WO2015029461A1

WO2015029461A1 - Display device and method for driving same

Info

Publication number: WO2015029461A1
Application number: PCT/JP2014/053257
Authority: WO
Inventors: 典昭山口; 宮田　英利
Original assignee: シャープ株式会社
Priority date: 2013-08-28
Filing date: 2014-02-13
Publication date: 2015-03-05

Abstract

A liquid-crystal panel is partitioned vertically into a plurality of regions, and in each field period, a process in which video data corresponding to the color of that field is written sequentially in the vertical direction is performed on each region in parallel. A backlight is also partitioned vertically into a plurality of regions, and in each field period, a process in which the color in a given region is set to the color of that field, sequentially in the vertical direction, is performed on each region in parallel. The write sequences for the regions of the liquid-crystal panel are switched on a per-region basis, and in accordance with said write sequences, the sequences in which the regions of the backlight are set to the color of the field are also switched on a per-region basis. This prevents color shift near region boundaries in a field-sequential-color display device in which a plurality of regions are driven in parallel.

Description

Display device and driving method thereof

The present invention relates to a display device and a driving method thereof, and more particularly to a display device that displays a plurality of fields in one frame period and a driving method thereof.

As a display device that performs color display, a display device of a field sequential color method (Field Sequential Color method: hereinafter referred to as FSC method) has been conventionally known. An FSC liquid crystal display device includes a liquid crystal panel including a plurality of pixel circuits and a backlight for switching emission colors, and displays a plurality of fields in one frame period. For example, when three fields are displayed in one frame period, video data corresponding to red is written in the liquid crystal panel in the first field period, and the backlight emits red light. In the second field period, video data corresponding to green is written on the liquid crystal panel, and the backlight emits green light. In the third field period, video data corresponding to blue is written on the liquid crystal panel, and the backlight emits blue light. This liquid crystal display device performs color display by displaying red, green and blue fields in order. The backlight includes, for example, a red LED (Light Emitting Diode) that emits red light, a green LED that emits green light, and a blue LED that emits blue light.

In order to realize a high color gamut, high brightness, and flickerless in an FSC liquid crystal display device, it is necessary to drive the liquid crystal panel at high speed. As a method of driving a liquid crystal panel at high speed, a method of dividing a liquid crystal panel into a plurality of regions and driving the plurality of regions in parallel has been conventionally known. Japanese Patent Application Laid-Open No. 2004-228688 describes an RGB writing order for pixel circuits in an FSC liquid crystal display device that drives a liquid crystal panel by dividing the liquid crystal panel into an upper region and a lower region in order to prevent color mixing that occurs near the boundary between the regions. It describes that the RGB lighting order of the backlight is shifted between regions (see FIG. 3 described later).

Japanese Unexamined Patent Publication No. 2006-22085

Generally, the light emitted from the LED included in the backlight diffuses at a wide angle. Therefore, in the liquid crystal display device described in Patent Document 1, the color of the previous field is likely to be mixed with the color of the current field in the upper region, and the color of the next field is likely to be mixed with the color of the current field in the lower region ( (See FIG. 5 described later). As described above, since the colors mixed in the current field are different above and below the boundary of the region, the display color is changed in different directions above and below the boundary of the region. For this reason, in the liquid crystal display device described in Patent Document 1, a color shift occurs near the boundary, and an unnatural display is performed.

Therefore, an object of the present invention is to prevent color misregistration that occurs near the boundary between regions in an FSC display device that drives a plurality of regions in parallel.

A first aspect of the present invention is a display device that displays a plurality of fields in one frame period,
A display panel including a plurality of pixel circuits arranged two-dimensionally;
A backlight including a plurality of light emitting elements;
The display panel is divided into a plurality of areas in the first direction, and in each field period, video data corresponding to the field color is sequentially written in the first direction in parallel with the plurality of areas of the display panel. A panel drive circuit to perform,
The backlight is divided into a plurality of regions in the first direction corresponding to the display panel, and processing for setting the colors in the regions in order to the field colors in the first direction in each field period And a backlight drive circuit that performs in parallel for a plurality of regions,
The panel driving circuit switches the writing order for each area of the display panel for each area, and the backlight driving circuit changes the order of setting the field colors in each area of the backlight according to the writing order. Switching is performed for each region.

According to a second aspect of the present invention, in the first aspect of the present invention,
The backlight has a configuration in which the plurality of light emitting elements are two-dimensionally arranged.

According to a third aspect of the present invention, in the first aspect of the present invention,
The backlight includes a light guide plate and a light emitting unit disposed on a side surface of the light guide plate,
The light emitting unit has a configuration in which the plurality of light emitting elements are arranged one-dimensionally.

According to a fourth aspect of the present invention, there is provided a display having a display panel including a plurality of pixel circuits arranged two-dimensionally and a backlight including a plurality of light emitting elements, and displaying a plurality of fields in one frame period. A method for driving an apparatus, comprising:
The display panel is divided into a plurality of areas in the first direction, and in each field period, video data corresponding to the field color is sequentially written in the first direction in parallel with the plurality of areas of the display panel. A panel driving step to be performed;
The backlight is divided into a plurality of regions in the first direction corresponding to the display panel, and processing for setting the colors in the regions in order to the field colors in the first direction in each field period A backlight driving step that is performed in parallel with respect to the plurality of regions,
In the panel driving step, the writing order for each area of the display panel is switched for each area, and in the backlight driving step, the order of setting the field colors in each area of the backlight is set in accordance with the writing order. Switching is performed for each region.

