JPH09331490A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display an excellent still image and an excellent moving image while suppressing power consumption. SOLUTION: In the case of displaying a still image, an 'H' level signal is given to a signal electrode line Xi and a scanning electrode line Yi to make transistors(TRs) 50, 52 conductive, and data of an 'H' level are given to an image data electrode line Di as still image data to make a TR 54 conductive and sill image data are applied to a display electrode 62 and the still image data are charged in a capacitor 60. The still image data stored in the capacitor 60 are stored till rewrite is required. In the case of displaying a moving image, a level of 'the inverse of H' is applied to the signal electrode line Xi included in a moving image display area in the display areas and an 'H' level is applied to the scanning electrode line Yi to make TRs 56, 58 conductive and to make the TR 50 conductive so as to apply moving image data to the display electrode 62 from the image data electrode line Di thereby displaying the image according to the moving image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device suitable for use as a TFT active matrix liquid crystal display for low power consumption.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal display device, for example,
Japanese Unexamined Patent Publication Nos. 2-153687 and 6-14292.
The ones described in Japanese Patent Publication No. Shunsuke Kobayashi, "Color Liquid Crystal Display" (Sangyo Tosho) are known. Among the liquid crystal display devices, TFT (Thin Film Trans)
In a TFT active matrix type liquid crystal display device using a system, a line sequential scanning system is adopted as a driving system. In the line sequential scanning method, a scanning pulse is applied to each scanning electrode once every one frame time. On the other hand, a liquid crystal driving voltage is simultaneously applied to each signal electrode in synchronization with the scanning pulse, and the liquid crystal driving voltage is simultaneously applied to the liquid crystal of one row of pixels to which the scanning pulse is applied. I have. A frame time of about 1/60 second is often used, and this pulse is usually applied to each scanning electrode while sequentially shifting the timing from the upper side to the lower side of the panel. Therefore, in a color panel of 640 × 480 dots as a pixel configuration, one pixel is composed of 3 dots, and the total number of lots is 1920 × 480 dots, which is 48 in one frame.
Since 0 scan electrodes (gate wirings) are scanned, the time width of the scan pulse is about 35 μs. Then, in the selected pixel to which the liquid crystal driving voltage is applied in synchronization with the scanning pulse, the voltage of the gate electrode of the TFT connected to the scanning electrode increases, and the TFT is turned on. At this time, the liquid crystal drive voltage is applied to the display electrode via the source and drain of the TFT. As a result, the pixel capacitance obtained by combining the liquid crystal capacitance formed between the display electrode and the counter electrode and the load capacitance arranged in the pixel is charged. By repeating this operation, the liquid crystal drive voltage is repeatedly applied to the pixel capacitance of the entire panel every frame time.

Since an AC voltage is required to drive the liquid crystal, a voltage whose polarity is inverted is applied to the signal electrode every frame time. Therefore, for a frame frequency of 60 Hz, the driving frequency of the liquid crystal is 30 Hz which is a half of this frequency.
A flicker called flicker is visible, making the display difficult to see. Therefore, a driving method of alternately inverting the polarity of the liquid crystal driving voltage for each of the vertically and horizontally adjacent pixels is adopted, and by using this driving method, it is possible to obtain a good display with no noticeable flicker. .

[0004]

In the prior art, the capacitance at the intersection of the wiring (scanning electrode line, signal electrode line) of the scanning electrode and the signal electrode is determined by the difference between the wiring and the counter electrode formed over the entire surface of the counter substrate. A large amount of power is consumed because the charge and discharge of the intervening liquid crystal is repeated by the scanning pulse every frame time.

Accordingly, the applicant of the present application has filed Japanese Patent Application No. 8-629.
No. 96 proposes a liquid crystal display device in which power consumption is reduced. This liquid crystal display device includes a display data holding circuit that takes in display data based on a signal from a scanning electrode and display data from a signal electrode, and holds the display data. According to this device, since the display data holding circuit holds two values of "1" and "0" as the display data, a scanning pulse is applied for each frame when there is no change in the contents of the display data. It is no longer necessary to reduce power consumption.

However, the liquid crystal display device described above does not give sufficient consideration to display a moving image (moving image), and when displaying a still image and a moving image, the display cannot be rewritten according to the moving image. . That is, when the above-described drive method of the apparatus is applied to a moving image, rewriting can be performed only for each pixel. Therefore, for example, when a moving image is displayed in 10 × 10 pixels, a process of rewriting 100 times is performed in one frame time. Must be done within. When such a process is performed, if the area for displaying the moving image becomes large, it takes time to rewrite the moving image, and when displaying the moving image on the entire display image, it becomes difficult to rewrite the display corresponding to the moving image, and the moving image becomes smooth. Video display becomes difficult.

An object of the present invention is to provide a liquid crystal display device capable of displaying good still images and moving images while suppressing power consumption.

