Display device and source driver

Abstract

To provide a display device capable of performing control of simple local dimming without correction of image data when the image data is supplied to driver ICs of a plurality of chips by a PtoP system.SOLUTION: A display device includes: a display panel; a plurality of source drivers for generating gradation voltage signals by receiving supply of image data via supply lines different from each other; and an illumination driver for controlling a light amount of backlight for illuminating each of a plurality of sub-areas obtained by dividing the display screen of the display panel. The plurality of source drivers generates, on the basis of the image data supplied to each of the source drivers, dimming data indicating the light amount of the backlight corresponding to the feature amount of the image data. One source driver of the plurality of source drivers receives supply of dimming data from the other source driver, and supplies a dimming data signal obtained by combining the dimming data of the one source driver and the dimming data of the other source driver to the illumination driver.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a display device and a source driver.

Background Art

[0002] As a driving method for display devices such as liquid crystal display devices and organic EL (Electro Luminescence), an active matrix driving method is adopted. In a display device using the active matrix driving method, the display panel is composed of a semiconductor substrate in which a pixel portion and pixel switches are arranged in a matrix. The on / off of the pixel switches is controlled by a gate pulse, and when the pixel switch is turned on, a gradation voltage signal corresponding to the video data signal is supplied to the pixel portion, and the luminance of each pixel portion is controlled to perform display. The driving circuit of the display device includes, for example, a gate driver that outputs a gate pulse to a gate line, a source driver that outputs a gradation voltage signal to a data line, and a timing controller that supplies image data and a timing signal to the source driver.

[0003] In such a display device, in order to increase the contrast ratio of different areas within the same screen, drive control of the backlight called local dimming is performed. As a display device that performs local dimming, an image display device has been proposed that calculates the luminance distribution of an image signal, controls the illumination light for each region based on the calculation result, and corrects the image signal (for example, Patent Document 1).

[0004] Also, in general local dimming, while performing drive control of the backlight, luminance correction is also performed on the image data. For this reason, a dedicated IC or FPGA (Field Programmable Gate Array) for performing local dimming is required, and the device scale becomes large. Therefore, in order to suppress an increase in the device scale, a display device has been proposed that has a so-called simple local dimming function in which only the control of the illumination light is performed without correcting the image data in the source driver (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] When the source driver is composed of driver ICs of multiple chips and image data is supplied in a PtoP (Point to Point) manner, only the image data corresponding to the area of the display panel driven by each driver IC (that is, the area where the pixel portions on the data lines to be driven are arranged) is supplied to each driver IC.

[0007] On the other hand, in a display device having a source driver composed of such driver ICs of multiple chips, when performing simple local dimming as in the above prior art, data calculation for local dimming control is performed in each driver IC. At that time, in order to perform data calculation for local dimming control, image data of the area around the target control area is required.

[0008] However, when image data is supplied in a PtoP manner as described above, since only the image data of the display area driven by each driver IC is supplied to each driver IC, at the boundary portion of the display areas of adjacent driver ICs, image data of the surrounding area cannot be used, and there is a problem that data calculation for local dimming control cannot be accurately performed.

[0009] In addition, there is also a case where the boundary of the display area by each driver IC does not coincide with the boundary of the local dimming control area, and there is a problem that local dimming control at the boundary portion cannot be appropriately performed.

[0010] The present invention has been made in view of the above problems, and when a source driver is composed of driver ICs of a plurality of chips and image data is supplied to each driver IC in a P-to-P manner, an object of the present invention is to provide a display device capable of performing control of simple local dimming without correction of the image data.

Means for Solving the Problems

[0011] A display device according to the present invention includes a display panel having a plurality of data lines, a plurality of gate lines, and a plurality of pixel portions provided in a matrix at each intersection of the plurality of data lines and the plurality of gate lines, and a plurality of source drivers arranged corresponding to each of a plurality of data line groups included in the plurality of data lines, receiving supply of image data corresponding to an image to be displayed on pixel portions on each corresponding data line group via different image data supply lines, and generating a gradation voltage signal for supplying pixel portions arranged on each corresponding data line group based on the image data, and an illumination drive unit for controlling the amount of light of a backlight that illuminates each of a plurality of sub-areas obtained by dividing a display screen of the display panel. The plurality of source drivers each generate dimming data indicating the amount of light of the backlight of a sub-area in which pixel portions to be supplied with the gradation voltage signal of each of the plurality of source drivers exist among the plurality of sub-areas based on the image data supplied thereto. One of the plurality of source drivers receives supply of the dimming data from other source drivers, and supplies a dimming data signal generated based on the dimming data of the one source driver and the dimming data of the other source drivers to the illumination drive unit.

