JP5303622B2 - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which displays a clear and bright moving image in spite of its extremely simple structure. <P>SOLUTION: A liquid crystal display device includes a liquid crystal display panel having a plurality of scan lines and a back light. The back light applies a plurality of quantities of light varying with time on the side of the liquid crystal display panel within a cycle to control the plurality of scan lines, and a screen is scanned to display black in one screen scan of a plurality of screen scans. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device including a liquid crystal display panel and a backlight disposed on the back surface of the liquid crystal display panel.

  This type of liquid crystal display device recognizes the light from the backlight as an image by observing the light through the liquid crystal display panel in which the light transmission amount is controlled for each pixel of the liquid crystal display panel.

  Here, the liquid crystal display panel includes a switching element that is driven by supply of a gate signal from a gate signal line to each pixel region on the liquid crystal side surface of one of the substrates that are opposed to each other through the liquid crystal. One having a pixel electrode to which a video signal from a drain signal line is supplied via a switching element is known.

  For example, an electric field is generated between the pixel electrode and a counter electrode disposed adjacent to the pixel electrode, and the light transmittance of the liquid crystal is controlled by the electric field.

  On the other hand, the backlight has a plurality of linear light sources (for example, cold cathode ray tubes) arranged in a plane parallel to the plane including the liquid crystal display panel in order to make the light irradiation uniform as the liquid crystal display panel becomes larger. In addition, a so-called direct type is used which is arranged on the back surface of the light source and is made up of a reflection plate that reflects light from the light source toward the liquid crystal display panel.

  The backlight is kept on as it is driven by the liquid crystal display panel.

  However, it has been pointed out that the liquid crystal display device configured in this manner can display a still image clearly, but cannot obtain a sufficient clarity regarding a moving image. .

  This is because, in recent years, such an inconvenience cannot be ignored as an attempt is made to display a television image on a liquid crystal display device.

  That is, in the display of moving images, the luminance change with respect to time of each pixel is large, and the driving of the liquid crystal cannot sufficiently follow the change. For example, the moving object to be displayed is moved from one place to another place. When moving, an afterimage at a certain location is recognized and the entire moving object is displayed in a blurred state.

  Therefore, the present invention has been made based on such circumstances, and an object of the present invention is to provide a liquid crystal display device capable of displaying a clear moving image in spite of an extremely simple configuration. .

  Another object of the present invention is to provide a liquid crystal display device capable of displaying a clear and bright moving image without increasing the power consumption of the backlight.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

Means 1.
The liquid crystal display device according to the present invention is, for example, a liquid crystal display device having a backlight, and the backlight outputs a first state that outputs a first amount of light and a second state that outputs a second amount of light. 2, and the time of the first state and the time of the second state are controlled.

Mean 2.
The liquid crystal display device according to the present invention is, for example, a liquid crystal display device having a backlight, and the backlight includes a first state to which a first voltage is applied and a second state to which a second voltage is applied. And the time of the first state and the time of the second state are controlled.

Means 3.
The liquid crystal display device according to the present invention is, for example, a liquid crystal display panel having a plurality of scanning lines and a liquid crystal display device having a backlight, and a first voltage and a second voltage are predetermined for the backlight. The predetermined period is synchronized with a period for controlling the plurality of scanning lines.

Means 4.
A liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel and a backlight disposed on the back surface of the liquid crystal display panel,
The backlight is characterized in that it is turned on and off repeatedly and includes means for controlling the ratio between the lighting time and the lighting time.

Means 5.
The liquid crystal display device according to the present invention includes, for example, a switching element that is driven by supplying a gate signal from a gate signal line to each pixel region on the liquid crystal side surface of one of the substrates that are opposed to each other with liquid crystal interposed therebetween. A liquid crystal display panel including a pixel electrode to which a drain signal from a drain signal line is supplied via the switching element, and a backlight disposed on the back surface of the liquid crystal display panel,
The backlight is characterized in that it is turned on and off repeatedly in synchronization with the start of supply of the scanning signal, and has a means for controlling the ratio between the lighting time and the lighting time.

Means 6.
The liquid crystal display device according to the present invention is characterized in that, for example, on the premise of the configuration of the means 3, the backlight is turned on and off once in a period between the data rewrite synchronization signal and the next synchronization signal. To do.

Means 7.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel and a backlight disposed on the back surface of the liquid crystal display panel,
The liquid crystal display panel constitutes a liquid crystal display unit composed of a collection of a large number of pixels in the spreading direction of the liquid crystal interposed between a pair of substrates, and each pixel includes a pixel electrode to which a video signal is independently supplied. Become
Detecting means for detecting the magnitude of a change in the video signal to the pixel electrode in each pixel region as the entire liquid crystal display unit;
When the change of the video signal is large by the detection means, the backlight blinking means for repeatedly turning on and off the backlight is provided.

Means 8.
The liquid crystal display device according to the present invention includes, for example, a backlight blinking control means for reducing the duty of the lighting time according to the magnitude of the change of the video signal by the detection means on the premise of the configuration of the means 7. It is characterized by comprising.

Means 9.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 8, the backlight blinking control means includes means for increasing the current supplied to the backlight when the duty of the lighting time is small. Is.

Means 10.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel and a backlight disposed on the back surface of the liquid crystal display panel,
The liquid crystal display panel constitutes a liquid crystal display unit composed of a collection of a large number of pixels in the spreading direction of the liquid crystal interposed between a pair of substrates, and each pixel includes a pixel electrode to which a video signal is independently supplied. Become
Detecting means for detecting a change in the video signal to the pixel electrode in each pixel region as a partial region of the liquid crystal display unit;
When the change of the video signal is large by the detection means, the backlight blinking means for repeatedly turning on and off the backlight is provided.

Means 11.
The liquid crystal display device according to the present invention includes, for example, a gate signal line extending in the x direction and juxtaposed in the y direction on the liquid crystal side surface of one substrate of the liquid crystal display panel, and extending in the y direction and parallel in the x direction. Each region surrounded by the drain signal line provided is a pixel region. In each pixel region, a switching element driven by a scanning signal from a gate signal line on one side, and a drain signal line from the drain signal line via this switching element A pixel electrode to which a video signal is supplied;
The partial area of the liquid crystal display unit is a collection area of each pixel area including pixel electrodes driven by partial gate signal lines arranged adjacent to each other.

Means 12.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 11, each region of the liquid crystal display unit includes pixel electrodes driven by gate signal lines that run substantially in the center of the liquid crystal display unit. The pixel area is a collection area.

Means 13.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 11, a part of the liquid crystal display unit is driven by each gate signal line running on at least one side excluding the substantially center of the liquid crystal display unit. The pixel region is a collection region of pixel regions each having a pixel electrode.

Means 14.
The liquid crystal display device according to the present invention includes, for example, a backlight blinking control means for reducing the duty of the lighting time according to the magnitude of the change of the video signal by the detection means on the premise of the configuration of the means 10. It is characterized by comprising.

Means 15.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 14, the backlight blinking control means includes means for increasing the current supplied to the backlight when the duty of the lighting time is small. Is.

Means 16.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel and a backlight disposed on the back surface of the liquid crystal display panel,
The liquid crystal display panel constitutes a liquid crystal display unit composed of a set of a large number of pixels in the spreading direction of the liquid crystal interposed between a pair of substrates, a pixel electrode to which a video signal is independently supplied to each pixel, A pixel electrode and a counter electrode that generates an electric field corresponding to the video signal;
When the video signal is large when the light transmittance of the liquid crystal is increased by the electric field,
Detecting means for detecting the magnitude of the video signal to the pixel electrode of each pixel region as an average of the entire liquid crystal display unit;
When the video signal is large by the detection means, the backlight blinking means for repeatedly turning on and off the backlight is provided.

Means 17.
The liquid crystal display device according to the present invention includes, for example, a backlight blinking control means for increasing the duty of the lighting time according to the magnitude of the video signal when the detection means is large on the premise of the configuration of the means 16. It is characterized by this.

Means 18.
The liquid crystal display device according to the present invention has, for example, a liquid crystal display panel and a backlight disposed on the back of the liquid crystal display panel,
The backlight includes a plurality of linear light sources extending in the x direction and arranged in parallel in the y direction on a surface substantially parallel to the surface of the liquid crystal display panel.
During display driving, among the light sources, the light source arranged at the center is repeatedly turned on and off, and the other light sources below are kept on.

Means 19.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 18, the liquid crystal display panel extends in the x direction on the liquid crystal side surface of one of the substrates opposed to each other via the liquid crystal. Each region surrounded by a gate signal line juxtaposed in the direction and a drain signal line extending in the y direction and juxtaposed in the x direction is defined as a pixel region, and scanning from the gate signal line on one side is performed on each pixel region. A switching element driven by a signal and a pixel electrode to which a video signal from a drain signal line is supplied via the switching element are provided.

