JP3534086B2 - Driving method of liquid crystal display device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving an active matrix type liquid crystal display device and a liquid crystal display device, and more particularly to an OCB (Opt) having a wide viewing angle and a high speed response.
ically self-Compensated B
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display driving method and a liquid crystal display using a liquid crystal mode.

[0002]

2. Description of the Related Art As is well known, a liquid crystal display device is widely used as a screen display device such as a computer device, but in the future, it is expected to be used for TV applications. However, TN (Twi, which is currently widely used)
Steed Nematic) mode has a narrow viewing angle and insufficient response speed, which causes a decrease in contrast due to parallax.
There is a big problem in display performance when used as a TV, such as blurring of moving images.

In recent years, research on the OCB mode in place of the TN mode has been advanced. OCB has characteristics of wider viewing angle and faster response than TN, and can be said to be a display mode more suitable for natural moving image display.

A conventional method of driving a liquid crystal display device and a conventional liquid crystal display device will be described below. In FIG. 2, X
, Xn are gate lines, Y1, Y2, ..., Ym
Is a source line, 207 is a thin film transistor (hereinafter referred to as TFT) as a switching element, and the drain electrode of each TFT is connected to the pixel electrode in the pixel 206. Each pixel 206 is composed of a pixel electrode, a counter electrode, and a liquid crystal held between both electrodes. The counter electrode is driven by the voltage supplied by the counter drive unit 205.

Reference numeral 204 is a gate driver for applying a voltage for turning on or off a TFT to the gate lines X1, X2, ..., Xn . The gate driver 204 synchronizes with the supply of data to the source line,
The on-potential is sequentially applied to the gate lines X1, X2, ..., Xn .

Reference numeral 203 denotes a source driver which outputs a voltage supplied to the pixel 206 to the source lines Y1, Y2, ..., Ym , and the phase of the voltage supplied has a relationship of the phase opposite to the phase of the voltage supplied to the counter electrode. Become. The difference between the voltage supplied to the counter electrode and the voltage supplied to the source lines Y1, Y2, ..., Ym and applied to each pixel 206 is the voltage applied to both ends of the liquid crystal in the pixel 206. To determine the transmittance of.

Such a driving method is the same whether an OCB cell or a TN type cell is used. However,
The OCB cell has a T
It requires a unique drive not found in N-type cells.

The OCB cell has a bend orientation in which an image can be displayed and a splay orientation in which an image cannot be displayed. In order to shift from the splay alignment to the bend alignment (hereinafter, referred to as transition), unique driving such as applying a high voltage for a certain period of time is required. However, since the driving related to this transition is not directly related to the present invention, further description will not be given.

In this OCB cell, even after the transition to the bend orientation by the above-mentioned unique driving, the bend orientation cannot be maintained and returns to the splay orientation if a state in which a voltage of a predetermined level or more is not applied for a certain period of time continues. (Hereinafter, this phenomenon is called reverse transition).

In order to suppress the occurrence of reverse transition, Japanese Patent Laid-Open No. Hei 11 (1999) has been proposed.
-109921 publication and the April 25, 1999 issue of the Liquid Crystal Society of Japan (Vol. 3. No. 2) P99 (17) to P
It is known that a high voltage may be applied periodically as described in 106 (24). Hereinafter, the drive for periodically applying a high potential and suppressing the reverse transition will be referred to as CR drive.

FIG. 3 shows a potential-transmittance curve of a general OCB.

In FIG. 3, reference numeral 301 denotes a potential-transmittance curve when a predetermined potential for preventing reverse transition is not inserted, 302
Is a potential-transmittance curve in the case of CR driving in which a predetermined potential for preventing reverse transition is inserted, 303 is a critical potential Vth at which reverse transition from bend alignment to splay alignment occurs without reverse transition prevention, 304 is the most The potential at the time of high transmittance (white potential), 305 is the potential at the time of lowest transmittance (black potential)
Is. If the reverse transition is not prevented, an appropriate transmittance cannot be obtained because the splay orientation is restored at Vth or less.
Therefore, it must be driven at a potential higher than Vth,
As shown in the figure, in that case, sufficient brightness cannot be obtained.
A liquid crystal represented by OCB or TN needs to be driven by a so-called alternating current, but the specific structure thereof is not described in the above-mentioned JP-A No. 11-109921 or the above journal of the Liquid Crystal Society of Japan. It is not possible to specify whether a proper AC reversal should be performed. Therefore, the CR drive, which is the most general drive, in which the line-by-line inversion and the frame-by-frame inversion are combined will be described as a conventional example. FIG. 19 is a diagram showing a configuration of a conventional liquid crystal display device, and FIG. 20 is a diagram showing timings of image signals and respective driver driving pulses. Hereinafter, the driving will be described with reference to FIGS. 19 and 20. In FIG. 19, reference numeral 1901 denotes a signal conversion unit that doubles the speed of an input image signal line by line and converts the input image signal into a double speed image signal and a double speed non-image signal, and 1902 generates a pulse for driving each driver of a source gate. 1903 is a source driver, 1904 is a gate driver, and 1905 is a liquid crystal panel. For convenience, in the description, the number of source lines of the liquid crystal panel 1905 is 10, the number of gate lines is 10, and similarly, one frame period consists of 10 horizontal periods.

Next, a conventional CR driving operation will be described. First, the input image signal is doubled in speed per line in the double speed signal conversion unit 1901 and the source driver 1903 is used.
Entered in. The specific configuration of the double speed signal conversion unit 1901 is shown in FIG. 6, and the timing of the double speed signal conversion operation is shown in FIG. The input image signal is written in the line memory 602 in synchronization with a clock (hereinafter, referred to as a write clock) generated from a synchronization signal synchronized with the image signal in the control signal generation unit 601. On the other hand, the line memory 6
In order to read the image signal from the control signal generator 02, the frequency of the image signal is doubled so that the control signal generator 6
The clock generated from the synchronization signal at 01 (hereinafter,
1 at the time of writing in synchronization with (read clock)
It is read from the line memory 602 in the period of / 2. While the image signal is being read from the line memory 602, the output signal selection unit 604 selects this image signal as an output. In the remaining period, the output signal selection unit 604
Selects the non-image signal output by the non-image signal generation unit 603 as the output. In this way, the double speed non-image signal and image signal are output in time series during one horizontal period of the input signal. The source driver supplies the input double speed signal to the source line of the panel while inverting the alternating current. FIG. 20 shows a configuration in which line-by-line inversion and frame-by-frame inversion are combined as an example of performing AC inversion. The polarity control signal for switching the AC polarity is a signal obtained by taking the exclusive OR of the line inversion signal (B) and the frame inversion signal (A) , and is generated by the control pulse generation unit 1902. FIG. 24 shows the input / output characteristics of the source driver 1903.
Shown in. In the figure, the signal output on the high side with respect to the reference potential is expressed as a positive polarity, and the low side is expressed as a negative polarity. In addition, this polarity is set to "+" during the selection period of each gate in FIG.
It is shown as "-". As shown in the figure, the source driver 1903 supplies a positive polarity voltage when the polarity control signal is HI and a negative polarity voltage when the polarity control signal is LOW. In FIG. 20, gate pulses P1 to P10 are pulses that select 10 gate lines on the panel 1905 during the HI period, and are as follows in accordance with the timing of the double speed signal input to the source driver. Driven. Figure 2
In the period T0_1 indicated by 0, the gate pulse P1 becomes HI, and the image signal S1 is written in the pixel on the gate line G1 with a positive polarity. In the subsequent period T0_2, the gate pulse P7 becomes HI, and the non-image signal is written in the gate line G7 with a negative polarity. In the period T0_3, the gate pulse P2 becomes HI, and the image signal S2 is written in the gate line G2 with a negative polarity. In the subsequent period T0_4, the gate pulse P8 becomes HI, and the non-image signal is written in the gate line G8 with a positive polarity. Below, polarity control signal (G)
Signals are sequentially written according to the polarity of. in this way,
All the gate lines on the panel are selected twice in one frame period, and the image signal and the non-image signal are written once to the pixels on each gate line. Next second frame T1_
1, the gate pulse P1 becomes HI and the gate line G1
The image signal S′1 is written in the upper pixel with a negative polarity opposite to that in the first frame. In the subsequent period T1_2, the gate pulse P7 becomes HI, and the non-image signal is written in the gate line G7 with the positive polarity opposite to that in the first frame. Similarly, signals having a polarity opposite to that of the first frame are sequentially written. By the above operation, the image signal and the non-image signal can be written periodically, and the reverse transition can be prevented by appropriately applying the voltage of the non-image signal.