According to the first or fourth aspect of the present invention, the writing order for each area of the display panel is switched for each area, and the order of setting the field color in each area of the backlight is set for each area in accordance with the writing order. Switch to. As a result, the color mixed in the current field is made the same above and below the boundary of the region, and the display color is changed in the same direction above and below the boundary, thereby preventing color misregistration occurring near the boundary.

According to the second aspect of the present invention, it is possible to prevent color misregistration that occurs near the boundary between regions using a backlight in which a plurality of light emitting elements are arranged two-dimensionally.

According to the third aspect of the present invention, using a backlight including a light guide plate and a light emitting unit in which a plurality of light emitting elements are arranged in a one-dimensional manner, preventing color misregistration that occurs near the boundary of the region. Can do. In addition, the structure of the backlight can be simplified and the display device can be thinned.

1 is a block diagram illustrating a configuration of a liquid crystal display device according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a detailed configuration of a control circuit of the liquid crystal display device illustrated in FIG. 1. It is a figure which shows the drive order of the liquid crystal panel and backlight in the conventional liquid crystal display device. It is a figure which shows the drive order of the liquid crystal panel and backlight in the liquid crystal display device shown in FIG. It is a figure which shows the example of the display screen of the conventional liquid crystal display device. It is a figure which shows the example of the display screen of the liquid crystal display device shown in FIG. It is a figure which shows the drive timing of the liquid crystal panel and backlight in the conventional liquid crystal display device. It is a figure which shows the light distribution characteristic of LED in the conventional liquid crystal display device. It is a block diagram which shows the structure of the liquid crystal display device which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the liquid crystal display device which concerns on the 3rd Embodiment of this invention. It is a figure which shows the drive order of the liquid crystal panel and backlight in the liquid crystal display device shown in FIG.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of the liquid crystal display device according to the first embodiment of the present invention. The liquid crystal display device 1 shown in FIG. 1 includes a liquid crystal panel 11, a backlight 12, a scanning line driving circuit 13, a data line driving circuit 14, a backlight driving circuit 15, and a control circuit 16. The liquid crystal display device 1 is a field sequential color liquid crystal display device. The liquid crystal display device 1 divides one frame period into three field periods (hereinafter referred to as first to third field periods), and three fields (hereinafter referred to as first to third fields) in one frame period. Is displayed. Hereinafter, m and n are integers of 2 or more, and the first to third fields correspond to red, green, and blue, respectively.

The liquid crystal panel 11 includes (m × n) pixel circuits (not shown) arranged two-dimensionally. In the horizontal direction of the display screen (the x direction shown in FIG. 1, hereinafter simply referred to as the horizontal direction), m pixel circuits are arranged side by side. In the vertical direction of the display screen (the y direction shown in FIG. 1, hereinafter simply referred to as the vertical direction), n pixel circuits are arranged side by side. The liquid crystal panel 11 is divided into an upper region A1 and a lower region A2 in the vertical direction. The upper region A1 includes (m / 2) scanning lines, n data lines, and (m / 2 × n) pixel circuits (all not shown). The (m / 2) scanning lines extend in the horizontal direction and are arranged side by side in the vertical direction. The n data lines extend in the vertical direction and are arranged side by side in the horizontal direction. (M / 2 × n) pixel circuits are provided corresponding to the intersections of (m / 2) scanning lines and n data lines. The lower area A2 has the same configuration as the upper area A1.

The scanning line driving circuit 13 and the data line driving circuit 14 drive the upper area A1 and the lower area A2 in parallel. More specifically, the scanning line driving circuit 13 includes two circuits (scanning

line driving circuits

13a and 13b) that operate in parallel, and the data line driving circuit 14 includes two circuits (data line driving circuit) that operate in parallel. 14a, 14b). The scanning line driving circuit 13a sequentially selects (m / 2) scanning lines in the upper region A1 in each field period. The data line driving circuit 14a applies n voltages corresponding to the video data corresponding to the field color to the n data lines in the upper area A1. Similarly to the scanning line driving circuit 13a, the scanning line driving circuit 13b drives (m / 2) scanning lines in the lower region A2. Similarly to the data line drive circuit 14a, the data line drive circuit 14b drives n data lines in the lower region A2.

The backlight 12 is a direct type backlight including a plurality of LEDs arranged two-dimensionally. The backlight 12 includes a plurality of red LEDs 17r, a plurality of green LEDs 17g, and a plurality of blue LEDs 17b. Each of the red LED 17r, the green LED 17g, and the blue LED 17b is two-dimensionally arranged.