[0008]

In order to achieve the above object, the present invention is directed to inserting a liquid crystal layer between a pair of substrates which are opposed to each other and at least one of which is transparent. A plurality of scan electrode lines are dispersedly arranged on the substrate, and a plurality of signal electrode lines intersecting in a matrix are dispersedly arranged on the plurality of scan electrodes, and the plurality of scan electrode lines of the one substrate are arranged. And a plurality of signal electrode lines, the display electrodes are respectively surrounded by a plurality of display regions, and a counter electrode is arranged so as to face each of the display electrodes with a liquid crystal layer interposed therebetween. In the display area, a still image switching element and a moving image switching element connected to each display electrode are arranged, and signals and still image data from each signal electrode line and each scanning electrode line are arranged. A still image control circuit for controlling each of the still image switching elements is arranged on the basis of the plurality of display regions, and signals and moving image data from each of the signal electrode lines and each of the scanning electrode lines are further arranged in the plurality of display areas. A moving image control circuit for controlling each of the moving image switching elements is arranged, and at the time of displaying a still image, a signal from the signal electrode line and the scanning electrode line to the still image control circuit belonging to the still image display area and When the still image data is held by supplying the still image data to turn on the still image switching element and the still image data is held, only the signal electrode lines and the scan electrodes are provided only to the moving image control circuit belonging to the moving image display area during the moving image display. A liquid crystal display device is constituted by applying a signal from a line and moving image data to turn on a moving image switching element.

In constructing the liquid crystal device, as a function at the time of displaying a still image, the still image control circuit which holds still image data among the still image control circuits belonging to the still image display area is set to a still image display mode. A function of stopping the supply of signals and still image data from the signal electrode lines and the scanning electrode lines while the image data is held can be added.

Further, according to the present invention, a pair of substrates arranged opposite to each other, at least one of which is transparent, a liquid crystal layer sandwiched between the pair of substrates, and one of the pair of substrates are dispersed. A plurality of scanning electrode lines that are arranged in a plurality, and a plurality of signal electrode lines that are arranged in a distributed manner on the same substrate as the plurality of scanning electrode lines and intersect the plurality of scanning electrodes in a matrix.
A plurality of display electrodes respectively arranged in a plurality of display regions surrounded by the plurality of scanning electrode lines and the plurality of signal electrode lines of the one substrate, and the liquid crystal layer on the plurality of display electrodes. A plurality of counter electrodes arranged to face each other in between, a plurality of image data electrode lines arranged corresponding to the plurality of signal electrode lines to guide image data to the plurality of display regions; A plurality of still image switching elements respectively connected to the display electrodes, a plurality of moving image switching elements respectively connected to the plurality of display electrodes, from the plurality of signal electrode lines and the plurality of scanning electrode lines When the signal and the still image data from the plurality of image data lines are received and the conditions satisfy the conditions for turning on the plurality of still image switching elements, the static image A plurality of still image control circuits that hold image data and control the plurality of still image switching elements to be in an ON state, respectively, signals from the plurality of signal electrode lines and the plurality of scanning electrode lines, and a plurality of the plurality of scanning electrode lines. A plurality of moving image data from the image data line are controlled to turn on each of the plurality of moving image switching elements when these states satisfy a condition for turning on the plurality of moving image switching elements. Control circuit for moving images, and a plurality of image data selection circuits for selecting still image data when displaying a still image, selecting moving image data when displaying a moving image, and outputting the selected image data to the plurality of image data electrode lines, respectively. A moving image display area designating unit for designating an area in which a moving image should be displayed among the plurality of display areas; Moving image data output means for outputting moving image data only to the image data selection circuit corresponding to the display area designated by the moving image display area designation means among the plurality of image data selection circuits according to the designation of the stage, and still image display A scanning pulse output unit for still image that outputs a scanning pulse sequentially to a designated scanning electrode line among the plurality of scanning electrode lines, and a designated scanning electrode line among the plurality of scanning electrode lines when displaying a moving image. A scanning pulse output means for moving images that sequentially outputs scanning pulses,
Still image liquid crystal drive signal output means for outputting still image liquid crystal drive signals to the plurality of signal electrode lines in synchronism with the scanning pulse output from the still image scan pulse output means, and the moving image scan pulse output A liquid crystal display device comprising a moving image liquid crystal drive signal output means for outputting a moving image liquid crystal drive signal to a designated signal electrode line among the plurality of signal electrode lines in synchronization with a scanning pulse output from the means. It was done.

In constructing the above liquid crystal display device,
The following elements can be added: (1) The moving image control circuit is connected to the still image control circuit and discharges the still image data held by the still image control circuit when the moving image is displayed.

(2) The still image control circuit includes a capacitor inserted between the input electrodes of a still image switching element having a display electrode as a load, and a pair of thin film transistors connected in series with the still image switching element. Have
The gate of one thin film transistor is connected to the signal electrode line, the gate of the other thin film transistor is connected to the scanning electrode line, and still image data is input to the drain.

(3) The moving image control circuit includes a discharge thin film transistor inserted between the input electrodes of a still image switching element having a display electrode as a load, and a moving image switching element having a display electrode as a load. And an image data input thin film transistor connected to, the gate of the discharge thin film transistor is connected to the signal electrode line together with the gate of the moving image switching element, the gate of the image data input thin film transistor is connected to the scanning electrode line, The moving image data is input to the drain.