[0012] In addition, the source driver according to the present invention is connected to a display panel having a plurality of pixel portions provided in a matrix at each intersection of a plurality of data lines and a plurality of gate lines, and an illumination driving unit that controls the amount of light of a backlight that illuminates each of a plurality of sub-areas obtained by dividing the display screen of the display panel. The source driver is arranged corresponding to a first data line group included in the plurality of data lines, receives the supply of first image data corresponding to an image to be displayed on the pixel portions on the first data line group via a first image data supply line, and generates a gradation voltage signal for supplying the pixel portions arranged on the first data line group as a supply target based on the image data. The source driver includes a local dimming function unit that generates first dimming data indicating the amount of light of the backlight of the sub-area where the pixel portions on the first data line group are located among the plurality of sub-areas based on the gradation of the pixels included in the first image data, acquires second dimming data indicating the amount of light of the backlight corresponding to the feature amount of the second image data from another source driver that is arranged corresponding to a second data line group included in the plurality of data lines and receives the supply of second image data corresponding to an image to be displayed on the pixel portions on the second data line group via a second image data supply line, a data post-processing unit that generates a dimming data signal based on the first dimming data and the second dimming data, and a communication unit that transmits the dimming data signal to the illumination driving unit.

Effect of the Invention

[0013] According to the display device of the present invention, when the source driver is composed of driver ICs of a plurality of chips and image data is supplied to each driver IC in a P-to-P manner, it is possible to perform simple local dimming control without correcting the image data.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail. In the following description and the accompanying drawings, the same reference numerals are assigned to substantially the same or equivalent parts.

[0016] FIG. 1 is a block diagram showing the configuration of a display device 100 according to Embodiment 1 of the present invention. The display device 100 is a liquid crystal display device using an active matrix driving method. The display device 100 includes a display panel 11, a gate driver 12, source drivers 13A, 13B, 13C, and an LED driver 14.

[0017] The display panel 11 is composed of a semiconductor substrate on which a plurality of pixel portions P11 to Pnm and pixel switches M11 to Mnm (n is an integer of 2 or more, m is an integer of 2 or more and a multiple of 3) are arranged in an n-row × m-column matrix. The display panel 11 has n gate lines GL1 to GLn which are horizontal scanning lines, and m data lines DL1 to DLm which are arranged so as to intersect and be orthogonal to these. The pixel portions P11 to Pnm and the pixel switches M11 to Mnm are provided at the intersection portions of the gate lines GL1 to GLn and the data lines DL1 to DLm and are arranged in a matrix.

[0018] The pixel switches M11 to Mnm are controlled to be turned on or off according to the gate signals Vg1 to Vgn supplied from the gate driver 12. The pixel portions P11 to Pnm receive the supply of the gradation voltage signals Gv1 to Gvm corresponding to the video data from the source drivers 13A, 13B, and 13C. When the pixel switches M11 to Mnm are each turned on, the gradation voltage signals Gv1 to Gvm are applied to the respective pixel electrodes of the pixel portions P11 to Pnm, and each pixel electrode is charged. The luminance of the pixel portions P11 to Pnm is controlled according to the gradation voltage signals Gv1 to Gvm at the respective pixel electrodes of the pixel portions P11 to Pnm, and display is performed.

[0019] In other words, by the operation of the gate driver 12, m pixel portions arranged along the extension direction of the gate line (that is, in a horizontal row) are selected as the supply targets of the gradation voltage signals Gv1 to Gvm. The source drivers 13A, 13B, and 13C apply the gradation voltage signals Gv1 to Gvm to the selected pixel portions in a horizontal row and display a color corresponding to the voltage. By selectively switching the pixel portions in a horizontal row selected as the supply targets of the gradation voltage signals Gv1 to Gvm and repeating in the extension direction of the data line (that is, in the vertical direction), the screen display for one frame is performed.

