JPS6064383A - Display unit for braun tube - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display device for a cathode ray tube, which constitutes a display device such as a microconbeater and is used to display characters, numbers, etc. on a cathode ray tube.

[Background technology and its problems]

In recent years, OA (Office Automation)
Microcomputers are rapidly becoming popular, and the number of users of microcomputers in ordinary households is also increasing. Therefore, display devices for displaying characters, numbers, etc. on cathode ray tubes, which constitute display devices such as microconverters, are becoming increasingly important.

The cathode ray tube display device currently in common use displays characters, numbers, etc. on the cathode ray tube pixel by pixel. It is composed of a character code memory 4, a character generator 5, and a shift register 6.

Line address counter 2 is supplied from synchronization signal generator 1 according to the vertical position of a predetermined display position on the screen, that is, the number of scanning lines (from what number to what number of scanning lines are required). The data is stored in the character code memory 4. Note that the reset is performed by the vertical synchronization signal V. Further, the dot address counter 3 counts the dot clock D supplied from the synchronization signal generator 1 according to the horizontal position (on the scanning line) among the predetermined display positions on the screen, is also stored in the character code memory 4. The character code memory 4 stores one field's worth of data supplied from the line address counter 2 and dot address counter 3 as described above, and accesses the character generator 5 by repeatedly reading out this data. Based on the data accessed from the character code memory 4, the character generator 5 generates a video signal of desired characters, numbers, etc., which is converted into a serial video signal by the shift register 6. The video signal is then supplied to a cathode ray tube for display. In addition,
A synchronizing signal is also supplied to the cathode ray tube from a synchronizing signal generator 1, and the video signal is synchronized with the synchronizing signal.

A case in which, for example, the characters rt L'' are displayed on the screen in the cathode ray tube display device that performs such an operation will be explained using FIG. 2. In the first field, as shown in FIG. 2A, Dots for displaying the characters 11L'' on the screen are arranged every other scanning line. Second
The video signal of the field is exactly the same as the video signal of the first field, and as shown in FIG. will be placed in However, because of the interlaced scanning method, each dot in the second field corresponding to each dot in the first field is located one scanning line above. Since the first field and the second field are switched and displayed every second by the horizontal synchronizing signal H, one frame becomes as shown in FIG. 2C. Accordingly, the character "L" displayed on the screen appears to move up and down in a cycle of seconds, resulting in the problem of so-called flickers.

[Purpose of the invention]

The present invention was developed in view of the above-mentioned conventional problems, and it is possible to reduce the flickering of letters, numbers, etc. displayed on the screen by adjusting the brightness of each dot for displaying the letters, numbers, etc. The purpose is to suppress it by partially changing it and to display it clearly.

[Summary of the invention]

In order to achieve the above-mentioned object, the cathode ray tube display device according to the present invention adds a video signal corresponding to one scanning line of the first field and a video signal of the first field one horizontal scanning period before the video signal. The present invention is characterized in that the video signal with the level of the video signal expressed as % is used as the video signal of the second field corresponding to one scanning line of the first field.

〔Example〕

Hereinafter, embodiments of a cathode ray tube display device according to the present invention will be described in detail with reference to the drawings.

The first embodiment of the cathode ray tube display device according to the present invention is as follows:
For example, it has a configuration as shown in FIG. 3, in which an I2 delay circuit 7, switches 10, 20, 30, and an adder 8 are added to the cathode ray tube display device shown in FIG. Therefore, the 1H delay circuit 7, the switch 10,
20.30, 4-, and each hook except for the adder element shall be given the same reference numerals as those of the cathode ray tube display device shown in Fig. 1 above.
A detailed explanation thereof will be omitted.

The connections after the shift register 6 are as follows.

The output of the shift register 6 is connected to one input terminal 12 of the switch 10 and one input terminal 21 of the switch 20, and is connected to the switch 30 via the IH delay circuit 7.
is connected to one input terminal 31 of the. In addition, each other input terminal 11 of each of the switches 10, 20, 30,
22 and 32 are each grounded, and each output terminal 13
23 and 33 are both connected to the adder 8. In addition,
Each of the switches 10, 20, and 30 is switched in conjunction with a field signal F, which is supplied from the synchronizing signal generator 1 and indicates the first field and the second field.

In order to display characters, numbers, etc. on the cathode ray tube in the cathode ray tube display device of this embodiment, first, the character generator 5 generates a video signal of the desired characters, numbers, etc. based on the data accessed from the character code memory 4. The video signal from the character generator 5 is converted into a serial video signal via the shift register 6. And each of the above switches 10, 2
When the field signal F indicating the first field is supplied from the synchronizing signal generator at 0.30, the output terminals 13, 23, and 33 of each switch are connected to the input terminals 12, 2, respectively.
2. Connected to the 32 side. In this case, each output terminal 23.
33 are respectively grounded, so that the video signal from the shift register 6 is directly added to the adder 8 as the video signal of the first field. Next, when the field signal F indicating the second field is supplied from the synchronizing signal generator 1 to each switch 10, 20.30, the output terminal 13.23° 33 of each switch is connected to the input terminal 11, 21, respectively. .31 side is connected. In this case, the output terminal 13 is grounded and therefore has no output, but the video signal from the shift register 6 is supplied to the output terminal 23 as the video signal of the second field, and the signal level is adjusted by an attenuator (not shown) or the like. It is added to the adder 8 after being 3AKed. Further, the video signal from the shift register 6 is delayed by one horizontal scanning period by the delay circuit 7, that is, the video signal from one horizontal scanning period before is also supplied to the output terminal 33 as the video signal of the second field. Similarly, the signal level is set to H by an attenuator (not shown) and then added to the adder 8. And adder 8
Therefore, the video signals of the first field and the second field are alternately supplied (every second) to the cathode ray tube for display.