The backlight 12 is divided into an upper region B1 and a lower region B2 in the vertical direction corresponding to the liquid crystal panel 11. The upper region B1 and the lower region B2 are each further divided into p blocks (p is an integer of 2 or more) in the vertical direction. The backlight drive circuit 15 divides each field period into p periods. The backlight drive circuit 15 selects k blocks (k is an integer less than or equal to 1 and less than p) from each of the upper region B1 and the lower region B2 in each period, and three types of the selected 2k blocks are selected. One of the LEDs 17r, 17g, and 17b is controlled to emit light.

FIG. 2 is a block diagram showing a detailed configuration of the control circuit 16. As illustrated in FIG. 2, the control circuit 16 includes a field data generation unit 41, a video division unit 42, an LED data generation unit 43, liquid crystal

timing control units

44 a and 44 b, and an LED timing control unit 45. A signal source 40 shown in FIG. 2 is provided outside the liquid crystal display device 1. The signal source 40 outputs video data D1 for color display to the liquid crystal display device 1. The video data D1 includes video data corresponding to red, video data corresponding to green, and video data corresponding to blue (hereinafter referred to as red video data, green video data, and blue video data). The frame rate of the video data D1 is, for example, 60 frames / second.

The field data generation unit 41 receives the video data D1 output from the signal source 40. First, the field data generation unit 41 extracts red video data from the video data D1 and outputs the red video data to the video division unit 42, and outputs a control signal indicating red to the LED data generation unit 43. Next, the field data generation unit 41 extracts green video data from the video data D1 and outputs the green video data to the video division unit 42, and outputs a control signal indicating green to the LED data generation unit 43. Next, the field data generation unit 41 extracts blue video data from the video data D1 and outputs it to the video division unit 42, and outputs a control signal indicating blue to the LED data generation unit 43.

The video dividing unit 42 divides the video data of each color output from the field data generating unit 41 into video data corresponding to the upper region A1 and video data corresponding to the lower region A2, and the former is the liquid crystal timing control unit 44a. And the latter to the liquid crystal timing controller 44b. The LED data generation unit 43 generates LED data indicating a block to be selected based on the control signal output from the field data generation unit 41, and outputs the generated LED data to the LED timing control unit 45.

The liquid crystal timing control unit 44a outputs the video data output from the video dividing unit 42 in accordance with the timing of the data line driving circuit 14a. The data line driving circuit 14a drives n data lines in the upper area A1 based on the video data output from the liquid crystal timing control unit 44a. The liquid crystal timing control unit 44b outputs the video data output from the video dividing unit 42 in accordance with the timing of the data line driving circuit 14b. The data line driving circuit 14b drives n data lines in the lower area A2 based on the video data output from the liquid crystal timing control unit 44b. The LED timing control unit 45 outputs the LED data output from the LED data generation unit 43 in accordance with the timing of the backlight drive circuit 15. The backlight drive circuit 15 drives the three types of LEDs 17r, 17g, and 17b in the backlight 12 based on the LED data output from the LED timing control unit 45.

The liquid crystal display device 1 is characterized by the driving order of the liquid crystal panel 11 and the backlight 12. Hereinafter, characteristics of the liquid crystal display device 1 will be described in contrast to the liquid crystal display device described in the second embodiment of Patent Document 1 (hereinafter referred to as a conventional liquid crystal display device). In the following description, p = 5 and k = 2 are assumed in order to facilitate comparison with the conventional liquid crystal display device.

FIG. 3 is a diagram showing a driving order of a liquid crystal panel and a backlight in a conventional liquid crystal display device. FIG. 4 is a diagram illustrating a driving order of the liquid crystal panel and the backlight in the liquid crystal display device 1. 3 and 4, the vertical axis represents the position in the vertical direction, and the horizontal axis represents time. Arrows with reference signs Wr, Wg, and Wb represent writing of red video data, green video data, and blue video data to the liquid crystal panel, respectively. The letters R, G, and B represent the light emission periods of the red LED, green LED, and blue LED, respectively. For example, the letter R written in the 0th period of the first block indicates that the red LED in the first block emits light in the 0th period.

In the conventional liquid crystal display device (FIG. 3), video data of each color is written to the liquid crystal panel in order from the top in line units. Specifically, the writing of the green video data to the pixel circuit in the first row is performed at the beginning of the third period. The writing of the green video data to the pixel circuits in the second to mth rows is performed one horizontal period after the writing of the green video data to the pixel circuits on the first row. The red video data is written to the pixel circuits in each row one field period before the green video data is written to the pixel circuits in the same row. The blue video data is written to the pixel circuits in each row one field after the green video data is written to the pixel circuits in the same row.

¡In accordance with the writing order of video data of each color, the LEDs of each color in the backlight emit light sequentially from the top in block units. Specifically, the green LED in the first block emits light in the fifth period and the sixth period. The green LEDs in the second to tenth blocks emit light one period after the emission period of the green LEDs in the upper block. The red LED in each block emits light one field period before the light emission period of the green LED in the same block. The blue LED in each block emits light after one field period of the light emission period of the green LED in the same block.

