JP6050932B2 - Display device - Google Patents

Description

  The present invention relates to a display device.

  Conventionally, display devices that perform so-called local dimming have been developed. Local dimming is a control method for controlling the brightness of the backlight for each block that divides the screen. As a result, in the block displaying a low gradation in the screen, the luminance of the backlight is lowered, and when it is desired to display black, it can be displayed as complete black. Further, in a block that displays a high gradation in the screen, the brightness of the backlight is high, so that a sufficiently bright display can be performed. Therefore, it is possible to improve the contrast and display a high-quality image. Furthermore, since the luminance of the backlight can be locally reduced, it is possible to reduce power consumption. For example, Patent Document 1 discloses a backlight capable of performing local dimming by causing each light emitting unit arranged two-dimensionally to emit light independently.

  Here, FIG. 5 shows a configuration of a conventional example of a liquid crystal display device that performs local dimming. A conventional liquid crystal display device 300 shown in FIG. 5 includes an image board 100 and a liquid crystal display unit 200. The image board 100 includes a CPU (Central Processing Unit) 101, a VDP (Video Display Processor) 102, and a ROM (Read Only Memory) 103. The liquid crystal display unit 200 includes a drive circuit 201, a liquid crystal panel 202, an image analysis / local dimming data creation circuit 203, a control circuit 204, and an LED (Light Emitting Diode) backlight unit 205.

  Under the control of the CPU 101, the VDP 102 reads image data 103A stored in advance in the ROM 103, and outputs the read image data from the output channel 102A to the drive circuit 201 and the image analysis / local dimming data creation circuit 203. The ROM 103 is detachable from the image board 100, and it is easy to change the content to be displayed. The image analysis / local dimming data creation circuit 203 analyzes the luminance level or gradation of the input image data, creates local dimming data including luminance information for each block in the screen, and creates the created local dimming data. Output to the control circuit 204. The control circuit 204 controls the brightness of each LED in each block in the LED backlight unit 205 based on the input local dimming data.

  The image analysis / local dimming data creation circuit 203 creates local dimming data and also generates a correction signal and outputs it to the drive circuit 201. This correction signal is a signal for correcting image data in consideration of local dimming. The drive circuit 201 drives the liquid crystal panel 202 based on the input image data and the correction signal. Thereby, the image display by local dimming can be performed.

JP 2011-151005 A

  However, the conventional liquid crystal display device requires a dedicated image analysis / local dimming data creation circuit on the liquid crystal display unit side. Also, if the analysis accuracy by this circuit is poor, appropriate local dimming cannot be performed.

  In particular, as a display device for amusement applications, there are cases where it is desired to aim for an image effect that is intentionally brightened or darkened. However, in the method of creating local dimming data by the image analysis / local dimming data creation circuit, In some cases, it was insufficient to aim for such an effect.

  In view of the above problems, an object of the present invention is to provide a display device that does not require a dedicated image analysis / light source control data creation circuit on the display unit side and can perform effective light source control. .

A display device according to one embodiment of the present invention includes:
A display panel;
A light source for illuminating the display panel;
A storage unit that stores light source control data that is control data of the light source when displaying an image related to the image data together with the image data;
It is characterized by providing.

In addition, a display device according to another aspect of the present invention includes:
A display panel;
A light source for illuminating the display panel;
An input unit for inputting light source control data, which is control data of the light source when displaying an image related to the image data, together with the image data;
It is characterized by providing.

  The input unit is, for example, an interface to which a receiving unit that receives broadcast content and an optical disc playback apparatus are connected.

  According to the present invention, a dedicated image analysis / light source control data generation circuit is not required on the display unit side, and effective light source control can be performed.

