JP2601417Y2 - Optical system adjustment circuit for projection type LCD TV - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system adjustment circuit for a projection type liquid crystal television, and more particularly to an optical system adjustment circuit for a projection type liquid crystal television having a simple structure. 2. Description of the Related Art A red, green and blue video signal extracted from a video signal is supplied to a liquid crystal (LCD) assembly for red, green and blue video signals. In a projection type liquid crystal television that projects an image on a display surface via a mirror, adjustment of an optical system such as a mirror has a large effect on the image quality of a projected image. FIG. 3 is a block diagram showing a configuration example of a conventional projection type liquid crystal television. The video signal V is a sync separation circuit 1
Thus, the vertical synchronizing signal V0 and the horizontal synchronizing signal H0 are separated and output. As is well known, the vertical timing adjustment circuit 2 performs vertical timing adjustment by appropriate means on the basis of the vertical synchronization signal from the synchronization separation circuit 1, and the vertical synchronization signal after the vertical timing adjustment is applied to the red liquid crystal assembly 7, It is supplied to the green liquid crystal assembly 8 and the blue liquid crystal assembly 9. A horizontal timing adjustment circuit 3 for red, a horizontal timing adjustment circuit 4 for green, and a horizontal timing adjustment circuit 5 for blue
Performs the same timing adjustment based on the horizontal synchronization signal H0 from the synchronization separation circuit 1 and supplies the same to the red liquid crystal assembly 7, the green liquid crystal assembly 8, and the blue liquid crystal assembly 9. The decoder / liquid crystal drive circuit 6 decodes the video signal V to generate a red video signal VR, a green video signal VG, and a blue video signal VB, and outputs the corresponding red liquid crystal assembly 7, green liquid crystal assembly 8, and blue liquid crystal. The image is supplied to the assembly 9 to reproduce the image. The reproduction is performed after adjusting an optical system component such as a mirror provided for each liquid crystal assembly to set it to an optimum state. Conventionally, the adjustment of the optical system components such as mirrors is performed by disconnecting the normal reproduction circuit system and supplying an adjustment liquid crystal control signal generated by another external circuit (such as a jig circuit) to each LCD assembly. Mirror adjustment. Also, the liquid crystal control signal generated in the projection type liquid crystal television is adjusted to an adjustment signal, and an optical system such as a mirror is adjusted. As described above, the adjustment of the optical system of the conventional projection type liquid crystal television is performed by adjusting the adjustment system from a jig circuit such as an adjustment control signal generating means provided separately. Since the adjustment is performed using signals, not only is the configuration complicated due to the addition of the hardware configuration not only a problem, but also a problem arises in that it must be readjusted to the original state after the adjustment is completed. Therefore, an object of the present invention is to provide an optical system adjustment circuit of a projection type liquid crystal television which makes it possible to adjust an optical system component such as a mirror very easily and does not require readjustment. In order to solve the above-mentioned problems, an optical system adjusting circuit of a projection type liquid crystal television according to the present invention comprises a vertical synchronizing signal, a horizontal synchronizing signal, and a liquid crystal assembly for red, green and blue. Supply test pattern signal including signal,
In an optical system adjustment circuit of a projection type liquid crystal television for adjusting an optical system such as a mirror, the same vertical synchronization signal and horizontal synchronization signal are switched and supplied to the red, green and blue liquid crystal assemblies during the optical system adjustment. It comprises a switch. In order to solve the above-mentioned problems, the optical system adjustment circuit of the projection type liquid crystal television according to the present invention comprises a liquid crystal assembly for red, green and blue, and a synchronization separation circuit for separating and outputting a horizontal synchronization signal from an input signal. Selecting a synchronization timing adjustment circuit provided for each of red, green and blue for adjusting and outputting synchronization timing from the horizontal synchronization signal, and selecting a test pattern signal including the input signal, a vertical synchronization signal and a horizontal synchronization signal. In an optical system adjustment circuit of a projection type liquid crystal television for adjusting an optical system such as a mirror of a projection type liquid crystal television having an input signal selection means to be supplied, the test pattern is selectively supplied by the input signal selection means at the time of optical system adjustment. And means for passing through the synchronization timing adjustment circuit. Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an optical system adjusting circuit of a projection type liquid crystal television according to the present invention. In FIG. 1, components denoted by the same reference numerals as those in FIG. 2 indicate components having the same functions as those in FIG. At the time of optical system adjustment, a video signal generated from the video test signal generator 10 is sent to the sync separation circuit 1 and the decoder / liquid crystal drive circuit 6. The decoder / liquid crystal drive circuit 6 generates a red video signal VR, a green video signal VG and a blue video signal VB in the same manner as in FIG. Supplied. On the other hand, the vertical synchronization signal V0 and the horizontal synchronization signal H0 separated by the synchronization separation circuit 1 are
The signals are supplied to the vertical timing adjustment circuit 2 and the horizontal timing adjustment circuits 3, 4, and 5 for red, green, and blue, respectively.