[0020] Each of the pixel portions P11 to Pnm includes a liquid crystal encapsulated between a transparent electrode connected to a data line via a pixel switch, a semiconductor substrate, and a counter substrate provided to face the semiconductor substrate and having a single transparent electrode formed over the entire surface thereof. Display is performed by changing the transmittance of the liquid crystal according to the voltage difference between the gradation voltage signals Gv1 to Gvm supplied to the pixel portions P11 to Pnm and the counter substrate voltage with respect to the backlight inside the display device.

[0021] The gate driver 12 receives the supply of a gate control signal and sequentially supplies gate signals Vg1 to Vgn to the gate lines GL1 to GLn based on the clock timing included in the gate control signal. The gate control signal is supplied from a display controller such as a timing controller (not shown).

[0022] The source drivers 13A, 13B, and 13C are arranged adjacent to each other along the horizontal direction (i.e., the extending direction of the gate lines GL1 to GLn). The source driver 13A is a source driver responsible for driving the data lines DL1 to DLi arranged at the leftmost position close to the gate driver 12 among the data lines DL1 to DLm. The source driver 13B is arranged at the central position among the three source drivers and is a source driver responsible for driving the data lines DLi+1 to DLk. The source driver 13C is a source driver responsible for driving the data lines DLk+1 to DLm arranged at the rightmost position far from the gate driver 12. The source drivers 13A, 13B, and 13C are each composed of separate semiconductor IC (Integrated Circuit) chips.

[0023] The source drivers 13A, 13B, and 13C receive the supply of image data together with a frame synchronization signal from a timing controller (not shown). In this embodiment, the image data is supplied in a PtoP (Point to Point) manner, and the image data is separately supplied to the source drivers 13A, 13B, and 13C via separate image data supply lines.

[0024] The source driver 13A is supplied with image data VD1, which is the image data of the display area corresponding to the pixel portions on the data lines DL1 to DLi. The source driver 13B is supplied with image data VD2, which is the image data of the display area corresponding to the pixel portions on the data lines DLi+1 to DLk. The source driver 13C is supplied with image data VD3, which is the image data of the display area corresponding to the pixel portions on the data lines DLk+1 to DLm. The image data VD1 to VD3 are serialized data signals composed of a series of pixel data pieces PD that represent the luminance level of each pixel in, for example, 256 luminance gradations of 8 bits.

[0025] Based on the image data VD1, the source driver 13A generates multi-level gradation voltage signals Gv1 to Gvi corresponding to the number of gradations thereof, and supplies them to the data lines DL1 to DLi. Based on the image data VD2, the source driver 13B generates multi-level gradation voltage signals Gvi+1 to Gvk corresponding to the number of gradations thereof, and supplies them to the data lines DLi+1 to DLk. Based on the image data VD3, the source driver 13C generates multi-level gradation voltage signals Gvk+1 to Gvm corresponding to the number of gradations thereof, and supplies them to the data lines DLk+1 to DLm.

[0026] The LED driver 14 is an illumination driving unit that controls the amount of light of the backlight that illuminates the display panel 11 by driving an illumination unit (not shown in FIG. 1) composed of LEDs (Light Emitting Diodes). The illumination unit is composed of a plurality of light sources, and the LED driver 14 can control the luminance of the backlight for each of a plurality of areas obtained by dividing the display panel 11 by controlling the light emission of each light source. The LED driver 14 receives the supply of a dimming data signal from the source driver 13A, and controls the luminance of the backlight by driving a plurality of light sources of the illumination unit accordingly.

[0027] FIG. 2 is a diagram schematically showing the arrangement relationship between the display panel 11 and the lighting unit 16. The lighting unit 16 is composed of a plurality of light sources LS arranged corresponding to each area obtained by dividing the display screen of the display panel 11 into a plurality of areas. Each of the plurality of light sources LS is composed of, for example, an emitter made of an LED. The light source LS and the LED driver 15 are each configured such that the emission luminance is separately controlled and the luminance can be switched in multiple steps.

[0028] FIG. 3 is a block diagram showing the configuration of the source drivers 13A, 13B, and 13C. The source drivers 13A to 13C each have an LCD (Liquid Crystal Display) driving unit 21, a local dimming control unit 22, a data post-processing unit 23, and an LED driver communication unit 24.