[0014]

However, in the above driving, paying attention to the relationship between the polarities of the image signals written in the pixels and the polarities of the non-image signals written in, the pixels written in the first line are written. The polarity of the image signal and the polarity of the non-image signal to be written are opposite,
Similarly, up to 5 lines have the opposite polarity, but 6 lines to 1
The 0 line has the same polarity and the phase relationship is broken.

On the contrary, regarding the polarities of the non-image signals written in the pixels and the polarities of the written image signals, 1 to 5 lines have the same polarity and 6 to 10 lines have the opposite polarities. If the line is broken at the line having the polarity inversion relationship, the charge on the liquid crystal is affected and the uniformity of the image quality is impaired.

Particularly, in recent years, liquid crystal panels have become large in size and high in definition, and accordingly, the wiring resistance in the glass substrate increases, and the charging time of pixels tends to be shortened.

Therefore, in spite of the technology of improving the performance of the pixel transistor, the influence of the collapse of the phase relationship on the charging of the pixel cannot be ignored. That is, in the above example, the brightness difference is recognized at the boundary between the fifth line and the sixth line on the screen.

Further, in the above example, the driving frequency is doubled as compared with the normal driving in which the non-pixel signal is not inserted, and the writing time of the pixel signal to each pixel is shortened to 1/2. Therefore, there may occur a case where data cannot be sufficiently written in the pixel. Therefore, an object of the present invention is to solve the above problems and to provide a driving method of a liquid crystal display device and a liquid crystal display device capable of displaying a good image.

[0019]

In order to solve this problem, a liquid crystal panel driving method according to a first aspect of the present invention comprises a source line to which a pixel signal is supplied, a gate line to which a scanning signal is supplied, and An image signal, which is a pixel signal corresponding to an image, including a pixel cell arranged corresponding to an intersection of the source line and the gate line and having a transmittance determined by an absolute value of an applied voltage ; The black surface has a constant transmittance regardless of the image signal.
A non-image signal that is a pixel signal shown, a method of driving a liquid crystal panel, which is applied by alternately applying to the source line,
In each pixel cell constituting all said pixel cells for displaying the image signal and the previous SL non-image signal are each synchronized with the frame period, the polarity is reversed with respect to the reference potential, and the polarity of the image signal And the polarity of the non-image signal intermittently applied within one frame period after the image signal has the same polarity with respect to a reference potential, and further, in one frame of the image, Saw
The image signal continuous with the non-image signal applied to the
The polarity of the signal is the same period as the non-image signal and the
It is characterized in that it is provided with any period having a polarity opposite to that of the non-image signal .

As a result, the degree of writing in each pixel is made uniform, and there is an effect that a uniform image display quality is obtained on the entire screen.

In the liquid crystal panel driving method according to the second aspect of the invention, the source line to which the pixel signal is supplied, the gate line to which the scanning signal is supplied, and the intersection of the source line and the gate line are arranged. The absolute value of the applied voltage and the transmittance
And a pixel cell is determined, the image signal is a pixel signal corresponding to the image, independent and constant with the image signal
A method of driving a liquid crystal panel, wherein a non-image signal, which is a pixel signal for black display with transmittance, is alternately applied to the source line to drive, and in each pixel cell forming all the pixel cells to be displayed. the image signal and the previous SL non-image signal are each synchronized with the frame period, the polarity is reversed with respect to the reference potential, and the polarity of the image signal intermittently within one frame period after the image signal The relationship with the polarity of the non-image signal applied to is that the polarity is opposite to the reference potential, and further, in one frame of the image.
The non-image signal applied to the source line.
The polarity of the image signal is the same as that of the non-image signal.
And the period in which the polarity is opposite to that of the non-image signal
It is characterized by being provided . As a result, the writing degree of each pixel is made uniform, and there is an effect that a uniform image display quality is obtained on the entire screen.

In the liquid crystal panel driving device according to the third aspect of the invention, the source line to which the pixel signal is supplied, the gate line to which the scanning signal is supplied, and the intersection of the source line and the gate line are arranged. The absolute value of the applied voltage and the transmittance
A pixel cell for which is determined , an image signal that is a pixel signal corresponding to an image, and a constant transmittance that is independent of the image signal.
And a non-image signal which is a pixel signal for black display, and a driving means for alternately applying to the source line, and in each pixel cell forming all the pixel cells to be displayed, the image signal and the non-image The signal means that the polarity with respect to the reference potential is inverted in synchronization with each frame period, and the polarity of the image signal and the non-image signal applied intermittently within one frame period after the image signal. relationship with the polarity of a same polarity relative to the reference potential, and further, the
Applied to the source line in one frame of the image
The polarity of the image signal continuous to the non-image signal is the
A period having the same polarity as the non-image signal and an opposite polarity to the non-image signal
It is characterized in that it is driven so as to have any of the sex periods . As a result, the writing degree of each pixel is made uniform, and there is an effect that a uniform image display quality is obtained on the entire screen.