On the other hand, in the liquid crystal display device 1 (FIG. 4), the writing of the video data of each color to the upper area A1 of the liquid crystal panel 11 is sequentially performed from the top in line units, and the video of each color to the lower area A2 of the liquid crystal panel 11 Data writing is performed in order from the bottom in line units. Specifically, the green video data is written to the pixel circuits in the first row and the m-th row at the beginning of the third period. The writing of the green video data to the pixel circuits in the second to (m / 2) rows is performed one horizontal period after the writing of the green video data to the pixel circuits in one row. Writing of the green video data to the pixel circuits in the (m / 2 + 1) to (m−1) rows is performed one horizontal period after the writing of the green video data to the pixel circuits in the lower row. The red video data is written to the pixel circuits in each row one field period before the green video data is written to the pixel circuits in the same row. The blue video data is written to the pixel circuits in each row one field after the green video data is written to the pixel circuits in the same row.

In accordance with the writing order of video data of each color, the LEDs in the upper area B1 of the backlight 12 emit light sequentially from the top in blocks, and the LEDs in the lower area B2 of the backlight 12 emit light sequentially from the bottom in blocks. To do. Specifically, the green LEDs 17g in the first and tenth blocks emit light in the fifth period and the sixth period. The green LEDs 17g in the second to fifth blocks emit light one period after the light emission period of the green LEDs 17g in the upper block. The green LEDs 17g in the sixth to ninth blocks emit light one period after the light emission period of the green LED 17g in the next lower block. The red LED 17r in each block emits light one field before the light emission period of the green LED 17g in the same block. The blue LED 17b in each block emits light after one field period of the light emission period of the green LED 17g in the same block.

Hereinafter, in the liquid crystal display device 1 and the conventional liquid crystal display device, consider the case where the red LEDs in the fifth and sixth blocks emit light. In the conventional liquid crystal display device (FIG. 3), the red LED in the fifth block emits light in the fourth period and the fifth period. In the fourth period, in addition to the red LED in the fifth block, the red LED in the fourth block and the blue LED in the ninth and tenth blocks emit light, so the portion corresponding to the fifth block of the liquid crystal panel is red. Blue is mixed in. In the fifth period, in addition to the red LED in the fifth block, the green LED in the first block, the red LED in the sixth block, and the blue LED in the tenth block emit light, so that the fifth block of the liquid crystal panel In the corresponding part, green and blue are mixed in red. In the portion corresponding to the fifth block of the liquid crystal panel, the display color changes in the blue direction because blue is mixed more than green.

The red LED in the sixth block emits light in the fifth period and the sixth period. In the fifth period, in addition to the red LED in the sixth block, the green LED in the first block, the red LED in the fifth block, and the blue LED in the tenth block emit light, so the sixth block of the liquid crystal panel In the portion corresponding to, green and blue are mixed with red. In the sixth period, in addition to the red LED in the sixth block, the green LED in the first and second blocks and the red LED in the seventh block emit light, so the portion corresponding to the sixth block of the liquid crystal panel is red. Green is mixed in. In the portion corresponding to the sixth block of the liquid crystal panel, the green color is mixed more than the blue color, so the display color changes in the green direction.

Thus, in the conventional liquid crystal display device, when red is displayed, the display color changes in the blue direction in the upper region and in the green direction in the lower region. In general, in the upper area, the color of the previous field is likely to be mixed with the color of the current field, and in the lower area, the display color of the next field is likely to be mixed with the color of the current field. As described above, in the conventional liquid crystal display device, the color mixed in the current field is different above and below the boundary of the region, and the display color is changed in different directions above and below the boundary. For this reason, in the conventional liquid crystal display device, a color shift occurs near the boundary, and an unnatural display is performed.

In contrast, in the liquid crystal display device 1 (FIG. 4), the red LED 17r in the fifth block emits light in the fourth period and the fifth period. In the fourth period, the red LED 17r in the fourth, sixth and seventh blocks emits light in addition to the red LED 17r in the fifth block, so that the color corresponding to the fifth block of the liquid crystal panel 11 is changed to red. Does not mix. In the fifth period, in addition to the red LED 17r in the fifth block, the green LED 17g in the first and tenth blocks and the red LED 17r in the sixth block emit light, so in the portion corresponding to the fifth block of the liquid crystal panel 11 Green is mixed with red.

The red LED 17r in the sixth block emits light in the fourth period and the fifth period. In the fourth period, the red LED 17r in the fourth, fifth and seventh blocks emits light in addition to the red LED 17r in the sixth block, so that the color corresponding to the sixth block of the liquid crystal panel 11 is changed to red. Does not mix. In the fifth period, in addition to the red LED 17r in the sixth block, the green LED 17g in the first and tenth blocks and the red LED 17r in the fifth block emit light, so in the portion corresponding to the sixth block of the liquid crystal panel 11 Green is mixed with red.

Thus, in the liquid crystal display device 1, when red is displayed, the display color changes in the green direction in both the upper region A1 and the lower region A2. In general, the display color of the next field tends to be mixed with the color of the current field in both the upper area and the lower area. Thus, in the liquid crystal display device 1, the color mixed in the current field is the same above and below the boundary of the region, and the display color changes in the same direction above and below the boundary. Therefore, according to the liquid crystal display device 1, it is possible to prevent color misregistration that occurs near the boundary and perform natural display near the boundary.

