JPH0916132A - Liquid crystal driving device - Google Patents

Abstract

PURPOSE: To obtain excellent picture quality and reduce power consumption when deterioration of liquid crystal is prevented by AC driving. CONSTITUTION: A liquid crystal display panel 17 has pixels 11-44 of 4×4 dots arrayed in matrix. The odd-array pixels and even-array pixels are connected alternately to drain lines D1, D2, D3, D4, and D5 by gate lines; and, for example, the odd-array pixels 21 and 41 and even-array pixels 12 and 32 are connected to the drain line D2 in a cross-stitch shape like the pixels 12, 21, 32, and 41, and the drain lines D3 and D4 are also connected similarly. Display data of the opposite polarities are supplied to the drain lines D1, D3, and D5 and drain lines D2 and D4, the gate lines G1-G4 are scanned in order, and liquid crystal in the respective pixel arrays is driven by being supplied with the display data of the different polarities from two drain lines, thereby performing bit inversion driving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal driving device,
More specifically, the present invention relates to a liquid crystal drive device that AC-drives a liquid crystal display panel in which pixels are arranged in a matrix.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal drive device generally includes a liquid crystal display panel (LCD), a drive circuit for driving the liquid crystal display panel, a power supply circuit, a control circuit, and the like.
A drive voltage having a plurality of voltage values is supplied from the power supply circuit to the drive circuit. When the liquid crystal is driven for display control, the alignment of the liquid crystal molecules is controlled by an electric field generated by applying a predetermined voltage to the liquid crystal of each pixel of the liquid crystal display panel, and the optical characteristics of each pixel are controlled. By changing.

In driving the above-mentioned liquid crystal, it is generally necessary to drive by alternating current. This is because the electric field is applied to the liquid crystal only in a single direction for a long time, so that the alignment film provided on the surface of the liquid crystal display panel facing the substrate may be burned,
This is to prevent deterioration of the liquid crystal or destruction of the liquid crystal.

FIG. 5 is a diagram showing a configuration example of a conventional active matrix type liquid crystal display panel 1 using a switching element. As shown in FIG. 5, each pixel includes 11 to 11 along the gate lines G1, G2, G3, and G4.
14, 21-24, 31-34, 41-44 are arranged in the row direction, and the above-mentioned pixels are arranged along the drain lines D1, D2, D3, D4 by 11-4.
1, 12 to 42, 13 to 43, and 14 to 44 are connected in the column direction. The gate of the switching transistor (MOS) of each pixel is connected to each gate line, the source is connected to each drain line, and the drain is connected to the pixel electrode of each pixel.

FIG. 6 is a diagram showing drive waveforms of a bit inversion drive system in which the polarities of display data are inverted pixel by pixel in the liquid crystal display panel 1 of FIG. 5, and FIG. 7 is a bit inversion drive system of FIG. FIG. 6 is a diagram showing a polarity reversal situation in the liquid crystal display panel 1 in FIG. In the case of the conventional bit inversion drive method,
As shown in FIG. 6 and FIG. 7, the display data supplied to the adjacent pixels always have opposite polarities and are inverted every frame, so that image data having different polarities are mixed in the screen. Together, a very good image quality with almost no noticeable flicker can be obtained.

However, the above-mentioned bit inversion driving method is
While good image quality can be obtained, there is a problem that power consumption increases. Therefore, liquid crystal driving methods other than the bit inversion driving method include, for example, a frame inversion driving method that inverts the polarities of the display data of all pixels of the liquid crystal display panel in frame units, and a display having an opposite polarity in adjacent data line units. A data line inversion driving method in which data is given and the polarity is inverted every predetermined period (for example, frame),
Alternatively, there is a scan line inversion drive method in which display data having opposite polarities are given in units of adjacent scan lines and the polarities are inverted every predetermined period (for example, frame).

From the viewpoint of power consumption, these liquid crystal driving methods are divided into a frame inversion driving method and a data line inversion driving method, in which the pixel capacity is Cg, the data line capacity is CL, and the high level drive voltage is VLCH. , Where the low-level drive voltage is VLCL, it can be expressed by the following equation (1).

{CL + Cg × (number of scanning line stages)} × (number of data line stages) × (VLCH−VLCL) 2 × (frame frequency) (1) Further, the scanning line inversion driving method and the bit inversion are performed. The power consumption of the driving method can be expressed by the following equation (2).

{CL × (number of scanning line stages-1) + Cg × (number of scanning line stages)} × (number of data line stages) × (VLCH-VLCL) 2 × (frame frequency) (2) The equation is for the case where there is no leak current in the all lighting state.

Then, the above equations (2) and (1) produce a power consumption difference represented by the following equation (3).

