JPS6126752B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a phase shift synchronization signal generation device, especially when output signals from a plurality of industrial television cameras are used in a time-division manner, to eliminate waiting time when using the same detection point. The present invention relates to a phase shift synchronization signal generator.

An example of a conventional synchronization signal generation system for a plurality of industrial television cameras (hereinafter referred to as ITV cameras) is shown in FIGS. 1a and 1b. In the figure, 1 is detected
ITV camera, 2 is a synchronization signal generator, 3 is a clock generator, 4 is a multiplexer, 5 is an input processing device, and 6 is a synchronization signal distributor. Further, 13 is a clock signal, 14 is a synchronization signal, 15 is a camera detection signal, and 21 is a multiplexer output signal. Now, in FIG. 1A, a plurality of synchronization signal generators 2 are provided, but the synchronization signals have no correlation with each other. On the other hand, in FIG. 1b, one synchronization signal generator 2 is used, and the synchronization signal is detected by each
Although it is distributed to the ITV camera 1 and the cost is low, each camera system has exactly the same synchronization relationship, and when using the same detection point in time-sharing, waiting time occurs.
That is, FIG. 2 shows the detection signal input timing in the configuration of FIG. 1b, and 31, 32
33 is a detection signal (i-th scanning line) by detection camera No. 1, 34 is a detection signal (i-th scanning line) by detection camera No. 2, 35 is a multiplexer output signal, 36 is a vertical synchronization signal (VS), 37 is a horizontal synchronization signal (HS), 38 is a detected white pattern, 3
9 is the detected background screen (assumed to be black level). As shown in Figure 2, for example, even if you try to switch and input signals from two cameras at the same location on each detection screen using one input device, the input signal from one of the cameras will be input to the next one. You will have to wait until the screen (field or frame) appears. This means that when high-speed processing is performed one screen at a time, one of the detection systems and input processing system will waste one screen completely, extending the overall detection processing time. It will have drawbacks.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, reduce the cost of the entire system by integrating the input device system from the camera, and eliminate the waiting time for use when using a time-sharing input method. An object of the present invention is to provide a synchronization signal generator configured so as not to increase detection processing time. In order to achieve this object, the present invention configures a phase shift synchronization signal generator as described below. That is,
The configuration of the present invention with n detection cameras and one input device is shown in FIG. This achieves the above-mentioned purpose by delaying the process. Note that the maximum value of n is determined by the processing capacity (processing time) of the input processing device 5 in one field. In FIG. 3a, the output of one clock generator 3 is input to a synchronization signal generator 7 which can be started externally, the horizontal synchronization signal 16 of the reference synchronization signal 22 is input to the counter 8, and the vertical synchronization signal 17
is input as the reset for the counter 8. The counter outputs 18 from this counter 8 are matched with different synchronization phase shift setting values 11 and 12, respectively, in order to give the amount of shift with respect to each reference synchronization signal 22 by the number of horizontal synchronization signals of the reference synchronization signal. It is input to circuit 9. The coincidence circuit output 19 from the coincidence circuit 9 is further input to a one-shot generator 10 for generating a start signal, and the synchronization signal generator 7 of each camera generates a synchronization signal 14 by shifting it by a fixed amount with respect to the reference synchronization signal 22. A start signal 20 is generated for generating. FIG. 3b shows a detected video waveform 33 based on a reference synchronizing signal, detected video signals 34, 41 obtained using synchronizing signals each delayed by one scanning (H) time, and a selected output signal 35 from a multiplexer. . As a result, the detection signals do not overlap as shown in FIG. 2, and there is no need to wait at the multiplexer output.

