KR100374378B1 - Liquid crystal display and driving method for liquid crystal display - Google Patents

Abstract

For the image display area, the scan signal circuit sequentially outputs the scan signal once per one horizontal period of the input signal, and inputs the pixel data signal from the display signal circuit to the liquid crystal panel. For the blanking area, a plurality of input pulses are input as scan signals in synchronization with the high speed clock signal, and the input pulses move to the blanking area. After simultaneously writing the blanking lines with 30 odd lines at the top of the liquid crystal panel, the blanking lines are simultaneously written with the 30 even lines at the top. Similarly, after writing the blanking lines with 30 odd lines at the bottom of the liquid crystal panel, the blanking lines are written simultaneously with the 30 even lines at the bottom. With this operation, when the number of scan signal lines of the liquid crystal panel is larger than the number of scan lines in one vertical period of the image input signal, the blanking area is made completely.

Description

Liquid crystal display and its driving method {LIQUID CRYSTAL DISPLAY AND DRIVING METHOD FOR LIQUID CRYSTAL DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using a liquid crystal panel, and more particularly, to a liquid crystal display device and a driving method thereof for performing a complete blanking display in a blanking area (blanking section) in which an image is not displayed at the top and bottom of a screen.

This application claims priority based on Japanese Patent Application No. 11-335170 filed November 25, 1999.

The conventional liquid crystal display device is provided with the control part 1 and the oscillation circuit 2, as shown in FIG. The control unit 1 receives the image input signal Iin supplied from the outside and the clock signal S2 supplied from the oscillation circuit 2. The control unit 1 generates and outputs an image data signal S1a, an input pulse S1b for generating a scan signal, a clock signal S1c, and an output enable signal S1d. The control unit 1 is connected to the display signal circuit 3 and the scan signal circuit 4. The display signal circuit 3 receives the image data signal S1a, generates the pixel data signal S3-1 to the pixel data signal S3-m, and generates the pixel data signal S3-1 to the pixel data signal. (S3-m) is output to the liquid crystal panel 5. The scan signal circuit 4 is provided with a shift register (not shown) which receives the input pulse S1b and moves in synchronization with the clock signal S1c, and receives the scan signal when receiving the output enable signal S1d. Input pulses S1b as (S4-1) to scan signal S4-n are output to the liquid crystal panel 5. The output side of the display signal circuit 3 is connected to the data signal lines Y1 to Ym of the liquid crystal panel 5. The output side of the scan signal circuit 4 is connected to the scan signal lines X1 to Xn of the liquid crystal panel 5. The liquid crystal panel 5 is provided with a plurality of pixel regions at the intersections of the data signal lines Y1 to Ym and the scan signal lines X1 to Xn, and the pixel data signals S3. The image is displayed by supplying the pixel data signal S3-m to the pixel region selected by the scan signals S4-1 to S4-n among all the pixel regions.

The operation of the conventional liquid crystal display will be described with reference to the timing chart shown in FIG.

The image input signal Iin and the clock signal S2 are input to the control unit 1. The image data signal S1a, the input pulse S1b, the clock signal S1c and the output enable signal S1d are output from the control unit 1. The image data signal S1a is input to the display signal circuit 3, and the pixel data signals S3-1 to S3-m are output from the display signal circuit 3. The input pulse S1b, the clock signal S1c and the output enable signal S1d are input to the scanning signal circuit 4. In the scan signal circuit 4, the input pulse S1b moves in synchronization with the clock signal S1c, and the scan signals S4-1 to S4-n are output enable signal S1d active. When in mode, i.e., at high level (hereinafter referred to as H level). The scan signals S4-1 to S4-n are not output when the output enable signal S1d is in an inactive mode, that is, at a low level (hereinafter referred to as L level). The pixel data signal S3-1 to pixel data signal S3-m and the scan signal S4-1 to scan signal S4-n are input to the liquid crystal panel 5. In the liquid crystal panel 5, the pixel data signals S3-1 to S3-m are supplied to the pixel region selected by the scan signals S4-1 to S4-n, and selected An image corresponding to the pixel data signal S3-1 to the pixel data signal S3-m is displayed.

