate G4 reflects light by the back surface of the bottom surface portion G3a of the light guide plate G3, the surface of the bottom surface portion G4a on the exit portion G4b side, and the side surface portion that separates the adjacent emission portions at the position of the boundary LDL. By emitting light from G4b, the light of the light source 51B provided at one end of the light guide plate G4 is guided to (y4). The light guide plate G5 is formed by the back surface of the bottom surface portion G4a of the light guide plate G4, the surface of the bottom surface portion G5a on the exit portion G5b side, the side surface portion that separates the adjacent emission portions at the position of the boundary LDL, and the other end LDW of the light guide plate G5. By reflecting the light by the side surface portion and emitting the light from the emission portion G5b, the light of the light source 51B provided at one end of the light guide plate G5 is guided to (y5). In this way, the light guide plates G1, G2, G3, G4, and G5 irradiate the display division region PA of the corresponding coordinates with light.

As shown in FIG. 33, the light guide plates G1, G2, G3, G4, and G5 are individually provided corresponding to y1, y2, ..., Y5. Further, each of the light guide plates G1, G2, G3, G4, and G5 is provided with a light source 51B on one end side in the Y direction. That is, the light source device 50B has a plurality of light sources 51B in which light is individually guided to (x1, y1), (x2, y1), ..., (X8, y5), (x9, y5). Of the light guide plates G1, G2, G3, G4, and G5, those located at both ends in the X direction (for example, the coordinates of x1 and x9) also reflect light by one side surface portion LDS1 and LDS2 in the X direction. ..

As described above, in the light source devices 50A and 50B of the second embodiment, one or more light sources are provided in each of the plurality of light guide regions. Specifically, the plurality of light sources 51A and 51B are individually provided for each of (x1, y1), (x2, y1), ..., (X8, y5), (x9, y5). In the example described with reference to FIG. 31 and FIGS. 32 and 33, the light source region corresponding to each of (x1, y1), (x2, y1), ..., (X8, y5), (x9, y5). Is provided with one light source 51A or light source 51B, but two or more light sources may be provided in one light guide region.

FIG. 34 is a diagram showing a main configuration example of the dimming unit 70B of the second embodiment. The dimming panel 80B of the second embodiment has a plurality of dimming regions LDB arranged in two intersecting directions. Specifically, the dimming panel 80B is provided with the light transmittance individually adjustable by (x1, y1), (x2, y1), ..., (X8, y5), (x9, y5). Has been done. As shown in FIG. 34, for example, the dimming panel 80B has first electrodes 81B individually provided at (x1, y1), (x2, y1), ..., (X8, y5), (x9, y5). Have. That is, in the example shown in FIG. 34, individual first electrodes 81B are provided in each of the plurality of dimming regions LDB.

The circuit unit 90 of the second embodiment individually controls the potentials of the first electrodes 81B having different coordinates. The signal processing unit 10 of the second embodiment is for individually controlling the light transmittance in the coordinate units of (x1, y1), (x2, y1), ..., (X8, y5), (x9, y5). Output the local dimming signal DI.

FIG. 35 is a schematic diagram showing an example of display output contents. In FIG. 35 and FIGS. 36 and 37 described later, boundary lines LDL between adjacent dimming region LDBs are shown for the purpose of clarifying the relationship with the dimming region. For example, as shown in FIG. 35, one of the plurality of display division area PAs includes a high-luminance section LP1 that requires light from a light source, and the other display has the lowest brightness (black). Imagine a case where output is required.

FIG. 36 is a schematic diagram showing an example of a light source luminance distribution corresponding to the display output content shown in FIG. 35. The light source device of the second embodiment (for example, the light source device 50A or the light source device 50B) irradiates light from a light guide region having the same coordinates as the display division region PA including the high-luminance portion LP1. The light source device does not irradiate light from other light guide regions. However, a part of the light from the light guide region having the same coordinates as the display division region PA including the high-luminance portion LP1 can reach the surrounding display division region PA adjacent to the display division region PA. Therefore, the light source luminance distribution LP2 centered on the position of the display divided region PA including the high luminance portion LP1 is generated. Assuming a display device that does not have the dimming unit 70B, black floating U will occur in the range of the light source luminance distribution LP2 by the same mechanism as the example described with reference to FIG.

