Image display method

Abstract

To provide an image display method capable of minimizing an adverse effect of a change in a balance of mixed colors of light emanating from a backlight.SOLUTION: An image display method includes a step of creating luminance setting data, which defines a set value of luminance in each of light emitting areas of a backlight, on the basis of each of plural input images, a step of creating grayscale setting data, which defines a set value of a first grayscale level of a first sub pixel included in each of pixels of a liquid crystal panel and a set value of a second grayscale level of a second sub pixel, on the basis of each of correction images obtained by correcting the respective input images using the luminance setting data, and a step of controlling the backlight on the basis of the luminance setting data, controlling the liquid crystal panel on the basis of the grayscale setting data, and displaying an image on the liquid crystal panel. For each of the light emitting areas, a luminance difference is calculated between the set value of luminance defined by the luminance setting data of a first input image and a set value of luminance defined by the luminance setting data of a second input image immediately preceding the first input image.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The embodiment relates to an image display method. [Background technology]

[0002] Conventionally, there has been known an image display device that includes a backlight having a plurality of light-emitting regions arranged in a matrix, each of which has a light source, a liquid crystal panel arranged above the backlight and having a plurality of pixels, and a controller. By using such an image display device, the controller can individually set the luminance of each light-emitting region according to an image to be displayed on the liquid crystal panel, and set the gradation of each pixel of the liquid crystal panel according to the luminance of each light-emitting region. This makes it possible to improve the contrast of an image displayed on the liquid crystal panel. This technology is called "local dimming."

[0003] A light source is provided in each light-emitting region of the backlight. Each light source includes a light-emitting element and a phosphor having a peak emission wavelength different from that of the light-emitting element. Each light source can emit white light by mixing light emitted by the light-emitting element and light emitted by the phosphor. However, when the controller changes the set value of the luminance of the light-emitting region, the light-emitting element responds faster than the phosphor, which may cause the balance of the mixed colors of the light emitted from the light source to be lost. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 124254 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the embodiment is to provide an image display method capable of reducing the influence of imbalance in the mixed colors of light emitted from a backlight. [Means for solving the problem]

[0006] An image display method according to an embodiment includes the steps of: creating brightness setting data for each of a plurality of consecutive input images input to a controller of a backlight having a plurality of light-emitting regions arranged in a matrix and a liquid crystal panel having a plurality of pixels, creating gradation setting data for determining a gradation setting value of each of the pixels of the liquid crystal panel based on the brightness setting data and each of the input images, controlling the backlight based on the brightness setting data, controlling the liquid crystal panel based on the gradation setting data, and displaying an image on the liquid crystal panel. The step of creating the brightness setting data for a first input image of the plurality of input images includes the steps of creating brightness data obtained by converting a maximum gradation of each area corresponding to each of the light-emitting regions of the backlight in the first input image to a brightness, and determining the brightness setting value of each of the light-emitting regions based on an average value of the brightness of each of the areas in the brightness data and the brightness setting value of each of the light-emitting regions in the brightness setting data created for a second input image of the plurality of input images immediately preceding the first input image.

[0007] An image display method according to an embodiment includes the steps of: creating brightness setting data for each of a plurality of consecutive input images input to a controller of a backlight having a plurality of light-emitting regions arranged in a matrix and a liquid crystal panel having a plurality of pixels, creating gradation setting data for determining a gradation setting value for each of the pixels of the liquid crystal panel based on the brightness setting data and each of the input images, and controlling the backlight based on the brightness setting data, controlling the liquid crystal panel based on the gradation setting data, and displaying an image on the liquid crystal panel. In the step of creating the brightness setting data for a first input image among the plurality of input images, the brightness setting value for each of the light-emitting regions of the backlight is determined such that a brightness difference between the brightness setting value of the brightness setting data created for a second input image among the plurality of input images immediately preceding the first input image is within a threshold value.

[0008] The image display method according to the embodiment includes the steps of: creating brightness setting data for each of a plurality of consecutive input images input to a controller of a liquid crystal panel having a backlight and a plurality of pixels arranged in a matrix, the brightness setting data defining a brightness setting value of each of the light-emitting regions of the backlight based on each of the input images; creating gradation setting data defining a first gradation setting value of a first sub-pixel and a second gradation setting value of a second sub-pixel included in each of the pixels of the liquid crystal panel based on each corrected image obtained by correcting each of the input images using the brightness setting data; controlling the backlight based on the brightness setting data, controlling the liquid crystal panel based on the gradation setting data, and displaying an image on the liquid crystal panel. Each of the light-emitting regions of the backlight is capable of emitting light including a first light and a second light having different emission peak wavelengths. Each of the first sub-pixels is capable of transmitting the first light, and each of the second sub-pixels is capable of transmitting the second light. In the process of creating the gradation setting data for a first input image of the multiple input images, a luminance difference between the luminance setting value of the luminance setting data of the first input image and the luminance setting value of the luminance setting data of a second input image of the multiple input images that immediately precedes the first input image is calculated for each of the light-emitting areas, and for the pixel in the liquid crystal panel that is located directly above the light-emitting area where the luminance difference exceeds a threshold value, the corrected image is corrected in accordance with a change in the ratio of the amount of the first light and the amount of the second light contained in the light emitted from the light-emitting area when the luminance setting value changes, to determine the first gradation setting value and the second gradation setting value. Effect of the Invention

[0009] According to the embodiment, it is possible to provide an image display method capable of reducing the influence of imbalance of mixed colors of mixed color light emitted from a backlight. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an exploded perspective view showing an image display device according to a first embodiment. [Diagram 2] 1 is a top view showing a surface light source in a backlight of an image display device according to a first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a top view showing a liquid crystal panel of the image display device according to the first embodiment. [Diagram 5] 5 is a cross-sectional view taken along line VV in FIG. 4. [Figure 6] 1 is a block diagram showing an image display device according to a first embodiment. [Figure 7] 4 is a flowchart showing an image display method according to the first embodiment. [Figure 8] 2 is a schematic diagram showing the relationship between pixels of an input image input to a controller, a light-emitting region of a backlight, and pixels of a liquid crystal panel in the image display device according to the first embodiment. FIG. [Figure 9] 4 is a schematic diagram showing a method of creating luminance setting data in the image display method according to the first embodiment. FIG. [Figure 10] 3A to 3C are schematic diagrams showing a method of creating gradation setting data in the image display method according to the first embodiment. [Figure 11] FIG. 11 is a schematic diagram showing a method of creating luminance setting data in an image display method according to a second embodiment. [Figure 12A] FIG. 11 is a schematic diagram showing a method of creating luminance setting data in an image display method according to a second embodiment. [Figure 12B] FIG. 11 is a schematic diagram showing a method of creating luminance setting data in an image display method according to a second embodiment. [Figure 13] FIG. 13 is a schematic diagram showing a method of creating luminance setting data in an image display method according to a third embodiment. [Figure 14] FIG. 13 is a schematic diagram showing a method of creating gradation setting data in an image display method according to a third embodiment. [Figure 15] FIG. 13 is a schematic diagram showing a method of creating gradation setting data in an image display method according to a third embodiment. [Figure 16]13A and 13B are schematic diagrams showing modified examples of the method of creating gradation setting data. [Figure 17] 13A and 13B are schematic diagrams showing modified examples of the method of creating gradation setting data. [Figure 18] 13A and 13B are schematic diagrams showing modified examples of the method of creating gradation setting data. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Each embodiment will be described below with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as the actual ones. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. Furthermore, in this specification and each drawing, elements similar to those explained with reference to the previous drawings are given the same reference numerals, and detailed explanations are omitted as appropriate.

[0012] In addition, in the following, for ease of explanation, the arrangement and configuration of each part of the image display device will be described using an XYZ orthogonal coordinate system. The X-axis, Y-axis, and Z-axis are mutually orthogonal. The direction in which the X-axis extends is the "X direction", the direction in which the Y-axis extends is the "Y direction", and the direction in which the Z-axis extends is the "Z direction". In addition, in order to make the explanation easier to understand, the Z direction is upward and the opposite direction is downward, but these directions are unrelated to the direction of gravity. In addition, in order to make the explanation easier to understand, in each figure, the direction of the arrow in the direction in which the X-axis extends is the "+X direction", and the opposite direction is the "-X direction". Similarly, in the direction in which the Y-axis extends, the direction of the arrow is the "+Y direction", and the opposite direction is the "-Y direction".

[0013] <First embodiment> First, the first embodiment will be described. FIG. 1 is an exploded perspective view showing an image display device according to the present embodiment. The image display device 100 according to this embodiment is a liquid crystal module (LCM) used in the display of devices such as televisions, personal computers, and game consoles. The image display device 100 includes a backlight 110, a backlight driver 120, a liquid crystal panel 130, a liquid crystal panel driver 140, and a controller 150. Each unit of the image display device 100 will be described below. Note that in FIG. 1, for ease of understanding, the electrical connection between components is shown by connecting the components with solid lines.

[0014] The backlight 110 can be driven by local dimming. The backlight 110 has a surface light source 111 and an optical member 118 arranged on the surface light source 111.