(4) The moving image liquid crystal drive signal output means is
When a scan pulse is output to one of the designated scan electrode lines, in response to this scan pulse, moving image data corresponding to the number of designated signal electrode lines is provided to the designated signal electrode line. It will be output sequentially.

According to the above-mentioned means, since the still image data is held by the still image control circuit at the time of displaying the still image, when the still image data is not changed, the scanning signal is changed frame by frame. It is not necessary to apply the voltage to the scan electrode lines, and the capacitance at the intersection of the scan electrode lines and the signal electrode lines and the liquid crystal capacitance that is the capacitance between the scan electrode lines, the signal electrode lines and the common electrode lines and the display electrodes are charged. The discharge scan can be reduced, and the power consumption can be reduced. Further, when the moving image is displayed, the moving image is displayed only in the designated display area of the display area, so that power consumption can be reduced.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a liquid crystal display device showing an embodiment of the present invention. In FIG. 1, the liquid crystal display device includes a color panel 10 of 640 × 480 dots as a TFT active matrix type liquid crystal display. In the present embodiment, only the color panel 10 and its peripheral circuits are shown, and the specific structure of the color panel such as the optical system is omitted. At least one of the color panels 10 is a pair of transparent substrates (not shown).
And the substrates are arranged to face each other with a liquid crystal layer (not shown) in between. A plurality of scanning electrode lines (Y-direction electrode lines) Y1 to Yn are dispersedly arranged on one substrate, and signal electrode lines (X-direction electrode lines) intersecting the scanning electrode lines Y1 to Yn in a matrix. ) X1 to Xn are dispersedly arranged. Then, on the surface of the color panel 10, a plurality of display areas A11 surrounded by 480 scanning electrode lines Y1 to Yn and 640 signal electrode lines X1 to Xn.
Ann is formed. In each display area, a display electrode as a pixel portion, a counter electrode, a still image switching element,
A moving image switching element, a still image control circuit, and a moving image control circuit are provided, and common electrode lines COM1 to COMn are arranged in parallel with the scanning electrode lines in the vicinity of each display area, and the image data electrode line D1 is provided. To Dn are arranged in parallel with the signal electrode lines. In addition, each electrode wire is wired while being insulated from each other.

On the color panel 10, as a peripheral circuit,
Panel display control circuit 12, X decoder circuit 14, Y register circuit 16, Y decoder circuit 18, data selection switches SW1 to SWn, moving image latch circuit 20, moving image shift register circuit 22, common electrode drive circuit 24, counter electrode drive. The circuit 26 is provided, and the common electrode drive circuit 24 is provided.
Are connected to the common electrode lines COM1 to COMn, and the counter electrode drive circuit 26 is connected to the counter electrodes in the respective display areas.

The panel display control circuit 12 constitutes a control means for controlling the entire peripheral circuit based on the display command, and a moving image display area designating means for designating a specific display area of the display area as a moving image display area. Is configured. The X decoder circuit 14 is the panel display control circuit 1
A still image liquid crystal drive signal or a moving image liquid crystal drive signal is generated based on the signal from the signal No. 2 and each of the signal electrode lines X1 to Xn is synchronized with a scanning pulse applied to the scanning electrode line when displaying a still image. A still image liquid crystal drive signal output means for outputting a still image liquid crystal drive signal is configured, and when a moving image is displayed, the moving image liquid crystal is displayed on a designated signal electrode line Xi in synchronization with a scanning pulse applied to the scanning electrode line. It is configured as a moving image liquid crystal drive signal output means for outputting a drive signal.

The Y shift register circuit 16 includes a Y decoder circuit 18 and pixel selection 2-input AND logic circuits AND1 to AND1.
Together with ANDn, a still image scan pulse output means and a moving image scan pulse output means for sequentially outputting scan pulses to designated scan electrode lines are configured based on a signal from the panel display control circuit 12. ing.