Means 20.
The liquid crystal display device according to the present invention is, for example, on the premise of the configuration of the means 18, a portion facing a plane determined by each light source that is repeatedly turned on and off, of a liquid crystal display unit comprising a set of pixel regions of a liquid crystal display panel At
It is characterized by comprising a backlight blinking control means for detecting a change in the video signal to the pixel electrode in each pixel area of the portion and increasing the duty of the lighting time according to the magnitude of the change. It is.

Means 21.
The liquid crystal display device according to the present invention has, for example, a liquid crystal display panel and a backlight disposed on the back of the liquid crystal display panel,
The backlight includes a plurality of linear light sources extending in the x direction and arranged in parallel in the y direction on a surface substantially parallel to the surface of the liquid crystal display panel.
When the display is driven, each of the light sources is repeatedly turned on and off, and the lighting duty of the light source arranged in the center is configured to be smaller than the lighting duty of the other light sources.

Means 22.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
The light source disposed at least in the central portion is repeatedly turned on and off, and the light source disposed on at least one of the sides of the central portion is kept on.

Means 23.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
When sequentially displaying each frame of the liquid crystal display panel, at least for each frame, the light source disposed at least in the center repeats turning on and off without changing the phase, and at least one of both sides of the center The light source to be arranged is configured to be repeatedly turned on and off with a phase shift.

Means 24.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
Each of the light sources repeats lighting and extinguishing with the same frequency, and at least the frequency of lighting and extinguishing of the light source arranged in the central part is turned on and off of the light source arranged on at least one of both sides of the central part It is characterized by being configured to be smaller than this frequency.

Means 25.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
Each of the light sources repeats turning on and off, and at least the light source lighting duty disposed in the central portion is configured to be smaller than the light source lighting duty disposed on at least one of the sides of the central portion. It is characterized by this.

Means 26.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
The light source arranged at least in the central part repeats lighting and extinguishing, and the light source arranged on at least one side of the central part maintains the lighting and supplies more current or voltage than the light source arranged in the central part. This is characterized in that it is configured so as to be small.

Means 27.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
Each light source arranged at least in the center repeats turning on and off, and the light source arranged on at least one of the sides of the center maintains lighting,
The light sources arranged on at least one of the two sides are characterized in that the arrangement pitch with other adjacent light sources is larger than the arrangement pitch of each light source arranged in the center.

Means 28.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
The light source disposed at least in the central portion repeats turning on and off, and the light source disposed on at least one of the sides of the central portion maintains lighting,
At least one of the light source disposed in the central portion and the light source disposed on at least one of both sides of the light source is configured to be able to control the magnitude of the supply current or the supply voltage. .

Means 29.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel in which each pixel group to which a video signal is supplied is selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back surface of the liquid crystal display panel. And
The backlight includes a plurality of linear light sources extending in parallel to the gate signal line in a plane substantially parallel to the surface of the liquid crystal display panel and arranged in parallel in a direction intersecting the gate signal line.
At least one of the light source arranged in the central portion and at least one of the light sources arranged on both sides of the light source is configured to be able to control the lighting duty for turning off.

Means 30.
The liquid crystal display device according to the present invention has, for example, a liquid crystal display panel and a backlight, and the backlight can be turned on and off repeatedly.
A liquid crystal display device having a configuration in which a display mode can be switched between a moving image and a still image, and turning on and off a backlight in the moving image display mode,
The screen rewriting frequency at the time of moving image display is higher than that at the time of still image display.

Means 31.
The liquid crystal display device according to the present invention has, for example, a mode in which moving images and still images are switched and displayed in each configuration of means 1 to 30, and in the moving image mode, the backlight is turned on and off repeatedly. It is a feature.

Means 32.
The liquid crystal display device according to the present invention is, for example, a liquid crystal display panel having a plurality of scanning lines and a liquid crystal display device having a backlight,
The backlight is configured to irradiate the liquid crystal display panel side with a plurality of light amounts that vary with time within a period in which the plurality of scanning lines are controlled.

Means 33.
In the liquid crystal display device according to the present invention, for example, in the configuration of the means 32, the plurality of light amounts include a first light amount, a second light amount, and a third light amount, and at least one of the light amounts is selected. The present invention is characterized in that the time length can be controlled.

Means 34.
A liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel having a plurality of scanning lines, and a backlight having a plurality of light sources arranged in parallel on a virtual plane substantially parallel to the liquid crystal display panel,
The plurality of light sources are repeatedly turned on and off after the start of supply of the scanning signal, and at least one light source is turned on with a delay in at least one cycle for controlling the scanning signal. It is.

Means 35.
In the liquid crystal display device according to the present invention, for example, the lighting of the light source that is turned on with a delay on the premise of the configuration of the means 34 is such that the time integral value of the cycle for controlling the scanning line is the lighting or scanning of another light source. It is characterized by being substantially the same as the time integral value of the other period for controlling the line.

Means 36.
The liquid crystal display device according to the present invention is characterized in that, for example, on the premise of the configuration of the means 34, the delay is in the range of minus 8 ms to plus 8 ms from the supply start time of the scanning signal.

Means 37.
The liquid crystal display device according to the present invention is, for example, a liquid crystal display panel having a plurality of scanning lines and a liquid crystal display device having a backlight,
The backlight is configured to irradiate the liquid crystal display panel side with a plurality of light quantities that vary with time within a period for controlling the plurality of scanning lines,
It is characterized in that it is configured to scan so that the screen is displayed black in one screen scan among a plurality of screen scans.

Means 38.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel having a plurality of scanning lines, and a direction in which the scanning lines extend in a virtual plane parallel to the liquid crystal display panel. A backlight comprising a plurality of extended light sources,
In one screen scan among a plurality of screen scans, the screen is scanned so as to display black,
In this scanning period, at least one of the light sources is configured to repeat a cycle in which the amount of light is changed.

Means 39.
The liquid crystal display device according to the present invention includes, for example, a liquid crystal display panel having a plurality of scanning lines, and a direction in which the scanning lines extend in a virtual plane parallel to the liquid crystal display panel. A backlight comprising a plurality of extended light sources,
In one screen scan among a plurality of screen scans, the screen is scanned so as to display black,
Within this scanning period, each light source has a cycle in which the amount of light changes, and the light amount of at least one of the light sources is configured to be minimum.

Means 40.
The liquid crystal display device according to the present invention is characterized in that, for example, on the assumption of the configuration of the means 38, the light source has a delay in the change start time of its light amount in the screen scanning cycle.

Means 41.
The liquid crystal display device according to the present invention is characterized in that, for example, on the premise of the configuration of the means 38, the light source has a substantially uniform change start time of the light quantity in the screen scanning cycle.

As is clear from the above description, according to the liquid crystal display device of the present invention, a clear moving image can be displayed despite an extremely simple configuration.
In addition, a clear, bright and highly uniform moving image can be displayed.

4 is a timing chart illustrating an example of blinking of a backlight of a liquid crystal display device according to the present invention. It is the top view which showed one Example of the liquid crystal panel of the liquid crystal display device by this invention. 1 is an exploded perspective view showing an embodiment of a liquid crystal display device according to the present invention. It is a top view which shows one Example of the pixel of the liquid crystal display device by this invention. 1 is a perspective view showing an embodiment of a backlight of a liquid crystal display device according to the present invention. It is a block diagram which shows one Example of the circuit which detects whether a moving image is displayed or a still image is displayed in the liquid crystal display device by this invention. It is a block diagram which shows one Example of the circuit which controls the lighting state of a backlight depending on whether a moving image is displayed or a still image is displayed in the liquid crystal display device by this invention. It is explanatory drawing which shows the luminance waveform of this backlight with respect to the control signal of a backlight. 6 is a timing chart showing another embodiment of the blinking of the backlight of the liquid crystal display device according to the present invention. It is a figure explaining the effect of the liquid crystal display device by this invention. It is a figure explaining the effect of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the reason for making the structure shown in FIG. It is explanatory drawing which shows the reason for making the structure shown in FIG. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is an experiment graph which shows the effect of the Example shown in FIG. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is an experiment graph which shows the effect of the Example shown in FIG. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the liquid crystal display device by this invention.

Embodiments of a liquid crystal display device according to the present invention will be described below with reference to the drawings.
Example 1.
[Equivalent circuit of liquid crystal display]
FIG. 2 is an equivalent circuit diagram showing an embodiment of the liquid crystal display device according to the present invention. Although this figure is a circuit diagram, it is drawn corresponding to the actual geometric arrangement.
In this embodiment, the present invention is applied to a liquid crystal display device adopting a so-called lateral electric field method that is known to have a wide viewing angle.

  First, there is a liquid crystal display panel 1, and the liquid crystal display panel 1 includes a transparent substrate 1 </ b> A or 1 </ b> B arranged opposite to each other with liquid crystal as an envelope. In this case, one transparent substrate (lower substrate in the figure: matrix substrate 1A) is formed slightly larger than the other transparent substrate (upper substrate in the figure: color filter substrate 1B), and the lower and right sides in the figure. The peripheral edge of each is arranged substantially flush.