[0015] The optical member 118 is not particularly limited, but is, for example, a sheet, film, or plate having a light adjustment function such as a light diffusion function. In this embodiment, the number of optical members 118 provided in the backlight 110 is one. However, the number of optical members provided in the backlight may be two or more.

[0016] FIG. 2 is a top view showing a surface light source in the backlight of the image display device according to this embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. In this embodiment, as shown in Figures 2 and 3, the surface light source 111 has a substrate 112, a light-reflecting sheet 112s, a light-guiding member 113, a plurality of light sources 114, a light-transmitting member 115, a first light adjustment member 116, and a light-reflecting member 117.

[0017] The substrate 112 is a wiring substrate having an insulating member and a plurality of wirings provided on the insulating member. In this embodiment, the shape of the substrate 112 when viewed from above is substantially rectangular, as shown in Fig. 2. However, the shape of the substrate is not limited to the above shape. The upper and lower surfaces of the substrate 112 are flat surfaces and are substantially parallel to the X and Y directions.

[0018] 3, the light reflecting sheet 112s is disposed on the substrate 112. In this embodiment, the light reflecting sheet 112s has a first adhesive layer, a light reflecting layer provided on the first adhesive layer, and a second adhesive layer provided on the light reflecting layer. The light reflecting sheet 112s is attached to the substrate 112 by the first adhesive layer.

[0019] The light guide member 113 is disposed on the light reflecting sheet 112s. At least a part of the lower surface of the light guide member 113 is attached to the light reflecting sheet 112s by a second adhesive layer. The shape of the light guide member 113 is plate-like in this embodiment. The thickness of the light guide member 113 is preferably, for example, 200 μm or more and 800 μm or less. The light guide member 113 may be configured as a single layer in the thickness direction, or may be configured as a laminate of multiple layers. In this embodiment, the shape of the light guide member 113 in a top view is approximately rectangular as shown in FIG. 2. However, the shape of the light guide member is not limited to the above shape.

[0020] Examples of materials that can be used for such light-guiding member 113 include thermoplastic resins such as acrylic, polycarbonate, cyclic polyolefin, polyethylene terephthalate, and polyester, thermosetting resins such as epoxy and silicone, and glass.

[0021] A plurality of light source arrangement sections 113a are arranged in the light guide member 113. The light source arrangement sections 113a are arranged in a matrix when viewed from above. In this embodiment, as shown in Fig. 3, each light source arrangement section 113a is a through hole that penetrates the light guide member 113 in the Z direction. However, the light source arrangement section may be a recess with a bottom provided on the lower surface of the light guide member.

[0022] Each light source 114 is disposed in each light source arrangement section 113a. Therefore, the plurality of light sources 114 are also arranged in a matrix as shown in FIG. 2. However, a light guide member is not necessarily required to be disposed in the planar light source. For example, the planar light source may not have a light guide member disposed therein, and may simply have a plurality of light sources arranged in a matrix on a substrate. Note that the light source arrangement section in the case where no light guide member is disposed refers to a portion of the substrate where the light sources are disposed.

[0023] Each light source 114 may be a single light emitting element, or may have a light emitting device in which a light emitting element is combined with, for example, a wavelength conversion member, etc. In this embodiment, as shown in Fig. 3, each light source 114 has a light emitting element 114a, a wavelength conversion member 114b, a second light adjustment member 114i, and a third light adjustment member 114j.

[0024] The light emitting element 114a is, for example, an LED (Light Emitting Diode), and includes a semiconductor laminate 114c and a pair of electrodes 114d, 114e that electrically connect the semiconductor laminate 114c to the wiring of the substrate 112. In the light reflecting sheet 112s, a through hole is provided in a portion located directly below each of the electrodes 114d, 114e. A conductive member 112m that electrically connects each of the electrodes 114d, 114e to the substrate 112 is disposed in the through hole.

[0025] The wavelength conversion member 114b includes a light-transmitting member 114f that covers the upper and side surfaces of the semiconductor laminate 114c, and a wavelength conversion material 114h that is disposed in the light-transmitting member 114f and converts the wavelength of light emitted by the semiconductor laminate 114c into a different wavelength. The wavelength conversion material 114h is, for example, a phosphor.

[0026] In this embodiment, the light emitting element 114a emits blue light Lb. On the other hand, the wavelength conversion member 114b is, for example, a CASN phosphor (e.g., CaAlSiN3:Eu), a quantum dot phosphor (e.g., AgInS2, AgInSe2), a KSF phosphor (e.g., K2SiF6:Mn), or a KSAF phosphor (e.g., K2(Si,Al)F6:Mn, more specifically, K2Si 0.99 Al 0.01 F 5.99 The phosphor 114r emitting red light Lr, such as (Si,Al)3(O,N)4:Eu, or the like (hereinafter referred to as red phosphor 114r), is a phosphor having a perovskite structure (e.g., CsPb(F,Cl,Br,I)3), a quantum dot phosphor (e.g., CdSe, InP), a β-sialon phosphor (e.g., (Si,Al)3(O,N)4:Eu), or a LAG phosphor (e.g., Lu3(Al,Ga)5O 12 and phosphor 114g (hereinafter referred to as green phosphor 114g) that emits green light Lg such as blue light Lb, green light Lg, and red light Lr having different emission peak wavelengths. Thus, each light source 114 can emit light Lw that includes blue light Lb, green light Lg, and red light Lr that are included in the light Lw. The ratio of the amount of blue light Lb, the amount of green light Lg, and the amount of red light Lr included in the light Lw is set to a ratio such that the color of the light Lw becomes white. Note that the wavelength conversion member 114b may be replaced with a translucent member that does not contain a phosphor. In this case, for example, a phosphor sheet containing a red phosphor and a green phosphor is disposed on the light guide member, or a phosphor sheet containing a red phosphor and a phosphor sheet containing a green phosphor are disposed on the light guide member, respectively, to obtain a similar white light.

[0027] The KSAF phosphor may have a composition represented by the following formula (I). M2[Si p Al q Mn r F s ] (I)

[0028] In formula (I), M represents an alkali metal and may contain at least K. Mn may be tetravalent Mn ions. p, q, r, and s may satisfy 0.9 ≦ p + q + r ≦ 1.1, 0 < q ≦ 0.1, 0 < r ≦ 0.2, and 5.9 ≦ s ≦ 6.1. Preferably, 0.95 ≦ p + q + r ≦ 1.05 or 0.97 ≦ p + q + r ≦ 1.03, 0 < q ≦ 0.03, 0.002 ≦ q ≦ 0.02 or 0.003 ≦ q ≦ 0.015, 0.005 ≦ r ≦ 0.15, 0.01 ≦ r ≦ 0.12 or 0.015 ≦ r ≦ 0.1, and 5.92 ≦ s ≦ 6.05 or 5.95 ≦ s ≦ 6.025. For example, compositions represented by K2[Si 0.946 Al 0.005 Mn 0.049 F 5.995 , K2[Si 0.942 Al 0.008 Mn 0.050 F 5.992 , K2[Si 0.939 Al 0.014 Mn 0.047 F 5.986 can be mentioned. According to such a KSAF-based phosphor, high luminance and red emission with a narrow full width at half maximum of the emission peak wavelength can be obtained.

[0029] The second light adjusting member 114i is disposed on the upper surface of the wavelength converting member 114b, and can control the amount and direction of light emitted from the upper surface of the wavelength converting member 114b. The third light adjusting member 114j is disposed on the lower surface of the light emitting element 114a and the lower surface of the wavelength converting member 114b so that the lower surfaces of the electrodes 114d and 114e are exposed. The third light adjusting member 114j can reflect light toward the lower surface of the wavelength converting member 114b and control the light to be emitted from the upper surface and side surface of the wavelength converting member 114b. Such second light adjusting member 114i and third light adjusting member 114j can each be composed of a light-transmitting resin and a light diffusing agent contained in the light-transmitting resin. The light-transmitting resin is, for example, a silicone resin, an epoxy resin, or an acrylic resin. Examples of the light diffusing agent include particles of TiO2, SiO2, Nb2O5, BaTiO3, Ta2O5, Zr2O3, Y2O3, Al2O3, ZnO, MgO, BaSO4, or glass. In addition, the second light adjusting member 114i may be made of a metal member such as Al or Ag so that the luminance directly above the light source 114 does not become too high.

[0030] A light-transmitting member 115 is disposed in the light source arrangement section 113a. The light-transmitting member 115 covers the light source 114. A first light adjustment member 116 is disposed on the light-transmitting member 115. The first light adjustment member 116 can reflect a part of the light incident from the light-transmitting member 115 and transmit the other part so that the luminance directly above the light source 114 does not become too high. For such a first light adjustment member 116, a member similar to the second light adjustment member 114i or the third light adjustment member 114j can be used.

[0031] Furthermore, the light guiding member 113 is provided with partitioning grooves 113b surrounding each light source arrangement section 113a in top view. The partitioning grooves 113b extend in a lattice pattern in the X and Y directions. The partitioning grooves 113b penetrate the light guiding member 113 in the Z direction. However, the partitioning grooves may be recesses provided on the upper or lower surface of the light guiding member. Furthermore, the partitioning grooves do not have to be provided on the light guiding member.