Similarly, the vertical timing and the horizontal timing are adjusted. The signals adjusted in timing by the vertical timing adjustment circuit 2 are supplied to liquid crystal assemblies 7, 8, and 9 for red, green, and blue. The signals adjusted by the horizontal timing adjustment circuit 3 for red, the horizontal timing adjustment circuit 4 for green, and the horizontal timing adjustment circuit 5 for blue are supplied to the input terminals B of the changeover switches 11, 12 and 13.
Is supplied to The horizontal synchronization signal H0 separated from the synchronization separation circuit 1 is supplied to the input terminals A of the switches 11 to 13.
Is supplied to The changeover switches 11 to 13 selectively output the input to the input terminal A by receiving the changeover signal S generated at the time of adjusting the optical system. The switches 11 to 13 selectively output the input terminal B to the red, green and blue liquid crystal assemblies 7, 8, and 9 except during the adjustment of the optical system, that is, at the time of video reproduction and mapping. That is, when the switching signal S is "L",
It is in the state of use as a television, and the changeover switches 11 to 1
The signal HR from the red, green and blue horizontal timing adjustment circuits provided exclusively for each of the input terminals B is supplied to the red, green and blue liquid crystal assemblies and supplied from the decoder / liquid crystal drive circuit 6. The video signal is displayed and projected via the mirror. Next, when adjusting an optical system such as a mirror, the switching signal S is set to “H”, and signals from the input terminals A of the switches 11 to 13 are supplied to each liquid crystal assembly. Since the horizontal synchronizing signals supplied to the input terminal A are the same signal, they have the same horizontal synchronizing timing supplied to the red, green and blue liquid crystal assemblies 7 to 9, so that the operation timing of each liquid crystal assembly is shifted. This does not occur, and adjustment of the optical system such as a mirror is facilitated. FIG. 2 shows another embodiment of the optical system adjusting circuit of the projection type liquid crystal television according to the present invention. In this embodiment, a test pattern generator 14 for generating a test pattern signal for adjusting an optical system of a projection type liquid crystal television is built in, and a changeover switch 15 switches and outputs a normal video signal. 2, the same reference numerals as those in FIG. 1 denote the same components. According to this embodiment, since the video test signal (test pattern signal) necessary for the adjustment is generated internally, the adjustment can be performed by the projection type liquid crystal television alone. As described above, according to the optical system adjusting circuit of the projection type liquid crystal television according to the present invention, at the time of adjusting the optical system, the synchronization timing adjustment provided exclusively for red, green and blue is performed. Since the same synchronization timing signal is supplied to the red, green and blue liquid crystal assemblies without passing through the circuit, the optical system adjustment can be performed easily and accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an optical system adjustment circuit of a projection type liquid crystal television according to the present invention. FIG. 2 is a block diagram showing another embodiment of the optical system adjusting circuit of the projection type liquid crystal television according to the present invention. FIG. 3 is a configuration diagram of a conventional projection type liquid crystal television. [Description of Signs] 1 Sync separation circuit 2 Vertical timing adjustment circuit 3 Horizontal timing circuit for red 4 Horizontal timing circuit for green 5 Horizontal timing circuit for blue 6 Decoder / liquid crystal drive circuit 7 Liquid crystal assembly for red 8 Liquid crystal assembly for green 9 Blue LCD assemblies 10 and 14 Test pattern signal generators 11 to 13 and 15

Claims (1)

(57) [Claims for utility model registration] Liquid crystal assemblies for red, green and blue, a sync separation circuit for separating and outputting a horizontal synchronization signal from an input signal, and adjusting and outputting a synchronization timing from the horizontal synchronization signal Synchronization timing adjustment circuits provided for red, green, and blue, respectively;
An optical system adjustment circuit for a projection type liquid crystal television for adjusting an optical system such as a mirror of a projection type liquid crystal television having input signal selection means for selectively supplying the input signal and a test pattern signal including a vertical synchronization signal and a horizontal synchronization signal. 5. The optical system adjusting circuit for a projection type liquid crystal television according to claim 1, further comprising: a means for selecting and supplying said test pattern by said input signal selecting means at the time of adjusting the optical system and passing through said synchronous timing adjusting circuit.