  As a result, the periphery of the left side of the transparent substrate 1A in the drawing and the periphery of the upper side in the drawing are extended outward with respect to the other base transparent plate 1B. As will be described in detail later, this portion is a region where the gate drive circuit 5 and the drain drive circuit 6 are mounted.

  Pixels 2 arranged in a matrix are formed in the overlapping region of each transparent substrate 1A, 1B. The pixels 2 extend in the x direction in the drawing and are arranged in parallel in the y direction. A switching element TFT formed in a region surrounded by video signal lines 4 extending in the direction and arranged in parallel in the x direction, and driven by supply of a scanning signal from one scanning signal line 3, and the switching element And a pixel electrode to which a video signal supplied from one video signal line 4 is applied via a TFT.

  Here, as described above, each pixel 2 adopts a so-called lateral electric field method, and includes a counter electrode and an additional capacitor element in addition to the switching element TFT and the pixel electrode, as will be described in detail later. It is supposed to be.

  Each scanning signal line 3 has one end (the end on the left side in the figure) extending to the outside of the transparent substrate 1B and is connected to an output terminal of a gate drive circuit (IC) 5 mounted on the transparent substrate 1A. It is like that.

  In this case, a plurality of gate driving circuits 5 are provided, and the scanning signal lines 3 are grouped together adjacent to each other, and the grouped scanning signal lines 3 are adjacent to each adjacent gate driving circuit 5. Each is connected.

  Similarly, each video signal line 4 has one end (upper end in the figure) extending to the outside of the transparent substrate 1B and is connected to the output terminal of the drain drive circuit (IC) 6 mounted on the transparent substrate 1A. Connected.

  Also in this case, a plurality of drain drive circuits 6 are provided, and the video signal lines 4 are grouped together adjacent to each other, and each of the grouped video signal lines 4 is adjacent to each other. Are connected to each other.

  On the other hand, there is a printed circuit board 10 (control board 10) disposed in the vicinity of the liquid crystal display panel 1 on which the gate drive circuit 5 and the drain drive circuit 6 are mounted, and the printed circuit board 10 includes a power supply circuit 11 and the like. In addition, a control circuit 12 for supplying input signals to the gate drive circuit 5 and the drain drive circuit 6 is mounted.

  The signal from the control circuit 12 is supplied to the gate drive circuit 5 and the drain drive circuit 6 via flexible wiring boards (gate circuit board 15, drain circuit board 16A, drain circuit board 16B). .

  That is, on the gate drive circuit 5 side, a flexible wiring board (gate circuit board 15) having terminals connected to face the input side terminals of the gate drive circuits 5 is arranged.

  A part of the gate circuit board 15 extends to the control board 10 side, and the extension part is connected to the control board 10 via the connection part 18.

  An output signal from the control circuit 12 mounted on the control board 10 is input to each gate drive circuit 5 via the wiring layer on the control board 10, the connection portion 18, and the wiring layer on the gate circuit board 15. It has come to be.

  Also, on the drain drive circuit 6 side, drain circuit boards 16A and 16B having terminals connected to face the input side terminals of the respective drain drive circuits 6 are arranged.

  The drain circuit boards 16A and 16B are partly extended to the control board 10 side, and are connected to the control board 10 via the connection parts 19A and 19B at the extended parts.

  The output signal from the control circuit 12 mounted on the control board 10 is driven by each drain through the wiring layer on the control board 10, the connection portions 19A and 19B, and the wiring layer on the drain circuit boards 16A and 16B. The signal is input to the circuit 6.

  The drain circuit boards 16A and 16B on the drain drive circuit 6 side are divided into two as shown in the figure. This is for preventing adverse effects due to thermal expansion due to, for example, an increase in the length of the drain circuit board in the x direction in the drawing as the liquid crystal display panel 1 is enlarged.

  The output from the control circuit 12 on the control board 10 is input to the corresponding drain drive circuit 6 via the connection part 19A of the drain circuit board 16A and the connection part 19B of the drain circuit board 16B.

  Further, a video signal is supplied to the control board 10 from the video signal source 22 through the interface board 24 by the cable 23 and is input to the control circuit 12 mounted on the control board 10.

  In this figure, the liquid crystal display panel 1, the gate circuit board 15, the drain circuit boards 16A and 16B, and the control board 10 are drawn so as to be positioned in substantially the same plane. Is bent at the gate circuit board 15 and the drain circuit boards 16A and 16B, and is positioned so as to be substantially perpendicular to the liquid crystal display panel 1.

This is because the so-called frame area is reduced. Here, the frame means an area between the outline of the outer frame of the liquid crystal display device and the outline of the display unit. By reducing this area, the area of the display unit can be increased with respect to the outer frame. be able to.
[LCD module]
FIG. 3 is an exploded perspective view showing an embodiment of the module of the liquid crystal display device according to the present invention.

  The liquid crystal display device shown in the figure is roughly divided into a liquid crystal display panel module 400, a backlight 300, a resin frame 500, a middle frame 700, an upper frame 800, etc., which are modularized.

  In this embodiment, a reflector constituting a part of the backlight 300 is formed on the bottom surface of the resin frame 500, and it is difficult to physically distinguish between the resin frame 500 and the backlight 300. Functionally, it can be distinguished as described above.

Hereinafter, each of these members will be described sequentially.
[LCD panel module]
The liquid crystal display panel module 400 is connected to the liquid crystal display panel 1, a gate driving IC 5 and a drain driving IC 6 each including a plurality of semiconductor ICs mounted around the liquid crystal display panel 1, and input terminals of these driving ICs. And a flexible gate circuit board 15 and drain circuit boards 16 (16A, 16B).

  That is, the output from the control board 10 described in detail later is input to the gate drive IC 5 and the drain drive IC 6 on the liquid crystal display panel 1 via the gate circuit board 15 and the drain circuit boards 16A and 16B, and the outputs of these drive ICs. Are input to the scanning signal line 3 and the video signal line 4 of the liquid crystal display panel 1.

  Here, as described above, the liquid crystal display panel 1 is composed of a large number of pixels whose display area is arranged in a matrix, and the configuration of one of these pixels is as shown in FIG. Yes.

  In the figure, scanning signal lines 3 and counter voltage signal lines 50 extending in the x direction are formed on the main surface of the matrix substrate 1A. A region surrounded by each of these signal lines 3 and 50 and a video signal line 4 extending in the y direction described later is formed as a pixel region.

  That is, in this embodiment, the counter voltage signal line 50 is formed so as to run between the scanning signal lines 3 and pixel regions are formed in the ± y directions with the counter voltage signal line 50 as a boundary. become.

  By doing in this way, the counter voltage signal line 50 arranged in parallel in the y direction can be reduced to about half of the conventional one, and the area closed by that can be shared to the pixel area side, The area of the pixel region can be increased.

  In each pixel region, the counter voltage signal line 50 is formed with counter electrodes 50A extending in the y direction integrally therewith, for example, at three true intervals. Each of these counter electrodes 50A extends close to each other without being connected to the scanning signal line 3, and two of them are arranged adjacent to the video signal line 4, and the other one is positioned at the center. It has been.

  Further, the main surface of the transparent substrate 1A on which the scanning signal line 3, the counter voltage signal line 50, and the counter electrode 50A are formed as described above is covered with the scanning signal line 3 and the like, and is made of, for example, an insulating film made of a silicon nitride film. A film is formed. This insulating film serves as an interlayer insulating film for insulating the scanning signal line 3 and the counter voltage signal line 50 with respect to the video signal line 4 to be described later, and serves as a gate insulating film with respect to the thin film transistor TFT as a storage capacitor Cstg. Is functioning as a dielectric film.

  On the surface of this insulating film, first, a semiconductor layer 51 is formed in the formation region of the thin film transistor TFT. The semiconductor layer 51 is made of, for example, amorphous Si, and is formed on the scanning signal line 3 so as to be superimposed on a portion adjacent to a video signal line 4 described later. As a result, a part of the scanning signal line 3 also serves as the gate electrode of the thin film transistor TFT.

  A video signal line 4 extending in the y direction and arranged in parallel in the x direction is formed on the surface of the insulating film. The video signal line 4 is integrally provided with a drain electrode 2A formed so as to extend to a part of the surface of the semiconductor layer 51 constituting the thin film transistor TFT.

  Further, a pixel electrode 53 connected to the source electrode 53A of the thin film transistor TFT is formed on the surface of the insulating film in the pixel region. The pixel electrode 53 is formed by extending the center of each counter electrode 50A in the y direction. That is, one end of the pixel electrode 53 also serves as the source electrode 53A of the thin film transistor TFT and extends in the y direction as it is, and further extends in the x direction on the counter voltage signal line 50 and then extends in the y direction. It has a letter shape.

  Here, a portion of the pixel electrode 53 that overlaps the counter voltage signal line 50 forms a storage capacitor Cstg that uses the insulating film as a dielectric film between the counter voltage signal line 50 and the portion. For example, when the thin film transistor TFT is turned off, the storage capacitor Cstg has an effect of storing video information in the pixel electrode 53 for a long time.