Next, one embodiment of the present invention will be described according to the drawings. Figure 4a shows a color television (hereinafter
An example of an automatic convergence measurement system (referred to as CPT) is shown below. As shown in FIG. 4b, the convergence is a vertical line 82 for each of the three primary colors, red, green, and blue, in the pattern of the CPT screen 81.
In order to measure the amount of deviation between signals 83 and 84 as times 91, 92, and 93 from the horizontal synchronizing signal 94 on the detection signal, the time interval measuring device 55 (hereinafter referred to as TIU) shown in FIG. 4a is used. . The example system measures the convergence of three CPTs simultaneously, but since TIUs are expensive, only one CPT is used.
The camera detection outputs 60 from the three detection ITV cameras 51 are switched and used in a time-sharing manner. Therefore, the amount of phase shift of the phase shift synchronization signal generator 59 of this embodiment is 1/3 field and 2/3 field (approximately 5.5 ms and 11 ms), respectively, with respect to the reference synchronization signal 61.
It has delayed synchronization signals 62 and 63 that are delayed by a certain amount. To describe the operation of this embodiment, first the CPU5
7 selects the multiplexers 52 and 53 for the detection signal output and start signal as camera No. 1, and the output of the multiplexer 52 is input to the convergence circuit 54, subjected to pre-processing such as level conversion, and then outputted as shown in FIG. The red, green, and blue stop signals 95, 96, and 97 shown in FIG. On the other hand, the horizontal synchronization signal of the i-numbered scanning line of camera No. 1 is taken out by the scanning line counter 58 in FIG. Measurement data output 69 from this start and stop is taken into the CPU 57 through the I/O 56. After that, the CPU 57 switches the multiplexers 52 and 53 to camera No. 2, and
Perform measurements at Similarly, the output signal of camera No. 3 is processed, but at this time, the synchronization signal is
Since the phase is shifted by three fields, enough time is secured for the processing execution time of the CPU 57 after the TIU measurement, and it is possible to automatically measure the convergence of three CPTs within one field. In this embodiment, there are three cameras, so in the worst case, the processing time would be three times as long as in the conventional technology shown in Fig. 2 compared to the case with one camera, but the processing time shown in Fig. 3b is With such an apparatus using the present invention, it is possible to process signals on three apparatuses within the same time as when using one apparatus, without any special software processing.

As explained above, according to the present invention, when using multiple detection ITV cameras in a time-sharing manner, each camera signal can be switched and captured within one field using a multiplexer, eliminating the occurrence of waiting time. This allows multiple detection ITVs to be used.
Since it is possible to use only one input processing device for the camera without increasing the detection time, it is possible to reduce the cost of the entire device, simplify the device, and facilitate maintenance.

[Brief explanation of the drawing]

Figures 1a and 1b are configuration diagrams showing configuration examples of a multiple detection ITV camera signal input system according to the prior art, Figure 2 is a detection signal input timing diagram in the configuration of Figure 1b, and Figure 3a is the main A block diagram showing the configuration of the phase shift synchronization signal generation device according to the invention and the configuration of a multiple detection ITV camera signal input system using the same, FIG. 3b shows detection in the configuration according to the invention shown in FIG. 3a. A signal input timing diagram, FIG. 4a is a block diagram showing a specific embodiment in which the present invention is applied as an automatic convergence measuring device, and FIG. 4b is a diagram for explaining the convergence measurement shown in FIG. 4a. It is a principle diagram. Explanation of symbols, 1...Detection ITV camera, 2...Synchronization signal generator, 3...Clock generator, 4...Multiplexer, 5...Input processing device, 6...Synchronization signal distributor, 7...Synchronization Signal generator, 8... Counter, 9... Coincidence circuit, 10... One shot generator, 11, 12... Synchronous phase shift amount setting value, 13...
... Clock signal, 14 ... Synchronization signal, 15 ... Camera detection signal, 16 ... Horizontal synchronization signal, 17 ...
Vertical synchronization signal, 18... Counter output, 19...
Matching circuit output, 20...Start signal, 21...
Multiplexer output signal, 22...Reference synchronization signal, 36...Vertical synchronization signal, 37...Horizontal synchronization signal, 51...Detection ITV camera, 52, 53...Multiplexer, 54...Convergence circuit, 5
5...Time interval measuring unit (TIU), 56...I/
O, 57...CPU, 58...Scanning line counter,
59...Phase shift synchronization signal generator, 60...Camera detection output, 61...Reference synchronization signal, 62, 63...
Delayed synchronization signal, 69...Measurement data output, 72...
...Start signal, 81...CPT screen, 94...
Horizontal synchronization signal, 95, 96, 97...stop signal.

Claims (1)

[Claims] 1. In a synchronization signal generation device for a detection system using multiple industrial television cameras, there is one reference clock generator and a plurality of externally startable clock generators that generate synchronization signals using the reference clock generator. a synchronization signal generator; a horizontal synchronization signal counter and matching circuit for determining the amount of phase shift of another synchronization signal with respect to a reference synchronization signal generated by one of the synchronization signal generators; and a start signal generation circuit for supplying a start signal to another synchronization signal generator, and the phase shift synchronization is characterized in that the circuit supplies a synchronization signal whose time axis is shifted by a fixed amount to each of the industrial television cameras. Signal generator.