Specifically, the Y shift register circuit 16
Is, as shown in FIG. 2, shift register circuits YR1 to YR1.
Rm is provided with two-input OR circuits YO2 to YOm, is connected to the panel display control circuit 12 via the clock electrode line Yclk, the start pulse electrode lines yc1 to ycm, and the reset electrode line RS1, and outputs the same. Logic circuits AND1 to AND through the electrode lines Yb1 to Ybm
m. The panel display circuit 12 supplies 480 clock pulses for each frame to the clock electrode line Y.
In addition to outputting to clk, the start pulse electrode line corresponding to the scan start position is selected according to the signal input to the scan start number electrode line 30, the start pulse is output to the selected start pulse electrode line, and the scan line number electrode line When a shift register circuit corresponding to the number designated by the signal input to 32 is set, a reset signal is output to the reset electrode line RS1. That is, Y
The shift register circuit 16 sets a start pulse from the start pulse electrode line yci designated by the panel display control circuit 12 in synchronization with a clock pulse, and outputs the set pulse as a scanning pulse to the output electrode line Ybi. It outputs to the OR circuit YOi of the next stage, and the scanning pulse corresponding to the designated number of scanning lines is output electrode line Ybi.
It is designed to sequentially output to. Further, the Y decoder circuit 18 is connected to the panel display control circuit 12 via the address electrode line 34, and responds to the address signal from the panel display control circuit 12 with the address signal lines Ya1 to Yam.
Y address data is output to. The logic circuits AND1 to AND output the scan pulse according to the logical product of the scan pulse from the Y shift register circuit 16 and the Y address data from the Y decoder circuit 18 to the scan electrode lines Y1 to Y1.
It is designed to output to Ym. In this case, when all the scanning electrode lines are designated, the scanning pulse is applied to all the scanning electrode lines, and only the designated scanning electrode lines are designated by the signals from the scanning start electrode lines 30 and the scanning number electrode lines 32. At times, the scan pulse is applied only to the designated scan electrode line.

The moving picture latch circuit 20 and the moving picture shift register circuit 22 are configured as moving picture data output means for outputting moving picture data only to a designated display area based on a signal from the panel display control circuit 12. . In particular,
As shown in FIG. 3, the moving image latch circuit 20 includes 640 latch circuits DL1 to DLn, and the moving image shift register circuit 22 includes a shift register circuit D.
R1 to DRn and two-input OR circuits DO2 to DOn are provided. The moving image shift register circuit 22
Is the clock electrode line Xclk, the start pulse electrode line da
1 to dan, and is connected to the panel display control circuit 12 via the reset electrode line RS2. Panel display control circuit 1
2 sequentially outputs clock pulses to the clock electrode line Xclk. The clock pulse is output at the timing of sequentially outputting 640 pieces of moving image data when the scanning pulse is applied to the scanning electrode lines.

Further, the panel display control circuit 12 outputs a start pulse to the start pulse electrode line corresponding to the scan start number designated by the signal from the scan start number electrode line 42 and is inputted to the scan number electrode line 44. A reset pulse is output to the reset electrode line RS2 when the number of shift register circuits designated by the signal are set. That is, the moving image shift register circuit 22 outputs the start pulse input to the start pulse electrode line corresponding to the scan start number among the start pulse electrode lines da1 to dan as the scan pulse to the output electrode line dbi, and outputs this pulse. The data is output to the OR circuit DOi in the next stage. Therefore, the moving image shift register circuit 2
From 2, the scan pulse is output only from the shift register circuit DRi corresponding to the designated moving image display area. The moving image latch circuit 20 is a moving image analog signal line 46.
Is connected to the panel display control circuit 12 via, and the moving image data input from the moving image analog signal line 46 is latched in response to the pulse from the output electrode line dbi, and the latched moving image data is moved to the moving image electrode. The lines Db1 to Dbn are output. That is, the moving image latch circuit 2
From 0, the moving image data is output only to the moving image electrode lines corresponding to the moving image display area among the moving image electrode lines Db1 to Dbn. Then, the moving image data is transferred to the image data electrode line D1 via the data selection switches SW1 to SWn.
To Dn.

The data selection switches SW1 to SWn select still image data when displaying a still image, select moving image data when displaying a moving image, and output any selected image data to the image data electrode lines D1 to Dn. It is configured as an image data selection circuit.

Specifically, as shown in FIG. 4, each of the data selection switches SW1 to SWn includes transistors P1 to Pn composed of p-type TFTs and transistors N1 to Nn composed of n-type TFTs. The gates of the respective transistors are connected to the panel control circuit 12 via the selection signal electrode lines C1 to Cm, and the sources are connected to the image data electrode lines D1 to Dn. Further, the drains of the transistors P1 to Pn are connected to the moving image latch circuit 20, and the drains of the transistors N1 to N are connected to the still image electrode line 48. Then, when a still image is displayed, when the level of the selection signal electrode line Ci becomes "H", the transistors N1 to Nn are turned on, and the still image electrode line 48 is turned on.
The still image data from is output to the image data electrode lines D1 to Dn. On the other hand, when displaying a moving image,
The level of the selection signal electrode line Ci becomes "L", the transistors P1 to Pn are turned on, and the moving image data from the moving image latch circuit 20 is output to the image data electrode lines D1 to Dn.

On the other hand, in each of the display areas A11 to Ann, as shown in FIG. 5, transistors 50, 52 and 54 composed of n-type TFTs, transistors 56 and 58 composed of p-type TFTs, and a display. Data holding capacitor 60,
A display electrode 62 and a counter electrode 64 are provided. The display electrode 62 is a transparent electrode, and the counter electrode 6 with the liquid crystal layer in between.
It is arranged opposite to No. 4. The alternating voltage Vcnt is applied to the counter electrode 64, and the display electrode 62 is connected to the transistor 54. The transistor 54 serves as a still image switching element, the source is connected to the display electrode 62, the drain is connected to the common electrode line COMi, the gate is connected to the source of the transistor 52, and the common electrode COMi is connected via the capacitor 60. It is connected to the. Transistor 52
Are connected in series with the transistor 50, the gate is connected to the signal electrode line Xi, and the drain is connected to the source of the transistor 50 and the drain of the transistor 56.
The gate of the transistor 50 is connected to the scan electrode line Yi, and the drain is connected to the image data electrode line Di. The transistors 50 and 52 and the capacitor 60 are configured as a still image control circuit that controls the ON state of the transistor 54.