1 is a configuration diagram of a liquid crystal display device according to a first embodiment of the present invention. It is a block diagram of the liquid crystal display device which concerns on 2nd Embodiment of this invention. It is a block diagram of the liquid crystal display device which concerns on 3rd Embodiment of this invention. It is a figure which shows an example of the relationship between a display image and the block of local dimming. It is the figure which extracted some blocks of FIG. 4A. It is a block diagram which shows the prior art example of a liquid crystal display device.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the above-described prior art, local dimming data is created on the liquid crystal display unit side, so there is no need to output it to the liquid crystal display unit side. However, in the present invention, an image board equipped with a VDP (Video Display Processor) is placed on the liquid crystal display unit side. Local dimming data needs to be output. Therefore, the first embodiment to the third embodiment (FIGS. 1 to 3) will be described separately for VDP output forms (one having two output channels and one having one output channel).

(First embodiment)
The configuration of the liquid crystal display device according to the first embodiment of the present invention is shown in FIG. A liquid crystal display device 30 shown in FIG. 1 includes an image board 10 and a liquid crystal display unit 20.

  The image board 10 includes a CPU (Central Processing Unit) 11, a VDP (Video Display Processor) 12, and a ROM (Read Only Memory) 13. The liquid crystal display unit 20 includes a drive circuit 21, a liquid crystal panel 22, a control circuit 23, and an LED (Light Emitting Diode) backlight unit 24.

  The CPU 11 is an arithmetic device that controls the VDP 12. The VDP 12 is an image output processor having two output channels, a first output channel 12A for image output and a second output channel 12B for local dimming data output.

  The liquid crystal display device 30 can be mounted on an amusement device (such as a pachislot machine) or a digital signage. Digital signage is arranged outdoors or in public facilities and displays advertising content, messages, and the like. Therefore, the ROM 13 stores image data 13A in advance as content to be displayed for amusement use and signage use. The image data 13A has a resolution of, for example, XGA (1024 × 768) and is composed of, for example, 8-bit RGB data for each pixel. The ROM 13 can be attached to and detached from the image board 10 and it is easy to change the content to be displayed.

  In addition to the image data 13A, the ROM 13 stores in advance local dimming data 13B, which is control data for local dimming.

  Here, the LED backlight unit 24 illuminates the liquid crystal panel 22 from behind, and has a plurality of blocks that divide the screen for backlight light source control. A plurality of LEDs are provided per block, and the luminance can be controlled for each block. Assuming that the number of pixels corresponding to one block is n × n, the local dimming data 13B has a resolution in which the number of vertical and horizontal pixels of the image data 13A is 1 / n. For example, when the image data 13A has a resolution of XGA (1024 × 768) and n = 64, the local dimming data 13B has a resolution of 16 × 12. The local dimming data 13B is composed of, for example, 8-bit luminance data per pixel.

  Under the control of the CPU 11, the VDP 12 reads the image data 13A and the local dimming data 13B from the ROM 13, outputs the read image data 13A to the drive circuit 21 from the first output channel 12A, and outputs the read local dimming data 13B to the second. The data is output from the output channel 12B to the control circuit 23.

  The drive circuit 21 drives the liquid crystal corresponding to each pixel of the liquid crystal panel 22 based on the image data 13A input from the first output channel 12A. The control circuit 23 controls the luminance for each block of the LED backlight unit 24 based on the local dimming data 13B input from the second output channel 12B. Thereby, an image by local dimming is displayed.

  For example, as shown in FIG. 4A, a local dimming block has a moon M, another block has a window W of a house H (lighted inside), and the other blocks are wrapped in darkness. If it is rare, in order to make the moon M most noticeable, the LED light quantity of the block (2B, 3B, 2C and 3C) of the moon M is made highest, and the LED light quantity of the block (5F) of the window W of the house H is increased. Control is performed so that the amount of LED light in the dark portion blocks (blocks other than the above) is the lowest. That is, local dimming data 13B for such control is prepared in advance.

  Further, image data 13A prepared in advance in consideration of this control is also corrected data. For example, the blocks of month M (2B, 3B, 2C, and 3C) have a high LED light amount, and therefore, the portion where month M is not present in the block range of month M (the shaded area in FIG. 4B) changes the black level to other blocks (for example, 1A, 2A, 3A, 4A, 1B, 4B, 1C, 4C, 1D, 2D, 3D, and 4D), and uniformizing the luminance level of the place without the moon M.