[0032] A light reflecting member 117 is disposed in the partition groove 113b. For example, a light-transmitting resin containing a light diffusing agent can be used as the light reflecting member 117. For example, the light diffusing agent can be particles of TiO2, SiO2, Nb2O5, BaTiO3, Ta2O5, Zr2O3, ZnO, Y2O3, Al2O3, MgO, BaSO4, or glass. For example, the light-transmitting resin can be silicone resin, epoxy resin, or acrylic resin. For example, a metal member such as Al or Ag can be used as the light reflecting member 117. The light reflecting member 117 covers a part of the side surface of the partition groove 113b in a layered manner. However, the light reflecting member may be disposed so as to fill the entire partition groove. Also, the light reflecting member may not be disposed in the partition groove.

[0033] In this embodiment, the output of the multiple light sources 114 can be individually controlled by the backlight driver 120. Here, "controllable output" means that it is possible to switch between on and off, and that the brightness in the on state is adjustable. For example, the surface light source may have a structure in which the output can be controlled for each light source, or may have a structure in which multiple light source groups are arranged in a matrix and the output can be controlled for each light source group.

[0034] In this specification, when the surface light source is divided into regions including light sources or light source groups whose output is individually controlled when viewed from above, each region is referred to as a "light emitting region." In other words, the light emitting region means the smallest region in the backlight whose luminance is controlled by local dimming. Therefore, in this embodiment, similar to the partition grooves 113b, when the surface light source 111 is divided into a lattice shape, each region corresponds to the light emitting region 110s.

[0035] Each light-emitting region 110s has a rectangular shape. In this embodiment, one light source 114 is provided in one light-emitting region 110s. Then, the backlight driver 120 controls the output of the plurality of light sources 114 individually, thereby controlling the luminance of the plurality of light-emitting regions 110s individually. As described above, when the output is controlled for each of the plurality of light source groups, one light source group, i.e., a plurality of light sources, is arranged in one light-emitting region, and the plurality of light sources are turned on or off simultaneously.

[0036] The light emitting regions 110s are arranged in a matrix in top view. In the following, in a matrix structure such as the light emitting regions 110s, a group of elements of the matrix of the light emitting regions 110s arranged in the X direction is referred to as a "row", and a group of elements of the matrix of the light emitting regions 110s arranged in the Y direction is referred to as a "column". For example, as shown in FIG. 2, the row located most in the +Y direction (the row located at the left) is referred to as the "first row", and the row located most in the -Y direction (the row located at the right) is referred to as the "last row". Similarly, as shown in FIG. 2, the column located most in the -X direction (the column located at the bottom) is referred to as the "first column", and the column located most in the +X direction (the column located at the top) is referred to as the "last column". The light emitting regions 110s are arranged to form N1 rows and M1 columns. Here, N1 and M1 are each any integer, and FIG. 2 shows an example in which N1 is 8 and M1 is 16.

[0037] 1, the backlight driver 120 is connected to the substrate 112 and the controller 150. The backlight driver 120 includes a drive circuit for the multiple light sources 114. The backlight driver 120 adjusts the luminance of each light emitting area 110s according to the backlight control data SG1 received from the controller 150.

[0038] FIG. 4 is a top view showing a liquid crystal panel of the image display device according to this embodiment. FIG. 5 is a cross-sectional view taken along line VV in FIG. A liquid crystal panel 130 is disposed on the backlight 110. As shown in Fig. 4, the shape of the liquid crystal panel 130 when viewed from above is substantially rectangular in this embodiment. In this embodiment, the liquid crystal panel 130 has a first polarizing plate 131, a first glass substrate 132, a plurality of individual electrodes 133, a liquid crystal layer 134, a common electrode 135, a color filter 136, a second glass substrate 137, and a second polarizing plate 138, as shown in Fig. 5.

[0039] A first glass substrate 132 is disposed on a first polarizing plate 131. A plurality of individual electrodes 133 are disposed on the first glass substrate 132. The plurality of individual electrodes 133 are arranged in a matrix in the X direction and the Y direction. A liquid crystal layer 134 is disposed on the plurality of individual electrodes 133. A common electrode 135 is disposed on the liquid crystal layer 134.

[0040] A color filter 136 is disposed on the common electrode 135. In this embodiment, the color filter 136 includes a blue filter 136b capable of transmitting blue light Lb of the light Lw emitted from the light source 114, a green filter 136g capable of transmitting green light Lg of the light Lw, and a red filter 136r capable of transmitting red light Lr of the light Lw. In this embodiment, a filter set 136s including one blue filter 136b, one green filter 136g, and one red filter 136r is arranged in a matrix in the X direction and the Y direction. In each filter set 136s, one blue filter 136b, one green filter 136g, and one red filter 136r are arranged in this order in the X direction. Each filter 136b, 136g, and 136r is disposed at a position overlapping each individual electrode 133 in a top view.

[0041] A second glass substrate 137 is disposed on the color filter 136. A second polarizing plate 138 is disposed on the second glass substrate 137. However, the specific configuration of the liquid crystal panel is not particularly limited to the above configuration.

[0042] Hereinafter, a portion of the liquid crystal panel 130 consisting of one filter set 136s, a portion located directly above it, and a portion located directly below it will be referred to as a "pixel 130p." Therefore, as shown in Fig. 4, in this embodiment, the liquid crystal panel 130 has a plurality of pixels 130p arranged in a matrix in the X direction and the Y direction.

[0043] In the following description, in one pixel 130p, a portion consisting of one blue filter 136b, a portion located directly above it, and a portion located directly below it is referred to as a "blue subpixel 130sb." The blue subpixel 130sb is capable of transmitting blue light Lb. Similarly, in one pixel 130p, a portion consisting of one green filter 136g, a portion located directly above it, and a portion located directly below it is referred to as a "green subpixel 130sg." The green subpixel 130sg is capable of transmitting green light Lg. Similarly, in one pixel 130p, a portion consisting of one red filter 136r, a portion located directly above it, and a portion located directly below it is referred to as a "red subpixel 130sr." The red subpixel 130sr is capable of transmitting red light Lr.

[0044] The driver 140 for the liquid crystal panel adjusts the voltage applied between the common electrode 135 and each individual electrode 133, thereby adjusting the light transmittance of each portion of the liquid crystal layer 134 located directly above each individual electrode 133. This adjusts the grayscale of each pixel 130p of the liquid crystal panel 130, more specifically, the grayscale of each sub-pixel 130sb, 130sg, and 130sr.

[0045] The pixels 130p are arranged in N2 rows and M2 columns. Here, N2 and M2 are each an arbitrary integer, and N2>N1 and M2>M1. In top view, the pixels 130p are arranged in each light-emitting region 110s. Note that, although FIG. 4 shows an example in which four pixels 130p correspond to one light-emitting region 110s, the number of pixels 130p corresponding to one light-emitting region 110s may be three or less, or five or more.

[0046] 1, the driver 140 for the liquid crystal panel is connected to the liquid crystal panel 130 and the controller 150. The driver 140 for the liquid crystal panel includes a drive circuit for the liquid crystal panel 130. The driver 140 for the liquid crystal panel adjusts the grayscale of each pixel 130p in accordance with the liquid crystal panel control data SG2 received from the controller 150.

[0047] FIG. 6 is a block diagram showing an image display device according to this embodiment. In this embodiment, the controller 150 includes an input interface 151, a memory 152, a processor 153 such as a CPU (central processing unit), and an output interface 154. These are connected to each other via a bus.

[0048] The input interface 151 is connected to an external device 900 such as a tuner, a personal computer, or a game machine. The input interface 151 includes a connection terminal to the external device 900 such as an HDMI (registered trademark) (High-Definition Multimedia Interface) terminal. The external device 900 inputs an input image IM to the controller 150 via the input interface 151.

[0049] The memory 152 includes, for example, a read-only memory (ROM) and a random-access memory (RAM), etc. The memory 152 stores various programs, various parameters, and various data for displaying images on the liquid crystal panel.

[0050] Processor 153 processes input image IM by reading a program stored in memory 152, determines a luminance setting value of each light-emitting region 110s of backlight 110 and a gradation setting value of each pixel 130p of liquid crystal panel 130, and controls backlight 110 and liquid crystal panel 130 based on these setting values. As a result, an image corresponding to input image IM is displayed on liquid crystal panel 130. Processor 153 includes a luminance setting data creation unit 153a, a gradation setting data creation unit 153b, and a control unit 153c.

[0051] The output interface 154 is connected to the backlight driver 120. The output interface also includes a connection terminal for the liquid crystal panel driver 140, such as an HDMI (registered trademark) terminal, and is connected to the liquid crystal panel driver 140. The backlight driver 120 obtains backlight control data SG1 via the output interface 154. The liquid crystal driver 140 obtains liquid crystal panel control data SG2 via the output interface 154.

[0052] The following describes an image display method using the image display device 100 according to this embodiment. The following also describes the functions of the processor 153 as the luminance setting data generator 153a, the gradation setting data generator 153b, and the controller 153c.

