JP2646774B2 - Convergence device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention is particularly useful for adjusting the convergence of R, G, B of a projection type cathode ray tube (hereinafter abbreviated as CRT) for any of various video signal systems. The present invention relates to a convergence device intended to be performed without any problem.

2. Description of the Related Art Video projectors and high-definition direct-view television receivers combine three beams (R, G, B) into one screen.
Requires convergence adjustment. Recently, convergence adjustment has also been changed from analog to digital, and the accuracy has been dramatically improved.

Further, a function as a display is required to be capable of receiving several types of sources (for example, NTSC, double-density NTSC, PAL, Hi-Vision, computer, etc.) having different video signal systems.

For that purpose, the convergence correction data is stored in the memory for each source, the video signal type is determined, the convergence data is read out from the memory according to the data signal, and the convergence is corrected to obtain the optimum image quality. You can do it.

FIG. 2 shows a conventional convergence device. In FIG. 2, there is a video signal input, and the signals of the various types described above are selectively output by the signal switching circuit 2, and the output is sent to the signal processing circuit 3 and the synchronization signal frequency detection circuit 5, and the detection circuit 5 The frequency of the horizontal and vertical synchronizing signals is measured from the signal of each system, and the system of the signal is determined. For example, in the case of the NTS system, the horizontal frequency is 15.734 KHz and the vertical frequency is 60 Hz,
The SC system has a horizontal frequency of about 31.5 KHz and a vertical frequency of 60 Hz, and it is determined which of the horizontal and vertical frequencies is used. The result of the determination is sent to the deflection circuit 6 and the microprocessor 7. The deflecting circuit 6 switches constants according to the signals of each system, and outputs an optimal deflecting waveform. Further, the microprocessor 7 reads convergence data corresponding to each system from a first memory, for example, an EEP-ROM 9, processes the data, sends it to a second memory, for example, a RAM 8, and sends the data to the D / A of the block 10. The signal is sent to the converter and amplified to be sent to the dynamic convergence and static convergence coils, and the CRTs 11, 12, and 13 are corrected.

The above operation is performed when a normal video signal is received.
However, when the video projector is first installed, it is necessary to write convergence data in the first memory 9. For this operation, a test pattern is first displayed on the screen, and the convergence of the R, G, and B CRTs 11, 12, and 13 is adjusted by the controller 4. After adjusting one signal system, a signal of the next system is selected and performed by the signal switching circuit 2. Here, the relationship between the first memory 9 and the second memory 8 is that the second memory 8 rewrites data during adjustment. When the adjustment is completed, the first memory 9 containing the old data is cleared, and the contents of the second memory 8 are written to the first memory 9 and stored. If the input signal is switched to a signal of a different system during adjustment, or the signal is interrupted due to dropout, the synchronous signal frequency detection circuit 5 performs the detection operation in the conventional device, and the deflection circuit 6 and the second convergence signal are detected. Of the data being adjusted is stored in the memory 8 of the first memory 9, but the data of the new signaling method is read out from the first memory 9 and written in the second memory 8, and the adjusted data is erased.

Problems to be Solved by the Invention As described above, conventionally, there has been a problem that when a signal of a different system is input during convergence adjustment, or when the signal is interrupted, the data being adjusted is erased.

The present invention solves the above problems, and when the signal changes or disappears during the adjustment, the cause is displayed on the display, the adjustment data is held, and the signal of the original system is input again. It is intended to provide a device which displays the time when the adjustment has been made so that the adjustment can be intermittently performed.

Means for Solving the Problems In order to solve the above problems, a convergence device of the present invention extracts a synchronization signal from a signal output from a video signal switching circuit, and extracts a video signal from the obtained horizontal synchronization signal and vertical synchronization signal. It has a detection circuit for discriminating the signal system, uses the detection output to control the deflection waveform of the deflection circuit, takes in the video system discrimination output to the microprocessor, reads convergence data corresponding to the video system from the first memory, The data is processed by the microprocessor and transferred to the second memory, and the D / A is transferred from the second memory.
In the device that transfers to the converter, increases the width, and drives the convergence coil, during convergence adjustment,
The first and second memories keep the convergence data unchanged even when the system of the input video signal changes and the system determination output changes, and display means for indicating that the system of the video signal has changed is provided. The display means has a display function of indicating that the video signal has returned to the format of the video signal before the change.

