JPS5819624Y2 - Graphic information reading device using a light pen - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a graphic information reading device using a light pen for reading coordinate information of an image on a refresh type CRT screen and supplying the information to a computer or the like.

The conventional method of inputting coordinates using a light pen is to set a location where the light pen is effective only in a predetermined area separate from the video signal, and then determine the position based on whether or not the light pen touches that area. While inputting a video signal, place a light pen on an arbitrary coordinate, then give a certain command, and with that command, temporarily interrupt the input of the video signal, output a scan signal other than the video signal to the CRT, and scan it. Coordinates were recognized by signals.

With these methods, it was not possible to input arbitrary coordinates on the screen, and since the input was done point by point, it was not possible to input coordinates continuously while tracing a solid object.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a graphic information reading device using a light pen that can convert any graphic into coordinate data, while eliminating the drawbacks of the conventional technology.

According to the present invention, the above-mentioned drawbacks are eliminated by time-divisionally projecting the video signal and the scan signal for position identification onto the CRT screen, and any figure can be converted into coordinate data simply by tracing on the CRT screen with a light pen. A graphic information reading device using a light pen is obtained.

In order to recognize the position on the screen from the image displayed on the CRT screen, it is necessary to detect the beam of light scanning the CRT screen with a light pen.

In the case of a figure with shading, a beam that uniformly scans the entire screen is required in addition to this image.

Therefore, the unblanking scan signal and the video signal within the range that the light pen can detect are alternately displayed at a certain ratio, and the light pen is controlled by a gate circuit so that it becomes effective only when the unblanking scan signal is displayed.

Then, the position of the beam is counted both horizontally and vertically by a counter, and when the light pen detects the scanning beam, the value of the counter is extracted.

As a result, when a figure on a CRT screen is traced with a light pen, the figure can be continuously converted into coordinate data.

Next, the present invention will be described in detail with reference to the drawings showing an embodiment of the present invention.

The drawing shows an embodiment of the present invention, in which a lesion image is projected from an X-ray television device 1 onto a television picture tube 2.

In this invention, only the luminance signal of this video signal is
The switching circuit 3 switches to the unblanking signal from the unblanking signal generator 4 once every 0 frames.

The switching timing is based on the synchronization signal from the vertical synchronization signal detection section 5.

Horizontal counter 6 and vertical counter 7 are clock generator 8
The horizontal synchronization signal detection section 9 counts the clock pulses from the
In response to the synchronization signal from the vertical synchronization signal detection section 5, the horizontal counter is reset for each line and the vertical counter is reset for each frame.

Here, when the light pen 10 is applied to a part of the screen, the light pen control section 11 outputs a beam detection signal, latches the values of the horizontal and vertical counters at that time, and transfers them to the digital computer 12.

By repeating this operation, the horizontal and vertical counter values (coordinate data) can be continuously input into the digital computer.

As explained above, the present invention can continuously convert a figure into coordinate data by combining a video signal and an unblanking scan signal.

[Brief explanation of the drawing]

The drawings are diagrams showing one embodiment of the present invention. In the figure, 1... Horizontal counter, 7... Vertical counter, 8... Clock generator, 9... Horizontal synchronization signal detection section, 10... Light pen, 11... Light pen control section, 12... Digital computer .

Claims (1)

[Scope of utility model registration request] A graphic information reading device using a light pen that reads the coordinate data of a graphic displayed on a CRT display with a light pen and supplies it to a computer, etc., which includes a position identification scan signal generator and a position identification scan signal that is output at a predetermined ratio. a switching circuit that sends the video signal to the CRT display in place of the video signal supplied to the CRT display; a light pen that detects the position identification scan signal via the CRT display in synchronization with the switching circuit; and a light pen that detects the position identification scan signal via the CRT display. It comprises a clock generation circuit that generates a clock signal synchronized with the signal, and a counter that counts the clock signal, latches the counter output by the output of the light pen, uses the output data as coordinate data, and displays the CRT display. A graphic information reading device using a light pen, characterized in that the counter is reset at the timing of a synchronization signal controlling the counter.