[0053] FIG. 7 is a flowchart showing an image display method according to this embodiment. In this embodiment, a plurality of successive input images IM are input to the controller 150. The image display method according to this embodiment includes, for each of the plurality of input images IM, an input image IM acquisition step S1, a brightness setting data D2 creation step S2, a gradation setting data D3 creation step S3, and an image display step S4.

[0054] Each step will be described in detail below. In the following, the kth input image IM k A method of displaying an image corresponding to the (first input image) on the liquid crystal panel 130 will be described below. Here, k is an arbitrary natural number.

[0055] First, the input image IM k The acquisition step S1 will now be described. First, as shown in FIG. 6, the input interface 151 of the controller 150 receives an input image IM from the external device 900. k The acquired input image IM k is stored in the memory 152.

[0056] FIG. 8 is a schematic diagram showing the relationship between pixels of an input image input to a controller, light emitting regions of a backlight, and pixels of a liquid crystal panel in an image display device according to this embodiment. Each input image IM has a plurality of pixels IMp arranged in a matrix. In the following, for ease of explanation, in data in which elements such as pixels IMp are arranged in a matrix, as in the input image IM, the arrangement direction of elements is expressed using an xy Cartesian coordinate system. In addition, among the directions in which the x axis extends, the direction of the arrow is defined as the "+x direction", and the opposite direction is defined as the "-x direction". Similarly, among the directions in which the y axis extends, the direction of the arrow is defined as the "+y direction", and the opposite direction is defined as the "-y direction". In addition, in the following, a group of elements of a matrix arranged in the x direction is referred to as a "row", and a group of elements of a matrix arranged in the y direction is referred to as a "column". For example, as shown in FIG. 8, the row located most in the +y direction (the row located most left) is defined as the "first row", and the row located most in the -y direction (the row located most right) is defined as the "last row". Similarly, as shown in FIG. 8, the column located furthest in the -x direction (the column located at the bottom) is defined as the "first column," and the column located furthest in the +x direction (the column located at the top) is defined as the "last column."

[0057] For ease of understanding, an example will be described below in which one pixel IMp of the input image IM corresponds to one pixel 130p of the liquid crystal panel 130. That is, in this embodiment, the multiple pixels IMp are arranged to form N2 rows and M2 columns. In the input image IM, an area IMs corresponding to one light-emitting region 110s of the backlight 110 includes multiple pixels IMp. However, the correspondence between the pixels of the input image and the pixels of the liquid crystal panel does not have to be one-to-one. In this case, the processor 153 of the controller 150 performs pre-processing on the input image so that the pixels of the input image and the pixels of the liquid crystal panel correspond one-to-one, and then performs the following processing.

[0058] A gradation is set for each pixel IMp. In this embodiment, the input image IM is a color image. Therefore, a blue gradation Gb(i,j), a green gradation Gg(i,j), and a red gradation Gr(i,j) are set for the pixel IMp located at the i-th row and j-th column. Here, i is an arbitrary integer from 1 to N2, and j is an arbitrary integer from 1 to M2. Each gradation Gb(i,j), Gg(i,j), and Gr(i,j) is a number from 0 to 255 when expressed in 8 bits, for example.

[0059] Next, the step S2 of creating the luminance setting data D2 will be described. FIG. 9 is a schematic diagram showing a method of creating luminance setting data in the image display method according to this embodiment. Hereinafter, the kth input image IM k The brightness setting data D2 created for k The luminance setting data generating unit 153a generates luminance setting data D2 that defines the luminance setting value of each light emitting area 110s of the backlight 110. k Create a.

[0060] Below, brightness setting data D2 k The specific method for creating the above will be explained. First, the luminance setting data generating unit 153a generates the luminance setting data for the input image IM k The maximum gradation Gmax of each area IMs corresponding to each light-emitting region 110s is expressed as the luminance L k Luminance data D1 converted to (n,m) k Create a.

[0061] Specifically, luminance setting data creation unit 153a first extracts area IMs that corresponds to light emitting area 110s located at the nth row and mth column. Next, luminance setting data creation unit 153a sets the maximum value among the blue gradation Gb(i,j), green gradation Gg(i,j), and red gradation Gr(i,j) of all pixels IMp included in this area IMs as the maximum gradation Gmax of this area IMs. Next, luminance setting data creation unit 153a calculates the maximum gradation Gmax as the luminance L kNext, the luminance setting data generating unit 153a converts this luminance L k (n,m) is the luminance data D1 k Element e1 located in the nth row and mth column of k Let the value be (n,m), where n is any integer between 1 and N1, and m is any integer between 1 and M1. The luminance setting data generating unit 153a performs this process for all areas IMs.

[0062] The luminance data D1 thus obtained k is a matrix of data having N1 rows and M1 columns. The luminance data D1 located in the nth row and mth column k Element e1 of k The value (n, m) is the luminance L converted from the maximum gray level Gmax of the area IMs located in the nth row and mth column. The luminance setting data generating unit 153a generates the luminance data D1 k is stored in the memory 152.

[0063] When the controller 150 changes the brightness setting of a certain light-emitting region 110s in order to change the image to be displayed on the liquid crystal panel 130, the amount of light from the light-emitting element 114a changes before the amount of light from the green phosphor 114g and the red phosphor 114r. The response speeds of the green phosphor 114g and the red phosphor 114r may also differ from each other. For example, when the response speed of the red phosphor 114r is slower than that of the green phosphor 114g, when the controller 150 increases the brightness setting of the light-emitting region 110s, the amount of light from the light-emitting element 114a and the green phosphor 114g increases before the amount of light from the red phosphor 114r, so that the light source 114 emits a greenish-blue (cyan) colored light Lw during the increase in brightness. Furthermore, when the controller 150 reduces the set value of the brightness of the light-emitting region 110s, the amount of light from the red phosphor 114r decreases later than the amount of light from the light-emitting element 114a and the green phosphor 114g, and therefore, reddish light Lw is emitted from the light source 114 while the brightness is decreasing.

[0064] In this way, when the brightness setting value of the light emitting region 110s is changed, the ratio of the amount of blue light Lb, the amount of green light Lg, and the amount of red light Lr contained in the light Lw changes. This causes the balance of the mixed colors of the light Lw to be lost. This loss of balance of the mixed colors of the light Lw is more noticeable the greater the change in the brightness setting value of the light emitting region 110s. Conventionally, a controller would k Luminance data D1 created based on k Based on this, the backlight 110 is controlled. Therefore, the amount of change in the luminance of the light emitting region 110s may become so large that the imbalance of the mixed colors of the light Lw becomes noticeable.

[0065] In contrast, in the image display method according to the present embodiment, the luminance data D1 k Luminance L k (n,m) and the k-1th input image IM k-1 Brightness setting data D2 created for k-1 (2nd input image) Luminance setting value L2 k-1 Based on the average value of (n,n), the input image IM k Brightness setting data for D2 k Brightness setting value L2 k Define (n,m).

[0066] Specifically, first, the luminance setting data generating unit 153a generates luminance data D1 k Element e1 located at the nth row and mth column in k Luminance L of (n,m) k (n,m) and brightness setting data D2 k-1 Element e2 located in the nth row and mth column of k-1 Luminance setting value L2 for (n,m) k-1 (n, m) and calculate the average value. Next, the luminance setting data creation unit 153a calculates the average value as the luminance setting data D2 k Element e2 located in the nth row and mth column of k The value of (n, m), that is, the brightness setting value L2 of the light-emitting region 110s located in the nth row and the mth column k Let (n,m). The luminance setting data generating unit 153a performs this process for all of the light emitting areas 110s of the backlight 110.

[0067] The brightness setting data D2 thus obtained k is a matrix of data having N1 rows and M1 columns. The brightness setting data D2 located in the nth row and mth column k Element e2 of k The value of (n, m) is the luminance setting value L2 of the light-emitting area 110s located in the nth row and the mth column of the backlight 110. k (n,m). The luminance setting data generating unit 153a generates the luminance setting data D2 k is stored in the memory 152.

[0068] Note that the k-1th input image IM k-1 Brightness setting data D2 created for k-1 is generated in advance by the luminance setting data generating unit 153a and stored in the memory 152. k-2 If the luminance setting data exists, the luminance setting data generating unit 153a generates the luminance setting data D2 k The brightness setting data D2 is created in the same way as k-1 Also, the k-1th immediately preceding input image IM k-2 does not exist, i.e., the input image IM k-1 is the first input image, the luminance setting data generating unit 153a k-1 The brightness data created based on the brightness setting data D2 k-1 It is also possible to use the following.

[0069] Next, the process S3 of creating the gradation setting data D3 will be described. FIG. 10 is a schematic diagram showing a method of creating gradation setting data in the image display method according to this embodiment. Hereinafter, the gradation setting data D3 created for the k-th input image IMk will be referred to as "gradation setting data D3 k The gradation setting data generating unit 153b generates the gradation setting data for the input image IM kand brightness setting data D2 k Based on this, the gradation setting data D3 that defines the gradation setting value of each pixel 130p of the liquid crystal panel 130 is k Create a.

