JPS582927A - Superposing device for detecting signal of light pen - Google Patents

Abstract

PURPOSE:To detect stably a scanning light independently of hue, by adding somewhat green and blue scanning lights at the timing of monochromic display of red or black when coordinates on the screen of a color CRT are detected by a light pen. CONSTITUTION:The scanning light on the screen of a color CRT1 is detected by a light pen 11 and is converted photoelectrically, and the converted pulse signal is given to a light pen pulse signal processing circuit 12 and an AND circuit 9, and the circuit 12 takes in address data of X address and Y address counters 5 and 6 to detect the position on the screen which is in contact with the pen 11. Simultaneously, the circuit 12 reads out data in storage addresses of a memory circuit 7 corresponding to these addresses and outputs signals of three primary colors, namely, red, green, and blue to a signal superposing circuit 8. The circuit 9 opens the gate to give a dot clock signal from a clock signal generator 2 to the circuit 8 when the pulse signal is given from the pen 11. The circuit 8 gives artificial information, where green and blue are added to the signal of red or black in a time shorter than one dot, to a CRT driving circuit 10 when the signal from the circuit 7 is red or black, thus driving the CRT with colors which are detected stably with the pen 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a superimposing device for detecting a light ben in a cathode ray tube display device, which stably outputs a signal detected from a light ben regardless of hue.

In cathode ray tube display devices used as display means for terminal devices such as computers, light beams are used as a means of man-machine communication. When the display screen is pressed, it is necessary to detect the position on the display screen where the light bevel contacts the display screen.

For example, in a cathode ray tube display device equipped with a memory device corresponding to each pixel composing the display screen, there is a case where it is desired to determine the write address when writing one character graphic information to this memory based on the light pen position on the display screen. be. In such a case, a light beam is applied to the display screen, a light receiving section provided at the tip detects the scanning light, and the light is photoelectrically exchanged to obtain an electrical signal. However, the afterglow characteristic of the fluorescent surface of a cathode ray tube is weak. This becomes noticeable when black is displayed on the screen. For this reason, it was not possible to stably detect red and black scanning light in particular with the light receiving part of the light pen, and it was proposed that the detection position by the light pen would increase the brightness of the non-scanning light, but the entire screen The problem is that the brightness makes it difficult to see the displayed information.

The present invention solves such problems and solves the problems of group 1. S
In a cathode ray tube display device 7 that displays eight colors using a combination of l bits for each blue color, *: and blue scanning light can be detected relatively stably even when monochromatic, and all green and blue scanning light can be displayed. When there is no color, that is, when black is displayed, the detection is unstable, so green is displayed at the timing when both are displayed.

By adding a small amount of blue scanning light, the visible scanning light is displayed as red or black, and the scanning light detected by the light pen is detected as a mixture of green and blue, and the scanning light is changed in hue. It is characterized by stable detection regardless of the

The present invention will be explained below with reference to the drawings.

FIG. 1 is a block circuit diagram showing the main structure of a cathode ray tube display device to which an embodiment of the present invention is applied. In FIG. 1, l is a clock signal generator that generates a color code CK for displaying characters, nine figures, etc. by a set of bright spots.

This clock signal CK is applied to, for example, a color CRT.
1 bright spot displayed on the screen of I (hereinafter referred to as 1 dot)
It consists of unit signals, so-called dot clock signals. 3 is a horizontal synchronization signal generator that generates a horizontal synchronization signal CK for horizontally scanning the color CRTI screen based on this dot clock signal CK; This is a vertical synchronization signal generator that creates vertical synchronization signals for vertical scanning.

5 and 6 are horizontal 2. This is an X and Y address counter that receives a vertical synchronization signal and a dot lock signal and outputs address data indicating coordinate positions in the X direction and Y direction of the color CRTI screen to the address bus ADK. 7 is a memory circuit that takes in display data sent from a computer, etc. (not shown) via a data bus DB, and stores it at a predetermined storage address designated by address data. corresponds to the screen coordinate position of the color CRTI on a 1:1 basis. The display data is composed of contents specifying which bright spot should emit light and in what color in order to depict the image to be displayed on the color CRTI screen. Reference numeral 8 denotes a signal superimposition circuit which is a main part of the present invention, which will be described later. When the light pen 11, which will be described later, does not operate, the display data read out from the memory circuit 7 is simply transferred to the next stage C.
RT drive.