Function The present invention is also applicable when a signal of a different system is switched and input during convergence adjustment, or when the signal is cut off.
The convergence data being adjusted until then is retained,
To provide a convergence device that indicates that a signal has changed and that indicates that the signal has been restored, and that does not erroneously adjust convergence in another signal mode. Can be done.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a convergence device according to an embodiment of the present invention. In FIG. 1, the microprocessor 7 keeps the data in the RAM 8 as it is, even if the detection circuit 5 detects that the input video signal is switched during the adjustment by the controller 4 and the detection circuit 5 detects that. I am trying to do it. Then, the fact is displayed on the CRTs 11, 12, and 13 through the screen display circuit 14.

In the above configuration, when a video is switched to a signal of a different system or no signal is received during image reception, the same operation as in the related art is performed.

A mode during convergence adjustment which is a feature of the present invention will be described.

In the first video signal mode, the first video signal is output from the signal switching circuit 2. The convergence is adjusted by the controller 4 and the data in the second memory (RAM) 8 is rewritten.

At that time, when a second video signal having a different video signal format is input from the same cable, the synchronization signal frequency detection circuit 5 and the deflection circuit 6 enter the second video signal mode as in the conventional case. However, here the microprocessor 7 operates as follows.

The RAM data of the second memory 8 is held as it is.

Next, the fact that the format of the video signal has changed from the first video signal to the second video signal is passed through the screen display circuit 14 and the signal processing circuit 3 to the CRTs 11, 12, and 13, for example, "NTSC → PAL". indicate.

Next, when the format of the video signal returns to the first video signal, the video signal is passed through the screen display circuit 14 and the signal processing circuit 3 again, and for example, the fact is displayed on the CRTs 11, 12, and 13 as "NTSC ←". I do.

On the other hand, when the video signal does not return to the first video signal, the adjuster cancels the data being adjusted stored in the second memory 8 from the controller 4, and cancels the second data stored in the first memory 9. The data in the storage area for the video signal is transferred to the second memory 8. If the convergence data of the second video signal has already been stored in the storage area, the data is read out, subjected to D / A and amplification processing, and applied to the convergence coil.

Next, the display on the CRTs 11 to 13 is set to, for example, “PAL ←”.

As described above, in such a configuration, while the convergence data of a certain video signal is being adjusted by the controller 4, the input video signal is suddenly switched to another video signal,
The microprocessor 7, which recognizes that the adjustment is being performed, retains the RAM data of the second memory 8 as it is, so that the adjustment up to that point is not wasted.
When the input video signal returns to the original first video signal, the convergence data of the first video signal can be continuously adjusted. Further, when the input video signal changes, the fact is displayed on the CRTs 11 to 13, so that there is an advantage that the adjuster can immediately understand that fact.

Effect of the Invention As described above, according to the present invention, even if the input video signal is unexpectedly switched or becomes no signal during the adjustment of the converter convergence, the convergence data of the video signal that has been adjusted up to that point is retained. There is no waste of adjustment time. In addition, by displaying how the video signal has changed, and seeing this display, the video signal can be returned to the original state, thereby eliminating erroneous operations. Therefore, even if various video signal systems appear in the future, convergence adjustment corresponding to each system can be performed without error.

[Brief description of the drawings]

FIG. 1 is a block diagram of a convergence device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a convergence device of a conventional example. DESCRIPTION OF SYMBOLS 1 ... Video signal, 2 ... Video signal switching circuit, 3 ... Video signal processing circuit, 4 ... Controller, 5 ... Synchronous signal frequency detection circuit, 6 ... Deflection circuit, 7 ... Microprocessor, 8 ... ... second memory (RAM), 9 ... first memory (ROM), 10 ... D / A converter and amplifier for convergence, 11 to 13 ... CRT, 14 ... screen display circuit.

Claims (1)

(57) [Claims] 1. A detecting means for determining a system from a synchronization signal of an input video signal, a microprocessor for outputting a control signal for convergence adjustment based on an output signal of the detecting means, and a convergence corresponding to the video signal system. A first memory for holding data, a second memory for adjusting convergence of a video signal being input by a signal from the microprocessor, and a convergence coil for performing D / A conversion of a signal from the second memory And a display means for displaying a change in the format of the input video signal on a screen, wherein the microprocessor adjusts to the second memory when the format of the input video signal changes. Outputs a control signal for holding the convergence data that has been in the middle or is being adjusted in the second memory. And outputting a control signal for transferring the convergence data for the video signal newly input to the first memory to the second memory. Convergence device.