In the liquid crystal panel driving device according to the fourth aspect of the present invention, the source line to which the pixel signal is supplied, the gate line to which the scanning signal is supplied, and the intersection of the source line and the gate line are arranged. The absolute value of the applied voltage and the transmittance
A pixel cell for which is determined , an image signal that is a pixel signal corresponding to an image, and a constant transmittance that is independent of the image signal.
And a non-image signal which is a pixel signal for black display, and a driving means for alternately applying to the source line, and in each pixel cell forming all the pixel cells to be displayed, the image signal and the non-image The signal means that the polarity with respect to the reference potential is inverted in synchronization with each frame period, and the polarity of the image signal and the non-image signal applied intermittently within one frame period after the image signal. relationship with the polarity of a polarity opposite to the reference potential, and further, the
Applied to the source line in one frame of the image
The polarity of the image signal continuous to the non-image signal is the
A period having the same polarity as the non-image signal and an opposite polarity to the non-image signal
It is characterized in that it is driven so as to have any of the sex periods . As a result, the writing degree of each pixel is made uniform, and there is an effect that a uniform image display quality is obtained on the entire screen.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) FIG. 7 is a diagram showing a configuration of a liquid crystal display device according to a first embodiment of the present invention. FIG. 1 shows timings of an image signal and respective driver driving pulses. It is the figure shown.

The driving will be described below with reference to FIGS. 1 and 7.

The configuration of the liquid crystal display device according to the first embodiment is a configuration in which the drive pulse generator 1902 in the liquid crystal display device according to the above-described conventional embodiment is replaced with 702. Other configurations are the same, and the same reference numerals are assigned to the configurations, and the description thereof will be omitted. For convenience, the number of source lines of the liquid crystal panel 1905 is 10 in the description.
The number of lines and gate lines is 10, and likewise, one frame period consists of 10 horizontal periods. Next, the CR drive operation in the first embodiment will be described. First, the input image signal is doubled in each line in the double speed signal conversion unit 1901 and input to the source driver 1903. The specific configuration of the double speed signal conversion unit 1901 is shown in FIG. 6, and the timing of the double speed signal conversion operation is shown in FIG. The description of the double speed conversion operation is omitted because it is the same as that of the conventional example, but the double speed signal conversion unit outputs the non-image signal doubled in speed in one horizontal period of the input signal and the image signal. The source driver supplies the input double speed signal to the source line of the panel while inverting the alternating current. FIG. 1 shows a configuration in which line-by-line inversion and frame-by-frame inversion are combined as an example of performing AC inversion. The polarity control signal for switching the AC polarity is generated in the control pulse generation unit 702 by the following method, for example, as shown in FIG. An image period signal (A) indicating HI during the image signal period, a frame inversion signal (B) synchronized with the writing of the image signal, a frame inversion signal (C) synchronized with the writing of the non-image signal, and an inversion for each line. Using the signal (D), (E) is the exclusive OR of (D) and (B), (F)
Generates an exclusive OR signal of (D) and (C), further generates a signal (G) that becomes (E) when (A) is HI and (F) when it is LOW, and sources it. The signal polarity control signal (G) is used. Note that in the present embodiment, the relationship between the frame inversion signal (B) synchronized with the writing of the image signal and the frame inversion signal (C) synchronized with the writing of the non-image signal is as shown in FIG. ) Must be a phase relationship that falls before. Using the polarity control signal (G) generated as described above, the source driver supplies a positive voltage when the control signal is HI and a negative voltage when the control signal is LOW. The input / output characteristics of the source driver 1903 are shown in FIG. In FIG. 1, the relationship between the positive polarity and the negative polarity is shown as "+" and "-" in the selection period of each gate. In FIG. 1, gate pulses P1 to P10 are pulses for selecting 10 gate lines on the panel 1905 during the HI period, and are as follows in accordance with the timing of the double speed signal input to the source driver. Driven. In the period T0_1 shown in FIG. 1, the gate pulse P1 becomes HI and the image signal S1 is written in the pixel on the gate line G1 with a negative polarity. Subsequent period T0_
2, the gate pulse P7 becomes HI and the gate line G7
A non-image signal is written in the positive polarity. In the period T0_3, the gate pulse P2 becomes HI, and the image signal S2 is written in the gate line G2 with a positive polarity. Subsequent period T
At 0_4, the gate pulse P8 becomes HI, and the non-image signal is written in the gate line G8 with a negative polarity. Hereinafter, signals are sequentially written according to the polarity of the polarity control signal (G). Further, in the period T0_10, the gate pulse P
1 becomes HI again, and the non-image signal is written in the pixel on the gate line G1 with a negative polarity. In this way, all gate lines on the panel are selected twice in one frame period,
The image signal and the non-image signal are written once to the pixels on each gate line. At T1_1 of the next second frame, the gate pulse P1 becomes HI, and the image signal S′1 is written to the pixel on the gate line G1 with the positive polarity opposite to that of the first frame. In the subsequent period T1_2, the gate pulse P7 becomes HI, and the non-image signal is written in the gate line G6 with the negative polarity opposite to that in the first frame. Same as below 1
Signals with the opposite polarity to the frame are sequentially written. As described above, according to the driving method of the liquid crystal display device according to the first embodiment of the present invention, the image signal and the non-image signal are alternately written in each pixel, and all the pixels are written in the pixel. The polarity of the image signal and the polarity of the non-image signal to be written are the same, which facilitates writing of the non-image signal. Therefore, the degree of writing of the non-image signal to each pixel is made uniform, and more uniform display image quality can be obtained. In the present embodiment, the basic driving method is so-called line inversion driving in which the polarity of the signal is inverted for each line, but the effect of the present invention is not limited to that, and adjacent pixels on each line The same applies to so-called column inversion driving, in which the polarities of the signals written in are inverted to each other.

(Second Embodiment) FIG. 7 is a diagram showing a configuration of a liquid crystal display device according to a second embodiment of the present invention, and FIG. 8 is a diagram showing timings of image signals and driver driving pulses. is there. Hereinafter, the driving will be described with reference to FIGS. 7 and 8. The configuration of the liquid crystal display device according to the second embodiment is the same as that of the liquid crystal display device according to the above-described conventional embodiment.
The configuration is replaced with 02. Other configurations are the same, and the same reference numerals are assigned to the configurations, and the description thereof will be omitted.

For convenience of explanation, it is assumed that the liquid crystal panel 1905 has 10 source lines and 10 gate lines, and one frame period consists of 10 horizontal periods. Next, the CR driving operation in the second embodiment will be described. First, the input image signal is a double speed signal conversion unit 1901.
In the source driver 19
It is input to 03. The specific configuration of the double speed signal conversion unit 1901 is shown in FIG. 6, and the timing of the double speed signal conversion operation is shown in FIG. The double speed conversion operation is the same as that of the first embodiment, and therefore the description thereof is omitted. However, the double speed signal conversion unit outputs the double speed non-image signal and the image signal in time series in one horizontal period in the input signal. Is output to. The source driver supplies the input double speed signal to the source line of the panel while inverting the alternating current.