However, the conventional liquid crystal display has the following problems.

7 shows that when the number of scan signals X1 to Xn is 1200, the number of scanning lines for the image display area (image display section) of the image input signal Iin is 1080, and the total number of scanning lines is 1125, It is a figure explaining the operation | movement of the conventional liquid crystal display device.

As shown in Fig. 7, in the state [1], the pixel data signal S3-1 to the pixel data signal S3-m of the first line with respect to the image display area (image display section) are changed to the liquid crystal panel 5; The scan signal S4-1 is indicated when it is written in. The output enable signal S1d is always in active mode. The input pulse S1b is moved in synchronization with the clock signal S1c, and the pixel data signal S3-1 to pixel data signal S3-m of the second line are written in the liquid crystal panel 5. In this way, the pixel data signals S3-1 to S3-m from the first to the 1080 lines are written in the liquid crystal panel 5. In the state [2], the scan signal S4-1080 is shown when the pixel data signal S3-1 to S3-m of the 1080th line is written in the liquid crystal panel 5.

Then, the blanking area (black belt) is written when the clock signal S1c is received. The blanking area (blanking section) includes 45 lines and the liquid crystal panel 5 becomes black in the blanking area. In the state [3], when the next line is the 1126th line, that is, when it returns to the next first line, the scan signal S4-1 of the first line and the scan signal S4-1126 of the 1126th line are received. Indicates. Therefore, with respect to the 1126th line and the next line, the pixel data signals S3-1 to S3-m are written similarly to the fifth to 1125 lines. In the state [4], an example of the liquid crystal panel 5 which displays the state in which the start of a blanking area is accepted as the start of an image display area is shown. In the state [4], the black portions represent the blanking regions 5a and 5c, and the white portions represent the image display region 5b. As shown in the state [4], the blanking areas 5a and 5c are written above and below the image display area 5b, and other image display areas 5d are displayed below the blanking area 5c at the bottom. do. Therefore, there is a problem in that a complete blanking area cannot be written on the top and bottom of the image display area.

To solve this problem, digital signal processing is performed on the image input signal Iin when the number of scan signal lines X1 to Xn is larger than the total number of scan lines in the vertical period. For example, the scan signal lines X1 to Xn of the liquid crystal panel 5 are 1200, the number of scan lines of the image input signal Iin in the image display area is 1080, and the total number of scan lines is 1125. In this case, the image input signal Iin is stored in the frame memory and performs a process of adding the blanking area. With this operation, the liquid crystal panel is executed so that the total number of scan lines becomes 1200 while the number of scan lines in the image display area is 1080. By the way, when the total number of scan lines is increased by performing such digital signal processing, there is a problem that components such as frame memory and frame memory controller increase, and the configuration is complicated and enlarged.

Further, in Japanese Patent No. 2820061, in a liquid crystal panel using polysilicon technology, a complex scan signal circuit is formed in the liquid crystal panel, and a plurality of scan signals are made in the active mode, so that a complete blanking area is formed at the top of the image display area. And written at the bottom. By the way, in the liquid crystal panel using the amorphous silicon technique which is mainly used recently, since the electron mobility is remarkably delayed compared with the liquid crystal panel using the polysilicon technique, it is not practical to form a complex scanning signal circuit in a liquid crystal panel. That is, since the scan signal circuit is a shift register with a simple structure, it is not possible to simultaneously generate a plurality of scan signals in the active mode by the conventional driving method shown in FIG.

As described above, an object of the present invention is to provide an image display area in a liquid crystal panel using an amorphous technique in the configuration of a conventional scan signal circuit, when the number of scan signal lines is larger than the total number of scan lines of the image signal with respect to the vertical period. An object of the present invention is to provide a liquid crystal display device capable of writing complete blanking at the top and the bottom of the substrate.

1 is a block diagram showing an electrical configuration of a liquid crystal display device according to a first embodiment;

FIG. 2A is a timing diagram illustrating the operation of the liquid crystal display of FIG. 1; FIG.

