JPS6029405B2 - CRT character display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a CRT character display device,
In particular, the present invention relates to a technique for detecting a display position on a screen using L (light) curves.

Conventionally, in this type of display device, the accuracy of detecting the position of the light spot has been determined by the time it takes to convert the optical signal emitted from the light spot of the plumber tube into an electrical signal.

Therefore, in order to accurately detect the position of a light spot, the time from sensing the light to outputting an electrical signal is short, and there is little variation in the time due to differences in the emitted color of the cathode ray tube and changes in brightness. You need to use Light Ben. However, such an L pen is expensive, and as a result, the display device as a whole has the disadvantage of being expensive. In addition, using an inexpensive light ben, as a method of highly accurate position detection, you can erase the entire display on the cathode ray tube by touching the light ben.
From one corner of the screen, display one character by shifting the position of an arbitrary symbol, etc., and repeat it in sequence until Light Ben detects light, and display the above-mentioned words when Light Ben detects light. There is a detection method that uses a similar position to that of a light ben. In this case, light that has nothing to do with the display screen flashes across the screen for a moment. There were drawbacks such as the time required for detection. Therefore, an object of the present invention is to provide a CRT character display device that solves the above-mentioned drawbacks by performing a correction process on the detection address of a light ben, and can accurately detect the position of a character touched by a light ben with character-by-character accuracy. The goal is to provide the following.

According to the present invention, after holding the electrical signal converted from the optical signal received by the light ben as an address signal corresponding to the memory, the memory contents of the address before and after the address on the memory are saved. Clear it and write only one character of the data in the memo IJ' evacuation area from the first cleared address. At this time, monitor for a certain period of time to see if the light signal is converted to an optical signal, and if no conversion is performed. If so, the write data is cleared again and the same operation is repeated for the next address.

At this time, the above operation is repeated for the address of the memory that has been cleared, but if conversion is performed during that time, this operation is aborted midway and the write address of the memory just written is detected as a corrected address signal by the write ben. The signal indicates the position where the When the position detection is completed, all the last saved memory contents are restored. In the present invention, the display position of a character can be detected with accuracy of one character, the detection time is short, and no light unrelated to the display runs. The invention will now be explained in detail with reference to the drawings of embodiments of the invention.

The drawings show embodiments of the invention, in which:
A CRT display monitor 1 and a monitor screen 2 therein, a light ben 3, a video character signal generation circuit 4, a memory 5, a save register 6, a control circuit 7, a memory address counter 8, and a light ben detection address register 9. and an address signal switching circuit 10. In the figure, monitor screen 2 is shown in horizontal direction n+ for convenience of explanation.
It is assumed that the image is divided into 1 equal parts and m+1 equal parts in the vertical direction, and characters are displayed in the spaces formed by each equal dividing line. For the sake of convenience, numbers for indicating the positions of the respective squares are given as 00, 01, . . . , mn. memory 5
corresponds to the monitor screen 2 and stores image data displayed on the screen. Monitor screen 2 of this memory 5 area
00', 01', 02'...
Add mn'. In the figure, a memory address counter 8 counts up in synchronization with the TV scanning of the monitor, creates an address for the memory 5, and reads out the stored contents of the memory 5. The contents read from the memory 5 are supplied as an electrical signal 6 to a video character signal generation circuit 4, where a video character signal a is generated. Video character signal a is monitor 1
A character pattern corresponding to the character code ' is displayed on the monitor screen 2. When the light pen 3 is pressed onto the display pattern on the monitor screen 2, the raster light on the cathode ray tube is immediately converted into an electrical signal 21 by the light pen 3 and supplied to the address register 9. The register 9 is constantly supplied with the address signal f from the memory address counter 8, but when the electric signal i from the pen 3 is input, the address signal f is stored in the register as the write-ben detection address signal h. Hold. The held information h is immediately transmitted to the control circuit 7. Even if the light ben detection address is stored in register 9, if the light receiving sensitivity of the light ben is low and the rise of the light receiving output is delayed, this detection address will be a later address than the address actually instructed by the light ben 3. Conceivable.