FIG. 37 is a schematic diagram showing a case where the sudden change lines ST2, ST3, ST4, and ST5 of the output luminance occur in the light source luminance distribution shown in FIG. 36. No light is required in the display division region PA other than the display division region PA including the high-luminance portion LP1. Therefore, if the dimming panel 80B is operated so that the dimming region LDB having the same coordinates as the display division region PA other than the display division region PA including the high-luminance portion LP1 has the minimum transmittance (BL_min), these It is possible to suppress the black floating U by lowering the output luminance in the display division region PA.

On the other hand, since the light from the light source is required in the display division region PA including the high-luminance portion LP1, the dimming region LDB having the same coordinates as the display division region PA has a transmittance higher than the minimum transmittance (BL_min) (for example,). Maximum transmittance (BL_max)). Therefore, as shown in FIG. 37, the black floating U is not suppressed in the display division region PA including the high-luminance portion LP1. As a result, the sudden change lines ST2, ST3, ST4, and ST5 of the output luminance are generated at the boundary between the display division region PA including the high-luminance portion LP1 and the display division region PA adjacent to the display division region PA.

Therefore, when the light transmittances of the two adjacent dimming region LDBs are different, the signal processing unit 10 of the second embodiment is located near the boundary between the two dimming region LDBs (for example, a predetermined number of pixels from the boundary (for example,). In the range of x_pix)), it functions as a control unit for increasing the output gradation value of the pixel located in the dimming region LDB where the light transmittance is low. As a result, it is possible to suppress the occurrence of the sudden change lines ST2, ST3, ST4, and ST5 of the output luminance.

FIG. 38 is a flowchart showing a processing flow by the signal processing unit 10 of the second embodiment. The signal processing unit 10 acquires required luminance information (step S21), calculates the transmittance of the dimming region LDB (step S22), generates an image correction coefficient (step S23), calculates the lighting amount (step S24), and reciprocals the luminance. (Step S25) and calculation of the output gradation value (step S26). Of the processes from step S21 to step S26, the processes from step S22 to step S23 and the processes from step S24 to step S25 may be executed in parallel after the process of step S21. After the processing of step S23 and step S25, the processing of step S26 is performed.

FIG. 39 is a diagram schematically showing an example of the processing contents of steps S21 to S25 of the flowchart shown in FIG. 38. In the following description, a case where the display device of the second embodiment includes the light source device 50B will be illustrated. When the display device of the second embodiment includes the light source device 50A, the light source 51B in the following description is read as the light source 51A. In the acquisition of the required luminance information (step S21), the required luminance information acquisition unit 101 acquires the luminance of the light source 51B required in each display division region PA. In FIG. 39, in step S21, the required luminances of the display division region PAs (x3, y1) and (x3, y3) are 100 [%] and 20 [%], respectively, and the other display division region PAs. The case where the required brightness is 0 [%] is illustrated.

In the transmittance calculation of the dimming region (step S22), the dimming gradation calculation unit 102A calculates the gradation value according to the transmittance and the transmittance of each dimming region LDB. In FIG. 39, in step S22, the transmittance of the dimming region LDB of (x3, y1) and (x3, y3) is the maximum transmittance (BL_max) (in FIG. 39, 100 [%] notation), and the other An example shows a case where the transmittance of the dimming region LDB of the coordinates is the minimum transmittance (BL_min) (0 [%] notation in FIG. 39).