2B is an explanatory diagram illustrating the operation of the liquid crystal display of FIG. 1;

3 is a block diagram showing an electrical configuration of a liquid crystal display device according to a second embodiment;

4 is a timing diagram illustrating an operation of the liquid crystal display of FIG. 3;

5 is a block diagram showing an electrical configuration of a conventional liquid crystal display device;

FIG. 6 is a timing chart for explaining the operation of the conventional liquid crystal display of FIG. 5; And

FIG. 7 is a view for explaining the operation of the conventional liquid crystal display of FIG. 5.

※ Explanation of main parts of drawing

1, 11, 21: control unit 2, 12: oscillation circuit

3, 13: display signal circuit 4, 14: scanning signal circuit

5, 15: liquid crystal panel

According to the first aspect of the present invention, a plurality of data signal lines for inputting image data signals, a plurality of scan signal lines for inputting scan signals, and a plurality of pixel regions arranged at intersections of data signal lines and scan signal lines are provided. And a liquid crystal panel which displays an image corresponding to the image data signal by supplying the image data signal to the pixel region selected by the scanning signal in the pixel region, and a display for transmitting the image data signal to the data signal line in accordance with the image input signal. Inputs a signal circuit, an input pulse for generating a scan signal, moves in synchronization with a clock signal, and transmits an input pulse as a scan signal to a scan signal line when an output command signal is input, and an image input signal And outputting input pulses, clock signals, and output command signals to the scanning signal circuit. And a control unit, wherein the control unit, when the number of scan signal lines is larger than the number of scan lines of the image input signal with respect to the vertical period, input pulses to the image display area in the vertical direction of the screen of the liquid crystal panel in the first operation mode, A clock signal and an output command signal are output, and in the second operation mode, an input pulse, a clock signal, and an output command signal are output for a blanking area in which no image is displayed in the upper and lower portions of the vertical direction of the screen.

As described above, in the first operation mode, the scan signal circuit outputs the scan signal once in one horizontal period of the image input signal, and in the second operation mode, the scan signal circuit simultaneously outputs a plurality of scan signals to the blanking area. Output is the preferred form.

In addition, in the first operation mode, the scan signal circuit outputs the scan signal a plurality of times in one horizontal period of the image input signal in order to enlarge the image, and in the second operation mode, the scan signal circuit simultaneously scans the plurality of scans for the blanking area. Outputting a signal is the preferred form.

In the second operation mode, it is preferable that the scan signal circuit outputs a plurality of scan signals to odd and even lines separated from the scan signal lines.

In the second operation mode, it is preferable that the scan signal circuit inverts the polarities of the scan signals of the odd lines and even lines.

Moreover, it is a preferable aspect that a liquid crystal panel is an active matrix liquid crystal panel which uses a thin film transistor of amorphous silicon as an active element.

According to the second aspect of the present invention, when the number of scan signal lines of the liquid crystal panel is larger than the number of scan lines of the image input signal with respect to the vertical period, the image input signal with respect to the image display area in the vertical direction of the screen of the liquid crystal panel Outputting a scanning signal once in one horizontal period, and simultaneously outputting a plurality of scanning signals to a blanking area in which an image is not displayed in the upper and lower portions of the vertical direction of the screen. Is provided.

According to the third aspect of the present invention, when the number of scan signal lines of the liquid crystal panel is larger than the number of scan lines of the image input signal with respect to the vertical period, one horizontal line of the image input signal to enlarge the image with respect to the image display area A method of driving a liquid crystal display device is provided, the method comprising: outputting a plurality of scan signals in a cycle, and simultaneously outputting a plurality of scan signals to a blanking area in which images are not displayed in the upper and lower portions of the vertical direction of the screen.

As described above, it is preferable that a plurality of scan signals are output separately in odd lines and even lines for a blanking area in which no image is displayed in the upper and lower portions of the vertical direction of the screen.

It is also a preferred form that the polarity of the scan signal is reversed for the odd and even lines.