(Number of scanning line stages-2) × (Number of data line stages) × (VLCH−VLCL) 2 × (Frame frequency) (3) FIG. 8 shows image quality and consumption in each conventional liquid crystal driving method. It is a figure which shows the comparison result of electric power.

Therefore, in the power consumption in each of the liquid crystal driving methods, as the frequency of polarity reversal, particularly the frequency of polarity reversal in each data line, increases, the number of charging / discharging on each line increases. Power consumption will increase. Looking at this in FIG. 8, the frame inversion drive method and the data line inversion drive method to which the formula (1) is applied consumes less power, but "○",
The power consumption increases in the scan line inversion driving method and the bit inversion driving method to which the formula (2) is applied.

Further, the image quality of the liquid crystal display image obtained by each of the liquid crystal driving methods described above, the inversion frequency becomes higher as the area in which the polarity inversion becomes smaller in units of frame, field, line and pixel. Accordingly, flicker becomes less noticeable and the image quality tends to improve.

As shown in FIG. 8, in the case of the frame inversion driving method, the polarity inversion is repeated for each frame, so that flicker is apt to stand out and the image quality becomes poor. However, in the case of the data line inversion driving method or the scanning line inversion driving method, the display data is inverted with a polarity opposite to that of the data line or the scanning line, and therefore the inversion data is mixed in the screen in a unit of flicker. Is not noticeable, and the degree of image quality is good. Further, in the case of the bit inversion driving method, the display data has the opposite polarity and is inverted for each adjacent pixel.
Flicker becomes even more inconspicuous because inversion data mixes on a pixel-by-pixel basis in the screen, resulting in extremely good image quality.

[0015]

As described above, in the conventional liquid crystal driving device, there are two contradictory demands for improving the image quality and reducing the power consumption, and one image quality should be improved. Then, the power consumption increases, and conversely, if an attempt is made to improve the power consumption, the image quality deteriorates. In particular, when the conventional bit inversion driving method shown in FIG. 6 is adopted, although very good image quality can be obtained, there is a problem that power consumption increases.

Therefore, the present invention has been made in view of the above problems, and when a liquid crystal is AC-driven to prevent deterioration of the liquid crystal, good image quality can be obtained and power consumption can be reduced. An object is to provide a liquid crystal driving device.

[0017]

According to a first aspect of the present invention, there is provided a liquid crystal driving device in which a plurality of scanning lines and a plurality of data lines are arranged in a liquid crystal display panel in a direction orthogonal to each other, and the scanning lines and the data lines are connected to each other. Pixels are formed in a matrix through switching elements connected to the plurality of scanning lines, and scanning signals are supplied to the plurality of scanning lines in a predetermined order to bring them into a selected state. In a liquid crystal driving device that supplies display data from a line to drive a liquid crystal, switching elements and pixels connected to each data line are alternately distributed to positions on the opposite side of each data line for each number of a scanning lines. Display data of opposite polarity is supplied to each of the data lines every b number of data lines. Is less than or equal to 2 and the other is less than or equal to 1/2 of the number of data lines or scanning lines, and the above object is achieved by AC driving the liquid crystal of each pixel formed in a matrix on the liquid crystal display panel. To do.

Further, in the liquid crystal drive device according to claim 2, for example, both a and b described in claim 1 may be 2.

In the liquid crystal driving device according to a third aspect of the present invention, for example, one of a and b described in the first aspect is 1, and the other is 1 / the number of data lines or scanning lines. It may be 2 or less.

Further, in the liquid crystal drive device according to claim 4, for example, both a and b described in claim 1 may be 1.

A liquid crystal drive device according to a fifth aspect of the present invention is, for example, for m pixels provided in the scanning line direction of the liquid crystal display panel according to any one of the first to fourth aspects. (M + 1) data lines are arranged, and from each data line at both ends of the liquid crystal display panel, every a scanning line number with respect to pixels arranged in the column direction at both ends of the liquid crystal display panel. And the data lines for supplying display data of each pixel are shifted by one line in accordance with the switching timing of the data lines connected to the pixels arranged in the column direction of the liquid crystal display panel. The polarity of the display data supplied to each data line may not be changed for a predetermined period.

Further, in the liquid crystal drive device according to claim 6, for example, the polarities of the display data supplied to the respective data lines according to any one of claims 1 to 5 are:
Further, it may be alternately inverted every predetermined vertical scanning period.

