JPH04292087A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain the liquid crystal display device with large screen with inconspicuous boundaries by using four sheets of liquid crystal panels. CONSTITUTION:Four sheets of unit liquid crystal display devices A to D are formed by connecting horizontal driving parts 3, 9, 17, and 21 to one horizontal direction edge part and vertical driving parts 5, 11, 15, and 23 to one vertical direction edge part in respective liquid crystal panels 1, 7, 13, and 19. One sheet of rectangular-shaped liquid crystal panel is formed by connecting unconnected edges of horizontal driving parts 3, 9, 17, and 21 and vertical driving parts 5, 11, 15, and 23 of these unite liquid crystal display devices A to D with each other.

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 that can easily provide a large screen.

0002

[Prior Art] Generally, in a liquid crystal display device, a horizontal drive unit that outputs a video signal according to the number of horizontal pixels of a rectangular liquid crystal panel is connected to both horizontal ends of the liquid crystal panel, and A vertical drive section is connected to each side to output a line drive signal corresponding to the number of vertical lines, and a sampled and held video signal for one line is output from the horizontal drive section to each pixel in the horizontal direction. Each vertical line is sequentially switched to an active state by a vertical drive unit, and transmitted light from the backlight is controlled intermittently for each pixel, thereby reproducing an image. The resolution of the reproduced image of the liquid crystal display device depends on the number of vertical and horizontal pixels of the liquid crystal panel.

0003

[Problem to be Solved by the Invention] However, if the size of individual liquid crystal display devices is increased, the yield decreases, so in order to obtain a large screen, it is necessary to connect liquid crystal display devices of a certain size vertically and horizontally. Therefore, there is a problem in that the boundaries between adjacent liquid crystal display devices become noticeable and the image quality is degraded. The present invention has been made to solve these conventional drawbacks. Even when a large screen is formed by connecting multiple liquid crystal display devices, the boundaries between adjacent liquid crystal display devices are difficult to stand out, and the image quality is improved. The purpose of the present invention is to provide a liquid crystal display device that does not cause a decrease in the quality.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the liquid crystal display device of the present invention comprises a plurality of unit liquid crystals each having horizontal and vertical drive sections on two adjacent sides of a rectangular liquid crystal display panel. It is formed by combining display devices, with the sides of the display devices that are not provided with the drive unit being joined together. In the present invention, at least one switching circuit for selecting a drive signal is provided.
It can be configured such that it is connected to a driving section of one unit liquid crystal display device, and a driving signal is input to the driving section via the switching circuit.

[0005]

[Operation] In the present invention equipped with such means, for example, 4
When unit liquid crystal display devices are combined into a rectangular shape, the horizontal driving parts of the unit liquid crystal display devices located in the horizontal direction are connected in series, and the vertical driving parts of the unit liquid crystal display devices located in the vertical direction are connected in series. One large liquid crystal display panel can be regenerated and driven by four unit liquid crystal display devices. In a configuration in which a switching circuit is connected to a driving section of a unit liquid crystal display device, a specific unit liquid crystal display device is driven via the switching circuit with a drive signal different from that of other unit liquid crystal display devices.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a liquid crystal display device according to the present invention. In FIG. 1, a liquid crystal panel 1 is a conventionally known TFT type having pixels X1 to XM in the horizontal direction and lines Y1 to YR in the vertical direction. A horizontal drive section 3 is connected to one end, and a vertical drive section 5 is connected to one end in the vertical direction, forming a unit liquid crystal display device A. The liquid crystal panel 7 has XM+1 to XN pixels in the horizontal direction and Y1 to YR lines in the vertical direction. A vertical drive unit 11 is connected to the end side of the unit liquid crystal display device B, and a unit liquid crystal display device B is formed.

The liquid crystal panel 13 has X1 to XM pixels in the horizontal direction and YR+1 to YL lines in the vertical direction.
A horizontal drive unit 17 is connected to one end in the horizontal direction among the sides, and a vertical drive unit 15 is connected to one end in the vertical direction, forming a unit liquid crystal display device C. The liquid crystal panel 19 has XM+1 to XN pixels in the horizontal direction and YR+1 to YL lines in the vertical direction. A vertical drive unit 23 is connected to the end side of the unit liquid crystal display device D, and a unit liquid crystal display device D is formed.