With the above structure, when the number of scan signal lines of the liquid crystal panel is the same as the number of scan lines of one vertical period of the image input signal, the control unit inputs to the image display area in the vertical direction of the screen of the liquid crystal panel in the first operation mode. Outputting a pulse, a clock signal, and an output command signal, and in the second operation mode, by outputting an input pulse, a clock signal, and an output command signal to a blanking area of the screen where no image is displayed in the upper and lower portions of the vertical direction of the screen, Amorphous silicon technology can be used to write complete blanking in the upper and lower portions of the image display area without performing digital signal processing using a relatively simple liquid crystal panel but using a frame memory or the like. In addition, when the controller receives an image input signal in which the number of pixels of the image input signal is 1/2 or less than the number of scanning pixels in the liquid crystal panel, the controller outputs a clock signal a plurality of times and the scanning circuit signal is scanned in synchronization with the clock signal. By outputting the signal a plurality of times, the image can be enlarged.

The objects, advantages and features of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

Preferred embodiments of the present invention will be described in more detail using various examples with reference to the accompanying drawings.

First embodiment

1 is a block diagram showing an electrical configuration of a liquid crystal display according to a first embodiment of the present invention.

As shown in FIG. 1, the liquid crystal display according to the first embodiment includes a control unit 11 and an oscillation circuit 12. The control unit 11 includes a plurality of logic circuits and the like, receives an image input signal Iin supplied from the outside and a clock signal S12 supplied from the oscillation circuit 12, and receives the image data signal S11a, and An input pulse S11b for generating a scan signal, a clock signal S11c, and an output command signal S11d are generated and output. In addition, when the number of scanning signal lines of the liquid crystal panel 15 is larger than the number of image input signals Iin for one vertical period, the control unit 11 displays an image of the liquid crystal panel 15 in the first operation mode. Outputs an input pulse S11b, a clock signal S11c and an output enable signal S11d in a direction perpendicular to the area, and blanking in which images are not displayed on the upper and lower portions of the liquid crystal panel 15 in the second operation mode. The input pulse S11b, the clock signal S11c and the output enable signal S11d are output in the vertical direction with respect to the area.

The control unit 11 is connected to the display signal circuit 13 and the scan signal circuit 14. The display signal circuit 13 receives the image data signal S11a and generates and outputs the pixel data signal S13-1 to the pixel data signal S13-m. The scan signal circuit 14 receives an input pulse ( A shift register that receives S11b and moves in synchronization with the clock signal S11c and the like, and receives the input pulse S11b from the scan signals S14-1 to S14 when receiving the output enable signal S11d. -n) The output side of the display signal circuit 13 is connected to the data signal line Y1 to the data signal line Ym of the liquid crystal panel 15, and the output side of the scan signal circuit 14 is the scan signal line X1 to the scan. It is connected to the signal line Xn. The liquid crystal panel 15 includes a plurality of pixel regions provided at the intersections of the data signal lines Y1 to Ym and the scan signal lines X1 to Xn, and the pixel data signals ( The image is displayed by supplying the S13-1 to the pixel data signal S13-m to the image region selected by the scan signals S14-1 to S14-n among all the image regions. The liquid crystal panel 15 is of an active matrix type, pixelated memory cells to store active elements of the TFT (thin film transistor) using amorphous silicon and pixel data signals S13-1 to S13-m. It is included as an area.

In the liquid crystal display device, the image input signal Iin and the output signal S12 are input to the control unit 11, and the image data signal S11a, the input pulse S11b and the clock signal S11c and the output enable signal ( S11d) is output from the control unit 11. The image data signal S11a is input to the display signal circuit 13 and the pixel data signal S13-1 to pixel data signal S13-n are output from the display signal circuit 13. The input pulse S11b, the clock signal S11c and the output enable signal S11d are input to the scanning signal circuit 14. In the scan signal circuit 14, the input pulse S11b moves in synchronization with the clock signal S11c, and the scan signals S14-1 to S14-n are output enable signals S11d of H. Outputs when level. The pixel data signal S13-1 to pixel data signal S13-m and the scan signal S14-1 to scan signal S14-n are input to the liquid crystal panel 15. In the liquid crystal panel 15, the pixel data signals S13-1 to S13-m are supplied to the pixel region selected by the scan signals S14-1 to S14-n, and the pixels An image corresponding to the data signal S13-1 to the pixel data signal S13-m is displayed.