In the generation of the image correction coefficient (step S23), the image correction coefficient generation unit 103A calculates the image correction coefficient (kpix (v)). In FIG. 39, in step S23, the target pixel is set in the display division area PA of (x3, y2) and (x3, y4), and the gradation value of the target pixel is (R, G, B) = (0,0). , 0) shows an example of calculating the correction value for increasing the gradation value. More specifically, among the pixels 48 included in the display division area PA of (x3, y2), the boundary between the display division area PA of (x3, y1) and the display division area PA of (x3, y2) is the most. The pixel 48 at a close position is set as one end, and the pixel 48 located within a predetermined number of pixels (x_pix) from one end side to the other end side is set as a target pixel. Further, among the pixels 48 included in the display division area PA of (x3, y2), the pixel 48 at the position closest to the boundary between the display division area PA of (x3, y2) and the display division area PA of (y3) is used. The other end is set, and the pixel 48 located within the range of a predetermined number of pixels (x_pix) from the other end side to the one end side is set as the target pixel. In this way, the predetermined number of pixels (x_pix) is determined in consideration of the case where the pixel 48 located within the range of the predetermined number of pixels (x_pix) from one end side and the other end side in one display division area PA is set as the target pixel. You may do so. For example, the predetermined number of pixels (x_pix) may be ½ or less of the number of pixels in the Y direction of one display division area PA. Further, in FIG. 39, among the pixels 48 included in the display division area PA of (y4), the position closest to the boundary between the display division area PA of (x3, y3) and the display division area PA of (x3, y4). Pixel 48 is set as one end, and pixel 48 located within a predetermined number of pixels (x_pix) from one end side to the other end side is set as a target pixel.

In the example shown in FIG. 39, the image correction coefficient (kpix (v)) in the Y direction in (x3) is illustrated, but the image correction coefficient generation unit 103A of the second embodiment has the same mechanism as (x3). The image correction coefficient (kpix (v)) in the Y direction other than the above is also calculated. However, in the example shown in FIG. 39, the required luminance of the display division region PA is 0 [%] at the coordinates in the X direction other than (x3). Therefore, in the image correction coefficient (kpix (v)) in the Y direction other than (x3), the correction value corresponding to the ratio (k) of the first contrast and the second contrast is not set.

Further, the image correction coefficient generation unit 103A of the second embodiment also calculates the image correction coefficient (kpix (h)) in the X direction by the same mechanism. Specifically, the image correction coefficient generation unit 103A sets the target pixel in the display division region PA of (x2, y1) and (x4, y1) when calculating the image correction coefficient (kpix (h)) of (y1). It is set and a correction value for increasing the gradation value is calculated when the gradation value of the target pixel is (R, G, B) = (0, 0, 0). Further, the image correction coefficient generation unit 103A sets the target pixel in the display division area PA of (x2, y3) and (x4, y3) when calculating the image correction coefficient (kpix (h)) of (y3). When the gradation value of the target pixel is (R, G, B) = (0,0,0), the correction value for increasing the gradation value is calculated. With the other image correction coefficients (kpix (h)) in the X direction, the correction value corresponding to the ratio (k) of the first contrast and the second contrast is not set.

In the calculation of the lighting amount (step S24), the lighting amount calculation unit 104 calculates the lighting amount of each of the plurality of light sources 51B. In FIG. 39, in step S24, the light source 51B of (x3, y1) and (x3, y3) sets the maximum luminance of the display division region PA of (x3, y1) and (x3, y3) to 120 [%], respectively. An example is shown in which the lighting amount is calculated so that the lighting amount can be set to 30 [%]. The lighting amount of 120 [%] is a display output with a brightness of 100 [%] at the brightnesses P6 and P7 at the position where the light from the light source 51B is the weakest in the display division area PA of (x3, y1). Possible brightness. Further, the lighting amount of 30 [%] can be displayed and output with a brightness of 20 [%] at the brightness P8 at the position where the light from the light source 51B is the weakest in the display division area PA of (x3, y3). Luminance.