  The surface of the semiconductor layer 51 corresponding to the interface between the drain electrode 2A and the source electrode 53A of the thin film transistor TFT described above is doped with phosphorus (P) to form a high concentration layer. Contact is being made. In this case, the high-concentration layer is formed over the entire surface of the semiconductor layer 51, and after forming each electrode, the high-concentration layer other than the electrode formation region is etched using the electrode as a mask. It can be set as said structure.

  A protective film made of, for example, a silicon nitride film is formed on the upper surface of the insulating film on which the thin film transistor TFT, the video signal line 4, the pixel electrode 53, and the storage capacitor Cstg are formed. An alignment film is formed to constitute a so-called lower substrate of the liquid crystal display panel 1.

  Although not shown, a liquid crystal side portion of a transparent substrate (color filter substrate) 1B serving as a so-called upper substrate has a black matrix (indicated by reference numeral 54 in FIG. 4) having openings in portions corresponding to the respective pixel regions. Corresponding) is formed.

  Further, a color filter is formed covering an opening formed in a portion corresponding to the pixel region of the black matrix 54. The color filter has a color different from that in the pixel region adjacent in the x direction, and has a boundary on the black matrix 54.

In addition, a flat film made of a resin film or the like is formed on the surface on which the black matrix and the color filter are formed, and an alignment film is formed on the surface of the flat film.
〔Backlight〕
A backlight 300 is disposed on the back surface of the liquid crystal display panel module 400.

  The backlight 300 is called a so-called direct type, and its details are shown in FIG. In the figure, a plurality of (eight in the figure) linear light sources 35 extending in the x direction and arranged in parallel in the y direction, and the light from the light sources 35 is displayed on the liquid crystal display. It is comprised from the reflecting plate 36 for irradiating the panel module 400 side.

  The reflection plate 36 is formed in a wave shape, for example, in the direction in which the light sources 35 are arranged side by side (y direction). That is, the liquid crystal display panel module has a circular arc-shaped concave portion where each light source 35 is disposed, and has a slightly sharp convex portion between the light sources 35. The shape is efficient to irradiate the side of the lens.

  In this case, the reflecting plate 36 is provided with side surfaces 37 on the sides orthogonal to the longitudinal direction of the respective light sources 35, and both end portions of the respective light sources 35 are fitted into slits 38 formed on the side surfaces 37. Movement in the installation direction is restricted.

  Each of these light sources 35 is, for example, a so-called cold cathode line, and can be turned on by applying a voltage to electrodes formed at both ends thereof.

Needless to say, the light source 35 may be a hot cathode fluorescent lamp, a xenon lamp, a vacuum fluorescent display tube, or the like.
(Resin frame)
The resin frame 500 constitutes a part of the outer frame of the modularized liquid crystal display device, and accommodates the backlight 300.

  Here, the resin frame 500 has a box shape having a bottom surface and a side surface, and a diffusion plate (not shown) disposed so as to cover the backlight 300 can be placed on the upper end surface of the side surface. Yes.

  This diffusing plate has a function of diffusing light from each light source 35 of the backlight 300, so that the liquid crystal display panel module 400 side can be irradiated with uniform light without unevenness of brightness. It has become.

In this case, the resin frame 500 is formed with a relatively small thickness. This is because the reduction in mechanical strength can be reinforced by the middle frame 700 described later.
[Medium frame]
An intermediate frame 700 is disposed between the liquid crystal display panel module 400 and a diffusion plate (not shown).

  The middle frame 700 is formed of a relatively thin metal plate having an opening 42 formed in a portion corresponding to the display area of the liquid crystal display panel module 400.

  The middle frame 700 has a function of pressing the diffusion plate against the resin frame 500 and a function of placing the liquid crystal display panel module 400.

  Therefore, a spacer 44 for positioning the liquid crystal display panel 1 is attached to a part of the upper surface of the middle frame 700 on which the liquid crystal display panel module 400 is placed. Thereby, the liquid crystal display panel 1 can be accurately positioned with respect to the middle frame 700.

  The inner frame 700 has a shape in which the side surface 46 is integrally formed. In other words, the inner frame 700 has a shape in which the opening 42 is formed on the bottom surface of a substantially metal plate.

  The middle frame 700 having such a shape is fitted to the resin frame 500 with a diffusion plate disposed therebetween. In other words, the middle frame 700 is stacked on the resin frame 500 so that the inner wall of the side surface 46 faces the outer wall of the side surface of the resin frame 500.

  The middle frame 700 of the metal plate configured in this way constitutes one frame (housing) together with the resin frame 500, and the mechanical frame without increasing the thickness of the resin frame 500. Strength can be improved.

That is, each of the middle frame 700 and the resin frame 500 is improved in mechanical strength by being fitted as described above even if the mechanical strength is not sufficient. It has strength against twisting around.
[Upper frame]
The upper frame 800 has a function of pressing the liquid crystal display panel module 400, the middle frame 700, and the diffusion plate toward the resin frame 500, and constitutes the outer frame of the module of the liquid crystal display device together with the resin frame 500. It is like that.

The upper frame 800 is formed with an opening (display window) 48 in a portion corresponding to the display area of the liquid crystal display panel module 400 on a metal plate having a substantially box shape, and is locked to the resin frame 500, for example. It can be attached.
<Image motion level detection circuit>
FIG. 6 is a circuit diagram showing an embodiment of a circuit for detecting the degree of movement of an image displayed on the liquid crystal display panel 1 (referred to as an image movement degree detection circuit in this specification). Is mounted on, for example, the control board 10 shown in FIG.

  In the figure, first, there is a gradation decoder 102, and input display data 101 is input to the gradation decoder 102.

  Here, the input display data 101 is output from a frame memory (not shown).

  The input display data 101 is composed of a large number of pixel data having each gradation from 0 to N, and the gradation decoder 102 divides each of the pixel data for each gradation, and according to each gradation. When there is pixel data corresponding to the gradation, for example, a “1” signal is output, and when there is no pixel data, for example, a “0” signal is output.

  In other words, the gradation decoder 102 includes (N + 1) output terminals, a signal indicating the presence / absence of pixel data of 0 gradation from the input display data 101, a signal indicating the presence / absence of pixel data of 1 gradation, and a signal of 2 gradations A signal indicating the presence / absence of pixel data,..., A signal indicating the presence / absence of pixel data of N gradations is output from the corresponding output terminal.

  Here, even when the input display data 101 includes a plurality of pixel data of N gradations, the gradation decoder 102 outputs a signal “1” from the corresponding output terminal regardless of the number of pixel data. It is designed to output.

  Each output from the gradation decoder 102 is input to a gradation register group 103 including a 0 gradation register, a 1 gradation register,...

  That is, a signal indicating the presence / absence of pixel data of 0 gradation output from the gradation decoder 102 is supplied to the 0 gradation register, a signal indicating the presence / absence of pixel data of 1 gradation is supplied to the 1 gradation register,. A signal indicating the presence or absence of tone pixel data is input to the N gradation register.

  As a result, each of the gradation registers of the gradation register group 103 stores either “1” signal or “0” signal.

  Further, each output from each gradation register is input to the adder 104.

  The adder 104 adds the outputs from the gradation registers and outputs a signal corresponding to the added value.

  For example, when all “1” signals are input from the 0 gradation register, 1 gradation register,..., N gradation register, signals corresponding to the added value (N + 1) of the respective signals are obtained. When a “1” signal is input from the 4 gradation register and the 6 gradation register and a “0” signal is output from the remaining gradation registers, A signal corresponding to the added value (2) is input.

  As is clear from this, the adder 104 detects the degree of change in gradation in the input display data 101.

  That is, the adder 104 detects the degree of change in gradation of the input display data 101, and whether the input display data 101 is a still image, a moving image, or a moving image depending on the degree of the change degree. In this case, even the magnitude of the movement can be determined by the output of the adder 104.

  The output from the adder 104 is input to the register 105 and held therein, and then output as the backlight control signal 106.

  Note that the vertical synchronization signal 107 is input to each gradation register and register 105 of the gradation register group 103, and each gradation register and register 105 is reset by this vertical synchronization signal 107.

As a result, a control signal from the register 105 to the backlight is generated for each input display data corresponding to one screen.
<< Backlight control circuit >>
FIG. 7 shows a backlight control circuit (a portion surrounded by a dotted line in the figure) that receives an output from the image motion level detection circuit and controls the driving of each light source 35 of the backlight 300. .

  In the figure, there is a signal information classification circuit 108 to which an output from the image motion degree detection circuit, that is, a backlight control signal 106 is input.

  In this signal information classification circuit 108, (1) a still image, (2) a moving image with slow movement, and (3) a moving image with normal movement, depending on the information of the backlight control signal 106. And (4) a moving image having a fast movement, and a signal corresponding to the classification is sent to the inverter 109.

