JPS595898B2 - Character pattern display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a character pattern display device using a storage tube as a refresh memory, in which the image quality of the displayed character pattern is not impaired and the strength, thickness, etc. of the displayed characters are made uniform. This is what was done.

Currently, so-called jima-type character pattern generation devices that generate character patterns by scanning matrix characters directly optically scan matrix characters and detect reflected or transmitted light to generate character patterns. One that converts it into a time-series electrical signal, one that uses electron beam scanning like a monoscope, one that forms an optical image of the letter and detects it with an image pickup tube, and one that uses a hologram to optically reproduce the letter and convert it into electricity. There are various methods such as The signals extracted from such a pattern generator are discriminated by a binarization circuit with a certain threshold in order to clarify the edges of the characters, remove noise, and keep the output signal level constant. , stored in refresh memory, scan converted, and converted into normal C
Displayed on RT. When a charge storage type storage tube is used as the refresh memory and normal TV scanning is used as a CRT display, the scanning of a matrix character and the scanning of recording on the storage tube are the same for one character; After recording one character, another character is recorded in the next predetermined area, and so on. At the end of recording, the storage tube enters the read mode and performs normal TV scanning to read the arranged and recorded characters. Display on CRT. In the above-mentioned apparatus, the signal to be recorded in the storage tube is a binary signal whose level has been made equal, and it has been considered that this is sufficient.

However, due to differences in the size of the characters to be recorded, the thickness of the lines, etc., differences in shading appear in the characters and graphics displayed on the CRT. The present invention eliminates the above drawbacks.

The details of the present invention will be explained below with reference to the drawings. The signal from the character pattern generator 1, which scans the matrix characters and generates a character pattern signal, is binarized by the binarization circuit 25 to become a signal with equal output level, and the signal is changed to an appropriate level by the level variable device 3. The data are adjusted to 1, stored in a storage device 4 consisting of a storage tube, and displayed on a CRT display device 5. 6
is a controller consisting of a minicomputer, a microcomputer, etc., and is used to control the character pattern generator 1, the binarization circuit 2, the level variable device 3, and the storage device 4; It also generates a signal that specifies the type of character to be displayed, such as large or small, Mincho or Gothic.

As the binarization circuit 2, floating slice method,
Various methods are used, including methods based on signal differentiation.

As the level variable device 3, there are various methods such as using a variable gain amplifier, simply changing the signal by switching transistors, and using an analog switch, but the pass signal band of the level variable device 3 is required. Any method is fine as long as it is. An example of this application will be described. For example, if you want to display the size of characters when recording on a storage tube, you can synchronize the scanning timing of the matrix characters and the scanning of the storage tube, and make only the scanning width of the storage tube variable. It is possible to make the size of the characters recorded in the font variable. For example, FIG. 2 shows an embodiment in which two types of display, large and small, are desired. When the scanning width is changed during recording, the signal recorded on the storage tube will become smaller as the scanning width increases if the input signal level is constant; if you want to record at a constant level, the character pattern displayed on the CRT will be a larger character. The text is thin and small letters become dark. Therefore, it is necessary to change the signal level when recording large characters and when recording small characters. The level of the output signal from the binarization circuit 2 shown in FIG. In this example, when recording in uppercase letters, the controller 6 outputs a signal specifying that the characters to be recorded are uppercase letters, and a low level control signal is output to the level variable device 3, and TrlO3 is turned off. The pattern signal to the storage tube 4 has a value divided by the resistor 101 and the input impedance of the storage tube 4. In the case of a lowercase letter, the signal from the controller 6 becomes high level, TrlO3 is turned on, and the signal is divided into the resistor 101 and the ratio of the parallel resistance value of the input impedance of the storage tube 4 and the resistor 102.
By appropriately selecting the values of resistors 101 and 102, the level of the signal recorded and read out (the brightness of the character pattern displayed on the CRT) will be constant regardless of the selection of large or small letters. . Resistor 105 is Trl
Capacitor 104 is a speed up capacitor for determining the base current of O3. The configuration of the level variable circuit is not limited to this example, and other configurations described above are also possible.
Next, we will discuss the case where the level is variable depending on the type of characters recorded on the storage tube.

For example, if Mincho typeface characters and Gothic typeface characters are recorded together, by setting the level for recording Mincho typeface a little higher than that for Gothic typeface, the font of the pattern displayed on the CRT can be changed. This makes it possible to eliminate concentration changes due to Also, a case will be described in which the number of scanning lines for one character is changed.

In the case of a pattern generator of the Jimo type, it is possible to vary the number of scanning lines for one character over a fairly wide range, and as the number of scanning lines increases, a pattern with better resolution can be obtained. When recording on a storage tube, if the number of scanning lines is increased while keeping the character size, that is, the scanning width of the storage tube constant, the degree of overlapping of the scanning beams increases, resulting in stronger recording.
The displayed character pattern appears dark and thick. Therefore, if the signal level is reduced by the increase in the number of scanning lines, this problem will no longer occur. Furthermore, a case will be described in which, after selectively erasing a part of a group of characters already arranged and recorded at a predetermined position in the storage tube, a new character pattern is recorded in that part.

The location of recording, erasing, and reading signals in the storage tube is determined by scanning the electron beam, and each mode of the storage tube is determined by the potential of the target. Selective erasure is possible by scanning the location with an electron beam. However, when recording a new pattern after selective erasure, if the erasure is not performed strongly enough, the previous pattern will remain when the new pattern is recorded. However, if the previous pattern has been sufficiently erased, the potential of that part of the target will be considerably lower than that of the other parts, so unless the signal level during recording is increased considerably, the potential of that part of the target will be considerably lower than that of the other part. When the pattern is read out, it becomes lighter than other patterns. FIG. 3 shows a case where an analog switch is used as the level variable circuit. The output signal of the binarization circuit 2 is transmitted through three variable resistors 106.
, 108, 110.

One of the analog switches 107, 109, and 111 is selected and turned on by the control circuit 6. At this time, the input level to the storage device 4 is instructed by the controller 6 to be rewritten, and is determined by the division ratio of the variable resistor connected to one designated analog switch. By increasing the number of analog switches and variable resistors, signal levels corresponding to each of the above cases can be obtained. As described above, according to the present invention, by using a very simple configuration without providing any special circuit, even if the size, character type, or number of scanning lines of the character signal pattern recorded on the storage tube changes, the storage tube surface remains unchanged. Even if the amount of energy per unit area changes, the brightness, thickness, etc. of the character pattern displayed on the CRT display device can be kept constant, and the same effect can be achieved on the recorded pattern after selective erasure. is obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a character pattern display device according to an embodiment of the present invention, FIG. 2 is a diagram of the main parts of FIG. 1, and FIG. 3 is a diagram of the main parts of FIG. 1 of a different embodiment. be. 1...Character pattern generator, 2...2
Value conversion circuit, 3...Level variable device, 4...
...Storage tube, 5...CRT display device, 6...
···controller.

Claims (1)

[Claims] 1. Means for electrically generating a two-dimensional character pattern signal as a time-series signal by scanning matrix characters, means for binarizing the generated electrical signal, and a means for binarizing the generated electrical signal A charge accumulation type storage tube is used as a means for accumulating a series signal and a means for displaying the same, and a binarized time series signal is used, and the binarized signal is recorded in the accumulation tube. A character pattern display device characterized in that it is provided with means for varying the level of a time-series signal.