In the generation of the reciprocal brightness (step S25), the brightness distribution generation unit 105 generates information indicating the brightness distribution obtained by the lighting amount of the plurality of light sources 51B calculated by the lighting amount calculation unit 104. After that, the luminance reciprocal generation unit 106 generates the luminance reciprocal gainpix (h, v) corresponding to the position of the pixel 48 of (h, v) based on the luminance distribution generated by the luminance distribution generation unit 105. In FIG. 39, in step S25, the luminance distribution in the Y direction and the luminance reciprocal gainpix (h, v) corresponding to the light source 51B of (x3) are illustrated.

FIG. 40 is a flowchart showing the flow of the output gradation value calculation process in FIG. 38. In the calculation of the output gradation value (step S26), the image processing unit 107A calculates the output gradation value of each pixel 48 that functions as the output image signal OP. Specifically, the image processing unit 107A determines whether or not the gradation value of one pixel 48 included in the input signal IP is (R, G, B) = (0,0,0) (step). S61). More specifically, the image processing unit 107A checks whether or not the gradation value is 0 for each sub-pixel 49 of one pixel 48, for example, as shown in step S61. That is, the image processing unit 107A has a gradation value (Rin (h, v)) of one first sub-pixel 49R included in the input signal IP, and a gradation value (Gin (h, v)) of one second sub-pixel 49G. v)) and the gradation value (Bin (h, v)) of one third sub-pixel 49B are individually checked to see if they are 0.

When the gradation value of one target pixel included in the input signal IP is (R, G, B) = (0,0,0) (step S61: Yes), the image processing unit 107A determines that the target pixel is the target pixel. The gradation value of each of the sub-pixels 49 included in the one pixel 48 is calculated using the following equations (5), (6), and (7) (step S64). However, in the process of step S64, when Tx (h, y) × Ty (x, v) = 1 (100%), it is replaced with Tx (h, y) × Ty (x, v) = 0. That is, when Tx (h, y) × Ty (x, v) = 1 (100%), Rout (h, v) = Gout (h, v) = Bout (h, v) = 0. Tx (h, y) is a preprocessing coefficient of each position (h) of the pixels 48 arranged in the X direction at a certain Y coordinate (y). Ty (x, v) is a preprocessing coefficient of each position (v) of the pixels 48 arranged in the Y direction at a certain X coordinate (x).
Rout (h, v) = k × Tx (h, y) × Ty (x, v) ... (5)
Gout (h, v) = k × Tx (h, y) × Ty (x, v) ... (6)
Bout (h, v) = k × Tx (h, y) × Ty (x, v) ... (7)

FIG. 41 is a diagram showing an example of preprocessing coefficients Tx (h, y) and Ty (x, v) used for calculating the gradation value of the target pixel in the second embodiment. The image processing unit 107A is one pixel 48 determined to be a target pixel by using the ratio (k) of the first contrast to the second contrast and the preprocessing coefficients Tx (h, y) and Ty (x, v). The gradation value of each of the sub-pixels 49 of the sub-pixel 49 is calculated. Specifically, in step S22, the transmittance of one of the two adjacent dimming region LDBs is the maximum transmittance (BL_max), and the transmittance of the dimming region LD at the other coordinate is the minimum transmittance (BL_min). ) Is satisfied or not. When the condition is satisfied, the pretreatment coefficients Tx (h, y) and Ty (x, v) of less than 1 (100%) in the range of a predetermined number of pixels (x_pix) from the boundary between the two dimming regions LDB. Is set. Specifically, within the range of a predetermined number of pixels (x_pix), the dimming region LDB having the highest transmittance (BL_max) is set as one end side, and the dimming region LDB having the lowest transmittance (BL_min) is set as the other end side. Pretreatment coefficients Tx (h, y) and Ty (x, v) that gradually decrease from the side to the other end side are set. Pretreatment coefficients Tx (h, y) and Ty (x, v) of 1 (100%) are set in the two dimming region LDBs that do not satisfy the conditions. The setting may be performed by the image processing unit 107A, the image correction coefficient generation unit 103, or another configuration of the signal processing unit 10.