FIG. 2A is a timing chart illustrating the operation of the liquid crystal display device according to the first embodiment when the number of scan signal lines X1 to Xn is larger than the total number of scan lines of the image input signal Iin. 2B is a diagram for explaining this. 2A and 2B show a liquid crystal display when the number of scan signal lines X1 to Xn is 1200, the number of image input signals Iin for the image display area is 1080, and the total number of scan lines is 1125. Indicates the operation of.

A liquid crystal display device will be described with reference to FIGS. 2A and 2B.

As shown in Figs. 2A and 2B, in the state [1], the output enable signal S11d is at the H level, the scan signal S14-1140 is output from the scan signal circuit 14, and is 1080 lines. The final pixel data signal S13-1 to final pixel data signal S13-m of the image display area with respect to are input from the display signal circuit 13 to the liquid crystal panel 15. In the transition period from the state [1] to the state [2] in FIGS. 2A and 2B, the output enable signal S11d becomes L level, and the scanning signal S14-1140 in the state [1] is inactive. do. At this time, thirty pulses inverted per one pulse of the clock signal S11c are input to the scan signal circuit 14 and move in the scan signal circuit 14 in synchronization with the clock signal S11c.

In the state [2] shown in Figs. 2A and 2B, the control unit 11 executes the operation in the second operation mode. The output enable signal S11d is at the H level, and 30 odd lines are separated from the 60 lines of the scan signals S14-1 to S14-60 in the upper blanking region from the scan signal circuit 14. It is output at the same time. As a result, the blanking lines are written simultaneously in the thirty odd lines on the top of the liquid crystal panel 15. In the state [3] shown in Figs. 2A and 2B, the control unit 11 executes the operation in the second operation mode. The output enable signal S11d becomes H level, the thirty input pulses S11b move in the scan signal circuit 14 in synchronism with one clock signal S11d, and move upward from the scan signal circuit 14. 30 even scan signals are simultaneously output from the 60 signals of the scan signals S14-1 to S14-60 in the blanking region of. As a result, the blanking lines are written to the 30 even lines at the top of the liquid crystal panel 15 at the same time. The polarities of these scan signals are opposite to the polarities of the 30 odd scan signals in state [2]. In the states [2] and [3] shown in Figs. 2A and 2B, in order to match the image display section for the image display region with the writing time, the clock signal in the section similar to the image display section is scanned signal circuit (14). ) Is entered. The intervals of state [2] and state [3] may be longer or shorter than the horizontal period. In the transition period from the state [3] to the state [4] in FIGS. 2A and 2B, the output enable signal S11d becomes L level, and the scan signal is in an inactive mode. At this time, one clock signal S11c is input to the scanning signal circuit 14, and 30 input pulses S11b move to the lower blanking area in synchronization with one clock signal S11c.

Then, in the state [4] shown in Figs. 2A and 2B, the output enable signal S11d becomes H level, and the thirty odd scan signals are the scan signals S14-1141 to the scan in the lower blanking area. It is output simultaneously from 60 signals of the signal S14-1200. As a result, blanking lines are written simultaneously to the thirty odd lines of the liquid crystal panel 15 at the bottom. In the state [5] shown in Figs. 2A and 2B, the output enable signal S11d is at the H level, and thirty input pulses S11b are one clock signal S14c in the scanning signal circuit 14. It moves in synchronization with, and 30 even scan signals are simultaneously output from the 60 scan signals of the scan signals S14-1141 to S14-1200 of the lower blanking area. As a result, the blanking line is written in 30 even lines of the lower liquid crystal panel 15. In the states [4] and [5] of Figs. 2A and 2B, to match the image display section with the writing time. The clock signal S11c having the same period as the image display area is input to the scanning signal circuit 14. The interval of states [4] and [5] may be longer or shorter than the horizontal period if blanking is written.