On the other hand, the transistor 56 serves as a moving image switching element, the source of which is connected to the display electrode 62,
The drain is connected to the source of the transistor 50, and the gate is connected to the signal electrode line Xi and the gate of the transistor 58. The drain of the transistor 58 is connected to the gate of the transistor 54, and the source thereof is the common electrode line COM.
connected to i. And transistors 50-54
6 is turned on when the level of the voltage applied to the gate is "H", and is kept off at other times, as shown in FIG. Transistors 56 and 58
6 is turned on only when the level of the voltage applied to the gate is "-H" as shown in FIG. 6, and is kept off otherwise. The transistor 58 is configured as a moving image control circuit together with the transistors 50 and 52.

Next, the driving state when displaying a still image in each display area will be described with reference to the timing chart of FIG. Note that Vdisp indicates the potential of the display electrode 62,
Vlcd represents a voltage applied to the liquid crystal between the display electrode 62 and the counter electrode 64.

In FIG. 7, first, when displaying a still image,
When still image data is selected by the data selection switch SWi and the potential of the image data electrode line Di is "H", if the levels of the signal electrode line i and the scan electrode line Yi both become "H", the transistor 50, Both 52 are turned on, and the transistor 54 is turned on according to the still image data from the image data electrode line Di. At this time, the potential Vmem of the gate of the transistor 54 becomes “H”,
The still image data is charged in the capacitor 60. Furthermore, with the conduction (ON state) of the transistor 54,
The potential Vdisp of the display electrode 62 is the potential Vc of the common electrode line.
It has the same potential as om. On the other hand, since the alternating voltage Vcnt is applied to the counter electrode 64, the voltage Vlcd, which is the difference between Vdisp and Vcnt, may be applied to the liquid crystal, and the liquid crystal may light up. When the liquid crystal (pixel) is lit by such a pixel selection operation, the liquid crystal that has been lit once will continue to be lit for a long time because the image data is held for a long time by the capacitor 60. This holding time is determined by the leak current value of the transistor 54 and the capacitance of the capacitor 60, but the leak current value of the transistor is usually very small and is sufficiently longer than the typical value of 16.7 ms of the frame time.

Since the liquid crystal which has been turned on once keeps the turned-on state for a certain period of time, when it is not necessary to change the state of the liquid crystal, a voltage based on the same image data is applied for each frame (16.7 ms). There is no need. Therefore, at the time of displaying a still image, it is necessary to charge and discharge for each frame the capacitance of the wiring crossing portion accompanying the wiring of each electrode line and the capacitance formed by the liquid crystal between the wiring and the counter electrode 64. Since it does not exist, power consumption can be reduced.

On the other hand, in the pixel selection operation, the transistor 5
When 0 and 52 are conductive and the level of the image data is “L”, the gain V of the gate of the transistor 54 is
mem becomes “L”, the electric charge stored in the capacitor 60 is discharged, and the transistor 54 becomes non-conductive. At this time, since Vdisp has the same potential as Vcnt, no voltage is applied to the liquid crystal, and the liquid crystal is turned off.

As described above, when a still image is displayed, when the signal electrode line Xi and the scanning electrode line Yi both become "H" and the pixel selecting operation is executed, the image data electrode line Di remains "H". When the image data is input, the liquid crystal is turned on, and when the image data of "L" is input, the liquid crystal is turned off. In this case, since the liquid crystal (pixel) that has been lit (displayed) once continues to be lit for a long time, the intervals of pixel selection operations for displaying a still image need not be periodic, and only when rewriting is necessary. It will be rewritten. Therefore, at the time of displaying a still image, it is not necessary to charge and discharge the capacitance formed at the wiring intersection or the capacitance formed between the wiring and the liquid crystal every frame, and the power consumption can be reduced.

Next, the drive state when displaying a moving image in each display area will be described with reference to the timing chart of FIG.

First, as a pixel selection operation during display of a moving image, when the voltage level of the signal electrode line Xi becomes "-H" and the voltage level of the scanning electrode line Yi becomes "H",
When “sign” is input as moving image data to the image data electrode line Di by the selection operation of the data selection switch SWi, the transistors 50, 56 and 58 are turned on and the moving image data is applied to the display electrode 62. . At this time, the transistor 52 is in a non-conducting state, so that Vme
The level of m becomes "L", and the transistor 54 becomes non-conductive. The image data such as a still image charged in the capacitor 60 is discharged by the conduction of the transistor 58. The voltage Vlcd applied to the liquid crystal is the voltage "Vcnt-Vdi" which is the difference between Vcnt and Vdisp.
sp ”, the liquid crystal is turned on according to the voltage difference, and a moving image is displayed. In this case, by setting the interval when the moving image is selected to 1/60 seconds, a good moving image without flicker can be obtained. Can be displayed.