  The inverter 109 includes a circuit for converting a DC voltage into an AC voltage, a current control circuit, a frequency modulation circuit, a booster circuit using a transformer, and the like.

  Then, the inverter 109 to which a signal corresponding to the still image segmentation is input is controlled so as to maintain each light source of the backlight 300 in a lighting state, as shown in FIG. .

  Further, the inverter 109, which receives a signal corresponding to a moving image that is slow in movement, repeats turning on and off each light source of the backlight 300 as shown in FIG. To be controlled.

  Further, the inverter 109 to which a signal corresponding to a moving image whose motion is normal is input, as shown in FIG. However, the lighting state is controlled to be shorter than in the former case.

  Furthermore, as shown in FIG. 1E, the inverter 109 that receives a signal corresponding to a moving image that has a fast movement is turned on and off by each light source of the backlight 300 as shown in FIG. Again, the lighting state is controlled so as to be even shorter than in the former case.

  In FIG. 1, (a) shows a synchronization signal (data rewrite cycle: 16.7 ms in this case). In the case of a moving image, the backlight 300 has a period between the synchronization signal and the next synchronization signal. It is designed to be turned on once and turned off once. In other words, the backlight 300 is repeatedly turned on and off in synchronization with the input start time of the gate signal.

  Further, if the moving image moves fast, that is, according to the modes (2) to (4), the lighting duty is reduced when the backlight 300 is turned on and off.

  In this way, the visibility of the moving image is improved, and the degree of visibility is made the same regardless of the speed of the moving image.

  Further, in this case, when a moving image is displayed (in the cases (2) to (4)), the backlight is repeatedly turned on and off, so that power consumption can be suppressed. become.

  FIGS. 8A to 8D show a synchronization signal (image information transmission timing), an image display signal, a lighting signal to the backlight 300, and a luminance waveform of light radiated from the backlight 300, respectively.

The lighting signal to the backlight 300 causes the backlight 300 to supply a first current (tube current) I ₁ for a time of Δt ₁ (first period), and then a second current smaller than the first current ( Tube current) I ₂ (= 0 mA) is supplied for a time of Δt ₂ (second period).

Such a lighting signal to the backlight 300 is synchronized with the synchronization signal, and the time of (Δt ₁ + Δt ₂ ) is the same as the period of each synchronization signal (here, 16.7 ms).

In this case, when the lighting signal has a relationship of Δt ₁ = Δt ₂ , the tube current is passed through the backlight 300 with a duty of 50%.

Then, when supplying the current i ₁ (6 mA) in the first period Δt ₁ shown in FIG. 8 to the light source,
(1) When the duty is 100% (light extinction period Δt ₂ = 0), the luminance is set to 100%, and the moving image visibility is set to 2 in a five-step evaluation.
(2) At a duty of 75%, the luminance decreased to about 80%, but the moving image visibility was 3 because the light from the backlight 300 was close to impulse emission.
(3) At a duty of 50%, the luminance decreased to about 60%, but the moving image visibility was 4.

  From this, as shown in FIG. 9 corresponding to FIG. 1, the tube current (luminance peak value α) to be supplied to each light source of the backlight 300 is sequentially increased as the duty becomes smaller. It is possible to improve the visibility of the moving image while avoiding a decrease in the brightness of the entire video.

  Further, when the effective value of the tube current supplied to each light source of the backlight 300 is made constant regardless of the change in the duty, the luminance on the entire display surface can be made constant.

  FIG. 10 is a graph showing the result of the subject test showing the relationship between the brightness of the display surface and the moving image visibility.

  As is apparent from this graph, there is a phenomenon that the visibility of a moving image is better as the luminance is higher.

  As described above, repeating lighting and extinguishing of the backlight 300 and increasing the tube current (increasing luminance) are factors that improve the visibility of moving images, respectively. If the tube current is increased when the value is reduced, a synergistic effect can be obtained.

  FIG. 11 is a graph showing that in any of the above modes (2) to (4) (pixel source), the moving image visibility is improved when the luminance is improved.

Example 2
In the above-described embodiment, when the image has a motion, the light source of the backlight 300 is repeatedly turned on and off.

  However, it goes without saying that when the screen of the display unit is bright and dark, the light source of the backlight 300 may be repeatedly turned on and off when the screen is dark.

  This is because, for example, when the scene imaged on the display unit is night, the screen becomes dark as a whole, and for example, it is difficult to recognize the outline of a subject moving within the screen. Even in this case, the visibility of the subject can be improved by repeatedly turning on and off the light source of the backlight 300.

  In this case, the backlight 300 may be repeatedly turned on and off without increasing the tube current. This is because the screen is slightly dark, but the visibility of the subject moving within the screen is improved. In this case, there is an effect of reducing power consumption.

  The means for detecting whether the screen of the display unit is bright or dark is selected from, for example, each piece of pixel information stored in the frame memory (in this case, each piece of pixel information over the entire area of the frame memory, or in a scattered manner). In other words, the pixel information may be determined) and the average value of the gradations is calculated.

  And in this case, it is divided into a plurality according to the degree of darkness, and the ratio of the duty of lighting and extinguishing is changed according to the classification, and when the duty of lighting is reduced, It goes without saying that the amount of tube current supplied to the minute backlight 300 may be increased.

Example 3
FIG. 12 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention.

In the figure, the display surface AR of the liquid crystal display panel 1 is conceptually divided into three areas such as a central area AR ₀ and upper and lower areas AR ₁ and AR ₂ , and light in the central area AR ₀ is divided. Each light source 35 (0) of the backlight 300 in charge of transmission is repeatedly turned on and off, and each of the light sources 35 (1) of the backlight 300 in charge of light transmission in the upper and lower areas AR ₁ and AR ₂ . 35 (2) keeps lighting.

  The center of the display surface AR is an area where the viewer's interest is concentrated, and a moving subject is usually imaged in this area. This is apparent from the shooting side and from the empirical rule of shooting with the portion where the observer's interest is concentrated at the center of the display surface.

  For this reason, it is highly likely that the moving part of the moving image is almost necessarily positioned at the center of the display surface, so that the light source of the backlight 300 that transmits the center of the display surface in advance is repeatedly turned on and off. Is set in advance.

  In this case, the repetition duty of turning on and off each light source may be fixed.

  However, it goes without saying that the movement of the image in this portion may be detected at the center of the display surface AR, and the duty cycle of turning on and off the light source may be changed according to the movement.

  In this case, if the input display data is output from a portion corresponding to the center of the display surface of the frame memory, for example, the techniques of FIGS. 6 and 7 can be applied as they are.

Further, in this embodiment, in each of the upper and lower areas AR ₁ and AR ₂ excluding the center of the display surface, it is not always necessary to keep the light sources of the backlight 300 that pass through the areas being kept lit (always lit). , so as to repeat turning on and off (and smaller than that of the area AR ₀ in the middle of the lamp off time) may be, as a matter of course.

  In short, in consideration of the high probability that a fast moving video is imaged at the center of the display surface, the lighting state of each light source of the backlight 300 that transmits the part and the other part is optimal in that part and the other part. What is necessary is just to make it respond | correspond to a different state.

  Further, as described above, when the light source lighting duty is reduced, the luminance of the entire display surface may be kept uniform by increasing the tube current.

  Furthermore, there is a display mode in which a character string moves with the image as a background at the lower or upper part of the display surface on which the image is displayed. In this case, light is transmitted to an area corresponding to the lower or upper part of the display surface. The light source may be repeatedly turned on and off.

  In this case, the visibility of each character of the moving character string can be improved.

Example 4
In each of the above-described embodiments, each of them describes a liquid crystal display device including a backlight 300 called a so-called direct type.

  However, as shown in FIG. 13, it is needless to say that the present invention can be applied to a so-called side type backlight using a light guide plate. 13A is a plan view, and FIG. 13B is a cross-sectional view taken along the line bb in FIG.

  In the figure, a light guide plate disposed substantially in parallel with the liquid crystal display panel is provided on the back surface of a liquid crystal display panel (not shown), and a linear light source 81 is provided on a side surface of the light guide plate (upper and lower side surfaces in the figure). Are arranged two by two.

  Light from the light source is irradiated into the light guide plate 80 from the side surface of the light guide plate 80 directly or indirectly (via the reflection plate 82), and after being reflected several times in the light guide plate 80, the liquid crystal display panel The liquid crystal display panel is irradiated from the opposite surface 80a.

  Since such a backlight cannot identify the light source responsible for irradiation in each region where the display unit of the liquid crystal display panel is divided ideally, the light source is turned on and off in some regions of the display unit. I can't.

  However, as shown in the first embodiment, it is detected whether the display image is a still image or a moving image, or as shown in the second embodiment, it is detected whether it is a bright screen or a dark screen. It is possible to keep the light source of the light from the backlight in the entire region in a lighting state or to repeatedly turn on and off.

  Similarly, the duty cycle of turning on and off the light source of the light from the backlight can be reduced in correspondence with the speed of the moving image or the degree of the dark screen.