The signal is relayed to the circuit 10. Based on the display data supplied from the CRT drive circuit 1 (llt measurement circuit 7), the red and green of the color CRT 1 are displayed.

Three electron guns for each blue color (hereinafter referred to as R, G, , and B) are simultaneously driven. Therefore, the display data read out from the memory circuit 7 is composed of 3-bit parallel pulses corresponding to R, G, and H, respectively, and the period of 1 bit is 1 which is displayed in color ○RT1.
It has been processed in advance by the memory circuit 7 to correspond to a dot. In other words, the display data has already been processed to correspond to that one bit period.

Reference numeral 11 detects the scanning light on the screen of the color CRT 1 with a light pen, photoelectrically converts it, shapes the waveform of this into a pulse signal, and supplies it to the light pen pulse signal processing circuit 12 at the next stage. Therefore, a pulse signal output from the light pen 11 is generated each time the scanning light crosses the field of view of the pen. Furthermore, when this pulse signal is given, the light pen pulse signal processing circuit 12 takes in the address data of the X and Y address counters 5 and 6, and detects the position on the screen where the tip of the light pen 11 is pressed. .

At the same time, the light pen pulse signal processing circuit I2 temporarily holds the address data after taking it in, and reads, rewrites, or erases the data stored at each storage address of the memory circuit 7 corresponding to this. . The commands for each read, rewrite, and erase function are as follows:
A keyboard (not shown) or the like is used as appropriate. Meanwhile, the light pen 11 is usually equipped with a switch (not shown) that is turned on and off when the light pen 11 is used. Therefore, when the tip of the light pen 11 is pressed against the screen of the color CRTI, this switch turns on and outputs the above-mentioned pulse signal.

Reference numeral 9 denotes an AND gate circuit to which this pulse signal and the dot clock signal CK output from the clock signal generator 2 are input. This AND gate circuit 9 opens its gate when a pulse signal is applied from the above-mentioned light pen 11, and provides a dot clock signal C'K to the signal superimposing circuit 8. Therefore, the signal superimposing circuit 8 superimposes the dot clock signal CK applied from the AND gate circuit 9 when relaying the display data as described above. This signal superimposition circuit 8 is constituted by a circuit as shown in FIG. 2, for example.

The apparatus according to the embodiment of the present invention is constructed as described above, and the main parts of the present invention are formed by the clock signal generator 2, the signal superimposing circuit 8, and the AND gate circuit 9. Therefore, the main parts of the basic configuration will be described below with reference to FIG. 2, although other parts may be modified as appropriate.

In FIG. 2, 81 to 83 are OR gate circuits that relay the 3-bit parallel pulse signals representing the display data already mentioned, and output the display data given to input terminals T and -T3 to output terminals T5 to T7, respectively. . Here, it is assumed that output terminals T1 to T3 and T5 to T7 correspond to display data for driving R, G, and B electron guns from above, respectively. Then, each data is converted into R signals s, , a, year S2 . B signal S3 and
The respective signals appearing at the output terminals T5 to T7 are referred to as 85 to S7, and are significant when the signals are at a high level (hereinafter referred to as "1").

84 is a NOR gate circuit which inputs the G signal S2 and the B signal S3, and its output is given to the AND gate circuit 85. The output of the AND gate circuit 85 is
1 to 83.

The dot clock signal CK supplied from the AND gate circuit 9 already mentioned is input to the terminal T4. This dot clock signal CK is applied to an AND gate circuit 85.