FIG. 5 is a diagram showing an example of a display screen of a conventional liquid crystal display device. FIG. 6 is a diagram illustrating an example of a display screen of the liquid crystal display device 1. On the display screen shown in FIGS. 5 and 6, a color bar including a red region, a green region, and a blue region is displayed. Hereinafter, in the vicinity of the boundary of the region, the part above the boundary is referred to as the upper part of the boundary, and the part below the boundary is referred to as the lower part of the boundary.

In the display screen (FIG. 5) of the conventional liquid crystal display device, the display color at the upper boundary in the red region changes in the blue direction, and the display color at the lower boundary in the red region changes in the green direction. The display color at the upper boundary in the green region changes in the red direction, and the display color at the lower boundary in the green region changes in the blue direction. The display color at the upper boundary in the blue region changes in the green direction, and the display color at the lower boundary in the blue region changes in the red direction. In this way, in the conventional liquid crystal display device, the display color changes in different directions above and below the boundary of the region, so that color misregistration occurs near the boundary and unnatural display is performed.

On the other hand, on the display screen of the liquid crystal display device 1 (FIG. 6), the display color at the upper boundary in the red region changes in the green direction, and the display color at the lower boundary in the red region also changes in the green direction. The display color at the upper boundary in the green region changes in the blue direction, and the display color at the lower boundary in the green region also changes in the blue direction. The display color at the upper boundary in the blue region changes in the red direction, and the display color at the lower boundary in the blue region also changes in the red direction. As described above, in the liquid crystal display device 1, since the display color changes in the same direction above and below the boundary of the region, it is possible to prevent a color shift occurring near the boundary and to perform natural display near the boundary.

FIG. 7 is a diagram showing the driving timing of the liquid crystal panel and the backlight in the conventional liquid crystal display device. Here, the size of the liquid crystal panel is 20 inches, the resolution of the liquid crystal panel is 960 × 1080 dots, and the frame rate is 100 frames / second (300 fields / second). The time required for writing video data to half of the liquid crystal panel is 2.33 ms, and the liquid crystal responds instantaneously. In addition, the backlight has a configuration in which a plurality of LED chips including a red LED, a green LED, and a blue LED are arranged one-dimensionally in the horizontal direction and arranged in the vertical direction. Suppose that it has the light distribution characteristic shown. In FIG. 8, the horizontal axis represents the distance normalized with the vertical size of the display screen being 1, and the vertical axis represents the luminance normalized with 1 being directly above. It is assumed that each color LED emits light over one field period from the writing of video data to the writing of the next video data.

When the above conditions are set, in the conventional liquid crystal display device, when red is displayed, the color difference ΔE * between the pixel immediately above the boundary and the pixel immediately below the boundary is 0.8. Since humans can recognize this color difference, an unnatural display is performed near the boundary. In contrast, in the liquid crystal display device 1, the color difference ΔE * is zero. Therefore, according to the liquid crystal display device 1, it is possible to prevent color misregistration that occurs near the boundary and perform natural display near the boundary.

As a method of reducing the above color difference in a conventional liquid crystal display device, a method of suppressing the diffusion of light emitted from the LED can be considered. However, this method has a problem that the cost of the liquid crystal display device is increased because the number of LEDs needs to be increased. On the other hand, in the liquid crystal display device 1, since the color difference does not occur, it is not necessary to increase the number of LEDs. Therefore, according to the liquid crystal display device 1, it is possible to prevent color misregistration that occurs near the boundary between regions at low cost without increasing the number of LEDs.

As described above, the liquid crystal display device 1 according to the present embodiment includes a display panel (liquid crystal panel 11) including a plurality of pixel circuits arranged two-dimensionally and a backlight including a plurality of light emitting elements (LEDs 17). 12, a panel drive circuit (scanning line drive circuit 13 and data line drive circuit 14), and a backlight drive circuit 15. The panel drive circuit divides the display panel into a plurality of regions (upper region A1 and lower region A2) in a first direction (vertical direction), and in each field period, video data corresponding to the field color is divided in the first direction. Are sequentially written in a plurality of areas of the display panel. The backlight drive circuit 15 divides the backlight 12 into a plurality of regions (upper region B1 and lower region B2) in the first direction corresponding to the display panel, and changes the color in the region to the first in each field period. The process of setting the field colors in order in the direction is performed on a plurality of areas of the backlight 12 in parallel. The panel drive circuit switches the writing order for each area of the display panel for each area (in the upper area A1, writing is performed in order from the top, and in the lower area A2 is sequentially performed from the bottom). The backlight driving circuit 15 switches the order of setting the field color in each area of the backlight 12 for each area in accordance with the writing order (in the upper area B1 in order from the top and in the lower area B2 in order from the bottom). To do).

In this way, the liquid crystal display device 1 switches the writing order for each area of the display panel for each area, and switches the order for setting the field color in each area of the backlight for each area in accordance with the writing order. Therefore, according to the liquid crystal display device 1 according to the present embodiment, the color mixed in the current field is the same above and below the boundary of the region, and the display color is changed in the same direction above and below the boundary to generate near the boundary. Color misregistration can be prevented.