  Thus, in the present embodiment, local dimming data is stored in advance in the ROM 13 together with image data, and the luminance control of the LED backlight unit 24 is performed based on the local dimming data. The image analysis / local dimming data creation circuit required on the side becomes unnecessary.

  Also, since local dimming data created corresponding to the image data can be prepared in advance, effective local dimming can be performed. In particular, if local dimming data created intentionally (the local dimming data described with reference to FIG. 4A is an example thereof) is prepared, an intentional image display effect can be achieved, especially for amusement and signage applications. It becomes effective. That is, normally, local dimming data that performs optimum luminance control based on an image is generated, but it is also possible to intentionally brighten or darken the effect.

(Second Embodiment)
The configuration of the liquid crystal display device according to the second embodiment of the present invention is shown in FIG. A liquid crystal display device 60 shown in FIG. 2 includes an image board 40 and a liquid crystal display unit 50. The present embodiment relates to a multilayer display having a structure in which two liquid crystal panels are stacked. Hereinafter, differences from the first embodiment will be described in detail.

  The image board 40 includes a CPU 41, a VDP 42, a ROM 43, a scaler IC 44, and a scaler IC 45. The liquid crystal display unit 50 includes a drive circuit 51, a front liquid crystal panel 52, a drive circuit 53, a rear liquid crystal panel 54, a control circuit 55, and an LED backlight unit 56.

  The VDP 42 has two output channels, a first output channel 42A for image output and a second output channel 42B for local dimming data output.

  In the ROM 43, local dimming data 43B is stored in advance together with the image data 43A. The image data 43A includes two image data 43A1 obtained by compressing the image for the front liquid crystal panel 52 in half in the horizontal direction and two image data 43A2 obtained by compressing the image for the rear liquid crystal panel 54 in half in the horizontal direction. They are arranged side by side, and so-called Side-by-Side format. When the front liquid crystal panel 52 and the rear liquid crystal panel 54 each have a resolution of, for example, XGA (1024 × 768), the image data 43A1 and 43A2 each have a resolution of 512 × 768 (that is, the image data 43A as a whole). 1024 × 768 resolution). As a result, even if the VDP 42 has only one output channel 42A for image output, two images can be displayed.

  Here, in the liquid crystal display unit 50, the LED backlight unit 56, the rear liquid crystal panel 54, and the front liquid crystal panel 52 are arranged in this order from the rear of the display unit. The LED backlight unit 56 illuminates the front liquid crystal panel 52 and the rear liquid crystal panel 54 from behind, and has a plurality of blocks that divide the screen for local dimming. A plurality of LEDs are provided per block, and the luminance can be controlled for each block. Assuming that the number of pixels corresponding to one block is n × n, the local dimming data 43B has a resolution in which the number of vertical and horizontal pixels of the image data 43A is 1 / n. For example, when the image data 43A has a resolution of XGA (1024 × 768) and n = 64, the local dimming data 43B has a resolution of 16 × 12.

  Under the control of the CPU 41, the VDP 42 reads the image data 43A and local dimming data 43B from the ROM 43, outputs the read image data 43A to the scaler IC 44 and scaler IC 45 from the first output channel 42A, and reads the read local dimming data 43B. Output from the second output channel 42B to the control circuit 55.

  The scaler IC 44 extracts the image data 43A1 from the image data 43A input from the first output channel 42A, and scales up the extracted image data twice in the horizontal direction. Further, the scaler IC 45 extracts the image data 43A2 from the image data 43A input from the first output channel 42A, and scales up the extracted image data twice in the horizontal direction. For example, when the image data 43A1 and 43A2 each have a resolution of 512 × 768, the resolution becomes 1024 × 768 when scaled up twice in the horizontal direction. In order to suppress the synchronization shift, it is desirable that the scaler ICs 44 and 45 use ICs having the same specifications (or model number / part number).

  The drive circuit 51 drives the liquid crystal corresponding to each pixel of the front liquid crystal panel 52 based on the scaled-up image data input from the scaler IC 44. The drive circuit 53 drives the liquid crystal corresponding to each pixel of the rear liquid crystal panel 54 based on the scaled-up image data input from the scaler IC 45.