Further, the liquid crystal drive device according to a seventh aspect of the present invention, for example, alternately inverts the polarity of the display data supplied to each data line for each frame as the predetermined vertical scanning period according to the sixth aspect. You may

[0024]

In the liquid crystal drive device according to the first aspect, the pixels in the column direction of the liquid crystal display panel connected to each data line through the switching element are arranged on the opposite side of each data line for every a scanning lines. The display data having opposite polarities are supplied to each data line every b data lines, and the number of either one of a and b is 2 or less. The other number is less than 1/2 of the data line or scanning line.

Accordingly, display data having different polarities can be appropriately dispersed and supplied to each pixel on the liquid crystal display panel without inverting the polarity of the data supplied to each data line in small increments. When AC driving of the liquid crystal is performed to prevent deterioration of the image quality, good image quality and low power consumption can be achieved.

In the liquid crystal driving device according to the second aspect, a and b are provided.
Since 2 and 2, the polarity of the display data changes in units of vertical and horizontal pixels of the liquid crystal display panel, so that image quality is further improved and power consumption is reduced, similar to bit inversion drive. it can.

In the liquid crystal drive device according to claim 3, a and b are provided.
One of the two is 1 and the other is 1/2 or less of the number of data lines or scanning lines. Therefore, the polarity of the display data for each pixel is at least in the vertical or horizontal direction of the liquid crystal display panel. Because of the change, the image quality is further improved and the power consumption can be reduced.

In the liquid crystal driving device according to claim 4, a and b
Since 1 and 2 are set, so-called bit inversion drive is performed, in which display data of opposite polarities are supplied between vertically and horizontally adjacent pixels, so that very good image quality is obtained and low power consumption is achieved. Can be planned.

In the liquid crystal driving device according to the fifth aspect, the number of data lines is one more than the number of pixels in the scanning line direction of the liquid crystal display panel, and each data line at both ends of the liquid crystal display panel is connected to the liquid crystal display panel. The display data of each pixel is supplied at the timing when the data lines connected to the pixels in the column direction of the liquid crystal display panel are alternately connected to the pixels in the column direction at both ends every a number of scanning lines. The data lines are shifted by one line so that the polarity of the display data supplied to each data line is not changed for a predetermined period.

Therefore, since the data lines for supplying the display data having different polarities are alternately switched to drive the liquid crystal of the pixels respectively arranged in the column direction of the liquid crystal display panel, the display data supplied from the respective data lines are driven. Even if the polarity of the pixel does not change for a predetermined period, the polarity of the display data supplied to the pixels arranged in the column direction of the liquid crystal display panel is switched and displayed, so that both low power consumption and good image quality are achieved. In addition, it is possible to prevent deterioration of the liquid crystal.

In the liquid crystal drive device according to the sixth aspect, the polarities of the display data supplied to the respective data lines are alternately inverted every predetermined vertical scanning period. Therefore, in order to invert the polarity of the display data having different polarities, which are supplied by being appropriately dispersed to each pixel on the liquid crystal display panel, every predetermined vertical scanning period,
With good image quality, low power consumption is possible, and deterioration of the liquid crystal can be prevented.

In the liquid crystal drive device according to the seventh aspect, the polarities of the display data supplied to the respective data lines are alternately inverted every frame. Therefore, it is possible to perform the bit inversion drive in which the polarity of the display data is inverted for each predetermined pixel region or each pixel only by inverting the polarity for each frame, and thus a very good image quality can be obtained. Therefore, the power consumption can be reduced and the deterioration of the liquid crystal can be reliably prevented.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 4 are views showing an embodiment of the liquid crystal drive device of the present invention. The liquid crystal display panel of the present embodiment comprises 2n pixels in the column direction and m pixels in the row direction, and scans 2n lines (gate lines) and (m + 1) data lines (drain lines) are arranged, and each pixel uses a thin film switching transistor made of amorphous silicon to perform active matrix driving TFT-LCD (Thin Film Transistor-Liquid C
It was implemented as a liquid crystal display device using a crystal display).

First, the structure will be described. FIG. 1 is a block diagram showing the configuration of the liquid crystal display device 11 according to this embodiment. The liquid crystal display device 11 includes a sync separation circuit 12, an A / D conversion circuit 13, a data conversion circuit 14, a control circuit 15, an interface circuit 16, a liquid crystal display panel 17, a gate driver 18, a drain driver 19, a glass substrate 20, and the like. It is configured.

The sync separation circuit 12 extracts the horizontal sync signal Hsync (φH) and the vertical sync signal Vsync (φV) from the analog video signal and outputs it to the control circuit 15. The A / D conversion circuit 13 performs A / D (analog / digital) conversion on the input analog video signal by sampling based on the timing signal input from the control circuit 15, and here, a 3-bit digital video signal. And When the input analog video signal is a color video signal, sampling is performed for each of the parallel analog video signals separated into R (red), G (green) and B (blue).