These unit liquid crystal display devices A to D have horizontal drive sections 3, 9, 1 for liquid crystal panels 1, 7, 13, 19.
7 and 21 and vertical drive units 5, 11, 15, and 23, adjacent unconnected sides are connected to form one rectangular liquid crystal display device. Horizontal drive section 3, 9, 17, 21
inputs a drive signal consisting of an RGB video signal and a timing signal, which will be described later, and samples and holds the number of pixels from X1 to XM or the number of pixels from XM+1 to XN corresponding to half of one horizontal line. It outputs a video signal for each pixel to liquid crystal panels 1, 7, 13, and 19, and horizontal drive units 3 and 9, 17, and 21 are connected in series. That is, as shown in FIG.
9, 17 and 19 drive one horizontal line.

The vertical drive units 5, 11, 15, and 23 input drive signals consisting of timing signals, and drive the Y1 to YR lines and YR lines of the liquid crystal panels 1, 7, 13, and 19 every horizontal line.
The R+1YL line is switched to become active, and vertical drive units 5 and 11, and 15 and 23 are connected in series. Note that the horizontal drive units 9 and 21 and the vertical drive unit 15
, 23 can be driven by inputting drive signals independently.

FIG. 3 is a block diagram showing a signal supply circuit for driving the above-described liquid crystal display device of the present invention. The RGB video signal for the main screen is connected to a signal inversion circuit 25, and the synchronization signal HV is connected to a timing signal generation circuit 27. The timing signal generation circuit 27 generates a horizontal timing signal as a horizontal start pulse or horizontal shift clock from the synchronization signal H, and a vertical timing signal as a vertical start pulse or vertical shift clock from the horizontal synchronization signal H and vertical synchronization signal V in the synchronization signal. Switch SW2, SW
4, output to one of the fixed terminals of SW6 and SW8.

Incidentally, since the horizontal and vertical timing signal systems can be illustrated in substantially the same way, the illustration of the vertical timing signal system is omitted in FIG. 3 in order to make the diagram easier to read, and will also be omitted in the following description. The signal inversion circuit 25 inverts the video signal line by line or field by field according to the horizontal or vertical timing signal from the timing signal generation circuit 27, and outputs it to one fixed terminal of the switches SW1, SW3, SW5, and SW7. . Among the RGB video signal and synchronization signal HV for the child screen, for example, the video signal and synchronization signal HV for picture-in-picture display,
The video signal is connected to a filter 29, and the synchronization signal HV is connected to a timing signal generation circuit 31.

The filter 29 appropriately thins out the video signal in one horizontal line to a data amount suitable for display, is formed by a two-dimensional filter or a one-dimensional filter, and is connected to the signal inversion circuit 33. The timing signal generation circuit 31 generates a horizontal timing signal as a horizontal start pulse or horizontal shift clock from the horizontal synchronization signal H in the synchronization signal, and generates a vertical start pulse or vertical shift clock from the horizontal synchronization signal H and vertical synchronization signal V in the synchronization signal. The vertical timing signals of switches SW2, SW4, SW6,
It is output to the other fixed terminal of SW8.

Similar to the signal inversion circuit 25, the signal inversion circuit 33 inverts the video signal using the horizontal or vertical timing signal from the timing signal generation circuit 27, and outputs it to the other fixed terminals of the switches SW1, SW3, SW5, and SW7. It is something to do. The movable terminals of the switches SW1 to SW8 are connected to the horizontal drive units 3, 9, 17, and 21 in FIG. For the vertical system, these horizontal drive units 3, 9, 17
, 21 may be replaced with vertical drive units 5, 11, 15, and 23. The switches SW1 to SW8 are operated at once or individually by changeover switches arranged on the operation panel of, for example, a television receiver to which the liquid crystal display device of the present invention is connected.

Next, the operation of the above-mentioned liquid crystal display device will be explained. First, a case will be described in which the switches SW1 to SW8 in FIG. 3 select the main screen signal. In this state,
The video signal is inverted line by line or field by field in the signal inversion circuit 25, and switches SW1, SW3, SW5, SW
7 to the horizontal drives 3, 9, 17, 21,
The synchronization signal HV is converted into a horizontal timing signal by the timing signal generation circuit 27, and the switches SW2, SW4, and S
It is applied to the horizontal drive units 3, 9, 17, and 21 via W6 and SW8. Therefore, unit liquid crystal display devices A to D in FIG.
In this case, the horizontal drive units 3 and 9, 17 and 21 become the drive units for one horizontal line in FIG. 2, and the vertical drive units 5 and 15, 11 and 2
3 is a drive unit for one field of vertical lines, and liquid crystal panels 1, 7, 13, and 19 function as one liquid crystal panel to display images.