[0029] The LCD driving unit 21 is a liquid crystal display driving unit that drives the display panel 11 by supplying a gradation voltage signal to the data lines to be driven by each of the source drivers 13A to 13C. For example, the LCD driving unit 21 of the source driver 13A receives the supply of the image data VD1, generates gradation voltage signals Gv1 to Gvi based on this, and outputs them to the data lines DL1 to DLi. The LCD driving unit 21 of the source driver 13A includes, for example, a data latch unit that sequentially fetches pixel data pieces PD from the image data VD1 and a gradation voltage conversion unit that converts the pixel data pieces PD into gradation voltage signals Gv1 to Gvi (not shown). The LCD driving units 21 of the source drivers 13B and 13C also have the same functions and configurations.

[0030] The local dimming control unit 22 is a functional block responsible for the execution control of simple local dimming, which is the control of the light amount of the backlight according to the image data. As described above, the source drivers 13A to 13C are supplied with the image data VD1 to VD3, which are the image data corresponding to different display areas, respectively. Therefore, the local dimming control unit 22 of the source driver 13A receives the image data VD1, the local dimming control unit 22 of the source driver 13B receives the image data VD2, and the local dimming control unit 22 of the source driver 13C receives the image data VD3, and generates a dimming data signal for controlling the light amount of the backlight that irradiates the display area of the display panel 11 corresponding to each image data.

[0031] Figure 4 is a block diagram showing the configuration of the local dimming control unit 22. Here, the configuration of the local dimming control unit of the source driver 13A is shown as a representative. The local dimming control unit 22 includes a pixel data processing unit 31, a gradation average calculation unit 32, a dimming amount calculation unit 33, and a dimming data writing unit 34.

[0032] The pixel data processing unit 31 extracts the pixel data pieces PD included in the image data VD1 and supplies them to the gradation average calculation unit 32.

[0033] Based on the pixel data pieces PD, the gradation average calculation unit 32 acquires, as a feature amount, the gradation (GS) of the pixels in the display area (hereinafter referred to as the display area corresponding to the source driver 13A) corresponding to the data lines DL1 to DLi that the source driver 13A drives when displaying the image data for one frame on the display panel 11, and calculates the average value thereof. The gradation average calculation unit 32 calculates the gradation average value for each of the sub-areas included in the display area corresponding to the source driver 13A among the plurality of sub-areas obtained by dividing the display area of the display panel 11.

[0034] The dimming amount calculation unit 33 calculates the dimming amount for each sub-area for controlling the light emission of the backlight based on the gradation average value for each sub-area calculated by the gradation average calculation unit 32. The dimming amount calculation unit 33 calculates the dimming amount in 10 steps from dimming amount 0 to 9. The dimming amount calculation unit 33 calculates the dimming amount by converting the gradation average value into the dimming amount using, for example, a conversion table.

[0035] FIG. 5 is a diagram showing an example of a conversion table for calculating the dimming amount based on the gradation average value. Here, the gradation average value is shown in 256 gradations from GS0 to GS255. When the gradation average is low, the dimming amount is small, and as the gradation average increases, the dimming amount increases. For example, the gradation average value GS0 has a dimming amount of 0, the gradation average values GS1 to 15 have a dimming amount of 1, ··· the gradation average values GS240 to 254 have a dimming amount of 8, and the gradation average value GS255 has a dimming amount of 9.

[0036] The dimming data writing unit 34 generates dimming data DD1 for setting the light amount of the backlight of the light source LS corresponding to each sub-area included in the display area corresponding to the source driver 13A based on the dimming amount calculated by the dimming amount calculation unit 33. The dimming data writing unit 34 supplies the generated dimming data DD1 to the data post-processing unit 23.

[0037] Referring to FIG. 3 again, the local dimming control unit 22 of the source driver 13C supplies the dimming data generated by its own dimming data writing unit, that is, the dimming data DD3 which is the dimming data for the display area corresponding to the source driver 13C, to the data post-processing unit 23 of the adjacent source driver 14B.

[0038] The local dimming control unit 22 of the source driver 13B supplies the dimming data generated by its own dimming data writing unit, that is, the dimming data DD2 which is the dimming data for the display area corresponding to the source driver 13B, to the data post-processing unit 23.