The data conversion circuit 14 is the A / D conversion circuit 1
The digital video signal converted in 3 is converted into a data format that can be driven by the drain driver 19 described later, and output to the drain driver 19. That is, the data conversion circuit 14 sequentially reads the digital video signal input from the A / D conversion circuit 13 according to the timing signal input from the control circuit 15, reads the video signal for one line, and then converts it into the video signal. A corresponding gradation signal is created and output to the drain driver 19 as display data.

The control circuit 15 controls the overall operation of the liquid crystal display device 11. For example, the sync separation circuit 1
A sync signal for driving the liquid crystal of each pixel of the liquid crystal display panel is generated on the basis of the horizontal sync signal (Hsync) and the vertical sync signal (Vsync) supplied from 2 and output to the interface circuit 16. To generate and supply a sampling clock for sampling in the A / D conversion circuit 13 based on each synchronization signal, or to sequentially read digital video signals input from the A / D conversion circuit 13 to the data conversion circuit 14. Supply timing signals.

The interface circuit 16 is the control circuit 1.
By supplying the horizontal synchronizing signal and the vertical synchronizing signal inputted from 5 to the drain driver 19 and the gate driver 18, respectively, an image is displayed while the liquid crystal display panel 17 is scanningly driven.

The above-mentioned vertical synchronizing signal C determines the gate line scanning start timing and the gate line selection width.
It is composed of a DB signal, a CFB signal which is a scan inversion signal for AC driving the liquid crystal in each frame, and a CNB signal which sequentially shifts the CDB signal in the gate driver 18.

The horizontal synchronizing signal is the CKN signal for outputting the display data latched for each pixel in the drain driver 19 to the liquid crystal display panel 17, the STI signal for starting the sampling of the display data, and the liquid crystal for each frame. CKF signal for AC driving, a basic clock signal for driving the drain driver 19, and the like.

The liquid crystal display panel 17 has a plurality of gate lines and a plurality of drain lines arranged in a direction orthogonal to each other, and a thin film switching transistor (TFT: Thin F) using amorphous silicon near each intersection of both lines.
The gate line of the transistor is connected to the gate line, the source is connected to the drain line, and the drain is connected to the pixel electrode forming a liquid crystal capacitor. The pixel electrodes are arranged in a matrix in the liquid crystal display panel 17, and pixels are formed at the pixel electrode positions.

The characteristic constitution of the present invention is that, in the liquid crystal display panel 17, first, pixel electrodes connected to respective drain lines via TFTs have odd pixel columns and even pixel pixels every other gate line. The lines are alternately distributed and connected. With this configuration, for example, even if the polarity of the display data supplied to each drain line is not inverted during one frame period, the pixels to which the display data of the same polarity are supplied are staggered on the liquid crystal display panel 17. Since it is dispersed and displayed in a hanging shape, FIG.
It is possible to realize the bit inversion drive shown in the conventional example in the same polarity inversion cycle as the frame inversion drive, and it is possible to achieve both low power consumption and high image quality.

In such a liquid crystal display panel 17, the transistor connected to the gate line is on / off controlled by the scanning signal supplied from the gate driver 18 to produce a selected / non-selected state, and the selected state is maintained. Display data is supplied to the pixel electrode from the drain line and the liquid crystal is driven for each pixel to display an image. In the liquid crystal display panel 17 of the present embodiment, 2n × m pixels are formed, and 2n gate lines and
(M + 1) drain lines. In addition,
The above gate lines may be composed of an odd number of lines, but here, in order to simplify the explanation, an even number of lines (2n lines) will be described.

The gate driver 18 generates a scanning signal and supplies the scanning signal to a plurality of gate lines of the liquid crystal display panel 17 in a desired sequence to bring it into a selected state. In this embodiment, 1 is set for each horizontal scanning period (1H).
Sequential scanning is performed by scanning line by line.

Although not shown, the drain driver 19 includes a data transfer circuit that sequentially transfers display data that is serially input and takes out in parallel as data of each drain line, and a data latch that holds data for each drain line. It is composed of a circuit and a driver circuit which inverts the polarity of the latched display data by an alternating signal and supplies it to the drain line.