Next, a case will be described in which one of the switches SW1 to SW8 in FIG. 3, for example, switches SW7 and SW8, selects a signal for a small screen. In this state, switch SW1
As for ~SW6, as described above, the drive signal for the main screen is applied to the horizontal drive sections 3, 9, and 17, and the main screen is displayed on the unit liquid crystal display devices A to C. On the other hand, the video signal for the child screen is subjected to signal thinning processing by the filter 29, inverted line by line or field by field by the signal inverting circuit 33, and applied to the horizontal drive unit 21 via the switch SW7, and the synchronizing signal HV is a timing signal. It is converted into a horizontal timing signal by the generation circuit 31 and sent to the horizontal drive unit 2 via the switch SW8.
1, the sub-screen is displayed as an image on the unit liquid crystal display device D. Therefore, the child screen is displayed in a picture-in-picture manner within the main screen. Switch SW1~S
If one switch SW1 to SW8 of W8 is switched relative to the other switches SW1 to SW8, picture-in-picture display can be performed on any unit liquid crystal display device A to D. By switching all the switches SW1 to SW8, it is possible to switch from the main screen to the child screen.

As described above, in the liquid crystal display device of the present invention, the screen size can be doubled by combining four unit liquid crystal display devices A to D, and the driving units can be arranged on two adjacent sides. Since the sides of the unit liquid crystal display devices A to D on which the drive unit is not arranged are connected, the adjacent liquid crystal display panels 1
, 7, 13, and 19 become less noticeable, improving image quality. Moreover, it is not necessary to increase the number of pixels of each liquid crystal display panel 1, 7, 13, 19 in order to enlarge the display screen.
The manufacturing yield of No. 3 and No. 19 is good, and the price does not increase.

Further, in the present invention, since each unit liquid crystal display device A to D can be driven independently, the switch SW1
~If you configure the configuration to switch with SW8, picture-in
In addition to picture display, it is also possible to display individual images on the four display screens, and picture-in-picture display is possible without using field memory, unlike display devices using CRTs, so the configuration does not become complicated. . In addition, in the embodiment of the present invention described above, four unit liquid crystal display devices A to D are used.
However, the object of the present invention can also be achieved by using two or more unit liquid crystal display devices. However, if four liquid crystal display panels 1, 7, 13, and 19 used in a conventional liquid crystal television receiver are used, a good image can be obtained without changing the aspect ratio.

[0018]

As explained above, the liquid crystal display device of the present invention comprises a plurality of unit liquid crystal display devices in which horizontal and vertical drive sections are provided on two adjacent sides of a rectangular liquid crystal display panel. Since the sides that are not provided are formed together, even if a plurality of liquid crystal display devices are connected to form a large screen, the boundaries between the liquid crystal display panels of adjacent liquid crystal display devices are less noticeable, and the image quality is improved. In addition, in a configuration in which a switching circuit for selecting a drive signal is connected to the drive unit of a unit liquid crystal display device, it is possible to apply a specific drive signal to a specific unit liquid crystal display device via the switching circuit, making it possible to easily display pictures.・In-picture images can be obtained.

[Brief explanation of the drawing]

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

FIG. 2 is a video signal waveform diagram illustrating one horizontal line driven by the horizontal drive section of FIG. 1;

FIG. 3 is a block diagram showing a signal supply circuit for operating the liquid crystal display device of the present invention.

[Explanation of symbols]

1, 7, 13, 19 liquid crystal display panel 3, 9, 17,
21 Horizontal drive sections 5, 11, 15, 23 Vertical drive sections 25, 33 Signal inversion circuits 27, 31 Timing signal generation circuit 29 Filters A, B, C, D Unit liquid crystal display devices SW1, SW2, SW3, SW4, SW5, SW6, S
W7, SW8 switch

Claims (2)

[Claims] 1. A plurality of unit liquid crystal display devices each having horizontal and vertical driving sections on two adjacent sides of a rectangular liquid crystal display panel are formed by combining the sides on which the driving sections are not provided. Characteristic liquid crystal display device. 2. A switching circuit for selecting a driving signal is connected to the driving section of at least one of the unit liquid crystal display devices, and the driving signal is input to the driving section via the switching circuit. The liquid crystal display device described.