FIG. 8 shows a configuration in which line-by-line inversion and frame-by-frame inversion are combined as an example of performing AC inversion. The polarity control signal for switching the AC polarity is generated in the control pulse generation unit 702 by the following method, as shown in FIG. 8 , for example. An image period signal (A) showing a positive value in the image signal period, a frame inversion signal (B) synchronized with writing of an image signal, a frame inversion signal (C) synchronized with writing of a non-image signal, and inversion for each line Using signal (D), (E) is (D) and (B)
, An exclusive OR signal of (D) and (C) is generated by (F), and (E), L when (A) is HI.
A signal (G) which becomes (F) at the time of OW is generated and used as a polarity control signal (G) of the source signal. In the present embodiment, the relationship between the frame inversion signal (B) synchronized with the writing of the image signal and the frame inversion signal (C) synchronized with the writing of the non-image signal is as shown in FIG. )
The phase relationship must be such that it falls earlier. Positive polarity voltage when the polarity control signal (G) is HI, LO
When W, the negative voltage is supplied by the source driver. The input / output characteristics of the source driver 1903 are shown in FIG. The relationship between the positive polarity and the negative polarity is shown as "+" and "-" in the selection period of each gate in FIG. In FIG. 8, gate pulses P1 to P10 are pulses for selecting 10 gate lines on the panel 1905 during the HI period. In the period T0_1 shown in the figure, the gate pulse P1 becomes HI, and the image signal S1 is written in the pixel on the gate line G1 with a negative polarity. Subsequent period T0_2
Then, the gate pulse P7 becomes HI, and the non-image signal is written in the gate line G7 with a negative polarity. In the period T0_3, the gate pulse P2 becomes HI, and the image signal S2 is written in the gate line G2 with a positive polarity. Subsequent period T
At 0_4, the gate pulse P8 becomes HI, and the non-image signal is written in the gate line G8 with a positive polarity. Hereinafter, signals are sequentially written according to the polarity of the polarity control signal (G). Further, in the period T0_10, the gate pulse P
1 becomes HI again, and the non-image signal is written in the pixel on the gate line G1 with a positive polarity. . In this way, all the gate lines on the panel are selected twice in one frame period, and the pixel on each gate line receives the image signal and the non-image signal one time.
It is written once. At T1_1 of the next second frame, the gate pulse P1 becomes HI, and the image signal S′1 is written to the pixel on the gate line G1 with the positive polarity opposite to that of the first frame. In the subsequent period T1_2, the gate pulse P7 becomes HI, and the non-image signal is written in the gate line G7 with the positive polarity opposite to that in the first frame. Similarly, signals having a polarity opposite to that of the first frame are sequentially written.
As described above, according to the driving method of the liquid crystal display device according to the second embodiment of the present invention, the image signal and the non-image signal are alternately written in each pixel, and all the pixels are written in the pixel. Since the polarity of the non-image signal and the polarity of the image signal to be written are the same, writing of the image signal becomes easy. Therefore, the degree of writing the image signal to each pixel is made uniform, and more uniform display image quality can be obtained. In the present embodiment, the basic driving method is so-called line inversion driving in which the polarity of the signal is inverted for each line, but the effect of the present invention is not limited to that, and adjacent pixels on each line The same applies to so-called column inversion driving, in which the polarities of the signals written in are inverted to each other.

Reference Embodiment 1 In the first embodiment, that is, the CR drive, the drive frequency is doubled as compared with the normal drive, and the writing time of the pixel signal for each pixel is shortened to 1/2. . Therefore, as the liquid crystal panel becomes larger and the resolution becomes higher, it may occur that data cannot be sufficiently written in the pixel. Therefore, in Reference Embodiment 1 of the present invention, image by the drive system of the first embodiment, immediately before the images signal write timing of the normal with respect to each pixel, and writes the non-image picture signal of the same polarity
To improve the writing of the image Motoshingo is to introduce a so-called pre-charge driving.

FIG. 9 is a diagram showing a configuration of the liquid crystal display device according to the first embodiment of the present invention, and FIG. 10 is a diagram showing timings of image signals and respective driver driving pulses. The driving will be described below with reference to FIGS. 9 and 10. In addition, reference
The configuration of the liquid crystal display device according to the first embodiment is the same as that of the drive pulse generation unit 19 in the liquid crystal display device according to the conventional embodiment.
This is a configuration in which 02 is replaced with 902. Other configurations are the same, and the same reference numerals are assigned to the configurations, and the description thereof will be omitted. For convenience, in the description, the liquid crystal panel 1
The number of source lines of 905 is 10, the number of gate lines is 11, and similarly, one frame period consists of 11 horizontal periods. Next, the CR driving operation in the first embodiment will be described. First, the input image signal is a double speed signal conversion unit 19
In 01, the speed is doubled for each line and input to the source driver 1903. The specific configuration of the double speed signal conversion unit 1901 is shown in FIG. 6, and the timing of the double speed signal conversion operation is shown in FIG. Since the double speed conversion operation is the same as that of the first embodiment, the description thereof will be omitted.
In the one horizontal period of the input signal, the double-speed non-image signal and the image signal are output in time series. The source driver supplies the input double speed signal to the source line of the panel while inverting the alternating current. FIG. 10 shows a configuration in which line-by-line inversion and frame-by-frame inversion are combined as an example of performing AC inversion. The polarity control signal for switching the AC polarity is generated by the control pulse generation unit 902 by the same method as in the first embodiment. The source driver supplies a positive voltage when the polarity control signal is HI and a negative voltage when the polarity control signal is LOW. Source driver 190
The input / output characteristics of No. 3 are shown in FIG. In FIG. 10, the relationship between the positive polarity and the negative polarity is shown as “+” and “−” in the selection period of each gate. In FIG. 10, gate pulses P1 to
P 11 is a pulse that selects 11 gate lines on the panel 1905 during the HI period. In the period T0_1 shown in the figure, the gate pulse P1 becomes HI, and the image signal S1 is written in the pixel on the gate line G1 with a positive polarity. In the subsequent period T0_2, the gate pulse P2
And P5 become HI, and the non-image signal is written in the gate lines G2 and G5 with a negative polarity. In the period T0_3, the gate pulse P2 becomes HI, and the image signal S2 is written in the gate line G2 with a negative polarity. In the following period T0_4,
The gate pulses P3 and P6 become HI, and the non-image signal is written in the gate lines G3 and G6 with a positive polarity. Thereafter, signals are sequentially written as shown in the figure. In this way, all the gate lines on the panel are selected three times in one frame period, and the image signal is written once and the non-image signal is written twice to the pixels on each gate line. T1 of the next second frame
In _1, the gate pulse P1 becomes HI and the gate line G
The image signal S′1 is written in the pixel on the upper side with the negative polarity opposite to that in the first frame. In the subsequent period T1_2,
The gate pulses P2 and P5 become HI, and the non-image signal is written in the gate lines G2 and G5 with the negative polarity opposite to that in the first frame. Similarly, signals having a polarity opposite to that of the first frame are sequentially written. As described above, according to the driving method of the liquid crystal display device and the liquid crystal display device according to the first embodiment of the present invention, the non-image signal of the same polarity immediately before the image signal is preliminarily written to charge the pixel. It is possible to more sufficiently perform the writing, and it is possible to improve the writing shortage due to the shortening of the writing time. As a result, a more desirable display image quality can be obtained. In FIG. 10, since the non-image signal is written 7.5 horizontal periods after the image signal is written, the non-image signal precharged immediately before the image signal has a phase relationship of 0.5 adjacent horizontal periods before. Has become. As shown in FIG. 11, if the non-image signal is written 6.5 horizontal periods after the image signal is written, the non-image signal to be precharged before the image signal is written is 1.
The phase relationship is 5 horizontal periods ago. In this way, the phase of the precharge signal is appropriately determined according to the phase relationship between the image signal and the non-image signal. When the precharge signal selection period and the image signal selection period are adjacent to each other as shown in FIG. 10, a non-selection period does not need to be inserted between the selection periods, so that the gate pulse It is possible to eliminate the influence of the slow transmission, and it becomes a more desirable configuration. Further, in the above-described reference embodiment , it is preferable that one frame period is an odd-numbered horizontal period, and a rate conversion unit using a memory or the like is provided so that one frame period is always an odd-numbered horizontal period. If the signal rate conversion is performed, a more desirable configuration is obtained. In this embodiment , the basic driving method is so-called line inversion driving in which the polarity of the signal is inverted for each line, but the effect of the present invention is not limited to that, and adjacent pixels on each line The same applies to so-called column inversion driving, in which the polarities of the signals written in are inverted to each other.