Further, the backlight 12 has a configuration in which a plurality of light emitting elements are arranged two-dimensionally. By using such a backlight 12, it is possible to prevent color misregistration that occurs near the boundary of the region. The panel drive circuit divides the display panel into two regions, and the backlight drive circuit 15 divides the backlight 12 into two regions. As a result, it is possible to prevent a color shift that occurs near the boundary of the region with a simple configuration. The display panel further includes a plurality of scanning lines arranged in the first direction and a plurality of data lines arranged in the second direction (horizontal direction), and the panel driving circuit includes the plurality of scanning lines. Are sequentially selected in the first direction, and a data line driving circuit 14 for applying a voltage corresponding to video data to a plurality of data lines. As a result, when the display panel and the backlight 12 are divided into a plurality of regions in the direction in which the scanning lines are arranged and the plurality of regions are driven in parallel, a color shift that occurs near the boundary between the regions can be prevented. .

(Second Embodiment)
FIG. 9 is a diagram showing a configuration of a liquid crystal display device according to the second embodiment of the present invention. The liquid crystal display device 2 shown in FIG. 9 is obtained by replacing the backlight 12 with the backlight 21 and replacing the backlight drive circuit 15 with the backlight drive circuit 24 in the liquid crystal display device 1 according to the first embodiment. is there. Among the constituent elements of the present embodiment, the same elements as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The backlight 21 includes an LED bar 22 and a light guide plate 23. The LED bar 22 has a structure in which a red LED 17r, a green LED 17g, and a blue LED 17b are repeatedly arranged one-dimensionally. The light guide plate 23 is provided on the back side of the liquid crystal panel 11, and the LED bar 22 is provided on the side surface of the light guide plate 23.

As in the first embodiment, the backlight 21 is vertically divided into an upper region B1 and a lower region B2, and the upper region B1 and the lower region B2 are each divided into p blocks. The backlight drive circuit 24 divides each field period into p periods. In each period, the backlight drive circuit 24 selects k blocks from the upper region B1 and the lower region B2, and 1 of the three types of LEDs 17r, 17g, and 17b corresponding to the selected 2k blocks. The type of LED is controlled to emit light. In order to perform this control, the backlight drive circuit 24 may individually drive the red LED 17r, the green LED 17g, and the blue LED 17b included in the LED bar 22.

In the liquid crystal display device 2 according to the present embodiment, the backlight 21 includes a light guide plate 23 and a light emitting unit (LED bar 22) disposed on a side surface of the light guide plate, and the light emitting unit includes a plurality of light emitting elements (LEDs 17). Are arranged one-dimensionally. By using the backlight 21 having such a configuration, it is possible to prevent color misregistration that occurs near the boundary of the region. Moreover, the structure of the backlight 21 can be simplified and the liquid crystal display device 2 can be made thin.

(Third embodiment)
FIG. 10 is a diagram showing a configuration of a liquid crystal display device according to the third embodiment of the present invention. The liquid crystal display device 3 illustrated in FIG. 10 includes a liquid crystal panel 31, a backlight 32, a scanning line driving circuit 33, a data line driving circuit 34, a backlight driving circuit 35, and a control circuit 16. Among the constituent elements of the present embodiment, the same elements as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

The liquid crystal panel 31 includes (m × n) pixel circuits (not shown) in the same manner as the liquid crystal panel 11 according to the first embodiment. In the liquid crystal display device 3, the liquid crystal panel 31 is divided into q (q is an integer of 3 or more) regions A1 to Aq in the vertical direction. Each of the regions A1 to Aq includes (m / q) scanning lines, n data lines, and (m / q × n) pixel circuits (all not shown).

The scanning line driving circuit 33 and the data line driving circuit 34 drive the regions A1 to Aq in parallel. More specifically, the scanning line driving circuit 33 includes q circuits (scanning line driving circuits 33-1 to 33-q) operating in parallel, and the data line driving circuit 34 includes two circuits operating in parallel ( Data

line driving circuits

34a and 34b) are included. The scanning line driving circuit 33-1 sequentially selects (m / q) scanning lines in the area A1. Similarly to the scanning line driving circuit 13a, the scanning line driving circuits 33-2 to 33-q drive (m / 2) scanning lines in the regions A2 to Aq, respectively. The data line driving circuit 34a responds to the video data corresponding to the field color (n × x / 2) for the data lines in the areas A1 to Aq / 2 (total of (n × q / 2) data lines). q / 2) voltages are applied. The data line driving circuit 34b drives the data lines in the regions Aq / 2 + 1 to An, similarly to the data line driving circuit 34a.

The backlight 32 has the same configuration as the backlight 12 according to the first embodiment. Similar to the liquid crystal panel 31, the backlight 32 is divided into q regions B1 to Bq in the vertical direction. Each of the regions B1 to Bq is further divided into p blocks in the vertical direction. The backlight drive circuit 35 controls one of the three types of LEDs 17r, 17g, and 17b to be in a light emitting state in each field period.