The characteristic feature of the present invention is also in this drain driver 19, and since the pixel electrodes are connected to each drain line of the liquid crystal display panel 17 in a zigzag pattern, every predetermined number of drain lines. Preferably, display data having different polarities are alternately supplied every other drain line. In the drain driver 19, the display data input from the data conversion circuit 14 to the data transfer circuit is latched for each drain line by the data latch circuit, and the display data supplied to each drain line is converted into alternating current by the driver circuit. The polarity should be reversed every other drain line. As a result, the pixels for displaying the display data of the same polarity, which are supplied from one drain line, are arranged in a zigzag pattern, and the display data having the opposite polarity is supplied between the adjacent drain lines.
Similar to the case of the bit inversion drive of the conventional example shown in (4), the display data is displayed so that the polarities of the display data of the vertically and horizontally adjacent pixels are opposite to each other. Moreover, since the polarity of the display data is not inverted in each drain line for a predetermined period, the power consumption required for charging and discharging the drain line can be significantly reduced.

In the drain driver 19, the polarity to be supplied to each drain line is further set for a predetermined period,
For example, by performing the inversion in units of one field or one frame, it is possible to perform AC driving that prevents deterioration of the liquid crystal.

As described above, in the liquid crystal drive device of the present embodiment, since the AC drive corresponding to the bit inversion drive can be performed, the flicker of the display image due to the polarity inversion is dispersed and becomes inconspicuous. Further, good image quality can be obtained, and the polarity inversion cycle of the display data supplied to each drain line extends in units of one field or one frame, so that the power consumption can be as low as the frame inversion drive.

The glass substrate 20 is a glass substrate constituting the liquid crystal display panel 17, and here, the glass substrate 20.
The gate driver 18 and the drain driver 19 are integrally formed on the upper portion to form a liquid crystal display device integrated with a drive circuit.

FIG. 2 shows a liquid crystal display panel 1 according to this embodiment.
It is a figure which shows the structural example of 7. As shown in FIG. 2, each pixel has 11 to 14, 21 to 24, 31 to 34, and 41 to 4 along the gate lines G1, G2, G3, and G4, respectively.
4 are arranged in the row direction. The above-mentioned pixels have the drain lines D1, D2, D3, D4, D5.
On the other hand, every other gate line is alternately connected to the odd-row pixels and the even-row pixels. For example, since pixels 21 and 41 of odd-numbered column pixels are connected to the drain line D2 and pixels 12 and 32 of even-numbered column pixels are connected to each other, the pixels are staggered in the order of pixel 12 → 21 → 32 → 41. Connected to each other. Similarly to this, the drain line D3,
D4 is also connected in a zigzag pattern. Further, the drain lines D1 and D5 at both ends of the liquid crystal display panel 17 are alternately connected to the pixel columns at both ends of the liquid crystal display panel like pixels 11, 31 or pixels 24, 44.

FIG. 3 is a timing chart of the scanning signal supplied to each gate line and the display data supplied to the drain line of the liquid crystal display panel 17 of FIG.
FIG. 4 is a diagram illustrating a state in which each pixel of liquid crystal display panel 17 is sequentially scanned based on the scanning signal and display data shown in FIG. 3.

Next, the operation of this embodiment will be described with reference to FIGS. First, as shown in FIG. 1, a horizontal separation signal Hsync (φH) and a vertical synchronization signal Vsync are input from an input analog video signal by a sync separation circuit 52.
(ΦV) are taken out and output to the control circuit 15. The control circuit 15 generates a sync signal for driving the liquid crystal of each pixel of the liquid crystal display panel based on the horizontal sync signal and the vertical sync signal to generate an interface circuit 16
And supplies the sampling clock generated based on the synchronization signal to the A / D conversion circuit 13,
Further, the data conversion circuit 14 is supplied with a timing signal for sequentially reading the digital video signals input from the A / D conversion circuit 13.

Then, the input analog video signal is
After being sampled by the A / D conversion circuit 13 and converted into a digital video signal, the data conversion circuit 14 sequentially reads the digital video signal by a timing signal input from the control circuit 15, and after reading the video signal for one line. , Create a gradation signal according to the video signal,
It is output to the drain driver 19 as display data.

Further, in the drain driver 19, the serially input display data is sequentially transferred by the data transfer circuit and taken out in parallel as data to be supplied to each drain line, and the display data to be supplied to each drain line is supplied to the data latch circuit. The latched display data is supplied to each drain line as predetermined polarity data by a driver circuit by an alternating signal.

In the liquid crystal display panel 17 of this embodiment, as shown in FIG. 2, the drain lines are alternately connected to the odd-numbered column pixels and the even-numbered column pixels in a zigzag pattern, and as shown in FIG. , The polarities of the display data supplied to the adjacent drain lines are alternately reversed.

Therefore, in the first frame of FIG. 3, the display data having the polarity of "H" is always supplied to the drain lines D1, D3 and D5, and the display data having the polarity of "L" is always supplied to the drain lines D2 and D4. Data is supplied. Here, in the liquid crystal display panel 17 of the present embodiment, as shown in FIG. 2, one more drain line is provided (five) than the number of pixels in the horizontal direction (four pixels), and Display data corresponding to the connection state of the drain lines D1 to D5 for each gate line and the pixels 11 to 44 is sent from the data conversion circuit 14 of FIG. 1 to the drain driver 19.

