JPS5930296B2 - Information detection method using light pen - Google Patents

Description

[Detailed Description of the Invention] The present invention particularly relates to an information detection method using a light pen.
The present invention relates to a novel information detection method using a light pen that enables information detection using a light pen without causing a decrease in the amount of displayed information.

As is well known, light pens are used to detect information on a display surface of a display device such as a cathode ray tube (CRT) or to display information at a desired position on the display surface.

Such a light pen is brought into contact with the display surface, detects light from the display surface, and generates a detection signal. This detection signal is sent to the control section of the display device, and a predetermined signal is sent to perform the desired function. Processing is done.

However, in conventional light pen devices like this, there is a time delay between when the light pen detects light and when it generates a light detection signal, and this time delay also varies depending on the intensity of the light being detected. A certain time is set for the information detection time on the display surface by the light pen, taking this time delay into account. This point will be explained below.

Figure 1a shows the main part of the display screen, character display areas C1, C
2, C3... is shown.

For example, move the light pen to the character display area at time T4.
7, the light pen outputs an H level signal 51 after a time delay TD as shown in FIG.
Upon receiving this H level signal, an interrupt signal is sent to the display control unit, and operations such as writing information to the part of the display surface that is in contact with the light pen are performed.
As mentioned above, there is a time delay in the generation of this light pen detection signal, and for example, on the display screen, the light pen is scanning the character display area C2 that is not in contact (that is,
A detection signal is output from the light pen during the character interrupt period (to the character display area), and an interrupt signal is sent to the display control section.

Therefore, characters are displayed from the display control unit to the display surface not in the character display area where the light pen touches, but in the first
In the case of Figure a, this is for the character display area C2. Conventionally, for this reason, the intervals between character display areas were set wide. This results in a decrease in the number of displayed characters, resulting in a decrease in information processing speed. The present invention has been made in view of the above, and aims to provide a new light pen detection method that enables information detection using a light pen without reducing the amount of information displayed. In an information detection method using a light pen, the information on the display surface is detected by specifying a position on the display surface with the light pen in contact with the display surface. divides the display area into a light pen field and a non-light pen field, and provides at least one scanning line as a light pen line, displays the light pen line in the light pen field on the display surface, and displays the light pen line in the non-light pen field on the display surface. The light pen line is not displayed, and information can be detected by the light pen only while the light pen line is being scanned.

Before explaining the embodiments, the basic idea of the present invention will be explained. As shown in FIG. and a non-light pen field (area where information detection with a light pen is prohibited) N, and scan lines 1, . . . , on the display surface as shown in FIG.
Among the lines 11, 121, 1-12, . . . , scanning lines on which information can be detected by a light pen are determined in advance.

In the case of FIG. 2b, for example, the character display area Cll, C, 2, .
5th scanning line 115, 12 for C2, .
5... is a light pen line. In other words, the detection signal from the light pen is made valid only while scanning this light pen line.

In a non-light pen field, dot information constituting a character is not displayed on the light pen line, but dots are displayed only on the light pen line of the light pen field. The non-light pen field is provided in consideration of the time delay of the light pen detection signal, so even if you touch any character display area in the light pen field, the detection signal will not be generated while the non-light pen field is being scanned. (however,
dot display). Therefore, when an interrupt signal is sent to the display control section in response to the light pen detection signal, the display control section receives the interrupt signal?
It is known that information has been detected by the light pen in the light pen field immediately before u and the others.

Therefore, no problem occurs even if characters are displayed in a non-light pen field. Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a configuration diagram of an embodiment of a light pen device for performing an information detection method using a light pen according to the present invention,
1 is a display memory, 2 is a line buffer, 3 is a character generator, 4 is a parallel-serial conversion circuit, 5 is a counter, 6 is a dot counter, 7 is a control memory, 8, 9, 1
0 and 11 are AND circuits, 12 is an 0R circuit, 13 is a light pen control circuit, 14 is a register, 15 is a light pen, 1
6 is a display section, and 17 is a display control section.

Next, the operation of the light pen device shown in FIG. 3 will be explained.
The character information corresponding to one line of the display surface of the cathode ray tube is inputted from the display memory 1 to the line buffer 2, and the character information inputted to the line buffer 2 is generated one by one by the character generator 3 into a dot string constituting the character. are output sequentially.