With the above configuration, when the display data read from the memory circuit 7 specifies red light emission, the signal superimposition circuit 8 outputs only the R signal S1 at 1" and the G signal S2 and the B signal S3. are both low level (hereinafter referred to as ゛O
”), the gate of the AND gate circuit 85 is opened, and the dot lock signal CK supplied from the terminal T4 is input to each of the OR gates 81 to 82.
give to At this time, the light pen 11
When the terminal T is not pressed against the screen, the AND gate circuit 9 shown in FIG. 1 closes the gate.
4 is not supplied with the dot clock signal CK and remains at "0". As a result, the AND gate circuit 85 receives the G signal S2. Since the B signal S3 becomes "0", the gate is closed even if the output of the NOR gate circuit 84 becomes 1'. This means that when the light pen 11 is not pressed against the screen of the color CRTI, the input terminals T1 to T
3, the display data given to OR gate circuits 81 to 83
The first signal is relayed through the terminal and appears at the output terminals T5 to T7. On the other hand, when the light ben 11 is being pressed, the dot clock signal CK supplied to the terminal T4 is transmitted to each of the OR gate circuits 81 to 85 via the AND gate circuit 85.
83, all "1" signals are output to the output terminals T5 to T7. However, as shown in FIG. 3(a), this dot lock signal CK is different from the 1-dot 0 preceding period α of the R, G, and B signals S1 to S3 of the display data in FIG. 3(b). As shown, since the period of "!" is 1'/Jl, the display data appearing at the output terminals T5 to T7 becomes as shown in FIG. 3() and ). As a result, on the color RTI screen, when black is displayed, K is grayish, and when R color is displayed, KFiG and B are slightly added to the emitted color, and when other colors are displayed, the logic matches, so the emitted color is has no effect. FIG. 3 shows the relationship between display data and various parts when the emitted light color differs in units of one dot.

As described above, only when the light pen is pressed against the CRT screen, a pulse signal that supplements the amount of red and black light emission, in other words, pseudo information is superimposed on the CRT drive signal.

Therefore, it is possible to obtain a sufficiently large output from the light pen that detects the scanning light of the CRT. In addition, the pulse signal created based on this is used to capture and hold address data indicating the screen coordinate position, so 1
．． The data retained can more accurately correspond to Ben's guess location. In addition, it is also possible to display the luminescent color included in the display data on the CRT screen without misidentifying it.

Although the above-described embodiment uses the dot clock signal CK supplied from the clock pulse generator 2 as a signal to be superimposed on the display data for driving the CRT, it is possible to change the duty ratio as appropriate. It is also possible to change the ratio of superimposition to the display period of one dot.

Furthermore, the signal superimposition circuit 8 may be replaced by other means instead of the logic circuit shown in FIG.

As described above, according to the present invention, there is provided a color cathode ray tube display device using a so-called three primary color demodulation excitation method in which the emitted color of one dot displayed on a color cathode ray is individually excited for each of the three primary colors according to display information. , only when the light emitting means detects the emitted light color on the screen and detects the red emitted light color, pseudo information that can control the excitation of the three primary colors individually in a period shorter than the excitation time of one dot is superimposed on the display information. It is something to do.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an example in which an embodiment of the light-ben detection signal superimposition device according to the present invention is applied to a cathode ray tube display device, and FIG. 2 is an implementation of the main part of the device of the present invention. A circuit diagram showing an example, FIG. 3 is a waveform diagram for explaining the circuit operation of FIG. 2. 1...Color cathode ray tube 2.3, 4, 5, 6, 11.12...Light pen means, ? , tio... control means, 2.7.8.9... superimposition means. 121m Figure 3

Claims (1)

[Claims] A scanning line is divided into a plurality of dots, and each dot is divided into three dots.
A color cathode ray tube in which the three primary colors are excited individually so that light is emitted by one of the primary colors obtained in an arbitrary combination, and the emission of the dot is detected at an arbitrary position on the screen of this color cathode ray tube, and this light is a color cathode ray tube display device, the color cathode ray tube display device having a light bend means for detecting the position on the screen coordinates of the arbitrary position by a pulse signal generated in accordance with the color cathode ray tube display device, wherein the color cathode ray a control means for individually controlling the excitation of the three primary colors of the tube; and a superimposing means for superimposing pseudo information on the display information that can individually excite and control the three primary colors in a period shorter than the excitation time of one dot in response to the detection output. A signal superimposition device for Light Ben detection is provided.