[0039] The data post-processing unit 23 of the source driver 13B receives the supply of the dimming data DD2 and DD3, and generates the dimming data DDX based on these. For example, among a plurality of sub-areas obtained by dividing the display screen of the display panel 11 into 6 rows (1 to 6) × 8 columns (A to H), the sub-areas in column F are arranged across the display area of the source driver 13B and the display area of the source driver 13C. Therefore, for the sub-areas in column F, by synthesizing the dimming data generated in each of the source driver 13B and the source driver 13C, the dimming data corresponding to each of the sub-areas in rows 1 to 6 is generated. The synthesis operation is performed, for example, by weighting the dimming data based on the ratio of the areas in the respective display areas of the source drivers 13B and 13C for each of the sub-areas in rows 1 to 6 in column F, and calculating the weighted average. The data post-processing unit 23 supplies the dimming data DDX generated based on the dimming data DD2 and DD3 to the data post-processing unit 23 of the adjacent source driver 14A.

[0040] The data post-processing unit 23 of the source driver 13A receives the supply of the dimming data DD1 from the local dimming control unit 22 (dimming data writing unit 34), and also receives the supply of the dimming data DDX from the data post-processing unit 23 of the adjacent source driver 13B. The data post-processing unit 23 generates a dimming data signal DD based on the dimming data DD1 and DDX. Among a plurality of sub-areas obtained by dividing the display screen of the display panel 11 into 6 rows (1 to 6) × 8 columns (A to H), the sub-areas in column C are arranged across the display area of the source driver 13A and the display area of the source driver 13B. Therefore, for the sub-areas in column C, by synthesizing the dimming data generated in each of the source driver 13A and the source driver 13B, the dimming data corresponding to each of the sub-areas in rows 1 to 6 is generated. The synthesis operation is performed, for example, by weighting the dimming data based on the ratio of the areas in the respective display areas of the source drivers 13A and 13B for each of the sub-areas in rows 1 to 6 in column C, and calculating the weighted average. The data post-processing unit 23 supplies the dimming data signal DD generated based on the dimming data DD1 and DDX to the LED driver communication unit 24.

[0041] The LED driver communication unit 24 is connected to the LED driver 14 and supplies the dimming data signal DD to the LED driver 14 through serial data communication.

[0042] As described above, in this embodiment, the data post-processing unit 23 of the source driver 13B generates the dimming data DDX based on the dimming data DD2 and the dimming data DD3. Also, the data post-processing unit 23 of the source driver 13A generates the dimming data signal DD based on the dimming data DD1 and the dimming data DDX.

[0043] FIG. 6 is a diagram schematically showing the configuration of the dimming data signal DD. The dimming data signal DD is composed of the calculation results of the dimming amount for each sub-area. In this embodiment, the dimming data signal DD is configured as a continuous serial data signal of the calculation results of the dimming amount for each sub-area obtained by dividing the display screen of the display panel 11 into 6 rows (1 to 6) × 8 columns (A to H) as shown in FIG. 3.

[0044] The upper part of FIG. 6 shows the positions of the sub-areas, and the lower part shows which of the source drivers 13A, 13B, and 13C calculated the data of the dimming amount for each sub-area. Note that "1st chip" represents the source driver 13A, "2nd chip" represents the source driver 13B, and "3rd chip" represents the source driver 13C.

[0045] For example, the sub-area at the first row of column A is the display area where the pixels on the data line driven by the source driver 13A are located and is included in the image data VD1. Therefore, the data of the dimming amount for the first row of column A (A-1 data) is calculated by the local dimming control unit 22 of the source driver 13A. Similarly, the data of the dimming amount for the second to sixth rows of column A and the first to sixth rows of column B (A-2 data, ··· B-6 data) are calculated by the local dimming control unit 22 of the source driver 13A (1st chip).

[0046] On the other hand, on the sub-areas from the first row to the sixth row of column C, there is a boundary BL1 between the display area corresponding to the source driver 13A and the display area corresponding to the source driver 13B. That is, each sub-area from the first row to the sixth row of column C is a display area where pixels on the data lines to be driven by the source driver 13A are located, and at the same time, it is a display area where pixels on the data lines to be driven by the source driver 13B are located. In the following description, such a sub-area is also referred to as a shared sub-area.