Reference Embodiment 2 In the second embodiment, that is, the CR drive, the drive frequency is doubled as compared with the normal drive, and the writing time for each pixel is shortened to 1/2. Therefore, the
The reference mode 2 is different from the drive system of the second embodiment in that
Immediately after the regular non-pixel signal write timing for each pixel, so-called dual charge drive is introduced in which the non-pixel signal of the same polarity is written to improve the writing of the non-pixel signal. FIG. 12 is a reference embodiment of the present invention.
2 is a diagram showing a configuration of a liquid crystal display device according to No. 2 , and FIG. 13 is a diagram showing timings of an image signal and each driver driving pulse. Hereinafter, the driving will be described with reference to FIGS. 12 and 13. The configuration of the liquid crystal display device according to the second embodiment is as follows.
In the liquid crystal display device according to the above-described conventional embodiment, the drive pulse generation unit 1902 is replaced with 1202. Other configurations are the same, and the same reference numerals are assigned to the configurations, and the description thereof will be omitted. For convenience, in the description, the number of source lines of the liquid crystal panel 1905 is 10,
The number of gate lines is 11, and likewise, 11 per frame period.
It is assumed to consist of horizontal periods. Next, the CR driving operation in the second embodiment will be described. First, the input image signal is doubled in each line in the double speed signal conversion unit 1901 and input to the source driver 1903. The specific configuration of the double speed signal conversion unit 1901 is shown in FIG. 6, and the timing of the double speed signal conversion operation is shown in FIG. The double speed conversion operation is the same as that of the first embodiment, and therefore the description thereof is omitted. However, the double speed signal conversion unit outputs the double speed non-image signal and the image signal in time series in one horizontal period in the input signal. Is output to. The source driver supplies the input double speed signal to the source line of the panel while inverting the alternating current. FIG. 13 shows a configuration in which line-by-line inversion and frame-by-frame inversion are combined as an example of performing AC inversion. The polarity control signal for switching the AC polarity is generated in the control pulse generation unit 1202 by the same method as in the second embodiment. When the polarity control signal is HI, the positive voltage, LO
When W, the negative voltage is supplied by the source driver. The input / output characteristics of the source driver 1903 are shown in FIG. The relationship between the positive polarity and the negative polarity is shown as "+" and "-" in the selection period of each gate in FIG. In FIG. 13, gate pulses P1 to P11 are pulses for selecting 11 gate lines on the panel 1905 during the HI period. In the period T0_1 shown in the figure, the gate pulse P1 becomes HI, and the image signal S1 is written in the pixel on the gate line G1 with a positive polarity. Subsequent period T0_
At 2, the gate pulses P5 and P7 become HI, and the non-image signal is written in the gate lines G5 and G7 with a positive polarity. In the period T0_3, the gate pulse P2 becomes HI, and the image signal S2 is written in the gate line G2 with a negative polarity. In the subsequent period T0_4, the gate pulses P6 and P8 are at H level.
I, and the non-image signal is written in the gate lines G6 and G8 with a negative polarity. Thereafter, signals are sequentially written as shown in the figure. In this way, all the gate lines on the panel are selected three times in one frame period, and the image signal is written once and the non-image signal is written twice to the pixels on each gate line. At T1_1 of the next second frame, the gate pulse P
1 becomes HI, and the image signal S is supplied to the pixel on the gate line G1.
'1' is written with the negative polarity opposite to that of the first frame. In the subsequent period T1_2, the gate pulses P5 and P7 become HI, and the non-image signal is written in the gate lines G5 and G7 with the negative polarity opposite to that in the first frame. Similarly, signals having a polarity opposite to that of the first frame are sequentially written. As described above, according to the driving method of the liquid crystal display device and the liquid crystal display device according to the second embodiment of the present invention, the non-image signal of the same polarity is prognostically written after the writing of the non-image signal,
It is possible to more sufficiently charge the pixel, and it is possible to improve the insufficient writing due to the shortened writing time. As a result, a more desirable display image quality can be obtained. Up to this point, the case where the non-image signal having the same polarity is prognostically written after the writing of the non-image signal has been described as an example. However, as shown in FIG. Precharging is possible as well. Note that in the above reference embodiment , it is preferable that one frame period is a horizontal period of an odd multiple, and a rate conversion unit using a memory or the like is provided so that one frame period is always a horizontal period of an odd multiple. If you do rate conversion,
More desirable. Further, in the present reference embodiment , the basic driving method is so-called line inversion driving in which the polarity of the signal is inverted for each line, but the effect of the present invention is not limited to that, and adjacent pixels on each line The same applies to so-called column inversion driving, in which the polarities of the signals written in are inverted to each other.