[0070] Below, gradation setting data D3 k A specific example of how to create the above will be described. In this embodiment, memory 152 stores in advance data D4 indicating the luminance distribution at each position on the XY plane when light source 114 in one light-emitting region 110s is turned on. Note that in Fig. 10, light-emitting region 110s in which light source 114 is turned on is shown as ON, and light-emitting region 110s in which light source 114 is turned off is shown as OFF.

[0071] In step S2, the brightness setting value of each light-emitting region 110s of backlight 110 was determined, but in reality, the brightness may differ depending on each position on the XY plane even within one light-emitting region 110s, as shown in data D4 indicating the brightness distribution in Fig. 10. Furthermore, when light source 114 in one light-emitting region 110s is turned on, light may propagate to the surrounding light-emitting regions 110s.

[0072] First, the gradation setting data generating unit 153b generates the luminance setting data D2 k From data D4 indicating the luminance distribution, a luminance value V(i,j) immediately below a pixel 130p located at the i-th row and j-th column of the liquid crystal panel 130 is estimated.

[0073] Specifically, the gradation setting data generating unit 153b generates the luminance setting data D2 k In this case, element e2 corresponding to the light emitting region 110s located directly below the pixel 130p k From the value of (n, m) (luminance setting value) and data D4 indicating the luminance distribution, luminance value V1(i, j) directly below this pixel 130p when only light source 114 in this light emitting region 110s is turned on is estimated. Furthermore, gradation setting data creation unit 153b estimates luminance value V1(i, j) directly below this pixel 130p when only light source 114 in this light emitting region 110s is turned on. k In this case, the element e2 corresponding to the light emitting region 110s surrounding the light emitting region 110s kFrom the values ​​of (s,t) and data D4 indicating the luminance distribution, luminance value V2(i,j) immediately below this pixel 130p when only light sources 114 in surrounding light-emitting regions 110s are turned on is estimated. Then, the sum of these luminance values ​​V1(i,j) and V2(i,j) is estimated as the luminance value V(i,j) immediately below this pixel 130p. In this way, gradation setting data creation unit 153b can estimate the luminance value V(i,j) immediately below this pixel 130p, incorporating both the luminance distribution within one light-emitting region 110s and light leakage from surrounding light-emitting regions 110s.

[0074] Next, the gradation setting data generating unit 153b calculates the estimated luminance value V(i,j) and the input image IM k In the correction formula Ef, the blue gradation Gb(i,j) of the pixel IMp corresponding to this pixel 130p is substituted into the correction formula Ef. The correction formula Ef converts the luminance into a gradation based on, for example, gamma correction, and converts the input image IM k The gradation setting data creation unit 153b substitutes the blue gradation Gb(i,j) into the correction equation Ef to obtain an output value Efb(i,j) of the correction equation Ef, which is set as the setting value of the blue gradation of the pixel 130p. The same process is performed for the green gradation Gg(i,j), and the output value Efg(i,j) of the correction equation Ef obtained thereby is set as the setting value of the green gradation of the pixel 130p. The gradation setting data creation unit 153b also performs the same process for the red gradation Gr(i,j), and the output value Efr(i,j) of the correction equation Ef obtained thereby is set as the setting value of the red gradation of the pixel 130p. That is, the gradation setting data creation unit 153b converts the output values ​​Efb(i,j), Efg(i,j), and Efr(i,j) into the gradation setting data D3 k Element e3 located in the i-th row and j-th column of k Set the value to (i,j).

[0075] The gradation setting data generating unit 153b performs this process for each pixel 130p(i,j) of the liquid crystal panel 130. As a result, the gradation setting data D3 k In this manner, in this embodiment, the brightness setting data D2 kThe input image IM k This creates the gradation setting data D3.

[0076] The gradation setting data D3 thus obtained k is a matrix of data with N2 rows and M2 columns. Element e3 located in the i-th row and j-th column in the gradation setting data D3 k The three values ​​(i,j) Efb(i,j), Efg(i,j), and Efr(i,j) correspond to the blue gradation setting value, the green gradation setting value, and the red gradation setting value, respectively, of pixel 130p located at the i-th row and j-th column of liquid crystal panel 130. The gradation setting data generating unit 153b generates the gradation setting data D3 k is stored in the memory 152.

[0077] Although an example of a method for creating the gradation setting data D3 has been described above, the method for creating the gradation setting data is not limited to the above method. For example, the luminance values ​​directly below all pixels of the liquid crystal panel may be estimated, and then each luminance value may be substituted into the conversion formula.

[0078] Next, the image display step S4 will be described. The control unit 153c sets the brightness setting data D2 k The backlight 110 is controlled based on the grayscale setting data D3 k The liquid crystal panel 130 is controlled based on the received signal, and an image is displayed on the liquid crystal panel 130.

[0079] Specifically, as shown in Fig. 6, the control unit 153c transmits backlight control data SG1 created based on the brightness setting data D2 to the backlight driver 120 via the output interface 154. The backlight control data SG1 is not particularly limited as long as it is data capable of controlling the driving of the backlight driver 120, and is, for example, data in a PWM (Pulse Width Modulation) format. The backlight driver 120 controls the output of each light source 114 based on the backlight control data SG1.

[0080] In addition, the control unit 153c outputs the gradation setting data D3 via the output interface 154. k The liquid crystal panel control data SG2 is sent to the liquid crystal panel driver 140. However, the liquid crystal panel control data SG2 includes the gradation setting data D3 k may be data obtained by converting the above-mentioned data into a format capable of controlling the driving of the liquid crystal panel driver 140. The liquid crystal panel driver 140 controls the light transmittance of each pixel 130p, more specifically, each of the sub-pixels 130sb, 130sg, and 130sr, based on the liquid crystal panel control data SG2.

[0081] Brightness setting data D2 k The timing of converting the grayscale setting data D3 into the backlight control data SG1 is not particularly limited as long as it is after step S2. k to the liquid crystal panel control data SG2, the timing of the conversion is not particularly limited as long as it is performed after step S3.

[0082] Next, the effects of this embodiment will be described. In the image display method according to the present embodiment, an input image IM k About brightness setting data D2 k The step S2 of creating the input image IM k In the backlight 110, the maximum gray level Gmax of each area IMs corresponding to each light emitting region 110s is expressed as the luminance L k Luminance data D1 converted to (n,m) k and a process of creating luminance data D1 k The luminance L of each area IMs k (n,m) and among multiple input images IM, input image IM k The input image IM immediately before k-1 Brightness setting data D2 created for k-1 The brightness setting value L2 of each light-emitting area 110s k-1 (n, m) and the brightness setting data D2 of each light emitting area 110s based on the average value of k Brightness setting value L2 k and determining (n, m).

[0083] Therefore, the input image IM k The brightness setting value L2 of each light-emitting area 110s k and the immediately preceding input image IM k-1 The brightness setting value L2 of each light-emitting area 110s in k-1 This can prevent the luminance difference between the light-emitting regions 110s from becoming large. This can prevent the amount of change in luminance of each light-emitting region 110s from becoming large when switching the image displayed on the liquid crystal panel 130. As a result, it is possible to provide an image display method that can reduce the influence of imbalance in the mixed colors of the light Lw emitted from the backlight 110.

[0084] <Second embodiment> Next, a second embodiment will be described. 11, 12A, and 12B are schematic diagrams showing a method of creating luminance setting data in the image display method according to this embodiment. In the image display method according to the present embodiment, the brightness setting data D22 k The creating step S2 differs from the image display method according to the first embodiment. In the following description, in principle, only the differences from the first embodiment will be described. The matters other than those described below are the same as the first embodiment. The same applies to the other embodiments described below.

[0085] Hereinafter, the kth input image IM k Brightness setting data for D22 k The creation step S2 will now be described. As shown in FIGS. 12A and 12B, the luminance setting data generating unit 153a generates the kth input image IM k The k-1th input image IM immediately before k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 The input image IM is calculated so that the brightness difference ΔL between (n,m) is within the threshold ΔLdet. k Regarding the luminance setting value L22 of each light emitting area 110s kDefine (n,m).

[0086] Specifically, first, the luminance setting data generating unit 153a generates the input image IM as shown in FIG. k Based on this, the luminance data D1 is obtained by the same method as in the first embodiment. k Create a.

[0087] Next, the luminance setting data generating unit 153a generates the luminance data D1 k Element e1 located in the nth row and mth column of k Luminance L of (n,m) k (n,m) and the k-1th input image IM k-1 Brightness setting data D22 created for k-1 Element e22 located in the nth row and mth column of k-1 Luminance setting value L22 for (n,m) k-1 Calculate the difference ΔLa between (n,m) and

[0088] Next, the luminance setting data generating unit 153a determines whether the difference ΔLa is equal to or smaller than a threshold value ΔLdet.

[0089] When it is determined that the difference ΔLa is equal to or smaller than the threshold ΔLdet, the luminance setting data generating unit 153a sets the luminance data D1 k Element e1 located in the nth row and mth column of k Luminance L of (n,m) k (n,m) is the brightness setting data D22 k Element e22 located in the nth row and mth column of k The value of (n, m), that is, the brightness setting value L22 of the light emitting region 110s located in the nth row and the mth column k Let (n,m).