In the state [5] of Figs. 2A and 2B, the H level input pulse S11b is input for one clock signal S11c. In the transition period from the state [5] to the state [6], one clock signal S11c is input to the scanning signal circuit 14. Thereafter, 30 input pulses S11b enter the inactive mode, and one input pulse S11b moves to the start of the image display area. In the state [6] of Figs. 2A and 2B, the control unit 11 executes the first operation mode, the output enable signal S11d is at the H level, and the scan signal S14-61 is the scan signal circuit ( The pixel data signal S13-1 to the pixel data signal S13-m of the first line of the image display area having 1080 lines, from the display signal circuit 13 to the liquid crystal panel 15; Is entered. Similarly, the scan signals S14-62 to S14-1140 are sequentially output from the display signal circuit 13 to the liquid crystal panel 15 per one horizontal period of the image input signal Iin. Thereafter, the pixel data signals S13-1 to S13-m of the corresponding lines are input from the display signal circuit 13 to the liquid crystal panel 15.

As described above, according to the first embodiment, when the number of scan signal lines of the liquid crystal panel 15 is larger than the number of scan lines in one vertical period of the image input signal Iin, the controller 11 controls the liquid crystal. In the image display area in the vertical direction of the panel 15, in the first operation mode, the input pulse S11b, the clock signal S11c and the output enable signal S11d are output, and the upper and lower portions of the vertical screen are displayed. With respect to the blanking area, the liquid crystal panel 15 having a relatively simple configuration using amorphous silicon technology is produced by outputting the input pulse S11b, the clock signal S11c and the output enable signal S11d in the second operation mode. Although used, complete blanks can be written at the top and bottom.

Second embodiment

Also, a second embodiment according to the present invention will be described.

3 is a block diagram illustrating an electrical configuration of a liquid crystal display according to a second exemplary embodiment of the present invention, and the same reference numerals are used for the same parts as in FIG. 1.

The liquid crystal display device is provided with a control part 21 different from the control part 11 of FIG. The control unit 21 receives an image input signal inH such as an interlaced signal of an HDTV signal whose scanning line for one vertical period is 1/2 or less than the scanning signal of the liquid crystal panel 15, and the liquid crystal panel 15 The input pulse S21b, the clock signal S21c and the output enable signal S21d are output in the first pupil mode with respect to the image display area in the vertical direction of the screen. In the first mode of operation, the scan signal circuit 14 receives the input pulse S21b, the clock signal S21 and the output enable signal S21d, and receives a plurality of signals for one horizontal period of the image input signal inH. Outputs a scanning signal.

4 is a timing diagram of each part for explaining the operation of the liquid crystal display device, in which the vertical axis represents a logic level and the horizontal axis represents time. Fig. 4 shows an operation when an interlaced signal of an HDTV in which the number of scanning lines in the image display area is 1080 and the total number of scanning lines is 1125 is written as the image input signal inH.

The operation of the second embodiment will be described different from the operation of the first embodiment.

That is, in the image display area, the control unit 21 outputs the clock signal S21c twice as the pixel data signal S13-1 to the pixel data signal S13-m in one line, and the scan signal circuit 14 ) Sequentially outputs the scan signal S14-k and the scan signal S14- (k + 1) in synchronization with the clock signal S21c. As a result, the same pixel data signal S13-1 to S13-m are written into the liquid crystal panel 15 of two lines, and the image is enlarged. At this time, the output enable signal S21d is not always in the active mode, the pulse width is made narrow, and the first writing time and the second of the pixel data signals S13-1 to S13-m are made. The pulse width for the write time is similar. Therefore, the pixel data signal S13- is avoided by slowing the rise of the pixel data signal S13-1 to the pixel data signal S13-m input to the data signal line Y1 to the data signal line Ym. The luminance difference between 1) and the pixel data signal S13-m does not occur. The other operation is similar to that of the first embodiment.