In FIG. 41, for the purpose of simplifying the explanation, the preprocessing coefficient Tx based on an example of the transmittance of the 16 dimming region LDB by the combination of the coordinates of x6, x7, x8, x9 and y1, y2, y3, y4. (H, y) and Ty (x, v) are shown. In FIG. 41, the dimming region LDBs (x8, y2) and (x9, y3) have the highest transmittance (BL_max), and the other dimming region LDBs have the lowest transmittance (BL_min). Therefore, in FIG. 41, for example, the preprocessing coefficient Tx (h, 2) in the horizontal pixel coordinates (h) of (y2) is on the (x8, y2) side of (x7, y2) and (x9, y2). In the range of a predetermined number of pixels (x_pix), a value less than 1 (100%) is included. Further, the preprocessing coefficient Tx (h, 3) in the horizontal pixel coordinates (h) of (y3) is 1 (x_pix) in the range of the predetermined number of pixels (x_pix) on the (x9, y3) side of (x8, y3). Contains values less than 100%). Further, the preprocessing coefficient Ty (8, v) in the vertical pixel coordinates (v) of (x8) is a predetermined number of pixels (y_pix) on the (x8, y2) side of (x8, y1) and (x8, y3). In the range of, the value is less than 1 (100%). Further, the preprocessing coefficient Ty (9, v) in the vertical pixel coordinates (v) of (x9) is a predetermined number of pixels (y_pix) on the (x9, y3) side of (x9, y2) and (x9, y4). In the range of, the value is less than 1 (100%). Further, the values set in these preprocessing coefficients Tx (h, 2), (h, 3), Ty (8, v), (9, v) are in the range of the specially mentioned predetermined number of pixels (y_pix). Is 1 (100%) except for. Further, the values set in the preprocessing coefficients Tx (h, 1) and (h, 4) in the horizontal pixel coordinates (h) of (y1) and (y4) are the coordinates (h) of the pixel 48 in the X direction. Regardless, it is 1 (100%). Further, the values set in the preprocessing coefficients Ty (6, v) and (7, v) in the vertical pixel coordinates (v) of (x6) and (x7) are the coordinates (v) of the pixel 48 in the Y direction. Regardless, it is 1 (100%).

As an example, when x_pix = 5, that is, when the range of the predetermined number of pixels (x_pix) has a width of 5 pixels, the value less than 1 (100%) set in the range of the predetermined number of pixels (x_pix) is one end. From the side to the other end, it is 0.99 (99%), 0.75 (75%), 0.50 (50%), 0.25 (25%), 0.01 (1%). Obtain, but this is just an example and is not limited to this. The specific value of x_pix and the specific value of less than 1 (100%) can be changed as appropriate. The change in the value from one end side to the other end side may be a linear linear shape or a curved line shape. Further, the value of y_pix may be the same as or different from x_pix.

As described above, in the range of the predetermined number of pixels (x_pix) in which the pixel 48 as the target pixel is located, at least one of the preprocessing coefficients Tx (h, y) and Ty (x, v) is less than 1 (100%). The value is set. Therefore, the image processing unit 107A can increase the gradation value of the target pixel by calculating the gradation value using the above equations (5), (6), and (7). Therefore, it is possible to make it more difficult to visually recognize the difference in brightness due to the difference in transmittance between the two adjacent dimming regions LDB. Therefore, it is possible to suppress the generation of band-shaped halo, and it is possible to improve the image quality and the contrast feeling by suppressing the black floating U.

