JPH03139622A - Projection type image display device - Google Patents

Abstract

PURPOSE:To easily change the display position of an image and to simplify an adjusting stage such as convergence adjustment by providing a means for changing the position of the image displayed on the liquid crystal panel of an image display device which projects the image on plural liquid crystal panels to a screen in a horizontal direction and a vertical direction on the display panel. CONSTITUTION:The means for changing the position of the image displayed on the liquid crystal panel 1 of the image display device which projects the image displayed on the plural liquid crystal panels 1 to the screen in the horizontal and vertical directions on the display panel is provided. Namely, a gate timing signal and a source timing signal are inputted in a gate driver 2 and a source driver 3 by changing the positions of the signals by means of a gate timing signal movement circuit 4 and a source timing signal movement circuit 6. Since scanning start timing in the vertical and horizontal directions is moved in the liquid crystal panel 1, the displayed image can be moved in the vertical and horizontal directions. Thus, the convergence adjustment of the projection type image display device is facilitated and the adjusting stage is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image display device that projects images displayed on a plurality of liquid crystal panels onto a screen.

2. Description of the Related Art In recent years, as video equipment such as video tape recorders and video software have become more available, the demand for large-screen image display devices for enjoying powerful images has increased.

As a conventional large-screen image display device, the cathode ray tube (
There was a projection type television that used a CRT (CRT), but since the CRT was used for the image display section, there were restrictions on miniaturization of the device due to the physical limitations of the CRT. In order to eliminate this limitation and make the device more compact, a projection type image display device using a liquid crystal panel in the image display section has been proposed.

Generally, a projection type image display device using a liquid crystal panel uses three liquid crystal panels for red, green, and blue to obtain a color image. Therefore, it is necessary to perform convergence adjustment to match the images of the three liquid crystal panels on the screen.

FIG. 3 shows a configuration diagram of an example of a conventional projection type image display device using a liquid crystal panel.

In FIG. 3, 51 is a screen, 52 is a projection lens, 53 is a red liquid crystal panel, 54 is a green liquid crystal panel, 55 is a blue liquid crystal panel, 56 is a guichroic prism for color synthesis, and 57 is a mirror, 58 is a gicroic mirror for color separation, 59 is a condensing lens, 60 is a light source, and 6] is a reflecting mirror. The light from the light source 6o is reflected by the reflecting mirror 6.
1 and a condenser lens 59, and is separated by a dichroic mirror 58 into red, green, and blue primary color lights. Each primary color light is guided to a liquid crystal panel by a mirror 57 or the like, combined by a guichroic prism 56, and then projected onto a screen 5I by a projection lens 52. LCD panel for red, green, and blue 53.54.5
Convergence adjustment for combining the optical images displayed on the screen 51 on the screen 51 is performed using a liquid crystal panel support means (not shown) while viewing the image projected on the screen 5.
Previously, the LCD panel was installed mechanically by adjusting its position by turning adjustment screws attached to the screen.

Problems to be Solved by the Invention However, conventional mechanical convergence adjustment has a problem in that when the liquid crystal panel is fixed after adjustment is completed, the liquid crystal panel tends to move easily, resulting in the need to perform adjustment again.

The present invention has been made in view of this point, and an object of the present invention is to provide a projection type image display device in which convergence adjustment is easy.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a method for adjusting the position of images displayed on liquid crystal panels of an image display device that projects images displayed on a plurality of liquid crystal panels onto a screen. The device is configured to include means for moving it horizontally and vertically on the liquid crystal panel.

Effects According to the present invention, with the above-described configuration, convergence adjustment of a projection type image display device using a plurality of liquid crystal panels can be easily performed, and the adjustment process can be simplified.

Embodiment Hereinafter, a projection type image cover device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a projection type image display device according to an embodiment of the present invention. Since each of the three liquid crystal panels has the same configuration, FIG. 1 shows the configuration of one liquid crystal panel. In FIG. 1, l is a liquid crystal panel, 2 is a gate driver for driving the liquid crystal panel 1, 3 is a source driver for driving the liquid crystal panel 1, and 4 is a gate timing for changing the operation timing of the gate driver 2. 5 is a gate timing signal movement amount setting circuit for setting the movement amount of the gate timing signal; 6 is a source timing signal movement circuit for changing the operation timing of the source driver 3; 7 is a source timing signal movement circuit; This is a source timing signal movement amount setting circuit for setting the amount. 1st
As shown in the figure, the gate timing signal and the source timing signal are input to the gate driver 2 and the source driver 3 after changing their positions by a gate timing signal moving circuit 4 and a source timing signal moving circuit 6, respectively. As a result, the scan start timings of the liquid crystal panel 1 in the vertical direction and the horizontal direction are moved, so that the displayed image can be moved in the vertical direction and the horizontal direction.

FIG. 2 is a timing diagram for explaining the timing of the source timing signal. FIG. 2(a) shows a video signal during one horizontal scanning period, and the period BB is the valid period of the video signal. The source timing signal that determines the timing to start scanning in the horizontal direction is normally generated at point A, which is slightly delayed from the starting point of the effective video signal, taking into consideration the amount of overscan, as shown in FIG. 2(b). If this source timing signal is delayed from the original source timing signal by the source timing shift circuit 6 as shown in FIG. image is displayed, and the displayed image can be moved to the left. The source timing shift circuit 6 can be easily configured using a counter circuit or the like.

Although the movement in the horizontal direction has been described in FIG. 2, the display position of the image can be moved in the same manner in the vertical direction.

In this way, by making it possible to move the image display position on each LCD panel in the horizontal and vertical directions,
There is no need to strictly perform mechanical convergence adjustment of the liquid crystal panel, and the adjustment process can be simplified.

Effects of the Invention As described above, the present invention provides an image display device that projects images displayed on a plurality of liquid crystal panels onto a screen, by adjusting the position of the image displayed on the liquid crystal panels in the horizontal direction on the liquid crystal panel. By configuring the image display device to include means for moving the image in the vertical direction, it is possible to easily change the display position of the image, and it is possible to simplify adjustment processes such as convergence adjustment.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a projection type image display device according to an embodiment of the present invention, FIG. 2 is a timing diagram for explaining timing in the horizontal scanning direction, and FIG. 3 is a configuration of a conventional projection type image display device. FIG. 1...Liquid crystal panel, 2...Gate driver 3...Source driver, 4...
- Gate timing signal movement circuit, 5... Gate timing signal movement amount setting circuit, 6... Source timing signal movement circuit, 7... Source timing signal movement amount setting circuit.

Claims (1)

[Claims] (1) An image display device that projects images displayed on a plurality of liquid crystal panels onto a screen, wherein the position of the image displayed on the liquid crystal panels is set in at least one of the horizontal and vertical directions on the liquid crystal panels. 1. A projection type image display device comprising means for moving in one direction.