As described above, according to the second embodiment, when the control unit 21 receives an image input signal inH whose scan line of one vertical period is 1/2 or less of the scan signal line of the liquid crystal panel 15, The control unit 21 outputs the clock signal S21c twice and the scan signal circuit 14 synchronizes the scan signals S14-k to S14- (k + 1) with the clock signal S21c. By outputting, the image is enlarged and the blanking lines are written in the upper and lower portions of the image display area in a relatively simple configuration.

The present invention is not limited to the above-described embodiments, and may be changed and modified without departing from the scope and spirit of the present invention.

For example, the liquid crystal panel is not limited to the active matrix type and may be used as the passive matrix type. Further, the number of scanning lines of the image input signal, the number of scanning lines of the blanking area, the number of scanning lines of the image display area, and the number of scanning lines of the liquid crystal panel 15 can be increased or decreased as necessary. In the second embodiment, the pixel data signals S13-1 to S13-m are not limited to two times but may be written three or more times in accordance with the number of scanning lines of the liquid crystal panel 15. The display signal circuit 13 shown in Figs. 1 and 3 may directly receive the image input signal Iin and output the pixel data signal S13-1 to the pixel data signal S13-m. Further, the present invention can also be applied to an apparatus for displaying an image by supplying pixel data to a pixel region selected by a scanning signal, for example, a PDP (plasma display panel).

As described above, according to the present invention, when the number of scan signal lines of the liquid crystal panel is the same as the number of scan lines in one vertical period of the image input signal, the control unit in the first operation mode is configured to display the screen of the liquid crystal panel in the vertical direction. Input pulses, clock signals, and output command signals are output to the image display area, and in the second operation mode, input pulses, clock signals, and outputs to blanking areas of the screen where images are not displayed at the top and bottom of the screen in the vertical direction. By outputting the command signal, it is possible to write complete blanking in the upper and lower portions of the image display area without performing digital signal processing using a relatively simple liquid crystal panel using an amorphous silicon technique but using a frame memory or the like. In addition, when the controller receives an image input signal in which the number of pixels of the image input signal is 1/2 or less than the number of scanning pixels in the liquid crystal panel, the controller outputs a clock signal a plurality of times and the scanning circuit signal is scanned in synchronization with the clock signal. By outputting the signal a plurality of times, the image can be enlarged.

Claims (17)