  The control circuit 55 controls the luminance for each block of the LED backlight unit 56 based on the local dimming data input from the second output channel 42B. As a result, an image obtained by combining the image on the front liquid crystal panel 52 and the image on the rear liquid crystal panel 54 is displayed while performing local dimming.

  Since the multi-layer display has a structure in which two liquid crystal panels are stacked, the power consumption of the backlight unit is five times or more larger than that of a standard liquid crystal display. Local dimming is a method for reducing power consumption particularly effective for such a multi-layer display. However, since each image is displayed on the front and rear liquid crystal panels in the multi-layer display, a sufficient power saving effect cannot be expected in the conventional local dimming based on one input image.

  On the other hand, according to the present embodiment, local dimming data created corresponding to two images to be displayed can be prepared in advance, so that local dimming effective in reducing power consumption can be achieved.

  In addition, when trying to perform local dimming using a conventional image analysis / local dimming data creation circuit in a multi-layer display, it is necessary to perform analysis / data creation considering both image data of two liquid crystal panels. Although this is complicated, the present embodiment does not require an image analysis / local dimming data creation circuit, and thus can be avoided.

(Third embodiment)
FIG. 3 shows a configuration of a liquid crystal display device according to the third embodiment of the present invention. A liquid crystal display device 90 shown in FIG. 3 includes an image board 70 and a liquid crystal display unit 80. Hereinafter, differences from the first embodiment will be described in detail.

  The image board 70 includes a CPU 71, a VDP 72, a ROM 73, a scaler IC 74, and a scaler IC 75. The liquid crystal display unit 80 includes a drive circuit 81, a liquid crystal panel 82, a control circuit 83, and an LED backlight unit 84.

  Unlike the first embodiment having two output channels, the VDP 72 has only one output channel 72A. Therefore, the ROM 73 stores in advance image / dimming composite data 73A in which image data and local dimming data are combined, and the image / dimming composite data 73A is output from the output channel 72A.

  The image / dimming composite data 73A is composed of image data 73A1 obtained by compressing the image for the liquid crystal panel 82 in half in the horizontal direction and two local dimming data 73A2 having the same resolution as the image data 73A1 in the horizontal direction. It consists of the so-called Side-by-Side format. When the liquid crystal panel 82 has a resolution of XGA (1024 × 768), for example, the image data 73A1 and the local dimming data 73A2 each have a resolution of 512 × 768 (that is, the entire image / dimming composite data 73A is 1024 ×. 768 resolution).

  Under the control of the CPU 71, the VDP 72 reads the image / dimming composite data 73A from the ROM 73, and outputs the read image / dimming composite data 73A to the scaler IC 74 and the scaler IC 75 from the output channel 72A.

  The scaler IC 74 extracts the image data 73A1 from the image / dimming composite data 73A input from the output channel 72A, and scales up the extracted image data 73A1 twice in the horizontal direction. For example, when the image data 73A1 has a resolution of 512 × 768, the resolution is 1024 × 768 when scaled up twice in the horizontal direction.

  Also, the scaler IC 75 extracts local dimming data 73A2 from the image / dimming composite data 73A input from the output channel 72A. The extracted local dimming data 73A2 is 1 / n in the vertical direction and 2 / n in the horizontal direction. Scale down. The number of pixels per block of the LED backlight unit 84 is n × n. For example, when the local dimming data 73A2 has a resolution of 512 × 768 and n = 64, the resolution is 16 × 12 when scaled down.

  In order to suppress the synchronization shift, the scaler ICs 74 and 75 are desirably ICs having the same specification (or model number / part number). Further, the image data 73A1 is not limited to the half compressed in the horizontal direction, and may be compressed to 80%, for example.

  The drive circuit 81 drives the liquid crystal corresponding to each pixel of the liquid crystal panel 82 based on the scaled-up image data input from the scaler IC 74. The control circuit 83 controls the luminance for each block of the LED backlight unit 84 based on the scaled down local dimming data input from the scaler IC 75. Thereby, the locally dimmed image is displayed.