FIG. 11 is a diagram showing a driving order of the liquid crystal panel and the backlight in the liquid crystal display device 3. In FIG. 11, t represents one frame period after time 0. As shown in FIG. 11, the writing of the video data of each color to the odd-numbered areas A1, A3,... Of the liquid crystal panel 31 is performed in order from the top in line units, and the even-numbered areas A2, A4,. Writing of video data of each color is performed in order from the bottom in line units. Specifically, the writing of the green video data to the pixel circuits in the uppermost row in the odd-numbered regions A1, A3,... And the pixel circuits in the lowermost row in the even-numbered regions A2, A4,. / 3. The green video data is written to the pixel circuits in the other rows in the odd-numbered areas A1, A3,... One horizontal period after the green video data is written to the pixel circuits in the first row. The green video data is written to the pixel circuits in the other rows in the even-numbered areas A2, A4,... One horizontal period after the green video data is written to the pixel circuits in the lower row. The red video data is written to the pixel circuits in each row one field period before the green video data is written to the pixel circuits in the same row. The blue video data is written to the pixel circuits in each row one field after the green video data is written to the pixel circuits in the same row.

As the video data of each color is written, the LEDs in the odd-numbered areas B1, B3,... Of the backlight 32 emit light sequentially from the top in block units, and the even-numbered areas B2, B4,. The LEDs emit light sequentially from the bottom in block units. Specifically, the green LED 17g in the uppermost block in the odd-numbered areas B1, B3,... And the green LED 17g in the lowermost block in the even-numbered areas B2, B4,. Light is emitted in a period from a little later to a little before 2t / 3. The green LEDs 17g in the other blocks in the odd-numbered areas B1 and B3 emit light with a delay of time T from the light emission period of the green LED 17g in the upper block. The green LEDs 17g in the other blocks in the even-numbered regions B2 and B4 emit light with a delay of time T from the green LEDs 17g in the next lower block. The red LED 17r in each block in each region emits light one field before the light emission period of the green LED 17g in the same block. The blue LEDs 17b in each block of each region emit light after one field period of the light emission period of the green LED 17g in the same block.

In the liquid crystal display device 3 according to the present embodiment, the panel drive circuit (scanning line drive circuit 33 and data line drive circuit 34) divides the display panel (liquid crystal panel 31) into three or more regions, and the backlight drive circuit 35. Divides the backlight 32 into three or more regions. As a result, the color misregistration occurrence range can be narrowed, and the color misregistration occurring near the boundary of the region can be prevented more effectively.

As described above, according to the display device of the present invention, the writing order with respect to each area of the display panel is switched for each area, and the order of setting the field color in each area of the backlight is set according to the writing order. By switching each time, the color mixed in the current field can be made the same above and below the boundary of the region, and the display color can be changed in the same direction above and below the boundary to prevent a color shift occurring near the boundary.

The following configuration is conceivable as a display device and a driving method thereof according to the present invention.

(Appendix 1)
A display device (1, 2, 3) for displaying a plurality of fields in one frame period,
A display panel (11, 31) including a plurality of pixel circuits arranged two-dimensionally;
A backlight (12, 21, 32) including a plurality of light emitting elements (17);
Panel driving in which the display panel is divided into a plurality of areas in the first direction, and in each field period, the video data corresponding to the field color is sequentially written in the first direction to the plurality of areas of the display panel in parallel. A circuit (13, 14, 33, 34);
The backlight is divided into a plurality of areas in the first direction corresponding to the display panel, and the process of setting the colors in the areas to the field colors in the first direction in each field period is performed on the plurality of areas of the backlight. And a backlight drive circuit (15, 24, 35) that performs in parallel with
The panel drive circuit switches the writing order for each area of the display panel for each area, and the backlight driving circuit switches the order of setting the field colors in each area of the backlight for each area in accordance with the writing order. It is characterized by.

According to such a configuration, the writing order for each area of the display panel is switched for each area, and the order for setting the field color in each area of the backlight is switched for each area in accordance with the writing order. As a result, the color mixed in the current field is made the same above and below the boundary of the region, and the display color is changed in the same direction above and below the boundary, thereby preventing color misregistration occurring near the boundary.

(Appendix 2)
The display device according to appendix 1, wherein the backlight (12, 32) has a configuration in which a plurality of light emitting elements (17) are two-dimensionally arranged.

According to such a configuration, it is possible to prevent a color shift that occurs near the boundary of a region by using a backlight in which a plurality of light emitting elements are two-dimensionally arranged.

(Appendix 3)
The backlight (21) includes a light guide plate (23) and a light emitting unit (22) disposed on a side surface of the light guide plate,
The display device according to appendix 1, wherein the light emitting unit has a configuration in which a plurality of light emitting elements (17) are arranged one-dimensionally.

According to such a configuration, it is possible to prevent a color shift that occurs near the boundary between regions using a backlight including a light guide plate and a light emitting unit in which a plurality of light emitting elements are arranged one-dimensionally. In addition, the structure of the backlight can be simplified and the display device can be thinned.

(Appendix 4)
The panel drive circuit (13, 14) divides the display panel (11) into two areas, and the backlight drive circuit (15, 24) divides the backlight (12, 21) into two areas. The display device according to attachment 1, wherein the display device is characterized.