Example 5 FIG.
In each of the above-described embodiments, for example, when all the light sources 35 are driven so as to be repeatedly turned on and off, the central portion of the screen of the liquid crystal display panel 1 is not particularly problematic. The phenomenon that the outline of the image imaged on the side looks double was recognized.

  For example, as shown in FIG. 14, when a bar-like pattern RP extending all over the screen is moved from left to right, the left edge (edge) of the bar-like pattern is at the center of the screen. Although it is clearly observed, the left edge of the bar-shaped pattern rises earlier than the center at the upper end, and a thin shadow is observed at the upper end, and the response of the left edge of the bar-shaped pattern is delayed at the lower end than that at the center. A thin shadow is still observed.

  The reason for this will be described with reference to FIG. First, assuming that data of one screen (one frame) is rewritten every 60 Hz (16.7 ms), for example, supply of a scanning signal (gate ON signal) to the gate signal line GL at the uppermost stage (first line) is started, for example. There is a delay of 16.7 ms from the start of supply of the scanning signal (gate ON signal) to the gate signal line GL in the lowest stage (n-th).

  This delay depends on the screen rewriting cycle, and the time is shortened when the cycle is 120 Hz or 240 Hz. In the case of using the thin film transistor TFT, the rewrite signal is a gate signal, but in the so-called TFD or time-division driving, it becomes a scanning signal or a common signal.

  This means that the response of the liquid crystal of each pixel is delayed from the upper side to the lower side of the screen.

  However, when the turning on and off of each light source 35 of the backlight are repeated at the same timing, the relationship between the turning on and off of the light source 35 and the response waveform of the liquid crystal is as shown in FIG.

  That is, the response waveform of the liquid crystal during the lighting period of the light source 35 is as shown in FIG. 15B, and the waveform shown in FIG. 15B is a luminance waveform that can be recognized by the observer of the liquid crystal display device as it is.

  As apparent from FIG. 15B, the response of the liquid crystal is apparently faster in the pixels formed along the uppermost gate signal line GL (along the n / 2th gate signal line in the figure). In comparison with the response of the liquid crystal of the pixel formed in this manner, the response of the liquid crystal is apparently delayed in the pixel formed along the lowermost gate signal line GL (n / 2nd gate signal line in the figure). Compared with the response of the liquid crystal of the pixels formed along). The correspondence between FIG. 15B and FIG. 14 is as shown in FIG.

  Therefore, in this embodiment, the occurrence of shadows at the edge of the image at the top and bottom of the screen is suppressed, and the description thereof will be described with reference to FIG.

  FIG. 17A shows each light source (lamp) 35 of the backlight. Here, for example, a light source having six light sources 35 is used.

  The uppermost (first) light source 35 irradiates the upper side of the screen of the liquid crystal display device, the lowermost (sixth) light source 35 irradiates the lower side of the screen, and each of the other light sources 35 is the center of the screen. The part is irradiated.

  Here, each of the second to fifth light sources 35 is driven to be turned on and off repeatedly as shown in the above-described embodiments. However, the first light source 35 and the sixth light source are driven. 35 is driven so as to maintain the lighting.

  FIG. 17B shows shaded periods along the time axis t corresponding to the light sources 35 by shading. FIG. 17B also shows the supply timing of the scanning signal to the gate signal line GL in the liquid crystal display panel formed at a position facing each light source 35.

  In this way, the apparent fast response and late response of the liquid crystal response are eliminated by always lighting the light source 35 at the upper and lower portions of the screen.

  FIG. 18 is an experimental graph showing the effect of this embodiment. A photodiode is disposed on each of a portion facing the first gate signal line GL, a portion facing the n / 2th gate signal line GL, and a portion facing the nth gate signal line GL on the screen, The output of each photodiode when the screen display is changed from white to black is observed with an oscilloscope.

  In the figure, the upper characteristic graph shows the output of the photodiode arranged in the portion facing the first gate signal line GL, and the middle characteristic graph shows the output in the portion opposed to the n / 2nd gate signal line GL. The characteristic graph in the lower stage shows the output of the photodiode arranged at the portion facing the nth gate signal line GL.

  When attention is paid to the change output from white to black of each photodiode, it is confirmed that all of them are gentle and the peak value at that time is not so different in each photodiode. Incidentally, when this difference is large, the difference is recognized by the observer as a luminance difference, and a double image appears at the edge of the moving image pattern. In addition, even if the peak luminance is the same, a double image appears even if the luminance integrated value of each frame is different.

  In this embodiment, when the screen is divided, the irradiation area that the first light source 35 takes charge of, the irradiation area that the second to fifth light sources 35 take charge, and the irradiation area that the sixth light source 35 takes charge of. Divided.

  However, this division may be divided into the central portion of the screen and its side portions, and the area of each region may be arbitrary.

  For example, in the diagram shown in FIG. 17, the irradiation area is assigned to the first light source 35, the irradiation area is assigned to the second to fourth light sources 35, and the irradiation area is assigned to the fifth and sixth light sources 35. You may do it.

  As shown in FIG. 17B, the light source 35 that repeatedly turns on and off is supplied with the fifth light source 35 turned on and the gate signal line GL facing the light source 35 because the turn-on of the light source is gentle. This is because the scanning signal does not match, and it may be better to keep the lighting of the fifth light source 35 in some cases.

  In the following description of the embodiments, unless otherwise specified, the area of each region defined by the difference in the lighting state of the light source 35 is not specified and is arbitrarily determined. Moreover, without specifying by the number of linear light sources, lighting and extinguishing may be repeated not at the center but above or below.

Example 6
FIG. 19 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  In the configuration different from the case of FIG. 17, first, the first light source 35 and the nth light source 35 are driven so as to be repeatedly turned on and off.

  In the sequential display of each frame (image), each light source 35 disposed in the second to fifth light source is turned on and off repeatedly without changing the phase for each frame, and the first and sixth light sources are repeated. The arranged light source 35 is repeatedly turned on and off with a phase shift.

  In such a case, in the continuous display of each frame, the respective light sources 35 arranged on the second to fifth are turned on and off at the timing shown in FIG. 17, but arranged on the first and sixth. Each lighting of the light source 35 is made up to compensate for the extinction at the time of display of the previous frame, and the light source 35 arranged at the first and sixth is always turned on at the time of display after several frames. It is recognized as being.

  That is, in this embodiment, the lighting of the first and sixth light sources 35 is maintained from the time-series aspect, and the same effects as in the case of the fifth embodiment are obtained.

  FIG. 20 is an experimental graph showing the effect of this embodiment, which was obtained under the same conditions as in FIG. It turns out that the same characteristics as shown in FIG. 18 can be obtained.

Example 7
FIG. 21 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  In the configuration different from the case of FIG. 19, the frequency of turning on and off each of the first and sixth light sources 35 is set higher than the frequency of turning on and off each of the second to fifth light sources 35.

  In this case, the first and sixth light sources 35 are turned on and off so that the phase is not shifted for each frame.

  In this case, the second light source 35 is irradiated to the arrangement region of the first light source 35, and the fifth light source 35 is irradiated to the arrangement region of the sixth light source 35, so that the first and sixth light sources 35 are irradiated. The light-out periods of the respective light sources 35 are compensated by the lighting of the second and fifth light sources 35, respectively.

  For this reason, it is recognized that the first and sixth light sources 35 are substantially maintained in the lighting state, and the same effects as those shown in the fifth and sixth embodiments are obtained.

  In this embodiment, the first and sixth light sources 35 are turned on and off so that the phase is not shifted for each frame. However, the present invention is not limited to this, and the phase is shifted for each frame. Of course, you may do it.

Example 8 FIG.
FIG. 22 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG. In FIG. 22, only the first part of each light source 35 is turned on and off.

  21 is different from the case of FIG. 21 in that the first and sixth light sources 35 are turned on and off at the same time as the second and fifth light sources 35 are turned on and off (for example, 60 Hz, 120 Hz, 180 Hz, 240 Hz).

  The lighting duty of each of the first and sixth light sources 35 is set larger than the lighting duty of each of the second to fifth light sources 35.

  For example, the lighting duty of each of the first and sixth light sources 35 is preferably set to 70%, and the lighting duty of each of the second to fifth light sources 35 is preferably set to 50%.

  In such a case, each of the first and sixth light sources 35 is close to a state in which the light is kept on, and has substantially the same effect as the fifth to seventh embodiments.

Example 9
FIG. 23 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG. FIG. 17 also shows the waveform of the current supplied to the light source 35.

  Compared to the case shown in FIG. 17, the first and sixth power sources 35 are driven while maintaining the lighting state, but in this embodiment, the supply current is second to fifth. It is smaller than the supply current of each main power source. That is, this makes the time integral value of the current equal between the central portion and the upper portion or the lower portion.

  Thereby, the luminance distribution in the direction in which the light sources 35 are arranged side by side (from the bottom of the screen to the top of the screen) is as shown in FIG. 23B, and the luminance is slightly reduced at the top and bottom of the screen.