In other words, in the case of a character displayed on the CRT display screen as shown in FIG.
D3l...D,l are output in parallel, and then the dots belonging to the second row are output. Thereafter, the dots belonging to the third row to the fifth column are sequentially output in parallel. The parallel-to-serial conversion circuit 4 serially outputs a group of dot information input in parallel to the parallel-to-serial conversion circuit 4 in synchronization with the count output signal from the dot counter 6. In other words, in the case of the letter H shown in Figure 4,
From the parallel-to-serial conversion circuit 4, the dots belonging to the first column are first converted to D.
,,,D,l,D3l...output at 1 of D,l,
In synchronization with the subsequent count output signal of the dot counter 6, the dots belonging to the second row, ie, D,2, are output. Thereafter, the dot information that is the same and finally belongs to the 5th column is D,...
, D2, . . . are output to 1 of D95. This dot information is input to the AND circuit 8, and when an H level signal is input to the other input terminal of the AND circuit 8, this dot information signal is output from the AND circuit 8.

The counter 5 corresponds to the scanning lines 111 to 11 on the CRT display screen.
, 121-12, . . . , the scanning line on which information should be detected by the light pen is specified, and in the case of FIG. 2b, the fifth scanning line /! of the scanning lines is specified. 1,,12
, . . . are light pen lines, and each time the value of the counter 5 reaches 5, the counter 5 outputs an H level signal, and at other values, the output from the counter 5 becomes an I level signal. It is ma\.

Even if an H level signal is output from the counter 5 while scanning the light pen line, it is inverted by the inverter I and becomes an L level, so the output of the AND circuit 9 becomes an L level and this L level signal is It is input to the AND circuit 8.

Therefore, while the light pen line is being scanned, the dot information output from the parallel-to-serial conversion circuit 4 is not output from the AND circuit 8. ·stomach. On the other hand, while scanning a scanning line that is not a light pen line, the counter 5 outputs an L level signal, but this signal is inverted by the inverter I and output as an H level signal, and the AND circuit 9 is input.

Therefore, while scanning a scan line that is not a light pen line, A
The ND circuit 8 outputs a signal representing dot information, that is, a video signal. On the other hand, when the output signal of the AND circuit 10 is examined, the output from the counter 5 and the control memory 7 is at H level. (during scanning), the AND circuit 10 outputs an H level signal. The 0R circuit 12 receives the output of Σ from the AND circuits 8 and 10 and displays it on the display section 16.
When the display section 16 receives the H level output from the 0R circuit 12, it displays a dot pattern on the display surface of the CRT.

Moreover, since the dots on this light pen line are displayed only in the light pen field, the light pen detects only the dot information on the light pen line of the light pen field. When the light pen detects dot information on the light pen line of the light pen field, an H level signal is input to the light pen control circuit 13 and the data of the counter 5 is transferred to the register 14. When the data is transferred to this register, an interrupt signal is input to the display control section 17, and desired information processing (such as information display on the part of the display surface that is in contact with the light pen) is performed.
As is clear from the above explanation, the light pen information detection method according to the present invention displays a dot pattern for information detection by the light pen only in the area where information can be detected by the light pen, so the delay in the detection signal caused by the light pen is taken into account. This eliminates the need to provide intervals between character display areas on the display surface, which has the advantage of increasing the amount of displayed characters and increasing the information processing speed.

[Brief explanation of the drawing]

Figure 1a is a diagram showing a character display area, Figure 1b is a diagram showing a light pen detection signal, Figures 2A and b are diagrams for explaining the information detection method using a light pen according to the present invention, and Figure 3 The figure is a block diagram of a device for implementing the information detection method using a light pen according to the present invention, and FIG. 4 is a diagram showing an example of character display. 1...Display memory, 2...Line buffer, 3...Character generator, 4...
...Parallel-to-serial conversion circuit, 5...Counter, 6.
...Dot counter, 7...Control memory, 8-11...AND circuit, 12...
0R circuit.

Claims (1)

[Claims] 1. An information detection method using a light pen, which includes a display unit having a display surface and a light pen, and the light pen that comes into contact with the display surface specifies a position on the display surface and detects information on the display surface. The display area of the display surface is divided into a light pen field and a non-light pen field, and at least one scanning line is provided as a light pen line, the light pen line in the light pen field is displayed on the display surface, and the non-light pen field is displayed on the display surface. A method for detecting information using a light pen, characterized in that a light pen line in a light pen field is not displayed, and information can be detected by the light pen only while the light pen line is being scanned.