The display division area PA having the same coordinates as the dimming region LDB having the highest transmittance (BL_max) and the dimming region LDB having the lowest transmittance (BL_min) adjacent to the dimming region LDB in both the X direction and the Y direction is in the X direction and the Y direction. It is considered to be affected by the light from both of them. Therefore, in the target pixel under such a condition, both the preprocessing coefficient Tx (h, y) and the preprocessing coefficient Ty (x, v) are less than 1 (100%). For example, the X coordinate SP (h) of one pixel 48 of the preprocessing coefficient Tx (h, 2) shown in FIG. 41 and the Y coordinate SP (v) of one pixel 48 of the preprocessing coefficient Ty (9, v). In the XY coordinates SP (h, v) in combination with), both the preprocessing coefficient Tx (h, y) and the preprocessing coefficient Ty (x, v) are less than 1 (100%). Here, when the preprocessing coefficient Tx (h, y) of the X coordinate SP (h) and the preprocessing coefficient Ty (9, v) of the Y coordinate SP (v) are 0.8 (80%), Tx ( h, y) × Ty (x, v) = 0.8 × 0.8 × 0.64. Further, in the display division region PA having the same coordinates as the dimming region LDB having the highest transmittance (BL_max) and the dimming region LDB having the lowest transmittance (BL_min) adjacent to the dimming region LDB in either the X direction or the Y direction, such 1 ( Multiplication of the preprocessing coefficients Tx (h, y) and Ty (x, v) less than 100%) does not occur. Therefore, the pretreatment coefficient Tx (h, y) or the pretreatment coefficient Ty (x, v) of the other dimming region LDB, which is not the maximum transmittance (BL_max), is 1 (100%). As a result, a value less than 1 (100%) set in the pretreatment coefficient Tx (h, y) or the pretreatment coefficient Ty (x, v) of one of the dimming region LDBs is reflected.

When the preprocessing coefficients Tx (h, y) and Ty (x, v) are both 1 (100%), the gradation value without exception to the equations (5), (6), and (7). When calculated, the correction value corresponding to the ratio (k) of the first contrast and the second contrast is reflected in addition to the target pixel. Therefore, in the case of Tx (h, y) × Ty (x, v) = 1 (100%), the first contrast and the first contrast are obtained by replacing with Tx (h, y) × Ty (x, v) = 0. The pixel 48 on which the correction value corresponding to the two contrast ratio (k) is reflected can be limited to the target pixel.

When the gradation value of one pixel 48 included in the input signal IP is not (R, G, B) = (0,0,0) (step S61: No), the image processing unit is the same as in the first embodiment. In 107A, the reciprocal brightness gainpix (h, v) is multiplied by the gradation value of each of the sub-pixels 49 of the determined pixel 48 (step S63). Except for the above-mentioned matters, the configuration of the display device of the second embodiment is the same as that of the display device 1 of the first embodiment.

As described above, according to the second embodiment, it is possible to suppress the generation of band-shaped halo in both of the two intersecting directions (for example, the X direction and the Y direction).

The display device 1 or the like according to the above-described embodiment and modification (embodiment or the like) is adopted for, for example, a head-up display, but this is only a specific adoption example of the display device 1 or the like and is limited to this. It is not something that can be done. The display device 1 and the like can be appropriately adopted for other uses, products and the like.

Further, in the above embodiment, when the dimming panel (for example, the dimming panel 80, 80B) is located between the image display panel 30 and the light source device (for example, the light source devices 50, 50A, 50B). However, this is an example of the mutual positional relationship between the image display panel 30, the dimming panel, the light source device, and the dimming panel, and is not limited to this. For example, the dimming panel may be located on the display surface side of the image display panel 30. The dimming panel may be provided on the display panel side with respect to the light source device.

Further, in the above-described embodiment or the like, the signal processing unit 10 functioning as a control unit determines the lighting amount of the light sources 51, 51A, 51B, but this is an example and the specific control content of the embodiment is described. It is not limited to. The lighting amount of the light sources 51, 51A, 51B may be a predetermined lighting amount.

Further, the concept of the correspondence between the transmittance and the correction value of the target pixel, such as the calculation formula in the description of the one-dimensional dimming region exemplified in the first embodiment, is based on the one-dimensional direction (for example, the X direction) in the second embodiment. ) Can be applied when the transmittance of the dimming region is uniform. This is because, in the second embodiment, the uniform transmittance of the dimming regions arranged in the one-dimensional direction (for example, the X direction) means that the dimming region is unilaterally adjusted. This is because it shows that.