[0090] If it is determined that the difference ΔLa is not equal to or less than the threshold ΔLdet, the luminance setting data generating unit 153a k (n,m) is the brightness setting value L22 k-1 Determine whether it is greater than (n,m).

[0091] Luminance L k(n,m) is the brightness setting value L22 k-1 If it is determined that the luminance setting data generating unit 153a determines that the luminance setting value L22 is larger than (n, m), as shown in FIG. 11 and FIG. 12A. k-1 The value obtained by adding the threshold value ΔLdet to (n, m) is the brightness setting data D22 k Element e22 located in the nth row and mth column of k The value of (n, m), that is, the brightness setting value L22 of the light emitting region 110s located in the nth row and the mth column k Let (n,m).

[0092] Luminance L k (n,m) is the brightness setting value L22 k-1 If it is determined that the luminance setting data generating unit 153a does not exceed the luminance setting value L22 as shown in FIG. 11 and FIG. 12B. k-1 The value obtained by subtracting the threshold value ΔLdet from (n, m) is used as the brightness setting data D22 k Element e22 located in the nth row and mth column of k The value of (n, m), that is, the brightness setting value L22 of the light emitting region 110s located in the nth row and the mth column k Let (n,m).

[0093] The luminance setting data generator 153a performs this process for all light emitting areas 110s of the backlight 110. As a result, the luminance setting data D22 k is created. The method of creating the luminance setting data is not limited to the above method. For example, the luminance setting data creating unit 153a may k (n,m) is the brightness setting value L22 k-1 By determining whether it is greater than (n,m), the luminance L k (n,m) and brightness setting L22 k-1 The magnitude relationship with (n,m) was judged. However, the luminance L k (n,m) and brightness setting L22 k-1 The method of determining the magnitude relationship with (n, m) is not limited to the above method. For example, the luminance setting data generating unit 153a may k (n,m) is the brightness setting value L22k-1 It may be determined whether it is smaller than (n,m).

[0094] As described above, in the image display method according to the present embodiment, the input image IM k About brightness setting data D22 k In step S2 of creating an input image IM k The input image IM immediately before k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 The brightness setting value L22 of each light emitting region 110s is set so that the brightness difference ΔL from (n, m) is within the threshold ΔLdet. k (n, m) is determined. Therefore, it is possible to prevent the amount of change in luminance of each light-emitting region 110s from exceeding the threshold value ΔLdet when changing the image displayed on the liquid crystal panel 130. As a result, it is possible to provide an image display method that can reduce the influence of imbalance in mixed colors in light Lw.

[0095] Also, the input image IM k About brightness setting data D22 k In the step S2 of creating an input image IM k The maximum gray level Gmax of each area IMs corresponding to each light emitting region 110s of the backlight 110 is expressed as the luminance L k Luminance data D1 converted to (n,m) k Then, the luminance data D1 k Luminance L k (n,m) and input image IM k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 For light-emitting area 110s where the difference ΔLa from (n, m) is within threshold ΔLdet, luminance data D1 k Luminance L k (n, m) is the brightness setting value L22 of this light emitting area 110s k Let (n,m).

[0096] In addition, in the backlight 110, the difference ΔLa exceeds the threshold ΔLdet, and the luminance data D1 k The luminance L(n,m) of the input image IM k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 For a light-emitting area 110s smaller than k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 The value obtained by subtracting the threshold value ΔLdet from (n, m) is the brightness setting value L22 of this light emitting area 110s. k Let (n,m).

[0097] In addition, in the backlight 110, the difference ΔLa exceeds the threshold ΔLdet, and the luminance data D1 k Luminance L k (n,m) is the input image IM k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 For a light emitting region 110s larger than (n,m), the input image IM k-1 Brightness setting data D22 created for k-1 Brightness setting value L22 k-1 The value obtained by adding the threshold value ΔLdet to (n, m) is the brightness setting value L22 of this light emitting area 110s. k Let (n,m).

[0098] Therefore, a simple method is used to obtain the input image IM k Brightness setting data D22 created for k Brightness setting value L22 k (n,m) and the previous input image IM k-1 Brightness setting data D22 created for k Brightness setting value L22 k-1 The luminance difference ΔL from (n, m) can be kept within the threshold ΔLdet.

[0099] <Third embodiment> Next, a third embodiment will be described. FIG. 13 is a schematic diagram showing a method of creating luminance setting data in the image display method according to this embodiment. 14 and 15 are schematic diagrams showing a method of creating gradation setting data in the image display method according to this embodiment. The image display method according to this embodiment uses brightness setting data D32 k Creation process S2 and gradation setting data D33 k The creating step S3 differs from the image display method according to the first embodiment.

[0100] In the following, an example will be described in which the difference in response speed between the light emitting element 114a and the green phosphor 114g is sufficiently small, and the difference in response speed between the light emitting element 114a and the red phosphor 114r is large. In the following example, the blue light Lb corresponds to the first light, and the red light Lr corresponds to the second light. The red phosphor 114r corresponds to the first phosphor. The blue subpixel 130sb corresponds to the first subpixel, and the red subpixel 130sr corresponds to the second subpixel.

[0101] First, the kth input image IM k Brightness setting data for D32 k The creation step S2 will now be described. The luminance setting data generating unit 153a generates luminance data D1 in the same manner as in the first embodiment as shown in FIG. k Create the brightness data D1 k The brightness setting data D32 k Therefore, in this embodiment, the brightness setting data D32 k Element e32 located at the nth row and mth column of k The value of (n,m) is the maximum gradation Gmax with the luminance L k The value converted to (n,m) is the luminance L k (n,m) is the brightness setting value L k (n,m)".

[0102] Next, the kth input image I k Gradation setting data for D33 k Next, the creation step S3 will be described. The gradation setting data generating unit 153b generates the brightness setting data D32 k The input image IM k Each corrected image IMa k Based on the above, the grayscale setting data D33 defines the grayscale setting value Exb(i,j) of the blue subpixel 130sb, the grayscale setting value Exg(i,j) of the green subpixel 130sg, and the grayscale setting value Exr(i,j) of the red subpixel 130sr included in each pixel 130p of the liquid crystal panel 130. k Create a.

[0103] First, the gradation setting data generating unit 153b generates a corrected image IMa as shown in FIG. k Specifically, the brightness setting data D32 is created. k Using data D4 indicating the brightness distribution, the brightness value V(i,j) immediately below the pixel located at the i-th row and j-th column is estimated. Then, the gradation setting data creation unit 153b uses the estimated brightness value V(i,j) and the correction formula Ef to calculate the input image IM k The gradation setting data creation unit 153b corrects the gradations Gfb(i,j), Gfg(i,j), and Gfr(i,j) of the pixel IMp located at the i-th row and j-th column of the corrected image IMa. k The output value Efg(i,j) is the blue gradation value of the pixel IMp located at the i-th row and j-th column of the corrected image IMa. k The output value Efr(i,j) is the green gradation value of the pixel IMp located at the i-th row and j-th column of the corrected image IMa k The red gradation value of the pixel IMp located in the i-th row and j-th column of the corrected image IMa k In the above, a pixel IMp located in the i-th row and j-th column is associated with a blue gradation value Efb(i,j), a green gradation value Efg(i,j), and a red gradation value Efr(i,j).

[0104] Next, the gradation setting data generating unit 153b generates the input image IM k Brightness setting data D32 k Element e32 located at the nth row and mth column ofk Luminance setting value L of (n,m) k (n,m) and the input image IM k-1 Brightness setting data D32 k-1 Element e32 located at the nth row and mth column of k-1 Luminance setting value L of (n,m) k-1 Calculate the luminance difference ΔL between (n,m) and

[0105] Next, the gradation setting data generating unit 153b judges whether the luminance difference ΔL is equal to or smaller than the threshold ΔLdet. k In step S104, an area IMs corresponding to light emitting region 110s located in the nth row and mth column is extracted.

[0106] If it is determined that the luminance difference ΔL is equal to or smaller than the threshold ΔLdet, the gradation setting data generating unit 153b generates the corrected image IMa k In the extracted area IMs, the blue gradation value Efb(i,j) of each pixel IMp included in the area IMs is not corrected and is set as the gradation setting data D33 k The corresponding element of e33 k Similarly, the gradation setting data generator 153b does not correct the green gradation value Efg(i,j) of each pixel IMp included in the extracted area IMs, but generates the gradation setting data D33 k The corresponding element of e33 k Similarly, the gradation setting data generator 153b generates the green gradation value Efr(i,j) of each pixel IMp included in the extracted area IMs without correction, as the gradation setting data D33 k The corresponding element of e33 k The setting value of the red gradation of (i,j) is represented as Exr(i,j).

[0107] If it is determined that the difference ΔLa is not equal to or less than the threshold ΔLdet, the luminance setting data generating unit 153a sets the luminance setting value L k (n,m) is the brightness setting L k-1 Determine whether it is greater than (n,m).