[0047] The dimming amount data of such a shared sub-area is calculated based on the calculation results of each of the two source drivers. For example, the image data of the image displayed in the sub-area of the first row of column C is included in the image data VD1 supplied to the source driver 13A and is also included in the image data VD2 supplied to the source driver 13B. Therefore, the dimming amount data (C-1 data) of the first row of column C cannot be calculated by the source driver 13A alone or the source driver 13B alone. Therefore, by performing an operation of synthesizing the calculation result (1st chip calculation) in the source driver 13A and the calculation result (2nd chip calculation) in the source driver 13B, the dimming amount data (C-1 data) of the first column of row C is generated.

[0048] Similarly, the dimming amount data (C-2 to C-6 data) of the second row to the sixth row of column C is also generated by performing an operation of synthesizing the calculation result of the source driver 13A and the calculation result of the source driver 13B. The operation is performed in the synthesis operation of the dimming data DD1 and DDX by the data post-processing unit 23 of the source driver 13A.

[0049] The dimming amount data (D-1 to E-6 data) of the first row to the sixth row of column D and the first row to the sixth row of column E is calculated by the local dimming control unit 22 of the source driver 13B. The dimming amount data (G-1 to H-6 data) of the first row to the sixth row of column G and the first row to the sixth row of column H is calculated by the local dimming control unit 22 of the source driver 13C.

[0050] On the sub-areas from the first row to the sixth row in column F, there is a boundary BL1 between the display area corresponding to the source driver 13B and the display area corresponding to the source driver 13C. That is, each sub-area from the first row to the sixth row in column F is a shared sub-area that is a display area where pixels exist on the data lines to be driven by the source driver 13B and is also a display area where pixels exist on the data lines to be driven by the source driver 13C. For this reason, the dimming amount data from the first row to the sixth row in column F is generated by performing an operation of synthesizing the operation result (2nd chip operation) in the source driver 13B and the operation result (3rd chip operation) in the source driver 13C. The said operation is performed in the operation of synthesizing the dimming data DD2 and DD3 by the data post-processing unit 23 of the source driver 13B.

[0051] The LED driver 14 receives the supply of the dimming data signal DD, and controls the light emission of the plurality of light sources LS in the illumination unit 16 so that the backlight is irradiated with the dimming amount indicated by the dimming data signal DD for each of the sub-areas of 6 rows (1 to 6) × 8 columns (A to H) of the display panel 11. For example, the LED driver 14 switches the light emission luminance of each of the plurality of light sources LS to 10 levels based on the dimming data signal DD. Thereby, the light amount of the backlight is adjusted according to the gradation of each sub-area in the display screen of the image data VD1 to VD3 for each frame, and an appropriate contrast ratio corresponding to the display image is obtained.

[0052] FIG. 7 is a diagram schematically showing an example of the gradation average value in each of the plurality of sub-areas of the display panel 11 calculated by the local dimming control units 22 of the source drivers 13A, 13B, and 13C. Here, the gradation average value for each sub-area obtained by dividing the display area DA1 into 8 columns (A to H) × 6 rows (1 to 6) is shown in 256 gradations from GS0 to GS255. Each of the sub-areas corresponds to the irradiation area of the backlight by the plurality of light sources LS shown in FIG. 2.

[0053] For example, when image data VD1 to VD3 is supplied in which the background is dark and a relatively bright object exists near the center on the left side compared to the background, as shown in FIG. 4, for sub-areas (for example, D-3, E-3, etc.) located at the center of the display panel 11, relatively high gradations (for example, GS120 to GS230) are calculated as the gradation average values, and for sub-areas (for example, A1 to A6, etc.) located at the peripheral part within the display panel 11, relatively low gradations (for example, GS0 to GS30) are calculated as the gradation average values.

[0054] FIG. 8 is a diagram showing an example of the dimming amount of each sub-area when the LED driver 14 performs light emission control of the lighting unit 16. For example, for the high-gradation sub-areas (D-3, E-3) located at the center of the display panel 11, the dimming amount is 7, and for the low-gradation sub-areas (A-1, A-6, etc.) located at the peripheral part within the display panel 11, the dimming amount is 0, and the LED driver 14 performs light emission control of the lighting unit 16.