The relationship between the supply state of the display data and the display image will be concretely described with reference to FIGS. That is, when scanning the gate line G1 shown in FIG.
The drain lines D1 to D4 and the pixels 11 to 14 correspond to each other, and display data such that dummy data is input to the drain line D5 is supplied, so that the drain lines D5 to D4 have polarities of "H, L, H, L". The liquid crystal is driven by the display data.

Next, the gate line G2 shown in FIG.
During scanning, the drain lines D2 to D5 and the pixels 21 to 21
Since 24 corresponds to the display data, dummy display data is supplied to the drain line D1.
The liquid crystal is driven by the display data of polarities in the order of “L, H, L, H”.

Next, the gate line G3 shown in FIG.
During scanning, the drain lines D1 to D4 and the pixels 31 to 31
34 corresponds to each other, display data such that dummy data is input to the drain line D5 is supplied,
The liquid crystal is driven by the display data of the polarities in the order of "H, L, H, L".

Next, the gate line G4 shown in FIG.
Of the drain lines D2 to D5 and the pixels 41 to
44 corresponds to the display data supplied to the drain line D1 such that dummy data is input,
The liquid crystal is driven by the display data of polarities in the order of “L, H, L, H”.

The liquid crystal driving operation for the second frame is almost the same as the operation for the first frame described above, but the polarities of the display data supplied to the respective drain lines are opposite. Specifically, as shown in FIG. 3, the drain line D
The polarity of the display data supplied to 1, D3, D5 is "H" →
It changes to "L" and the polarity of the display data supplied to the drain lines D2 and D4 changes from "L" to "H" and is supplied. As in the first frame, the gate lines G1 → G2
Sequential scanning is performed in the order of → G3 → G4. In addition, 3
In the liquid crystal driving operation of the frame, the same operation as that of the first frame is repeated.

As described above, by performing the liquid crystal driving operation of the present embodiment, the conventional bit inversion driving is shown in FIG.
7B, the display is alternately performed on a frame-by-frame basis, so that display data in which pixels vertically and horizontally adjacent to each other have opposite polarities is displayed, and flicker (flicker) of the display image due to polarity reversal is displayed. ) Is dispersed and becomes inconspicuous, and good image quality is obtained.

Moreover, in the conventional bit inversion drive, the polarity of the display data supplied to each drain line had to be inverted little by little every one horizontal scanning period (1H), but the liquid crystal drive of the present embodiment. In the device, it is not necessary to invert the polarity for at least one vertical scanning period (1V), for example, for one frame period here, so that the power consumption can be significantly reduced. In particular, in the case of this polarity inversion on a frame-by-frame basis, the power consumption can be as low as that of the conventional frame inversion drive (see FIG. 8).

As described above, in the present embodiment, the pixels connected to each drain line are alternately connected to the odd-numbered column pixels and the even-numbered column pixels in a zigzag pattern, and therefore, depending on the gate line for scanning. By shifting the drain line that supplies the display data in the direction of the gate line by one pixel, the polarity can be changed to the opposite polarity without changing the display image. Therefore, good image quality can be obtained as with the bit inversion drive. To be Further, in this case, since the polarity inversion of the display data supplied to each drain line is not performed for a predetermined period, for example, for one frame, the number of times of charging / discharging due to the polarity inversion of the display data in each drain line is conventionally. Compared to the above, the power consumption is significantly reduced,
This AC driving can prevent deterioration of the liquid crystal.

Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

In particular, in the above-mentioned embodiment, the liquid crystal driving device of the driving circuit integrated type in which the driving circuit is formed on the glass substrate, and the amorphous silicon is used for the driving circuit, the mobility is low, Since it tends to be high resistance, lower the polarity reversal frequency of the display data as much as possible,
Although it is necessary to reduce power consumption, this request can be met in this embodiment.

In the above embodiment, the odd-numbered column pixels and the even-numbered column pixels connected to each drain line are alternately connected every other gate line, but every two gate lines or every other multiple gate line. It is also possible to alternately connect to.

Further, in the above-mentioned embodiment, the polarity of the display data supplied to each drain line is opposite every other drain line. However, the polarity of the display data is changed according to the connection state of the pixels connected to the drain line. The polarities of the display data supplied to the drain lines can be reversed every two drain lines or every other plural drain lines.