  According to the present embodiment, since the created image / dimming composite data can be prepared in advance, even when the VDP has only one output channel, it is possible to display an image while performing effective local dimming.

  Although one embodiment of the present invention has been described above, the embodiment can be variously modified within the scope of the gist of the present invention. For example, a rewritable storage device (HDD (Hard Disk Drive), SSD (Solid State Drive), etc.) may be used as the storage unit that stores local dimming data together with image data.

  In addition to storing image data and local dimming data in the ROM, the receiving unit receives broadcast content including image data and local dimming data, and receives the received image data and local dimming data from the VDP. You may make it output. Broadcast content including image data and local dimming data is transmitted from a transmission device installed in a broadcast station. For example, a local dimming data stream may be multiplexed in addition to a video stream, an audio stream, and a data broadcast stream and transmitted as MPEG-TS (transport stream). Alternatively, local dimming data may be stored in the header of a video packet constituting the MPEG-TS, or a payload for local dimming may be prepared in the video packet.

  Note that transmission by broadcasting as described above is not limited to broadcasting by radio waves such as terrestrial digital broadcasting, but may be applied to closed broadcasting systems such as cable television broadcasting, in-house broadcasting, and Internet broadcasting.

  In addition, image data and local dimming data are recorded as contents on an optical disk such as a DVD, the optical disk is reproduced by an external optical disk reproducing apparatus connected to a display device such as a USB terminal, and the reproduced image data and local data are recorded. The dimming data may be input to the display device and output from the VDP. In this case, the image data, audio data, and local dimming data may be stored in the same file, or the local dimming data may be stored in a file different from the file in which the image data and audio data are stored.

  Further, the backlight light source is not limited to the LED, and a CCFL (cold cathode tube) may be adopted. In this case, for example, light source control data including luminance data corresponding to the average luminance of the entire image may be output from the VDP.

10 Image board 11 CPU
12 VDP
12A First output channel 12B Second output channel 13 ROM
13A Image data 13B Local dimming data 20 Liquid crystal display unit 21 Drive circuit 22 Liquid crystal panel 23 Control circuit 24 LED backlight unit 30 Liquid crystal display device 40 Image board 41 CPU
42 VDP
42A First output channel 42B Second output channel 43 ROM
43A Image data 43B Local dimming data 44, 45 Scaler IC
DESCRIPTION OF SYMBOLS 50 Liquid crystal display unit 51 Drive circuit 52 Front side liquid crystal panel 53 Drive circuit 54 Rear side liquid crystal panel 55 Control circuit 56 LED backlight unit 60 Liquid crystal display device 70 Image board 71 CPU
72 VDP
72A Output channel 73 ROM
73A Image / Dimming Composite Data 74, 75 Scaler IC
80 Liquid Crystal Display Unit 81 Drive Circuit 82 Liquid Crystal Panel 83 Control Circuit 84 LED Backlight Unit 90 Liquid Crystal Display Device

Claims (4)

A display panel;
A plurality of blocks that divide the display screen, and a light source that controls the brightness of each block to illuminate the display panel;
A storage unit including a ROM that stores light source control data that is control data of the light source when displaying an image related to the image data together with the image data;
Equipped with a,
One output channel in a format in which the image data and light source control data stored in the storage unit, the image data obtained by compressing the image for the display panel in the horizontal direction, and the light source control data are arranged in the horizontal direction on the screen A display device comprising an output unit for outputting from the display. A first scaler to scale up the output image data from said output unit, a second scaler for scaling down the output light source control data from the output unit, to claim 1, characterized in that it comprises a The display device described. A display panel;
A plurality of blocks that divide the display screen, and a light source that controls the brightness of each block to illuminate the display panel;
A receiver that receives broadcast content including light source control data that is control data of the light source when displaying an image related to the image data together with the image data;
A display device comprising: The display device according to any one of claims 1 to 3 , which can be mounted on an amusement device or a digital signage.

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