[0055] As described above, in the display device 100 of the present embodiment, the source drivers 13A, 13B, and 13C provided corresponding to different data line groups (DL1 to DLIi, DLi+1 to DLIk, DLk+1 to DLIi) are supplied with the image data VD1, VD2, and VD3 in a PtoP manner, respectively. The source drivers 13A, 13B, and 13C generate dimming data DD1, DD2, and DD3 based on the image data supplied to themselves. The source driver 13B receives the supply of the dimming data DD3 from the source driver 13A, generates the dimming data DDX based on the dimming data DD2 and the dimming data DD3, and supplies it to the source driver 13A. The source driver 13A generates a dimming data signal DD based on the dimming data DD1 and the dimming data DDX, and supplies it to the LED driver 14.

[0056] According to such a configuration, the dimming data of the shared sub-area where the boundaries of the display areas of adjacent source drivers (i.e., the boundaries of the data line groups corresponding to each source driver) are located can be calculated based on the calculation results of the dimming data in both source drivers. Therefore, only the image data displayed on the pixel portions on the data line groups corresponding to each source driver is supplied to the plurality of source drivers in a P-to-P manner, and even when the image data displayed on the pixel portions on the data line groups corresponding to other adjacent source drivers is not supplied, the dimming data of the shared sub-area including the boundary portion of the display area can be generated, and it becomes possible to perform simple local dimming control without correction of the image data.

[0057] Note that the present invention is not limited to those shown in the above embodiments. For example, in the above embodiments, when a part of the sub-area straddles the boundary of the display areas of adjacent source drivers, that is, when the boundary of the sub-area to be subjected to local dimming control does not coincide with the boundary of the display area to be driven by the source driver and a shared sub-area is generated, this case has been described as an example. However, even when the boundaries coincide and no shared sub-area is generated, the configuration of the local dimming control unit in the display device 100 of this embodiment is useful.

[0058] FIG. 9 is a diagram showing the arrangement of sub-areas and each source driver when the boundary of the sub-area to be subjected to local dimming control coincides with the boundary of the display area to be driven by the source driver.

[0059] The source driver 13A is supplied with the image data VD1X corresponding to the display of rows 1 to 6 in columns A, B, and C. Therefore, the source driver 13A can calculate the dimming data corresponding to rows 1 to 6 in column C using the image data corresponding to rows 1 to 6 in column C. However, in order to calculate the dimming data of each sub-area, it is necessary to use a part of the image data of the adjacent sub-area.

[0060] For example, in order to calculate the dimming data corresponding to the second row of column C, in addition to the image data of the area SA indicated by the hatching in FIG. 9, that is, the image data of the second column of row C, a part of the image data of columns 1 to 3 of row B, a part of the image data of columns 1 and 3 of row C, and a part of the image data of columns 1 to 3 of row D need to be used. If, different from this embodiment, there is no exchange of dimming data between source drivers, the source driver 13A alone cannot accurately calculate the dimming data of the second column of row C.

[0061] On the other hand, according to the configuration of the display device 100 of this embodiment, since the data post-processing unit 23 of the source driver 13A receives the supply of dimming data from the source driver 13B and performs a synthesis operation, the dimming data of the second column of row C can be accurately calculated. Therefore, even when the boundary of the sub-area to be locally dimmed coincides with the boundary of the display area to be driven by the source driver, by adopting the configuration of each source driver of this embodiment, it is possible to perform detailed control of simple local dimming.

[0062] In the above embodiment, a light source is provided for the sub-areas obtained by dividing the display area DA1 of the display panel 11 into 6 rows × 8 columns, the gradation average value of the image data is obtained for each sub-area, and an example of controlling the LED driver by calculating the dimming amount based on this has been described. However, the number of sub-areas is not limited to this, and for example, it may be divided into more sub-areas than 6 rows × 8 columns.

[0063] Also, when calculating the dimming amount for each sub-area, instead of calculating the dimming amount using only the gradation average value of the corresponding sub-area, the dimming amount of each sub-area may be calculated by referring to the gradation average values of adjacent sub-areas in addition to this.

[0064] In addition, when calculating the dimming amount, the dimming amount may be calculated using a calculation method other than the average of the gradations. Further, other elements than the gradations may be calculated as feature amounts, and the dimming amount may be calculated based on the calculated feature amounts. That is, based on the image data VD1 to VD3, the feature amounts of the pixel data signals corresponding to the respective sub-areas are calculated, predetermined calculations are performed based on the calculated feature amounts, and any method may be used as long as the dimming amount for each sub-area is calculated.