[0108] Brightness setting value L k (n,m) is the brightness setting L k-1 If it is determined that the value is greater than (n, m), the gradation setting data generator 153b multiplies the blue gradation value Efb(i, j) of each pixel IMp included in the extracted area IMs by the correction coefficient K1. Then, the multiplied value is stored as the gradation setting data D33 k The corresponding element of e33 k (i,j) is set as the blue gradation setting value Exb(i,j). Similarly, the gradation setting data generator 153b multiplies the green gradation value Efg(i,j) of each pixel IMp included in the extracted area IMs by the correction coefficient K1. The multiplied value is then stored as the gradation setting data D33 k The corresponding element of e33 k The gradation setting data generator 153b does not correct the red gradation value Efr(i,j) of each IMp included in the extracted area IMs, but generates the gradation setting data D33 k The corresponding element of e33 k The setting value of the red gradation of (i,j) is represented as Exr(i,j).

[0109] Brightness setting value L k (n,m) is the brightness setting L k-1 If it is determined that the value is not greater than (n, m), the gradation setting data generator 153b multiplies the blue gradation value Efb(i, j) of each pixel IMp included in the extracted area IMs by the correction coefficient K2. Then, the multiplied value is stored as the gradation setting data D33 k The corresponding element of e33 k (i,j) is set as the blue gradation setting value Exb(i,j). Similarly, the gradation setting data generator 153b multiplies the green gradation value Efg(i,j) of each pixel IMp included in the area IMs by the correction coefficient K2. The multiplied value is then stored as the gradation setting data D33 k The corresponding element of e33 kThe gradation setting data generator 153b does not correct the red gradation value Efr(i,j) of each pixel IMp(i,j) included in the extracted area IMs, but generates the gradation setting data D33 k The corresponding element of e33 k The setting value of the blue gradation of (i,j) is represented as Exr(i,j).

[0110] The gradation setting data generating unit 153b performs the above processing on the corrected image IMa k This is performed for all pixels IMp in the subpixels 130sb, 130sg, and 130sr. As a result, the gradation setting data D33 that defines the gradation setting values ​​Exb(i,j), Exg(i,j), and Exr(i,j) of the subpixels 130sb, 130sg, and 130sr is obtained. k is created.

[0111] In this embodiment, in the light-emitting region 110s where the luminance rises beyond the threshold value ΔLdet, the amount of light from the light-emitting element 114a and the green phosphor 114g increases faster than the amount of light from the red phosphor 114r, so that the color of the light Lw becomes greenish blue (cyanish). Therefore, in this embodiment, the correction coefficient K1 is set to a value smaller than 1, and multiplied by the blue gradation value Efb(i,j) and the green gradation value Efg(i,j). As a result, for the pixel 130p located directly above the light-emitting region 110s where the luminance rises beyond the threshold value ΔLdet, the set values ​​Exb(i,j) and Exg(i,j) of the gradations of the sub-pixels 130sb and 130sg are determined so that the transmission amounts of the blue light Lb and the green light Lg are reduced.

[0112] In addition, in this embodiment, in the light-emitting region 110s where the luminance falls beyond the threshold value ΔLdet, the amount of light from the red phosphor 114r decreases slower than the amount of light from the light-emitting element 114a and the green phosphor 114g, so that the color of the light Lw becomes reddish. Therefore, in this embodiment, the correction coefficient K2 is set to a value greater than 1 and multiplied by the blue gradation value Efb(i,j) and the green gradation value Efg(i,j). As a result, for the pixel 130p located directly above the light-emitting region 110s where the luminance falls beyond the threshold value ΔLdet, the set values ​​Exb(i,j) and Exg(i,j) of the gradations of the sub-pixels 130sb and 130sg are determined so that the transmission amounts of the blue light Lb and the green light Lg are increased.

[0113] In this manner, by adjusting the transmittance of the lights Lb and Lg of the sub-pixels 130sb and 130sg of the liquid crystal panel 130, the influence of imbalance in the mixed colors of the lights Lw emitted from each light-emitting region 110s can be reduced.

[0114] Next, the effects of this embodiment will be described. In the image display method according to the present embodiment, an input image IM k Regarding gradation setting data D33 k In the step S3 of creating an input image IM k Brightness setting data D32 k Brightness setting value L k (n,m) and among multiple input images IM, input image IM k The input image IM immediately before k-1 Brightness setting data D32 k-1 Luminance setting value L of (n,m) k-1 Then, for pixels 130p located directly above light-emitting region 110s in liquid crystal panel 130 where the luminance difference ΔL exceeds threshold ΔLdet, a corrected image IMa is generated according to the change in the ratio of the amount of blue light Lb, the amount of green light Lg, and the amount of red light Lr contained in light Lw emitted from light-emitting region 110s when the luminance setting value is changed. kare corrected to determine a blue gradation setting value Exb(i,j), a green gradation setting value Exg(i,j), and a red gradation setting value Exr(i,j).

[0115] In this way, the influence of imbalance in the mixed color of light Lw emitted from each light-emitting region 110s can be reduced by adjusting the balance of the transmittance of light Lb, Lg, and Lr of each of the sub-pixels 130sb and 130sr of the liquid crystal panel 130.

[0116] In this embodiment, the corrected image IMa k Each pixel IMp in the input image IM is associated with a blue gradation value Efb(i,j) corresponding to the blue light Lb, a green gradation value Efg(i,j) corresponding to the green light Lg, and a red gradation value Efr(i,j) corresponding to the red light Lr. k Regarding gradation setting data D33 k In the process of creating the corrected image IMa, for light-emitting region 110s where the luminance difference ΔL exceeds threshold ΔLdet, correction coefficients K1 and K2 are determined according to the change in the ratio of the amount of blue light Lb, the amount of green light Lg, and the amount of red light Lr contained in light Lw emitted from light-emitting region 110s when the luminance setting value is changed. Then, for pixel 130p located directly above light-emitting region 110s where the luminance difference ΔL exceeds threshold ΔLdet, correction coefficients K1 and K2 are applied to corrected image IMa. k The blue gradation value Efb(i,j) and the green gradation value Efg(i,j) of the liquid crystal panel 130 are multiplied by the correction coefficients K1 and K2 to determine the blue gradation setting value Exb(i,j) setting value Exr(i,j) and the green gradation setting value Exg(i,j). Therefore, the balance of the transmittance of the light Lb, Lg, and Lr of each sub-pixel 130sb, 130sr of the liquid crystal panel 130 can be adjusted by the simple method of multiplying by the correction coefficients K1 and K2.

[0117] Also, the input image IM k Brightness setting data D32 k Brightness setting value L k (n,m) is the input image IM k-1 Brightness setting data D32 k-1 Brightness setting value L k-1For light emitting areas 110s larger than (n, m), the correction coefficient K1 is set to a value smaller than 1. k Brightness setting data D32 k Brightness setting value L k (n,m) is the input image IM k-1 Brightness setting data D32 k-1 Brightness setting value L k-1 For luminous areas 110s smaller than (n, m), correction coefficient K2 is set to a value greater than 1. For pixels 130p located directly above luminous areas 110s where the luminance difference ΔL exceeds the threshold ΔLdet, correction coefficients K1 and K2 are set to a value greater than 1 for corrected image IMa k Therefore, the balance of the transmittance of the light Lb, Lg, and Lr of each of the sub-pixels 130sb and 130sr of the liquid crystal panel 130 can be adjusted by the simple method of multiplying the correction coefficients K1 and K2.

[0118] 16 to 18 are schematic diagrams showing modified examples of the method of creating gradation setting data in the image display method according to the present embodiment. As shown in Fig. 16, a correction coefficient K1 may be set to a value smaller than 1 and multiplied by the blue gradation value Efb(i,j) and the green gradation value Efg(i,j), and a correction coefficient K2 may be set to a value smaller than 1 and multiplied by the red gradation value Efr(i,j). In the liquid crystal panel 130, in a light-emitting region 110s where the luminance falls beyond the threshold value ΔLdet, the color of the light Lw becomes reddish. Therefore, for a pixel 130p located directly above a light-emitting region 110s where the luminance falls beyond the threshold value ΔLdet, a setting value Exr(i,j) of the gradation of the red sub-pixel 130sr may be determined so that the amount of transmission of the red light Lr is reduced, as shown in Fig. 16.

[0119] 17, the correction coefficient K1 may be set to a value greater than 1, and the red gradation value Efr(i,j) may be multiplied by the correction coefficient K1, and the correction coefficient K2 may be set to a value greater than 1, and the blue gradation value Efb(i,j) and the green gradation value Efg(i,j) may be multiplied by the correction coefficient K2. In a light-emitting region 110s where the luminance increases beyond the threshold value ΔLdet, the color of the light Lw becomes greenish blue (cyanish). Therefore, for pixel 130p located directly above light-emitting region 110s where the luminance increases beyond the threshold value ΔLdet, the setting value Exr(i,j) of the gradation of red sub-pixel 130sr may be determined so that the amount of transmission of red light Lr increases, as shown in FIG.