In particular, in the above-described embodiment, the odd-numbered column pixels and the even-numbered column pixels connected to each drain line are alternately connected every other gate line, and the polarity of the display data supplied to each drain line is set to one. By setting the reverse polarity for every drain line and reversing the polarity in frame units,
Although the example in which the bit inversion driving is performed is shown, the present invention is not limited to this, of course.

For example, in addition to the above embodiment, at least one of the gate line interval in which pixels are alternately connected to each drain line and the drain line interval in which display data of opposite polarity is supplied to each drain line is set. By setting the line interval to 2 or less and the other to 1/2 or less of the number of drain lines or the number of gate lines, display data having a reverse polarity is mixed as compared with the data line inversion drive or the scan line inversion drive (see FIG. 8). Is displayed. The effect in this case is that it is possible to obtain a better image than the above-described data line inversion drive or scan line inversion drive, and at least to achieve lower power consumption than the scan line inversion drive, and to prevent deterioration of the liquid crystal. can do.

In addition, at least one of the gate line interval in which pixels are alternately connected to each drain line and the drain line interval in which display data of opposite polarity is supplied to each drain line is set as one line interval, and the other is set. Is set to be equal to or less than 1/2 of the number of drain lines or the number of gate lines, display data having a polarity opposite to that of the immediately preceding example can be mixed and displayed. Therefore, a better image can be obtained and low power consumption can be achieved,
It is possible to prevent deterioration of the liquid crystal.

Further, in addition to the above-described embodiment, odd-numbered column pixels and even-numbered column pixels connected to each drain line are alternately connected every two gate lines, and the polarity of the display data supplied to each drain line is set to two. Pseudo-bit inversion drive in which the polarity of display data is reversed in units of 4 pixels in each of vertical and horizontal 2 pixels by making every drain line an opposite polarity and inverting the polarity every predetermined period (for example, each frame). It can be performed. The effect in this case is that a good image similar to the above-mentioned bit inversion drive can be obtained, and
The same low power consumption can be achieved and the deterioration of the liquid crystal can be prevented.

Further, in the present embodiment, as shown in FIG. 4, by using the display data in which the dummy data is inserted in the drain line D1 or D5 as the display data in the predetermined gate line, each drain line is used. It is possible to shift the display data supplied to each pixel by one pixel in the gate line direction. Because of this, while displaying the display data at the proper pixel position, the drain line that supplies the display data is alternately switched,
It is possible to perform display in which display data having different polarities are mixed, and good image quality can be obtained. The display data in which the dummy data is inserted at a predetermined position may be data in which such data is previously inserted in the input analog video signal itself, or the data conversion circuit 14 or the like. Therefore, display data in which dummy data is inserted may be generated according to the configuration of each liquid crystal display panel 17.

[0074]

According to the liquid crystal drive device of the first aspect,
Pixels in the column direction of the liquid crystal display panel, which are connected to each data line through a switching element, are arranged alternately on the opposite side of each data line for each number of a scanning lines. The display data of opposite polarity is supplied to the line every b data lines,
The number of either of the lines b and b is 2 or less, and the number of the other is 1/2 or less of the data line or the scanning line.

Therefore, display data having different polarities can be appropriately dispersed and supplied to each pixel on the liquid crystal display panel without inverting the polarities supplied to the respective data lines in small increments. When AC driving of the liquid crystal is performed to prevent deterioration of the image quality, good image quality and low power consumption can be achieved.

According to the liquid crystal driving device of the second aspect, a
Since b and 2 are set to 2, the polarity of the display data changes in units of vertical and horizontal 2 pixels of the liquid crystal display panel. Therefore, similar to the bit inversion drive, the image quality is further improved and the power consumption is reduced. be able to.

According to the liquid crystal drive device of the third aspect, a
Since one of b and b is 1 and the other is less than 1/2 of the number of data lines or scanning lines, at least one of the display data for each pixel in the vertical or horizontal direction of the liquid crystal display panel. The image quality is further improved and the power consumption can be reduced because the polarity of is changed.

According to the liquid crystal driving device of the fourth aspect, a
Since b and 1 are set to 1, so-called bit inversion drive is performed in which display data of opposite polarities are supplied between pixels vertically and horizontally adjacent to each other, so that very good image quality is obtained and low power consumption is achieved. Can be achieved.

According to the liquid crystal driving device of the fifth aspect, the number of data lines is one more than the number of pixels in the scanning line direction of the liquid crystal display panel, and the liquid crystal display is performed from each data line at both ends of the liquid crystal display panel. The display data of each pixel is alternately connected to the pixels in the column direction on both ends of the panel every a number of scanning lines, and the display data of each pixel is synchronized with the timing of switching the data line connected to the pixel in the column direction of the liquid crystal display panel. The data line to be supplied is shifted by one line so that the polarity of the display data supplied to each data line is not changed for a predetermined period.