This difference varies depending on the characteristics of the light ben 3, how the ben is applied, the color of the characters displayed on the monitor screen 2, etc. In the present invention, the control circuit 7 uses r from this address based on the write-ben detection address (this address is now x).
(For example, 4) previous address (x-r), (X
-r+1)...(x-1), and using this address x, this address (x-r), (x-r+1)...
- Save the data in the memory 5 corresponding to (x-1), x to the save register 6, and then clear the data in the memory 5 corresponding to these addresses. Next, after clearing, move the original data one area at a time in order from the memory area at address (x-r) in memory 5, and in this state check whether Light Ben 3 receives the light of the displayed characters based on this data. investigate. Then, the address when the light ben 3 receives the light becomes the corrected address indicating the actual light ben indicated position. Next, this operation will be explained in detail.

The control circuit 7 first generates a memory address (x-r), switches the switch 10 to the e side, and transfers this address to the memory 5.
The contents of address (x-r) are read out and stored in the save register 6. Note that the storage address of the register 6 is specified by the control circuit 7 at this time. Subsequently, the control circuit 7 generates an address signal (x-r1), reads data corresponding to this address from the memory 5, and stores it in the next address of the register 6, as described above. The control circuit 7 sequentially counts up the value of the address and finally stores the contents of the address x in the register 6. Then, the control circuit 7 again outputs (x-r) as the value of the address signal, and writes a space code (no display) in the area of the memory 5 indicated by the address signal. Next, the control circuit 7 sets the value of the address signal to (x-r+1) and writes a space code in the same manner as described above. The control circuit 7 sequentially repeats such operations, and finally the space code is written in the area of the memory 5 at address x. When this is completed, the value of the address corresponding to the memory 5 is set to (x-r), and the data stored in the save register 6 is written. Next, the switch 10
Return it to the f side and see if it receives an electrical signal from Light Ben 3 within a certain period of time. If there is no reception, control circuit 7
Sets the switch to e side and writes a space code to address (x-r) of memory 5. Next, the address signal (x
-r11), write the data saved in the register 6 to the area of the memory 5 indicated by this memory address, and check whether the light ben receives light in this state. The control circuit 7 sequentially counts up the address value and repeats this procedure until the light ben detects light. According to the above procedure, when the light ben 3 detects light, an electric signal i (detection information) is transmitted to the control circuit 7.

The control circuit 7 outputs the address outputted to the memory 5, similar to the transmission signal, to the outside as final write-ben detection address information. When the final detection address is output, the control circuit 7 further moves the register 6 and the memory 5 to return all the data saved in the register 6 to the memory 5.
control. The control procedure at this time is the same as that at the time of evacuation. In the above description of the embodiment, the control circuit 7 has been explained as a control device, but it can be easily realized by using a microcomputer and the same software (program). According to the present invention, as explained above, it is possible to correct the light bend address without generating unnecessary light on the monitor screen or requiring a long time for detection, and to correct the light bend address with low accuracy. Highly accurate address detection is also possible using

In addition, in the drawing, a memory address counter and a counter that generates an address for write ben in synchronization with raster scan are provided separately, and in order to take into account the delay in detecting a write ben, the count of the memory address counter is set by a few clocks from the counter for write ben. When speeding up the processing, the save data in the memory 5 created based on the address detected by the light ben is set to (x±Q), and the data extending before and after the detected address is adopted.

[Brief explanation of drawings]

The drawings are diagrams showing one embodiment of the present invention. In the figure, 1...CRT display monitor, 2
...CRT...Monitor screen, 3...Light Ben, 4
...Video character signal generation circuit, 5...Memory, 6...
- Save register, 7... Control circuit, 8... Memory address counter, 9... Light Ben detection address register, 10... Address switch.

Claims (1)

[Claims] 1 a CRT display, a memory corresponding to the display screen of the CRT display and storing image data, means for creating a video signal based on the data read from the memory and sending it to the CRT display; a light pen that is applied to the display screen of the display; an address counter that generates an address for reading the memory in synchronization with the raster scan of the CRT display; a first register storing an output address of the first register; an address generator generating a neighboring address including the address stored in the first register; and an image in the memory corresponding to the output address of the address generator. A second register is provided for evacuating and storing data, and predetermined data is independently given one by one to areas where image data is empty in the memory, and at this time, the light pen is applied to the predetermined areas. A CRT character display device, characterized in that it detects whether or not light is received based on an image based on data, and sets an output address of the address generator when the light pen receives light as an instruction address of the light pen.