Reference Embodiment 3 FIG. 14 is a diagram showing a configuration of a liquid crystal display device according to Reference Embodiment 3 of the present invention. The configuration of the liquid crystal display device according to the third embodiment is a configuration in which the drive pulse generation unit 1902 and the signal conversion unit 1901 are replaced with 1402 in the liquid crystal display device according to the above-described conventional embodiment. Other configurations are the same, and the same reference numerals are assigned to the configurations, and the description thereof will be omitted. However, in this reference embodiment , for convenience, the liquid crystal panel 1905 has 10 source lines and 12 gate lines, and similarly, 1 frame period is 1 line.
It is supposed to consist of two periods. Hereinafter, the reference form of the present invention
A method for driving the liquid crystal display device in the third mode will be described with reference to FIGS.
6, further referring to FIG. FIG. 15 is a diagram showing an internal configuration of the signal conversion unit 1401. 16
FIG. 9 is a timing chart showing the operation of the signal conversion unit 1401.
FIG. 17 is a diagram showing the timing of the input image signal, the output image signal of the signal conversion unit 1401 and the gate driver drive pulse. FIG. 24 is a diagram showing the input / output characteristics of the source driver 1903. According to the driving method of the liquid crystal display device of the present invention, an image signal to be input to each pixel on the liquid crystal panel and a non-image signal necessary for suppressing the reverse transition phenomenon of the OCB liquid crystal, regardless of the image signal. Driving is performed once for 1 frame period, and the signal conversion unit 1401 converts the driving frequency for that purpose. Book
In the reference mode , the frequency conversion of 1.25 times is performed as an example, in which five lines including one line of the non-image signal are transferred to the source driver in four horizontal periods of the input image signal. This 1.25 times frequency conversion will be described. The input image signal is supplied to the control signal generation unit 15
In 01, data is written in the line memory 602 in synchronization with a clock (hereinafter, referred to as a write clock) generated from a synchronization signal synchronized with the image signal. On the other hand, when the image signal is read from the line memory 602, the frequency is 1.25 times the write clock,
The line memory 60 is synchronized with a clock (hereinafter, referred to as a read clock) generated from a synchronization signal in the control signal generation unit 1501 during a period of 4/5 of writing.
It is read from 2. While the image signal is being read from the line memory 602, the output signal selection unit 604 selects this image signal as an output. In the remaining period, the output signal selection unit 604 selects the non-image signal output by the non-image signal generation unit 603 as the output. As described above, the non-image signal and the image signal, which are speeded up by 1.25 times in one horizontal period in the input signal, are output from the double speed signal conversion unit as 1
It is output in time series at a ratio of 4. Source driver 19
FIG. 24 shows the input / output characteristics of No. 03. Source driver 19
03 receives the output signal of the signal conversion unit 1501 and inverts the polarity of the signal line by line and outputs the signal. In FIG. 17, the relationship between the positive polarity and the negative polarity is “+” during the selection period of each gate.
The polarity is switched by a polarity control signal generated by the control pulse generator 1402. In FIG.
Is a pulse for selecting each of the 12 gate lines on the panel 1905 during the HI period. In the period T0_0 shown in FIG. 17, the gate pulses P5 to P8 simultaneously become HI, and the non-image signal is written in the pixels on the gate lines G5 to G8 with a positive polarity. Subsequent period T0_1 to T0
In _4, the gate pulses P1 to P4 sequentially become HI, and the gate lines G1, G2, G3, and G4 receive the image signal S1,
S2, S3, and S4 are sequentially written with positive polarity. Period T
In 0_5, the gate pulses P9 to P12 simultaneously become HI, and the non-image signal is written in the gate lines G9 to G12 with a negative polarity. In the subsequent periods T0_6 to T0_9, the gate pulses P5 to P8 sequentially become HI, and the image signals S5, S6, S are applied to the gate lines G5, G6, G7, G8.
7 and S8 are sequentially written in the negative polarity. Here, each pixel on the gate lines G5, G6, G7, and G8 is T0.
_0 to T0_5, T0_0 to T0_6, T0_0 to T0
The non-image signal is held during the period _7 and T0_0 to T0_8. In this way, all the gate lines on the panel are selected twice in one frame period, and the image signal and the non-image signal are written once to the pixels on each gate line. In the period T1_0 of the next frame period, the gate pulses P5 to P8 simultaneously become HI, and the gate lines G5 to G8.
On the other hand, the non-image signal is written in the negative polarity, which is the reverse of the previous frame. Similarly, the subsequent periods T1_1 to T1
In _4, the gate pulses P1 to P4 sequentially become HI, and the image signals S ′ are applied to the gate lines G1, G2, G3, and G4.
1, S′2, S′3, and S′4 are sequentially written with the negative polarity opposite to that of the previous frame. As described above, the present invention
According to the driving method of the liquid crystal display device according to the reference mode 3 , the image signal and the non-image signal are alternately written in each pixel, and the non-image signal is written in all the pixels with respect to the state in which the image signal is written in the pixel. , The polarity of the image signal written in the pixel is the same as the polarity of the non-image signal written, and the writing of the non-image signal becomes easy. On the contrary, when the image signal is written in the state where the non-image signal is written in the pixel, the polarity of the non-image signal written in the pixel is opposite to the polarity of the written image signal with respect to the reference potential, Writing an image signal is disadvantageous. As a result, the degree of writing of the image signal to each pixel is made uniform, and the display image quality is improved. This reference form
In the state , the basic driving method is so-called line inversion driving, in which the polarity of the signal is inverted line by line, but the effect of the present invention is not limited to that, and a signal written to an adjacent pixel on each line is used. The polarities of
The same applies to so-called column inversion driving. Also, this reference
In the mode , the drive frequency is converted to 1.25 times, but for example, the number of gate lines for simultaneously writing the non-image signal is n (n =
The effects of the present invention can be similarly obtained when (n + 1) / (n) double speed conversion of 2, 3, 4, ...