Next, when a still image and a moving image are displayed together, as shown in FIG. 9, the display area is divided into the still image region and the moving image region {(Xn1, ..., Xnn) to (Ym).
1, ..., Ymm)} can be displayed separately.

When displaying a still image in the still image area, the output of the Y shift register circuit 16 becomes "H",
Address signals input from the panel display control circuit 12 are sequentially output from the Y decoder circuit 18. Therefore, Y address data corresponding to the address signal is output from the logic circuit ANDi. The X decoder 14 sequentially outputs X address data according to the address signal input from the panel display control circuit 12. Further, the data selection switch SWi selects the still image data from the still image electrode line 34 and outputs the selected still image data to the image data electrode line Di. Therefore, X address data is applied to the signal electrode line Xi designated in the still image area, Y address data is applied to the scanning electrode line Yi, and still image data is applied to the image data electrode line Di.
It is applied in synchronization with the X address data.

On the other hand, when a moving image is displayed in the moving image area, a scanning pulse is output from the designated output electrode lines (a plurality of output electrode lines corresponding to the moving image display area) of the Y shift register circuit 16 and the Y decoder. The "H" signal is output from the 18 designated address signal lines (a plurality of address signal lines corresponding to the moving image display area). And logic circuit A
A scanning pulse is output from NDi to a designated scanning electrode line (a plurality of scanning electrode lines corresponding to the moving image display area) Yi.
Further, the "-H" signal is output from the X decoder circuit 14 to a designated signal electrode line (a plurality of signal electrode lines corresponding to the moving image display area) Xi. And the data selection switch SW
i selects moving image data from a specified moving image electrode line (a plurality of moving image electrode lines corresponding to the moving image display area) of the moving image latch circuit 20, and the selected moving image data is set to the image data electrode line Di. Output. Then, a signal "-H" is applied to each signal electrode line Xi corresponding to the moving image display area, a scanning pulse is applied to the scanning electrode line Yi, and moving image data is scanned pulse to the image data electrode line Di. It is applied in synchronization with. The above relationships are summarized in Table 1 below.

[0038]

[Table 1]

When the lighting, erasing, and holding of the image data are executed in the still image area, and when the lighting and holding of the image data are executed in the moving image area, the potential relationship between the electrode lines is It is represented in Table 2 below.

[0040]

[Table 2]

When a still image is displayed (lighted) in the still image area, the scanning electrode line Yi and the signal electrode line X are displayed.
i, “H”, “H”, and
By applying “H”, the potential of the display electrode 62 becomes the same potential as the potential “Vcom” of the common electrode line, and the liquid crystal is turned on. On the other hand, when erasing the illuminated still image, “H” is set to the scanning electrode line Yi and the signal electrode line Xi is set.
Is applied to the image data electrode line Di and "L" data is applied to the image data electrode line Di, so that the potential of the display electrode 62 becomes "Vcn".
The image has the same electric potential as that of t "and the image is erased. To hold the still image that has been lit once, either the scanning electrode line Yi or the signal electrode line Xi may be set to" L ". At this time, even if a signal of "L" or "H" is applied to the image data electrode line Di, the state of the display electrode 62 does not change, and display is performed even when "-H" is applied to the signal electrode line Xi. The state of the electrode 62 does not change.

On the other hand, a moving image is displayed (lighted) in the moving image area.
When the scanning electrode line Yi, the signal electrode line Xi, and the image data electrode line Di are respectively made “H”, “−H”, and “s”.
By applying "ign", moving image data "sign" is applied to the display electrode 62, and the moving image is displayed by lighting the liquid crystal. When the displayed moving image is held, the scanning electrode line Yi , The level of the signal of one of the signal electrode lines Xi is “L”, and at this time, no matter what signal is applied to the image data electrode line Di, the display electrode 6
The state of 2 does not change.

Next, as shown in FIG. 9, the operation when displaying a moving image and a still image in a state where the still image display area and the moving image display area are mixed will be described with reference to the timing chart of FIG. . The time for one frame is 1 /
It is about 16.7 ms in 60 seconds. Of the electrode lines corresponding to the moving image display area, the scanning electrode lines are Ym1 to Ym.
m, the signal electrode lines are set to Xn1 to Xnn, and the image data electrode lines are set to Dn1 to Dnn, and the still image display region and the moving image display region are set in accordance with commands from the panel display control circuit 12, respectively. Further, the time for displaying a still image or the time for selecting a still image and the time for displaying a moving image or the time for selecting a moving image are driven separately.

First, when the process for displaying an image of one frame is started, a command for displaying a still image is output from the panel display control circuit 12, and the scanning electrode lines Yi and signals belonging to the still image display area are output. The data and signals shown in Table 1 are sequentially applied to the electrode lines Xi and the image data electrode lines Di. Then, the liquid crystal belonging to the still image display area is turned on, erased, and held according to the still image data. That is, the liquid crystal in the still image display area is turned on, erased, and held in the driving state shown in Table 2, and the still image according to the image data is displayed.