  If the supply currents of the first and sixth power sources 35 are the same as the supply currents of the second to fifth power sources, the luminance is higher than the central portion at the top and bottom of the screen, and the display is visually recognized. This is because the property (uniformity) is lowered, which is not preferable in terms of display quality.

  In this embodiment, the luminance of the light source 35 itself is lowered by reducing the current. However, when a light source whose luminance is lowered by lowering the voltage is used, it may be so. Needless to say.

Example 10
FIG. 24A is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  In the configuration different from that shown in FIG. 23A, the current supplied to the first and sixth light sources 35 is substantially the same as the current supplied to the second to fifth light sources 35.

  Then, as shown in FIG. 24B, which is a sectional view of the light sources 35 in the juxtaposed direction, the first and sixth light sources 35 are arranged according to their arrangement pitch in the second to fifth light sources 35. It is separated from other adjacent light sources 35 at a large pitch.

  Thereby, since each of the first and sixth light sources 35 has to take charge of irradiation of a relatively large area, it is possible to apparently reduce the luminance.

  The luminance distribution in the direction in which the light sources 35 are arranged side by side (from the bottom of the screen to the top of the screen) can be as shown in FIG. 24C, and the same effect as that shown in Example 9 can be obtained.

  In this embodiment, one light source is maintained at the top and bottom of the screen to maintain lighting. However, even if these are arranged in two or three, for example, their arrangement pitch can be made larger than the arrangement pitch of each light source arranged in the central portion. Moreover, it does not depend on the cross-sectional shape of the light source.

Example 11
FIG. 25 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  The configuration different from that in FIG. 17 can control the magnitude of the current supplied to each light source 35. In FIG. 25 (a), the current is increased, and in FIG. 25 (b), the current is increased. The current is reduced.

  Specifically, this can be achieved by interposing a current adjusting means between power supply devices that supply power to each light source 35.

  As a result, the luminance of the entire screen can be adjusted.

  As another embodiment, the magnitude of the current supplied to each of the first and sixth power supplies 35 is controlled independently, or the magnitude of the current supplied to each of the second to fifth power supplies 35 is controlled. You may make it control independently. In this case, the configuration as shown in FIG. 23 can be adjusted.

  Further, when the luminance is changed by controlling the magnitude of the voltage supplied to each light source 35, the magnitude of the supplied voltage may be controlled.

Example 12
FIG. 26 is an explanatory diagram showing another embodiment of the liquid crystal display device according to the present invention. The lighting duty of each of the first and sixth power supplies 35 and the lighting duty of each of the second to fifth power supplies 35 are shown. It is configured to control.

  For example, in FIG. 26A, the lighting duty of each of the first and sixth power sources 35 is adjusted to 100%, while the lighting duty of each of the second to fifth power sources 35 is adjusted to 50%. In FIG. 26B, the lighting duty of each of the first and sixth power sources 35 is adjusted to 50%, and the lighting duty of each of the second to fifth power sources 35 is adjusted to 25%. Even if it does in this way, there exists an effect which can aim at the adjustment of the brightness | luminance of the whole screen.

  As another embodiment, the lighting duty of each of the first and sixth power supplies 35 is controlled independently, or the lighting duty supplied to each of the second to fifth power supplies 35 is controlled independently. You may do it. In this case, the configuration as shown in FIG. 22 can be adjusted.

Example 13
FIG. 27 is an explanatory view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  A configuration different from that in FIG. 26 is to provide a pause period in which the lighting is paused between the lighting periods of the second to fifth light sources 35.

  In this case, the flicker that occurs in the video on the screen can be greatly suppressed.

In addition, each light source 35 is turned on in the mode shown in FIG. 27A at the time of an image of a certain frame, each light source 35 is turned on in the mode shown in FIG. Even when the light sources 35 are turned on sequentially in the manner shown in FIG. 27A at the time of the next frame image, the flickering generated on the screen image can be suppressed.
In the above description of the fifth to thirteenth embodiments, the lighting states of the light sources facing the central area of the screen and the areas on both sides (up and down) are different. However, it goes without saying that the lighting states of the light sources respectively facing at least one area (upper or lower area) on both sides and the other areas including the center may be made different.

  Also, any of the configurations of the first to thirteenth embodiments may be configured to switch between application and non-application by processing using an image, hardware, or software switch.

  In this case, for example, when the PC screen is fully lit and when any of the configurations of the first to thirteenth embodiments is used when displaying a moving image, both still image quality and moving image improvement can be achieved at a higher level. This is particularly effective for reducing flicker during still images.

  It is also effective in reducing flicker to increase the screen rewriting frequency during moving images than during still images.

  Of course, this is not limited to the case of the idea disclosed in the first to thirteenth embodiments, and any configuration having a state in which the backlight is repeatedly turned on and off is effective.

Example 14
In some of the embodiments described above, when each light source 35 is repeatedly turned on and off, for example, it is synchronized with the scanning signal supplied to the gate signal line 3, but as shown in FIG. Within the period of the signal and the next synchronization signal (defined as one frame, 60 Hz, 16.7 ms), from lighting with a light intensity of one luminance peak value 100% and light intensity of one luminance peak value 0% There is a light extinction.

  However, as shown in FIG. 28 (b), during the lighting period, the light is first driven to have a light intensity peak value of 100% and then to a light quantity less than that, for example, the light intensity peak value is 50%. It goes without saying. This is because a light-off period only needs to exist to achieve the object of the present invention.

  In this case, it is effective to repeat such turn-off when the fall of the liquid crystal response speed is slow.

  From this point of view, as shown in FIG. 28C, during the lighting period, for example, the luminance peak value is first set to about 50% light amount, and then the luminance peak value is set to 100% light amount. Of course it is good.

  In this case, it is effective to repeat such turn-off when the rise of the liquid crystal response speed is slow.

  Furthermore, as shown in FIG. 28 (d), during the lighting period, the first luminance peak value is set to any value of light from 100% to 0%, and then the luminance peak value is set to 100%. Furthermore, it goes without saying that the luminance peak value may be driven so as to have a light amount of any value from 100% to 0%.

  In this case, it is effective to repeat such extinction when there is a difference between the rise and fall of the response speed of the liquid crystal. It is also effective for improving the uniformity of the screen.

  FIG. 29 shows, for example, FIG. 28 (b) as an example. When the light is turned off, the luminance peak value is not necessarily 0%, but may be a value close to that (for example, about 5%). Show.

  In this case, the brightness at the next lighting can be improved by preheating at the time of extinguishing the light, and this is particularly effective when the liquid crystal display device is used at a low temperature or immediately after the power is turned on.

  Needless to say, this can also be applied to the driving shown in FIGS. 28 (a), 28 (c), and 28 (d).

  Further, in the lighting of the light source 35, a plurality of states having different light amounts exist, but it goes without saying that the time ratio of each of these states may be freely controlled. . In lighting, for example, when each ternary light amount is changed over time, for example, when controlling the time of the first light amount, when controlling the time of each of the first and next light amounts, and further, for each light amount It is conceivable that the time is controlled. In short, the light amount of any one value may be controlled at least.

  This is the same idea as the purpose of changing the on / off duty to the optimum state in the above-described embodiment, and accordingly, appropriate light quantity distribution can be performed.

Example 15.
In the repetition of turning on and off of the light source 35 shown in the fourteenth embodiment, when the light quantity of the lighting is changed with time, the change is performed stepwise or stepwise.

  However, as shown in FIG. 30, it is needless to say that the change may be continuously changed in an analog manner.

  When a cold cathode ray tube or a light-emitting diode is used as the light source 35, a delay of 2 to 3 ms occurs in the rise of the luminance, and the afterglow characteristic is present at the same time. It ’s analog and not continuous.

  For this reason, by turning on the light source 35 as shown in FIG. 30, the rise and fall characteristics of the response of the liquid crystal have a response time of several ms to 10 ms, so that a rather natural moving picture characteristic is obtained. Will be obtained.

Example 16
In each of the embodiments described above, when each light source 35 is repeatedly turned on and off, for example, it is synchronized with a scanning signal supplied to the gate signal line 3, for example.

  However, in view of the observation of the liquid crystal display device by the human eye, even if a slight delay occurs in the period between frames, there is no problem as long as the time average value is substantially constant. This is because the brightness of the human eye is sensed by time integration every several ms.

  From this, for example, as shown in FIG. 31, even if some of them have a delay of +2 ms and −2 ms, for example, at the rising of lighting in each cycle, the object of the present invention can be sufficiently achieved.

  As shown in FIG. 31, the gate writing start timing coincides with the lighting start timing in the first cycle, a delay of +2 ms occurs in the next cycle, the delay becomes 0 in the next cycle, and the next cycle This is because, when a delay of -2 ms occurs, the delay is almost zero as seen from the time average value, and the luminance perceived by humans does not change.

Example 17.
Furthermore, since the liquid crystal display device is observed by human eyes as described above, the coincidence between the gate writing start time and the lighting start time of the light source 35 is moderate, and is not strictly interpreted. Absent.