Description of Reference Numerals

[0065] 100 Display device 11 Display panel 12 Gate driver 13A Source driver 13B Source driver 13C Source driver 14 LED driver 16 Lighting unit 21 LCD driving unit 22 Local dimming control unit 23 Data post-processing unit 24 LED driver communication unit 31 Pixel data processing unit 32 Gradation average calculation unit 33 Dimming amount calculation unit 34 Dimming data writing unit

Claims

1. A display panel having a plurality of data lines, a plurality of gate lines, and a plurality of pixel portions provided in a matrix at each intersection of the plurality of data lines and the plurality of gate lines; A plurality of source drivers disposed corresponding to each of a plurality of data line groups included in the plurality of data lines, receiving supply of image data corresponding to an image to be displayed on pixel portions on each corresponding data line group via different image data supply lines, and generating a gradation voltage signal for supplying pixel portions disposed on each corresponding data line group based on the image data; An illumination driving unit that controls the amount of light of a backlight that illuminates each of a plurality of sub-areas obtained by dividing the display screen of the display panel; characterized by comprising: Based on the image data supplied to each of the plurality of source drivers, the plurality of source drivers generate dimming data indicating the amount of light of the backlight of the sub-area in which pixel portions that are supply targets of the gradation voltage signals of the plurality of source drivers exist among the plurality of sub-areas; One of the plurality of source drivers receives supply of the dimming data from other source drivers, and supplies a dimming data signal generated based on the dimming data of the one source driver and the dimming data of the other source drivers to the illumination driving unit. A display device characterized by the above.

2. When the one source driver is a shared sub-area in which a sub-area where pixel portions that are supply targets of the gradation voltage signal from the one source driver exist is also a sub-area where pixel portions that are supply targets of the gradation voltage signal from other source drivers exist among the dimming data for each sub-area, the one source driver performs an operation of synthesizing the dimming data of the one source driver and the dimming data of the other source drivers for the shared sub-area. The display device according to claim 1, characterized by the above.

3. Each of the plurality of source drivers has a local dimming function unit that calculates a feature amount of the image data corresponding to each of a group of sub-areas where each corresponding data line group is located among the plurality of sub-areas based on the gradation of pixels included in the image data supplied to each, and generates the dimming data for each sub-area based on the calculated feature amount. The display device according to claim 1, characterized by the above.

4. The one source driver A data post-processing unit that synthesizes the dimming data generated by the local dimming function unit and the dimming data supplied from the other source driver to generate the dimming data signal indicating the light amount of the backlight for each sub-area. A communication unit that transmits the dimming data signal to the illumination driving unit. The display device according to claim 3, characterized by comprising the above.

5. A display panel having a plurality of pixel units arranged in a matrix at each intersection of a plurality of data lines and a plurality of gate lines, and an illumination driving unit that controls the light amount of a backlight that illuminates each of a plurality of sub-areas obtained by dividing the display screen of the display panel. The source driver is connected to the illumination driving unit, is arranged corresponding to a first data line group included in the plurality of data lines, receives the supply of first image data corresponding to an image to be displayed on the pixel units on the first data line group via a first image data supply line, and generates a gradation voltage signal for supplying the pixel units arranged on the first data line group based on the image data. A local dimming function unit that generates first dimming data indicating the light amount of the backlight of the sub-areas where the pixel units on the first data line group are located among the plurality of sub-areas based on the gradation of the pixels included in the first image data. A data post-processing unit that acquires second dimming data indicating the light amount of the backlight corresponding to the feature amount of the second image data from another source driver arranged corresponding to a second data line group included in the plurality of data lines and receiving the supply of second image data corresponding to an image to be displayed on the pixel units on the second data line group via a second image data supply line, and generates a dimming data signal based on the first dimming data and the second dimming data. A communication unit that transmits the dimming data signal to the illumination driving unit. The source driver is characterized by comprising the above.

6. When the sub-area where the pixels on the first data line group exist among the dimming data for each sub-area is a shared sub-area where the pixels on the second data line group also exist, the data post-processing unit performs an operation of synthesizing the first dimming data and the second dimming data for the shared sub-area. The source driver according to claim 5, characterized by the above.

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