At the timing of displaying a moving image in the moving image display area in the process of performing selective scanning of the scanning electrodes, the scanning electrode lines Yi, the signal electrode lines Xi, and the image data electrode lines Di belonging to the moving image display area are reached. Signals and moving image data as shown in Tables 1 and 2 are applied to, and moving images are sequentially displayed in the moving image display area. This moving image display time exists once per frame, and the processing of moving images belonging to this time is repeated for each frame.

Further, when displaying a still image, the selection operation is not executed for the liquid crystal belonging to the display area once displayed until rewriting is required, and the written state remains until rewriting is required. Retained.

As described above, according to the present embodiment, even when a still image and a moving image are mixedly displayed in the display area, when the still image is displayed in the still image area, the pixels related to the still image once displayed are displayed. Since the selection operation is not executed until rewriting is required, the capacitance formed at the intersection of the wiring and the capacitance formed by the liquid crystal between the wiring and the counter electrode 64 are charged / discharged for each frame. It is not necessary to perform the above, and the power consumption can be reduced.

Further, even when a moving image is displayed, the moving image is displayed only in a specific area without displaying the moving image in all areas, so that power consumption can be reduced. Further, within a period in which one scanning electrode line Yi is selected, scanning is performed by sequentially applying the moving image data to all the signal electrode lines Xi belonging to the moving image display area among the signal electrode lines intersecting with the scanning electrode line Yi. Therefore, the moving image can be displayed well.

[0049]

As described above, according to the present invention,
When displaying a still image, the state of the displayed still image is held until rewriting is necessary, and when the moving image is displayed, the moving image is displayed only in a designated area. It is not necessary to charge and discharge the capacitance between various wirings including the signal electrode lines and the image data electrode lines and the capacitance formed by the liquid crystal between the wirings and the counter electrode for each frame, thus reducing power consumption. In addition, the still image and the moving image can be displayed in good condition.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a Y shift register circuit.

FIG. 3 is a schematic configuration diagram of a moving image signal circuit.

FIG. 4 is a schematic configuration diagram of an image data selection switch.

FIG. 5 is a schematic configuration diagram of a display area.

FIG. 6 is a Vgs-Ids characteristic diagram of a TFT.

FIG. 7 is a timing chart for explaining a writing state of a still image.

FIG. 8 is a timing chart for explaining a writing state of a moving image.

FIG. 9 is a diagram showing a setting state of a region when a moving image and a still image are displayed in a display region.

FIG. 10 is a timing chart showing an operation when a still image and a moving image are mixedly displayed.

[Explanation of symbols]

 10 color panel 12 panel display control circuit 14 X decoder circuit 16 Y shift register circuit 18 X decoder circuit 20 moving image latch circuit 22 moving image shift register circuit 24 common electrode drive circuit 26 counter electrode drive circuit Xi signal electrode line Yi scanning electrode line Di image data electrode line SWi data selection switch

Claims (7)