  Therefore, as shown in FIG. 32, for example, the gate writing start timing coincides with the lighting start timing in the first cycle, a delay of +1 ms occurs in the next cycle, and the delay becomes +2 ms in the next cycle. Of course, a delay of +3 ms may occur in the next period. For example, as long as it is within the range of +8 ms and −8 ms from a rule of thumb, the object of the present invention can be sufficiently achieved.

  This is because when one cycle is 60 Hz, as long as the delay is about this level, it can be considered that the gate writing start timing and the lighting start timing of the light source 35 substantially coincide with each other.

  From this, as shown in FIG. 33, some of the plurality of light sources (lamps) 35 (lamp 1 and lamp 8 in the figure) may be delayed in each cycle.

  Further, as shown in FIG. 34, a plurality of light sources 35 may be delayed in a specific period, and the delays may be different from each other.

Example 18
In each of the embodiments described above, for example, assuming that the gate writing cycle is 60 Hz, even if the delay occurs an integer number of times per second (corresponding to 61 or 62, 58 or 59 Hz), there is no sense of incongruity in the display observation. Of course, this may be the case.

Example 19.
In each of the embodiments described above, when the gate writing time and the lighting cycle of the light source 35 are different by an integral multiple, for example, even when the gate writing time is 60 Hz and the lighting cycle of the light source 35 is 120 Hz, there is no sense of incongruity in display observation. It has been confirmed.

Example 20.
In each of the above-described embodiments, a so-called horizontal electric field type liquid crystal display device known as having a wide viewing angle has been described. This type of liquid crystal display device has a characteristic in which the difference between the black and white response and the halftone response is small, and is extremely effective for displaying a moving image such as a television or a movie with many halftone displays.

  Further, in the horizontal electric field type liquid crystal display device, the liquid crystal molecules are aligned in parallel to the substrate surface, and the alignment is changed by an electric field parallel to the substrate surface. However, it goes without saying that this mode can also be applied to a so-called vertical electric field type liquid crystal display device.

  Such a liquid crystal display device has a characteristic of quick black and white response, and is more effective for displaying moving images.

  Further, not only nematic liquid crystal but also ferroelectric liquid crystal such as smectic liquid crystal does not cause any inconvenience.

Example 21.
Of course, the present invention can also be applied to a TN mode liquid crystal display device which is a vertical electric field type, in which liquid crystal molecules are aligned parallel to the substrate surface (a slight tilt angle exists) and has a twisted structure.

  This liquid crystal display device has a fast black and white response and is effective for displaying moving images. Furthermore, no inconvenience arises when applied to a vertical alignment type liquid crystal display device.

Example 22.
In each of the embodiments described so far, the gate writing cycle has been described as 60 Hz. However, when data scanning is performed a plurality of times during this cycle, for example, scanning is performed twice, the scanning cycle is 120 Hz, and the display signal of the first time is displayed. Of course, a method of writing and displaying black display data for the second time may be adopted.

  In this case, by making the light source 35 blink at 60 Hz so that the light source 35 is turned off when writing black data, the black period of the light source 35 becomes clearer and the moving image display is improved.

  As a blinking method of the light source 35, the light source 35 is synchronized with the data scanning, each of the light sources 35 is scanned and blinked, the upper and lower parts are alternately blinked, and each is blinked at a lighting duty of 40% or more. Of course it is good.

  Also, the blinking luminance ratio of the light source 45 may be a binary value of 100% and 0%, but since black data is written, it is not always necessary to have a luminance of 0%. Can play. The purpose of the blinking of the light source 35 is to obtain a cooling effect during the extinguishing period, and it is not always necessary to set the luminance to 0 and the light source power to 0 as long as the power efficiency is good.

Example 23.
Among the embodiments described above, there is one that improves the moving image visibility by detecting the motion of the image and changing the duty cycle of turning on and off the light source 35 in accordance with the motion.

  However, it goes without saying that the duty may be changed by an electric signal different from the above-described electric signal.

  In view of the fact that liquid crystal materials generally have low response speed at low temperatures and low video visibility, and high response speed and high video visibility at high temperatures, the circuit shown in FIG. Good.

  In FIG. 35A, the temperature is detected by the temperature detector, and a pulse corresponding to this temperature is generated by the pulse generator. The generated pulse is input to an inverter circuit lighting signal generator, and lighting control of the light source 35 is performed based on the output.

  As the temperature detector, for example, a thermistor is attached to the liquid crystal display device, and for example, any one of the outer peripheral temperature, the surface temperature of the device, and the surface temperature of the light source 35 is detected, and a pulse signal having a duty corresponding to the temperature is detected. Generate.

  When the temperature is low, the light emission efficiency of the light source 35 is also low. Therefore, as shown in FIG. 35 (b), the duty of the pulse is increased, rather, continuous light emission close to hold-type light emission is performed, and when the temperature is high, FIG. ) Shorten the duty of the pulse as shown in

  Alternatively, since the response speed of the liquid crystal is slow at low temperatures, the duty is reduced to make it closer to the impulse type light emission close to the CRT (Cathode Ray Tube) in order to avoid the influence, and the liquid crystal material When the response speed is fast, the duty may be increased.

Example 24.
As described above, the liquid crystal material generally has a low response speed and low moving image visibility at low temperatures, and a high response speed and high moving image visibility at high temperatures.

  This is particularly noticeable depending on the usage time after the liquid crystal display device is turned on. This is because the liquid crystal material becomes high temperature due to heat generated by the light source 35 and the inverter power supply circuit after a long time has passed since the power was turned on (about 30 minutes later). This means that the liquid crystal material is at a low temperature immediately after the power is turned on, because the influence of heat generation is small.

  Therefore, in order to avoid the effect on the video visibility of the temperature change with the passage of time immediately after the power is turned on, the duty is increased when the temperature immediately after the power is turned on. When the temperature after the power-on time has elapsed is high, the duty may be reduced.

  By doing in this way, it is possible to perform display with constant video visibility immediately after the power is turned on.

  In addition, as described above, any of the configurations of the fourteenth to twenty-fourth embodiments may be configured to switch between application and non-application by processing using an image, hardware, or software switch.

  In this case as well, for example, when the PC screen is fully lit, and when any of the configurations of the fourteenth to twenty-fourth embodiments is used when displaying a moving image, both still image quality and moving image improvement can be achieved at a higher level. This is particularly effective for reducing flicker during still images.

  Of course, increasing the screen rewriting frequency for moving images than for still images is also effective in reducing flicker.

  Of course, this is not limited to the case of the idea disclosed in Examples 14 to 24, and any configuration having a state in which the backlight is repeatedly turned on and off is effective.

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display panel, 2 ... Video signal line, 3 ... Scanning signal line, 35 ... Light source, 53 ... Pixel electrode, 50A ... Counter electrode, 300 ... Backlight.

Claims (7)

Each pixel group to which a video signal is supplied has a liquid crystal display panel selected by a scanning signal supplied to a gate signal line, and a backlight disposed on the back of the liquid crystal display panel,
The backlight includes a plurality of light sources,
When sequentially displaying each frame of the liquid crystal display panel, at least one of the light source that irradiates at least the central portion of the liquid crystal display panel and both sides of the central portion of the liquid crystal display panel is irradiated for each frame. The liquid crystal display device is characterized in that a lighting duty is different from the light source . The light source that irradiates the central portion of the liquid crystal display panel is repeatedly turned on and off, and the light source that irradiates at least one of both sides of the central portion of the liquid crystal display panel remains turned on. The liquid crystal display device described . The light source that irradiates at least one of both sides of the central portion of the liquid crystal display panel has an arrangement pitch with another light source adjacent to the other light source adjacent to the light source that irradiates the central portion of the liquid crystal display panel. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is larger than the arrangement pitch . The liquid crystal duty of lighting of the light source for irradiating a central part of the display panel, according to claim 1, wherein the smaller than the duty of lighting of the light source for irradiating at least one of both sides of the central portion of the liquid crystal display panel A liquid crystal display device according to 1. Each of the light sources repeats turning on and off at the same frequency, and the frequency of turning on and off the light source that irradiates the central portion of the liquid crystal display panel is at least one of both sides of the central portion of the liquid crystal display panel. The liquid crystal display device according to claim 1, wherein the frequency is lower than the frequency of turning on and off the light source that irradiates the light source . The light source that irradiates the central portion of the liquid crystal display panel repeats turning on and off, and the light source that irradiates at least one of both sides of the central portion of the liquid crystal display panel remains on and the central portion of the liquid crystal display panel The liquid crystal display device according to claim 1, wherein a supply current or a supply voltage is smaller than that of a light source that emits light. The backlight includes a plurality of linear light sources extending in parallel to the gate signal lines and arranged in parallel to the gate signal lines on a plane substantially parallel to the plane of the liquid crystal display panel. The liquid crystal display device according to any one of claims 1 to 6.

Images