According to such a configuration, the display panel and the backlight are each divided into two regions, and the two regions are driven in parallel, so that the color shift that occurs near the boundary between the regions can be simplified. Can be prevented.

(Appendix 5)
The panel driving circuit (33, 34) divides the display panel into three or more areas, and the backlight driving circuit (35) divides the backlight (32) into three or more areas. The display device according to 1.

According to such a configuration, the display panel and the backlight are each divided into three or more regions, and the three or more regions are driven in parallel, thereby narrowing the range of occurrence of color misregistration. Color misregistration that occurs in the vicinity of the boundary can be more effectively prevented.

(Appendix 6)
The display panel (11, 31) further includes a plurality of scanning lines arranged in the first direction and a plurality of data lines arranged in the second direction,
The panel driving circuit (13, 14, 33, 34) includes a scanning line driving circuit (13, 33) for sequentially selecting a plurality of scanning lines in the first direction, and a voltage corresponding to video data with respect to the plurality of data lines. The display device according to appendix 1, further comprising: a data line driving circuit (14, 34) for applying a voltage.

According to such a configuration, when the display panel and the backlight are divided into a plurality of regions in the scanning line alignment direction and the plurality of regions are driven in parallel, the color shift that occurs near the boundary of the regions is prevented. Can be prevented.

(Appendix 7)
It has a display panel (11, 31) including a plurality of pixel circuits arranged two-dimensionally and a backlight (12, 21, 32) including a plurality of light emitting elements (17). A display device (1, 2, 3) driving method for displaying a field of
Panel driving in which the display panel is divided into a plurality of areas in the first direction, and in each field period, the video data corresponding to the field color is sequentially written in the first direction to the plurality of areas of the display panel in parallel. Steps,
The backlight is divided into a plurality of areas in the first direction corresponding to the display panel, and the process of setting the colors in the areas to the field colors in the first direction in each field period is performed on the plurality of areas of the backlight. And a backlight driving step to be performed in parallel,
In the panel driving step, the writing order for each area of the display panel is switched for each area, and in the backlight driving step, the order of setting the field color in each area of the backlight is switched for each area in accordance with the writing order. It is characterized by.

According to such a configuration, the same effect as the display device described in Supplementary Note 1 can be obtained.

Since the display device of the present invention has a feature that color misregistration that occurs near the boundary between regions can be prevented, a variety of field sequential color methods such as a field sequential color liquid crystal display device that drives a plurality of regions in parallel can be used. It can be used for a display device.

DESCRIPTION OF

SYMBOLS

1, 2, 3 ... Liquid

crystal display device

11, 31 ...

Liquid crystal panel

12, 21, 32 ... Back light 13, 33 ... Scanning

line drive circuit

14, 34 ... Data

line drive circuit

15, 24, 35 ... Backlight drive circuit 16 ... Control circuit 17 ... LED
DESCRIPTION OF SYMBOLS 22 ... LED bar 23 ... Light guide plate 40 ... Signal source 41 ... Field data generation part 42 ... Image division part 43 ... LED data generation part 44 ... Liquid crystal timing control part 45 ... LED timing control part

Claims

A display device that displays a plurality of fields in one frame period,
A display panel including a plurality of pixel circuits arranged two-dimensionally;
A backlight including a plurality of light emitting elements;
The display panel is divided into a plurality of areas in the first direction, and in each field period, video data corresponding to the field color is sequentially written in the first direction in parallel with the plurality of areas of the display panel. A panel drive circuit to perform,
The backlight is divided into a plurality of regions in the first direction corresponding to the display panel, and processing for setting the colors in the regions in order to the field colors in the first direction in each field period And a backlight drive circuit that performs in parallel for a plurality of regions,
The panel driving circuit switches the writing order for each area of the display panel for each area, and the backlight driving circuit changes the order of setting the field colors in each area of the backlight according to the writing order. A display device, wherein switching is performed for each region.
The display device according to claim 1, wherein the backlight has a configuration in which the plurality of light emitting elements are two-dimensionally arranged.
The backlight includes a light guide plate and a light emitting unit disposed on a side surface of the light guide plate,
The display device according to claim 1, wherein the light emitting unit has a configuration in which the plurality of light emitting elements are arranged one-dimensionally.
A display device driving method for displaying a plurality of fields in one frame period, comprising a display panel including a plurality of pixel circuits arranged two-dimensionally and a backlight including a plurality of light emitting elements,
The display panel is divided into a plurality of areas in the first direction, and in each field period, video data corresponding to the field color is sequentially written in the first direction in parallel with the plurality of areas of the display panel. A panel driving step to be performed;
The backlight is divided into a plurality of regions in the first direction corresponding to the display panel, and processing for setting the colors in the regions in order to the field colors in the first direction in each field period A backlight driving step that is performed in parallel with respect to the plurality of regions,
In the panel driving step, the writing order for each area of the display panel is switched for each area, and in the backlight driving step, the order of setting the field colors in each area of the backlight is set in accordance with the writing order. A method for driving a display device, wherein switching is performed for each region.