[Claims] 1. A liquid crystal layer is inserted between a pair of substrates, which are opposed to each other and at least one of which is transparent, and a plurality of scanning electrode lines are arranged in a distributed manner on one of the pair of substrates, and A plurality of signal electrode lines that intersect in a matrix form are dispersedly arranged on a plurality of scan electrodes, and a plurality of displays surrounded by the plurality of scan electrode lines and the plurality of signal electrode lines on the one substrate, respectively. A switching element for a still image connected to each display electrode in each of the plurality of display regions, the counter electrode being disposed in each of the regions, and the counter electrode being disposed to face each display electrode with a liquid crystal layer in between. And a switching element for a moving image, and a static element for controlling the switching element for a still image based on signals and still image data from the signal electrode lines and the scanning electrode lines. An image control circuit is arranged, and a moving image for controlling each of the moving image switching elements based on signals and moving image data from each of the signal electrode lines and each of the scanning electrode lines in the plurality of display areas. When a still image is displayed, the still image control circuit is provided and signals from the signal electrode lines and scan electrode lines and still image data are supplied to the still image control circuit belonging to the still image display area to turn on the still image switching element. When the moving image is displayed, the signals and signal data from the signal electrode lines and the scanning electrode lines and the moving image data are given only to the moving image control circuit belonging to the moving image display area. Liquid crystal display device in which the switching element for use is turned on. 2. A liquid crystal layer is inserted between a pair of substrates which are arranged opposite to each other and at least one of which is transparent, and a plurality of scan electrode lines are dispersedly arranged on one substrate of the pair of substrates and A plurality of signal electrode lines that intersect in a matrix form are dispersedly arranged on a plurality of scan electrodes, and a plurality of displays surrounded by the plurality of scan electrode lines and the plurality of signal electrode lines on the one substrate, respectively. A switching element for a still image connected to each display electrode in each of the plurality of display regions, the counter electrode being disposed in each of the regions, and the counter electrode being disposed to face each display electrode with a liquid crystal layer in between. And a switching element for a moving image, and a static element for controlling the switching element for a still image based on signals and still image data from the signal electrode lines and the scanning electrode lines. An image control circuit is arranged, and a moving image for controlling each of the moving image switching elements based on signals and moving image data from each of the signal electrode lines and each of the scanning electrode lines in the plurality of display areas. When a still image is displayed, the still image control circuit is provided and signals from the signal electrode lines and scan electrode lines and still image data are supplied to the still image control circuit belonging to the still image display area to turn on the still image switching element. While the still image data is held, the still image data is held, and for the still image control circuit which holds the still image data among the still image control circuits belonging to the still image display area, the signal electrode is held while the still image data is held. Stops the supply of signals and still image data from the lines and scan electrode lines, and when moving images are displayed, signals are sent only to the moving image control circuits that belong to the moving image display area. The liquid crystal display device which gives a signal and a moving picture data from polar scan electrode line made by the switching element moving image in the ON state. 3. A pair of substrates which are opposed to each other and at least one of which is transparent, a liquid crystal layer which is sandwiched between the pair of substrates, and one of the pair of substrates are dispersedly arranged. A plurality of scanning electrode lines; a plurality of signal electrode lines that are dispersedly arranged on the same substrate as the plurality of scanning electrode lines and intersect the plurality of scanning electrodes in a matrix; A plurality of display electrodes respectively arranged in a plurality of display areas surrounded by a scanning electrode line and the plurality of signal electrode lines, and arranged so as to face each other with the liquid crystal layer interposed between the plurality of display electrodes. A plurality of counter electrodes, a plurality of image data electrode lines arranged corresponding to the plurality of signal electrode lines to guide image data to the plurality of display regions, and a plurality of image data electrode lines respectively connected to the plurality of display electrodes. Still image switch Element, a plurality of moving image switching elements respectively connected to the plurality of display electrodes, signals from the plurality of signal electrode lines and the plurality of scanning electrode lines, and still images from the plurality of image data lines. When the data is received and these conditions satisfy the conditions for turning on the plurality of still image switching elements, the still image data is held and the plurality of still image switching elements are controlled to be on. Receiving a plurality of still image control circuits, signals from the plurality of signal electrode lines and the plurality of scanning electrode lines, and moving image data from the plurality of image data lines, these states are used for the plurality of moving images. A plurality of motions for controlling each of the plurality of moving image switching devices to be in an on state when a condition for turning on the switching device is satisfied. An image control circuit, a plurality of image data selection circuits that select still image data when displaying a still image, select moving image data when displaying a moving image, and output the selected image data to the plurality of image data electrode lines, respectively. A moving image display area designating unit that designates an area in which a moving image is to be displayed among the plurality of display areas, and the moving image display area designating unit of the plurality of image data selection circuits according to the designation of the moving image display area designating unit. A moving image data output means for outputting the moving image data only to the image data selection circuit corresponding to the display area specified by
Scan pulse output means for still image that sequentially outputs a scan pulse to a designated scan electrode line of the plurality of scan electrode lines when a still image is displayed; and a designated scan of the plurality of scan electrode lines when a moving image is displayed. Still image liquid crystal drive signals are output to the plurality of signal electrode lines in synchronism with the scanning pulse output from the moving image scanning pulse output means for sequentially outputting scanning pulses to the electrode lines and the output from the still image scanning pulse output means. A still image liquid crystal drive signal output means and a moving image liquid crystal drive signal to a designated signal electrode line of the plurality of signal electrode lines in synchronization with the scanning pulse output from the moving image scan pulse output means. And a liquid crystal drive signal output unit for outputting a moving image. 4. The moving picture control circuit is connected to the still picture control circuit, and the still picture data held by the still picture control circuit is discharged when the moving picture is displayed. Liquid crystal display device. 5. The still image control circuit includes a capacitor inserted between input electrodes of a still image switching element having a display electrode as a load, and a pair of thin film transistors connected in series with the still image switching element. The gate of one of the thin film transistors is connected to the signal electrode line,
5. The liquid crystal display device according to claim 1, wherein the gate of the other thin film transistor is connected to the scanning electrode line, and still image data is input to the drain. 6. A moving image control circuit includes a discharge thin film transistor inserted between input electrodes of a still image switching element having a display electrode as a load, and a moving image switching element having a display electrode as a load in series. And a thin film transistor for inputting image data connected, the gate of the thin film transistor for discharging is connected to the signal electrode line together with the gate of the switching element for moving image, the gate of the thin film transistor for image data input is connected to the scanning electrode line, and the drain The moving image data is input to the above.
Or the liquid crystal display device according to item 5. 7. The moving image liquid crystal drive signal output means, when a scan pulse is output to one of the designated scan electrode lines, responds to the scan pulse to designate the designated signal electrode line. 4. The liquid crystal display device according to claim 3, wherein moving image data corresponding to the number of designated signal electrode lines is sequentially output.