Reference Embodiment 4 In Reference Embodiment 3 , the driving frequency is 1.25 times that of normal driving, and the pixel signal writing time for each pixel is shortened to 1 / 1.25. Therefore in Reference shaped state 4 of the present invention, the drive system of the reference embodiment 3, just before the normal of the pixel signal writing timing for each pixel, improve the writing of the pixel signals by writing the pixel signals of the same polarity The so-called pre-charge driving is introduced. FIG. 18 is a diagram showing the configuration of the liquid crystal display device according to the fourth embodiment of the present invention. The configuration of the liquid crystal display device according to the fourth embodiment is the same as that of the liquid crystal display device according to the third embodiment except that the drive pulse generation unit 1402 is 1802.
The configuration is replaced with. Other configurations are the same,
The same reference numerals are given to the configuration and the description is omitted. Hereinafter, the driving method of the liquid crystal display device according to the fourth embodiment of the present invention will be described focusing on the points different from the third embodiment . FIG. 21 shows an input image signal / signal conversion unit 14 in the method of driving the liquid crystal display device according to the fourth embodiment of the present invention.
It is a figure showing the timing of the output image signal of 01 and a gate driver drive pulse. Similar to the third embodiment , the signal conversion unit 1401 converts the driving frequency of the input image signal to 1.25 times, and in the four horizontal periods of the input signal,
5 lines including a non-image signal for the source driver
Transfer the line. Also, the source driver 1903
Receives the output signal of the signal conversion unit 1401 and inverts the polarity of the signal on a line-by-line basis and outputs the signal. In the period T0_0 shown in FIG. 21, the gate pulses P1 and P5 to P8 simultaneously become HI, and a positive non-image signal is written in the pixels on the gate lines G1 and G5 to G8. Subsequent period T0
In _1, the gate pulse P1 and P2 are H
I, and the positive image signal S1 is applied to the gate lines G1 and G2.
Written to each pixel above. At this time, the positive non-image signal is written in each pixel on the gate line G1 immediately before, and the positive image signal S1 is easily written.
In the next period T0_2, the gate pulses P2 and P3 simultaneously become HI, and the positive image signal S2 is similarly written to each pixel on the gate line G2 where the positive image signal S1 has already been written. It will be easy. Similarly, in the period T0_3, the gate pulses P3 and P4 simultaneously become HI, and the positive polarity image signal S3 is written to each pixel on the gate line G3 where the positive polarity image signal S2 has already been written. It will be easy. Further, in the subsequent period T0_4, only the gate pulse P4 becomes HI, and the positive polarity image signal S4 is easily written to each pixel on the gate line G4 where the positive polarity image signal S3 has already been written. Become. In the next period T0_5,
The gate pulses P5 and P9 to P12 simultaneously become HI,
A non-image signal having a negative polarity is written in the pixels on the gate lines G5 and G9 to G12. In the subsequent period T0_6, the gate pulse P5 and further P6 become HI,
The image signal S5 having a negative polarity is written in each pixel on the gate lines G5 and G6. A negative non-image signal has already been written in each pixel on the gate line G5, which makes it easy to write the negative image signal S5. In addition, each pixel on the gate line G5 holds the non-image signal during the period T0_0 to T0_5, and the period other than the frame period is the image signal holding period. Hereinafter, while reversing the polarity, five gate lines are simultaneously selected and non-image signals are written in the period T0_10, and two gate lines are sequentially selected and image signals are written in the other periods. In the period T0_10, the gate pulse P1
~ P4 and P9 simultaneously become the HI of the gate line, and a positive non-image signal is written to the pixels on the gate lines G1 to G4 and G9. Regarding the writing of the non-image signal to the gate lines G1 to G4, the writing is easy because the positive polarity image signals S1 to S4 are written in the periods T0_1 to T0_4. Further, driving in the next frame will be described. First period T1_ of the next frame
At 0, the gate pulses P1 and P5 to P8 simultaneously become HI of the gate line, and a negative non-image signal opposite to the previous frame is written in the pixels on the gate lines G1 and G5 to G8. In the subsequent period T1_1, the gate pulse P1 and further P2 become HI, and the negative image signal S'1 opposite to the previous frame is written to each pixel on the gate lines G1 and G2. Here, the polarity of the image signal is reversed from that of the previous frame in order to avoid the burn-in phenomenon of the liquid crystal display that occurs when the signal of the same polarity is held for a long time as in the case of driving a general liquid crystal. Is. At this time,
A negative non-image signal is written immediately before in each pixel on the gate line G1, which facilitates writing of the negative image signal S′1. In the next period T1_2, the gate pulses P2 and P3 become HI at the same time, and the negative polarity image signal S′2 is written to each pixel on the gate line G2 where the negative polarity image signal S′1 has already been written. Writing becomes easy. As described above, in the reference embodiment 4 of the present invention, in the driving for writing the pixel signal twice to each pixel in one frame period, the image signal and the non-image signal shown in the reference embodiment 3 of the present invention By precharging each pixel while maintaining the polarity control, it becomes possible to improve the insufficient writing due to the shortened writing time. In this embodiment , the basic driving method is so-called line inversion driving in which the polarity of the signal is inverted for each line, but the effect of the present invention is not limited to that, and adjacent pixels on each line The same applies to so-called column inversion driving, in which the polarities of the signals written in are inverted to each other. Further, although the drive frequency is converted to 1.25 times in the present embodiment , for example, the number of gate lines for simultaneously writing the non-image signals is n (n = 2, 3, 4, ...) (n + 1).
The effects of the present invention are also obtained when the / (n) double speed conversion is performed.

Reference Embodiment 5 In order to perform the writing shown in the fifth and reference embodiments in consideration of the polarities of the image and non-image signals to each gate line without deteriorating the image quality, the line of one frame period is used. There are restrictions on the number. In the driving method shown in the third embodiment , when the number of gate lines for simultaneously writing non-image signals is N lines, the total number Y of lines in one frame period is N × (2M + 1) lines (M is 1). Must be an integer greater than or equal to). In the driving method shown in the reference mode 4 , the number of gate lines for simultaneously writing non-image signals is N
When set to lines, the total number of lines in one frame period Y
Must be (N−1) × (2M + 1) lines (M is an integer of 1 or more). FIG. 22 shows the drive timing in the case of Y = 13 as an example in the case where the above Y is not (N−1) × (2M + 1) in the drive method shown in the fourth embodiment . As is clear from this figure, the gate lines G5, G
6, G7, and G8 hold T0_6 to T0_14 and T0_7 to T0_1, respectively, while the image signals are held.
4, T0_8 to T0_14, T0_9 to T0_14. Further, the period in which each pixel on the gate line G5 holds the image signal is the same as the period in which each pixel on the gate line G1 holds the image signal, and similarly, the gate lines G6, G
The period in which each pixel on 7 and G8 holds the image signal is the same as the period in which each pixel on the gate lines G2, G3 and G4 holds the image signal. On the other hand, the gate line G
The periods in which the pixels on 9, G10, G11, and G12 hold the image signals are T0_11 to T1_4 and T0_, respectively.
12-T1_4, T0_13-T1_4, T0_14-
T1_4, which is different from the period in which each pixel on the other gate line holds the image signal. Thereby, the gate lines G1 to G1
There is a difference in brightness between the display portion for G4 and the display portion for the gate lines G5 to G13. Therefore, in the fifth embodiment of the present invention, a means for adjusting the number of gate lines scanned in one frame period is newly provided, and the total number Y of scanning lines in one frame period of an input image signal is (N-1) * (2M +
1) If it is not a line, change it to (N-1) x (2M +
1) The line is adjusted. FIG. 23
FIG. 9 is a diagram showing a configuration of a liquid crystal display device according to a fifth embodiment of the present invention. In FIG. 23, the liquid crystal display device according to the fifth embodiment is the liquid crystal display device according to the fourth embodiment shown in FIG. 18 that additionally includes a line number adjustment unit 2306 and a frame memory 2307. Hereinafter, reference of the present invention
A method for driving a liquid crystal display device according to mode 5 will be described in Reference Mode 4.
The explanation will focus on the parts different from. FIG. 22 shows a reference of the present invention.
In the driving method of the liquid crystal display device according to consideration 5 , the total number of lines Y in one frame period of the input image signal is N ×
Line number adjusting unit 23 when not (2M + 1) lines
6 is a diagram for explaining the timing of the input / output signal between 06 and the frame memory 2307. FIG. The image signal is written into and read from the frame memory in synchronization with the reference timing of a predetermined image signal. At this time, the frequency of the clock used to read the image signal from the frame memory is set lower than the frequency of the clock used to write the image signal from the frame memory. Here, while maintaining the number of image signals in the horizontal period to extend the horizontal period, the number of lines in one frame period is adjusted by maintaining the one frame period. As described above, the number of lines Y in one frame period of the input image signal is (N−1) ×
If it is not (2M + 1) lines, this is (N-1) ×
By adjusting the line to (2M + 1) and unifying the polarities of the image signal and non-image signal written in all pixels on the liquid crystal panel, while suppressing variations in the retention period of the image signal, high-quality display is possible. Becomes

In this reference embodiment , the operation when the total number of lines Y ′ in one frame period after conversion is set to Y or less has been described. This is because the image signal generally includes a blanking period that is not related to the display image, and even if the total number of lines in one frame period is reduced, a part of the displayed image is not lost and the number of lines is This is because it is more advantageous to perform the adjustment in the direction of reducing the number, because it leads to the reduction of the operating frequency. If Y is less than or equal to the number of lines of the image signal to be displayed, the frequency of the clock used to read the image signal from the frame memory is higher than the frequency of the clock used to write the image signal from the frame memory. By doing so, it is also possible to make an adjustment such that Y ′> Y. Further, in the present reference embodiment , the drive for performing precharge has been described as an example, but it is not always necessary to perform precharge drive together.