A plurality of data signal lines for inputting pixel data signals, a plurality of scan signal lines for inputting scan signals, and a plurality of pixel regions arranged at intersections of the data signal lines and the scan signal lines, wherein A liquid crystal panel which displays an image corresponding to the pixel data signal by supplying the pixel data signal to the pixel region selected by the scan signal; A display signal circuit for transmitting the pixel data signal to the data signal line in accordance with an image input signal; A scan signal circuit which inputs the scan signal generation input pulses, moves in synchronization with a clock signal, and transmits the input pulses as the scan signals to the scan signal lines when an output command signal is input; And A control unit for inputting the image input signal and outputting the input pulse, the clock signal and the output command signal to the scan signal circuit; The control unit is further configured to, when the number of scan signal lines is greater than the number of scan lines of the image input signal with respect to a vertical period, in the first operation mode, the input pulse, for the image display area in the vertical direction of the screen of the liquid crystal panel, Outputting the clock signal and the output command signal, and outputting the input pulse, the clock signal, and the output command signal to a blanking area in which images are not displayed on the upper and lower portions of the vertical screen in the second operation mode. A liquid crystal display device, characterized in that. The method of claim 1, In the first operation mode, the scan signal circuit outputs the scan signal once in one horizontal period of the image input signal, and in the second operation mode, the scan signal circuit outputs the plurality of the scans to the blanking area. A liquid crystal display device which outputs signals simultaneously. The method of claim 1, In the first operation mode, the scan signal circuit outputs the scan signal a plurality of times in one horizontal period of the image input signal to enlarge the image, and in the second operation mode, the scan signal circuit is in the blanking area. And outputting a plurality of the scanning signals simultaneously with respect to the. The method of claim 1, And in the second operation mode, the scan signal circuit outputs the plurality of scan signals to odd and even lines separated from each of the scan signal lines. The method of claim 4, wherein In the second operation mode, the scan signal circuit inverts the polarity of the scan signals of the odd and even lines. The method of claim 1, And the liquid crystal panel is an active matrix liquid crystal panel using a thin film transistor of amorphous silicon as an active element. When the number of scan signal lines of the liquid crystal panel is larger than the number of scan lines of the image input signal with respect to the vertical period, scanning is performed once in one horizontal period of the image input signal with respect to the image display area in the vertical direction of the screen of the liquid crystal panel. And outputting a signal and simultaneously outputting a plurality of scan signals to a blanking area in which no image is displayed on the upper and lower portions of the vertical screen. The method of claim 7, wherein And outputting the plurality of scan signals by dividing the plurality of scan signals into odd and even lines with respect to the blanking area in which the image is not displayed on the upper and lower portions of the screen in the vertical direction. . The method of claim 8, And inverting the polarity of the scanning signal with respect to an odd line and an even line. When the number of scan signal lines of the liquid crystal panel is larger than the number of scan lines of the image input signal with respect to the vertical period, one horizontal of the image input signal to enlarge the image with respect to the image display area in the vertical direction of the screen of the liquid crystal panel Outputting a plurality of scan signals in a cycle, and simultaneously outputting a plurality of scan signals to a blanking area in which no image is displayed on the upper and lower portions of the vertical screen; . The method of claim 10, And outputting the plurality of scan signals by dividing the plurality of scan signals into odd and even lines with respect to the blanking area in which the image is not displayed on the upper and lower portions of the screen in the vertical direction. . The method of claim 11, And inverting the polarity of the scan signal with respect to an odd line and an even line. A plurality of data signal lines for inputting pixel data signals, a plurality of scan signal lines for inputting scan signals, and a plurality of pixel regions arranged at intersections of the data signal lines and the scan signal lines, wherein A liquid crystal panel which displays an image corresponding to the pixel data signal by supplying the pixel data signal to the pixel region selected by the scan signal; A display signal circuit for transmitting the pixel data signal to the data signal line in accordance with an image input signal; A scan signal circuit which inputs the scan signal generation input pulses, moves in synchronization with a clock signal, and transmits the input pulses as the scan signals to the scan signal lines when an output command signal is input; And A control unit for inputting the image input signal and outputting the input pulse, the clock signal and the output command signal to the scan signal circuit; If the number of the scanning signal lines is greater than the number of the scanning lines of the image input signal with respect to the vertical period, the controller may include the input pulse, for the image display section in the vertical direction of the screen of the liquid crystal panel, in the first operation mode; Outputting the clock signal and the output command signal, and outputting the input pulse, the clock signal, and the output command signal in a blanking section in which no image is displayed on the upper and lower portions of the vertical screen in the second operation mode. A liquid crystal display device, characterized in that. The method of claim 13, In the first operation mode, the scan signal circuit outputs the scan signal once in one horizontal period of the image input signal, and in the second operation mode, the scan signal circuit generates a plurality of scans for the blanking interval. A liquid crystal display device which outputs signals simultaneously. The method of claim 13, In the first operation mode, the scan signal circuit outputs the scan signal a plurality of times in one horizontal period of the image input signal to enlarge the image, and in the second operation mode, the scan signal circuit performs the blanking period. And outputting a plurality of the scanning signals simultaneously with respect to the. When the number of scanning signal lines of the liquid crystal panel is larger than the number of scanning lines of the image input signal with respect to the vertical period, scanning is performed once in one horizontal period of the image input signal with respect to the image display section in the vertical direction of the screen of the liquid crystal panel. And outputting a signal and simultaneously outputting a plurality of scan signals for a blanking section in which no image is displayed on the upper and lower portions of the vertical screen. When the number of scan signal lines of the liquid crystal panel is larger than the number of scan lines of the image input signal with respect to the vertical period, one horizontal of the image input signal to enlarge the image with respect to the image display section in the vertical direction of the screen of the liquid crystal panel Outputting a plurality of scan signals in a cycle, and simultaneously outputting a plurality of scan signals in a blanking section in which images are not displayed on the upper and lower portions of the vertical screen. .