[0120] Also, as shown in FIG. 18, the correction coefficient K1 may be set to a value greater than 1 and the red gradation value Efr(i,j) may be multiplied by the correction coefficient K1, and the correction coefficient K2 may be set to a value less than 1 and the red gradation value Efr(i,j) may be multiplied by the correction coefficient K2.

[0121] The specific values ​​of the correction coefficients K1 and K2 can be appropriately set according to the type of the light emitting element 114a and the types of the phosphors 114g and 114r. In addition, when the difference in response speed between the light emitting element 114a and the green phosphor 114g is large enough to affect the imbalance of the mixed color of the light Lw, the correction image IMa is adjusted according to the change in the ratio of the amount of the blue light Lb and the amount of the green light Lg. k may be corrected to determine the blue gradation setting value Exb(i,j) and the green gradation setting value Exg(i,j).

[0122] The methods in the above-mentioned embodiments can be appropriately combined as long as there is no contradiction. For example, the method in the first embodiment and the method in the third embodiment can be combined. Specific methods are described in detail below.

[0123] As in the first embodiment, the luminance data D1 k The luminance L of each area IMs k (n,m) and brightness setting data D2 k-1 The brightness setting value L2 of each light-emitting area 110sk-1 Based on the average value of (n, m), the brightness setting data D2 k The brightness setting value L2 of each light-emitting area 110s k Define (n,m).

[0124] Next, as in the third embodiment, the brightness setting data D2 k The input image IM k Corrected image IMa k Create a.

[0125] Next, for each light emitting area 110s, the brightness setting data D2 k Brightness setting value L k (n,m) and brightness setting data D2 k-1 Luminance setting value L of (n,m) k-1 Calculate the luminance difference ΔL between (n,m) and

[0126] Next, for pixels 130p located directly above light-emitting areas 110s where the luminance difference ΔL exceeds the threshold ΔLdet, the luminance setting value L k-1 (n,m) to the brightness setting value L k A corrected image IMa is generated according to the change in the ratio of the amount of blue light Lb, the amount of green light Lg, and the amount of red light Lr contained in the light Lw emitted from the light emitting region 110s when the light intensity changes to (n, m). k are corrected to determine a blue gradation setting value Exb(i,j), a green gradation setting value Exg(i,j), and a red gradation setting value Exr(i,j). [Industrial Applicability]

[0127] The present invention can be used in displays of devices such as televisions, personal computers, and game consoles. [Explanation of symbols]

[0128] 100: Image display device 110: Backlight 110s: Light emitting area 111: Planar light source 112: Substrate 113: Light guide member 113a: Light source placement part 113b : Partition groove 114 :Light source 114a: Light emitting element 114b: Wavelength conversion material 114c: Semiconductor laminate 114d, 114e: Electrode 114f: Translucent member 114h: Wavelength conversion material 114g, 114r: phosphor 114i: Second light adjustment member 114j: Third light adjustment member 116: First light adjustment member 117: Light reflecting material 118: Optical components 120: Backlight driver 130: LCD panel 130p :pixels 130sb, 130sg, 130sr: Subpixel 131: First polarizing plate 132: First glass substrate 133: Individual electrode 134: Liquid crystal layer 135: Common electrode 136: Color filter 136b, 136g, 136r: Filters 136s: Filter set 137: Second glass substrate 138: Second polarizing plate 140: LCD panel driver 150: Controller 151: Input interface 152: Memory 153: Processor 153a: Brightness setting data creation unit 153b: Gradation setting data creation section 153c: Control section 154: Output interface 900: External equipment D1k: Luminance data D2, D2 k , D2 k-1 D22 k , D22 k-1 : Brightness setting data D3, D3 k , D32 k , D32 k-1 , D33 k , : Brightness setting data D4: Data showing luminance distribution Ef: Correction formula Efb, Efg, Efr: Output value (tone value of corrected image) Exb, Exg, Exr: Gradation setting value Gb, Gg, Gr: Gradation of the input image Gmax: Maximum gradation IM, IM k , I.M. k-1 , I.M. k-2 : Input image IMa k : Corrected image IMp : Pixel IMs :Area L(n,m): Luminance L2 k , L2 k-1 , L22 k , L22 k-1 : Brightness setting value Lb, Lg, Lr, Lw: Light SG1: Backlight control data SG2: LCD panel control data V(i,j): Luminance value K2, K1: Correction coefficients ΔL: Luminance difference ΔLa: Difference ΔLdet: threshold

Claims

1. For each of a plurality of consecutive input images input to a controller of a backlight having a plurality of light-emitting regions arranged in a matrix and a liquid crystal panel having a plurality of pixels, creating luminance setting data that defines a luminance setting value for each of the light-emitting regions of the backlight based on each of the input images; creating gradation setting data that defines a first gradation setting value of a first sub-pixel and a second gradation setting value of a second sub-pixel included in each pixel of the liquid crystal panel, based on each corrected image obtained by performing a first correction on each of the input images based on the luminance setting data; controlling the backlight based on the luminance setting data, controlling the liquid crystal panel based on the gradation setting data, and displaying an image on the liquid crystal panel; Equipped with Each of the light-emitting regions of the backlight is provided with a light-emitting element that emits a first light of blue, and a first phosphor that receives the first light and emits a second light of red, and each of the light-emitting regions is capable of emitting light including the first light and the second light having different emission peak wavelengths; Each of the first sub-pixels is capable of transmitting the first light, and each of the second sub-pixels is capable of transmitting the second light, In the step of generating the gradation setting data for a first input image of the plurality of input images, calculating a luminance difference between the luminance setting value of the luminance setting data of the first input image and the luminance setting value of the luminance setting data of a second input image immediately before the first input image among the plurality of input images, for each of the light emitting regions; an image display method in which, in the liquid crystal panel, for the pixel located directly above the light-emitting region where the luminance difference exceeds a threshold value, a second correction is performed on the corrected image so that a change in a ratio between the amount of transmission of the first light in the first subpixel and the amount of transmission of the second light in the second subpixel is reduced in accordance with a change in a ratio between the amount of light of the first light and the amount of light of the second light contained in the light emitted from the light-emitting region when a setting value of the luminance is changed, thereby determining a setting value of the first gradation and a setting value of the second gradation.

2. a first gradation value of a color corresponding to a color of the first light and a second gradation value of a color corresponding to a color of the second light are associated with each pixel of the correction image; In the step of creating the gradation setting data for the first input image, for the pixel located directly above the light emitting region where the luminance difference exceeds the threshold, 2. The image display method according to claim 1, wherein in the second correction, a correction coefficient corresponding to a change in a ratio of the amount of the first light and the amount of the second light contained in the light emitted from the light-emitting region when the brightness setting value is changed is multiplied by the first gradation value or the second gradation value of the corrected image to determine the first gradation setting value and the second gradation setting value.

3. For the light-emitting region in which the luminance setting value of the luminance setting data of the first input image is greater than the luminance setting value of the luminance setting data of the second input image, the correction coefficient is set to a value smaller than 1; for the light emitting region in which the luminance setting value of the luminance setting data of the first input image is smaller than the luminance setting value of the luminance setting data of the second input image, the correction coefficient is set to a value greater than 1; The image display method according to claim 2 , further comprising: multiplying the first gradation value of the corrected image by the correction coefficient for the pixel located directly above the luminous region where the luminance difference exceeds the threshold value.

4. For the light-emitting region in which the luminance setting value of the luminance setting data of the first input image is greater than the luminance setting value of the luminance setting data of the second input image, the correction coefficient is set to a value greater than 1; for the light emitting region in which the luminance setting value of the luminance setting data of the first input image is smaller than the luminance setting value of the luminance setting data of the second input image, the correction coefficient is set to a value smaller than 1; The image display method according to claim 2 , further comprising: multiplying the second gradation value of the corrected image by the correction coefficient for the pixel located directly above the luminous region where the luminance difference exceeds the threshold value.

5. For the light-emitting region in which the luminance difference exceeds the threshold, the correction coefficient is set to a value smaller than 1; for the pixel located directly above the light emitting region where the luminance difference exceeds the threshold value and the luminance setting value of the luminance setting data of the first input image is greater than the luminance setting value of the luminance setting data of the second input image, multiplying the first gradation value of the corrected image by the correction coefficient; 3. The image display method according to claim 2, wherein for the pixel located directly above the light-emitting region where the brightness difference exceeds the threshold value and the brightness setting value of the brightness setting data of the first input image is smaller than the brightness setting value of the brightness setting data of the second input image, the second gradation value of the corrected image is multiplied by the correction coefficient.

6. For the light-emitting region in which the luminance difference exceeds the threshold, the correction coefficient is set to a value greater than 1; for the pixel located directly above the light emitting region where the luminance difference exceeds the threshold value and the luminance setting value of the luminance setting data of the first input image is greater than the luminance setting value of the luminance setting data of the second input image, multiplying the second gradation value of the corrected image by the correction coefficient; 3. The image display method according to claim 2, wherein for the pixel located directly above the light-emitting region where the luminance difference exceeds the threshold value and the luminance setting value of the luminance setting data of the first input image is smaller than the luminance setting value of the luminance setting data of the second input image, the correction coefficient is multiplied by the first gradation value of the corrected image.

Images