Therefore, since the data lines for supplying the display data having different polarities are alternately switched to drive the liquid crystals of the pixels arranged in the column direction of the liquid crystal display panel, the display data supplied from the respective data lines are driven. Even if the polarity of the pixel does not change for a predetermined period, the polarity of the display data supplied to the pixels arranged in the column direction of the liquid crystal display panel is switched and displayed, so that both low power consumption and good image quality are achieved. In addition, it is possible to prevent deterioration of the liquid crystal.

According to the liquid crystal drive device of the sixth aspect, the polarities of the display data supplied to the respective data lines are alternately inverted every predetermined vertical scanning period. Therefore, the display data having different polarities, which are appropriately dispersed and supplied to the respective pixels on the liquid crystal display panel, are reversed in polarity every predetermined vertical scanning period, so that good image quality and low power consumption can be achieved and deterioration of the liquid crystal can be prevented. can do.

According to the liquid crystal drive device of claim 7, 1
The polarity of the display data supplied to each data line is alternately inverted for each frame. Therefore, only by inverting the polarity in each frame unit, or for each predetermined pixel area, or
Since it is possible to perform the bit inversion drive for inverting the polarity of the display data for each pixel, it is possible to obtain very good image quality, reduce power consumption, and reliably prevent deterioration of the liquid crystal. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a liquid crystal display device according to an embodiment.

FIG. 2 is a diagram showing a configuration example of a liquid crystal display panel according to the present embodiment.

3 is a timing chart of a scanning signal supplied to each gate line and display data supplied to a drain line of the liquid crystal display panel of FIG.

FIG. 4 is a diagram illustrating a state in which each pixel of the liquid crystal display panel is sequentially scanned based on the scanning signal and the display data shown in FIG.

FIG. 5 is a diagram showing a configuration example of a conventional active matrix type liquid crystal display panel using switching elements.

6 is a diagram showing drive waveforms of a bit inversion drive method in which the polarities of display data are inverted pixel by pixel in the liquid crystal display panel of FIG.

7 is a diagram showing a state of polarity inversion in a liquid crystal display panel in the bit inversion drive system of FIG.

FIG. 8 is a diagram showing a comparison result of image quality and power consumption in each conventional liquid crystal driving method.

[Explanation of symbols]

 11 liquid crystal display device 12 sync separation circuit 13 A / D conversion circuit 14 data conversion circuit 15 control circuit 16 interface circuit 17 liquid crystal display panel 18 gate driver 19 drain driver 20 glass substrate

Claims (7)

[Claims] 1. A liquid crystal display panel is provided with a plurality of scanning lines and a plurality of data lines arranged in a direction orthogonal to each other, and pixels are arranged in a matrix through switching elements connected to the respective scanning lines and the respective data lines. A liquid crystal drive that drives a liquid crystal by supplying scanning signals to the plurality of scanning lines in a predetermined order to bring them into a selected state and supplying display data from the data line to each pixel on the selected scanning line. In the device, switching elements and pixels connected to each of the data lines are arranged alternately on the opposite side of each data line for each number of a scanning lines, and each of the data lines has b Display data of opposite polarities are supplied for every number of data lines of the book, one of the a and b is 2 or less, and the other is the data line or Equal to or less than half the number of scan lines, a liquid crystal driving device which is characterized in that the AC drive the liquid crystal of each pixel formed in a matrix on the liquid crystal display panel. 2. The liquid crystal drive device according to claim 1, wherein both a and b are 2. 3. A liquid crystal drive device according to claim 1, wherein one of said a and b is 1, and the other is 1/2 or less of the number of data lines or scanning lines. 4. The liquid crystal drive device according to claim 1, wherein both a and b are 1. 5. The data line is set to (m +) for m pixels provided in the scanning line direction of the liquid crystal display panel.
1) This arrangement is performed, and from each data line at both ends of the liquid crystal display panel, pixels arranged in the column direction at both ends of the liquid crystal display panel are alternately connected every a scanning line number. The data lines for supplying the display data of each pixel are shifted by one line in accordance with the switching timing of the data lines connected to the pixels arranged in the column direction of the liquid crystal display panel and are supplied to each data line. The liquid crystal drive device according to claim 1, wherein the polarity of the display data is not changed for a predetermined period. 6. The polarity of the display data supplied to each of the data lines is further alternately inverted every predetermined vertical scanning period, according to any one of claims 1 to 5. Liquid crystal drive device. 7. The liquid crystal drive device according to claim 6, wherein the polarity of the display data supplied to each data line is alternately inverted for each frame in the predetermined vertical scanning period.