[Brief description of drawings]

FIG. 1 is a diagram illustrating control performed by a driving method of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a liquid crystal panel.

FIG. 3 is a diagram showing a potential-transmittance curve of OCB.

FIG. 4 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 5 is a timing diagram illustrating an operation of a double speed signal conversion operation.

FIG. 6 is a diagram showing an internal configuration of a signal conversion unit of a conventional liquid crystal display device.

FIG. 7 is a diagram showing a configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating control performed by a driving method of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 10 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 11 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 12 is a diagram showing a configuration of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 13 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the second embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of a liquid crystal display device according to Embodiment 3 of the present invention.

FIG. 15 is a diagram showing an internal configuration of a signal conversion unit of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 16 is a timing diagram illustrating the operation of the signal conversion unit of the liquid crystal display device according to the third embodiment of the present invention.

FIG. 17 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the third embodiment of the present invention.

FIG. 18 is a diagram showing a configuration of a liquid crystal display device according to Embodiment 4 of the present invention.

FIG. 19 is a diagram showing a configuration of a conventional liquid crystal display device.

FIG. 20 is a diagram illustrating control performed by a driving method of a conventional liquid crystal display device.

FIG. 21 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the fourth embodiment of the present invention.

FIG. 22 is a diagram illustrating control performed by the driving method of the liquid crystal display device according to the fifth embodiment of the present invention.

FIG. 23 is a diagram showing a configuration of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 24 is a diagram showing input / output characteristics of a source driver.

[Description of Reference Signs] 203, 1903 Source driver 204, 1904 Gate driver 205 Opposed drive unit 206 Pixel 207 TFT 301 Predetermined potential for reverse transition prevention Potential-transmittance curve 302 Predetermined for reverse transition prevention Potential-transmittance curve 303 in the case of CR driving in which a potential is inserted Critical potential 304 Potential 305 at the highest transmittance potential 702, 902, 1202, 1402, 1802, 19 at the lowest transmittance
02, 2302 Drive pulse generators 601, 1501 Control signal generator 602 Line memory 603 Non-image signal generator 604 Output signal selectors 1401, 1901 Signal converter 1905 Liquid crystal panel 2306 Line number adjuster 2307 Frame memory

Front page continuation (51) Int.Cl. ⁷ Identification code FI G09G 3/20 G09G 3/20 642C 3/36 3/36 H04N 5/66 102 H04N 5/66 102B (72) Inventor Yoshinori Furubayashi Osaka Prefecture 1006 Kadoma, Kadoma-shi, Matsushita Electric Industrial Co., Ltd. (56) Reference JP 2000-122596 (JP, A) JP 4-218023 (JP, A) JP 7-64056 (JP, A) JP-A-2000-298259 (JP, A) JP-A-2000-347634 (JP, A) JP-A-2001-42282 (JP, A) JP-A-1-296221 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/133

Claims (4)

(57) [Claims] 1. A source line to which a pixel signal is supplied, a gate line to which a scanning signal is supplied, and a source line which is arranged corresponding to an intersection of the source line and the gate line and which is transmitted by an absolute value of an applied voltage. An image signal, which is a pixel signal corresponding to an image, and a non-image signal, which is a pixel signal of black display irrespective of the image signal and having a constant transmittance , are alternately provided in the source. the method of driving a liquid crystal panel driven by applying to the line, in each pixel cells constituting all the pixel cells for displaying the image signal and the previous SL non-image signal are each synchronized with the frame period , The polarity with respect to the reference potential is inverted, and the relationship between the polarity of the image signal and the polarity of the non-image signal applied intermittently within one frame period after the image signal is relative to the reference potential. Same polarity Furthermore, in one frame of the image , the source line
Of the image signal continuous to the non-image signal applied to
The polarity is the same as the non-image signal in the period and the non-image signal.
A method of driving a liquid crystal panel , comprising: a period having a polarity opposite to that of the image signal . 2. A source line to which a pixel signal is supplied, a gate line to which a scanning signal is supplied, and a gate line which is arranged corresponding to an intersection of the source line and the gate line and which is transmitted with an absolute value of an applied voltage. An image signal, which is a pixel signal corresponding to an image, and a non-image signal, which is a pixel signal of black display irrespective of the image signal and having a constant transmittance , are alternately provided in the source. the method of driving a liquid crystal panel driven by applying to the line, in each pixel cells constituting all the pixel cells for displaying the image signal and the previous SL non-image signal are each synchronized with the frame period , The polarity with respect to the reference potential is inverted, and the relationship between the polarity of the image signal and the polarity of the non-image signal applied intermittently within one frame period after the image signal is relative to the reference potential. Reverse polarity Furthermore, in one frame of the image , the source line
Of the image signal continuous to the non-image signal applied to
The polarity is the same as the non-image signal in the period and the non-image signal.
A method of driving a liquid crystal panel , comprising: a period having a polarity opposite to that of the image signal . 3. A source line to which a pixel signal is supplied, a gate line to which a scanning signal is supplied, and a gate line which is arranged corresponding to an intersection of the source line and the gate line and is transmitted by an absolute value of an applied voltage. A pixel cell whose rate is determined , an image signal which is a pixel signal corresponding to an image, and a non-image signal which is a pixel signal of black display irrelevant to the image signal and having a constant transmittance are alternately supplied to the source line. In each pixel cell that constitutes all of the pixel cells to be displayed, comprising a driving means for applying, the image signal and the non-image signal, the polarity with respect to the reference potential is inverted in synchronization with each frame period, Moreover, the relationship between the polarity of the image signal and the polarity of the non-image signal applied intermittently within one frame period after the image signal is the same as the reference potential, and image In one frame, the source line
Of the image signal continuous to the non-image signal applied to
The polarity is the same as the non-image signal in the period and the non-image signal.
A driving device for a liquid crystal panel, characterized in that it is driven so as to have a period having a polarity opposite to that of the image signal . 4. A source line to which a pixel signal is supplied, a gate line to which a scanning signal is supplied, and a source line which is arranged corresponding to an intersection of the source line and the gate line and which is transmitted by an absolute value of an applied voltage. A pixel cell whose rate is determined , an image signal which is a pixel signal corresponding to an image, and a non-image signal which is a pixel signal of black display irrelevant to the image signal and having a constant transmittance are alternately supplied to the source line. In each pixel cell that constitutes all of the pixel cells to be displayed, comprising a driving means for applying, the image signal and the non-image signal, the polarity with respect to the reference potential is inverted in synchronization with each frame period, and, wherein the polarity of the image signal, the relationship between the polarity of the non-image signal is intermittently applied within one frame period after the image signal is a reverse polarity with respect to the reference potential, and further, the image In one frame, the source line
Of the image signal continuous to the non-image signal applied to
The polarity is the same as the non-image signal in the period and the non-image signal.
A driving device for a liquid crystal panel, characterized in that it is driven so as to have a period having a polarity opposite to that of the image signal .