Further, it is naturally understood that the other effects brought about by the embodiments described in the embodiments and the like are apparent from the description of the present specification, or those which can be appropriately conceived by those skilled in the art are brought about by the present invention. ..

1 Display device 10 Signal processing unit 20 Display unit 30 Image display panel 50, 50A, 50B Light source device 51, 51A, 51B Light source 60 Light source control circuit 70, 70B Dimming unit 80, 80B Dimming panel 90 Circuit unit 101 Required brightness information Acquisition unit 102, 102A Dimming gradation calculation unit 103, 103A Image correction coefficient generation unit 104 Lighting amount calculation unit 105 Brightness distribution generation unit 106 Brightness inverse number generation unit 107, 107A Image processing unit 111 Required brightness correction coefficient generation unit 112 Required brightness Correction unit 113 Brightness inverse correction unit LD, LDB Dimming area

Claims (6)

A display panel with multiple pixels and
The light guide plate provided on the back side of the display panel and
A light source that irradiates light from the side of the light guide plate and
A dimming panel provided on the display panel side with respect to the light guide plate, and
At least a control unit that controls the operation of the display panel and the dimming panel is provided.
The dimming panel has a plurality of dimming regions arranged in the irradiation direction of the light from the light source.
A plurality of dimming regions are provided so that the light transmittance can be individually changed according to the light intensity required for displaying an image by the display panel.
When the light transmittance of each of the two adjacent dimming regions is different, the control unit has a predetermined range from the boundary between the two dimming regions among the pixels in which the dimming region having the low light transmittance is located. When the input gradation value of all the pixels located in the dimming region where the light transmittance is low, which is the input gradation value indicated by the input signal input from the outside, is 0. The target pixel is corrected by adding an image correction coefficient to the input gradation value of the target pixel to increase the output gradation value of the target pixel, and in the correction, the target pixel is closer to the boundary between the two dimming regions. A display device that increases the image correction coefficient added to the light . The display device according to claim 1, wherein the light source irradiates light from one end side of the light guide plate. The display device according to claim 1, further comprising a plurality of light sources provided at positions facing each other across the light guide plate. The display device according to any one of claims 1 to 3 , wherein the dimming region extends in a direction intersecting the irradiation direction of light from the light source to the light guide plate. The light guide plate has a plurality of emission portions arranged in a direction intersecting the irradiation direction of light from the light source and a plurality of guide portions for guiding light to each of the plurality of emission portions.
One or more light sources are provided in each of the plurality of guide portions, and the plurality of guide portions are provided with one or more light sources.
The display device according to any one of claims 1 to 3, wherein the dimming panel has a plurality of dimming regions arranged in a direction intersecting the irradiation direction of light from the light source. A display panel with multiple pixels and
The light guide plate provided on the back side of the display panel and
A light source that irradiates light from the side of the light guide plate and
A dimming panel provided on the display panel side with respect to the light guide plate, and
At least a control unit that controls the operation of the display panel and the dimming panel is provided.
The dimming panel has a plurality of dimming regions arranged in the irradiation direction of the light from the light source.
A plurality of dimming regions are provided so that the light transmittance can be individually changed according to the light intensity required for displaying an image by the display panel.
When the light transmittances of the two adjacent dimming regions are different, the control unit has a predetermined range from the boundary between the two dimming regions among the pixels in which the dimming region having the low light transmittance is located. When the input gradation value of all the pixels located in the dimming region where the light transmittance is low, which is the input gradation value indicated by the input signal input from the outside, is 0. , The input gradation value of the target pixel is corrected to increase the output gradation value of the target pixel.
The light guide plate has a plurality of emission portions arranged in a direction intersecting the irradiation direction of light from the light source and a plurality of guide portions for guiding light to each of the plurality of emission portions.
One or more light sources are provided in each of the plurality of guide portions, and the plurality of guide portions are provided with one or more light sources.
The dimming panel is a display device having a plurality of dimming regions arranged in a direction intersecting the irradiation direction of light from the light source.

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