In the cathode ray tube display device of this embodiment that performs the above-described operation, the case where, for example, the characters rt I,'' are displayed on the screen will be explained using FIG. 4. The letters It appear on the screen as shown in
Each dot du of equal brightness to display L 11
kto to d, t←con are arranged every other scanning line. In the second field, as shown in FIG.
3s are arranged every other scanning line. The dot d21 corresponds to the dot dll in the first field, and since there is no dot in the first field one horizontal scanning period before the dot dos, the brightness of the dot d21 is equal to that of each dot in the first field. The brightness becomes 1/2. The dot dB corresponds to the dots d+ and + in the first field, and since the dot do exists in the first field one horizontal scanning period before the dot du, the brightness of the dot d2z is the same as that of the first field. is equal to the brightness of each dot. Similarly,
The brightness of each dot)dzs and dz4 is equal to the brightness of each dot in the first field, and each dot)clzs~
The brightness of dza is H of the brightness of each dot in the first field. Further, for each dot d29 to d3s, there is no corresponding dot in the first field, but each dot d+4 to dls exists in the first field l horizontal scanning period before, so each dot is dot d
The brightness from 29 to dsa is % of the brightness of each dot in the first field. Then, the first field and the second field are
Since the fields are changed and displayed every second by the horizontal synchronizing signal H, one frame becomes as shown in FIG. 4C. As is clear from this figure, the brightness of each dot in the second field corresponding to each dot in the first field is partially changed to provide an appropriate difference in brightness for each dot in the first field. Therefore, the displayed characters LtL”
The display does not appear to move up and down, and is clearly displayed.

FIG. 5 shows a second embodiment of a cathode ray tube display device according to the present invention. In this embodiment, the configuration before the character code memory 4 is the same as that of the first embodiment, and detailed explanation thereof will be omitted. In order to display characters, numbers, etc. on the screen in the cathode ray tube display device of the second embodiment, data is first transferred from the character code memory 4 to the first character generator 41 and the second character generator 42, respectively. be accessed. Then, based on the data, the first character generator 41 generates a video signal corresponding to the characters, numbers 10-, etc. to be displayed, and the second character generator 42
A video signal generated one horizontal scanning period earlier than the video signal generated by is generated. These video signals are then supplied to the multiplexer 43, where the video signals for one field generated by the synchronizing signal generators 1 to 41 are selectively supplied to the shift register 44 and serially transmitted. converted to a video signal. The video signal from the shift register 44 is divided into two, and the level thereof is converted into a percentage by an attenuator (not shown). However, in the case of the first field, the two divided video signals are exactly the same, so the cathode ray tube ends up with an adder. Only the video signal from the first character generator 41 is supplied via the character generator 45. That is, the brightness of each dot on the screen corresponding to displayed characters, numbers, etc. is constant. During the second field, video signals for one field generated by the first character generator 41 and the second character generator 42 are simultaneously supplied to the shift register 44 and converted into serial video signals. In this case, the levels of the video signals divided into two from the shift register 44, that is, the video signals generated by the first character generator 41 and the second character generator 42, are each set to %, so the adder 45 The second field video signal supplied to the cathode ray tube via the second field has a brightness intermediate between the corresponding first field video signal and the first field video signal one horizontal scanning period before. The brightness of each dot on the screen will be partially different.

FIG. 6 shows a third embodiment of a cathode ray tube display device according to the present invention. In this embodiment as well, the structure before the character code memory 4 is the same as that of the first embodiment, and detailed explanation thereof will be omitted. 3rd above
In the cathode ray tube display device according to the embodiment, data of K for displaying characters, numbers, etc. on the screen is first accessed from the character code memory 4 to the character generator 51. The field signal F is supplied from the synchronization signal generator 1 to the character generator 51, and when it is the first field, it corresponds to the characters, numbers, etc. displayed by the character generator 51 based on the data from the character code memory 4. A video signal is generated in which the brightness of each dot on the screen is constant, and in the second field, a video signal in which the brightness of each dot is partially changed is generated. These video signals are then supplied to a shift register 52, converted into serial video signals, and supplied to a cathode ray tube.

In the cathode ray tube display devices of the second and third embodiments, for example, when displaying the characters tr L II on the screen, as shown in FIG. 4 used in the explanation of the first embodiment, The brightness of each dot in the second field corresponding to each dot in the first field is partially changed to provide an appropriate brightness difference for each dot in the first field, so Table 13- shows. Characters tr: [, n do not appear to move up and down, and are clearly displayed.

〔Effect of the invention〕

As is clear from the description of the above embodiments, according to the present invention, flickering of characters, numbers, etc. displayed on the screen can be reduced by partially adjusting the brightness of each dot for displaying the characters, numbers, etc. By changing it, it can be suppressed and clearly displayed, and the intended purpose can be fully achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a cathode ray tube display device commonly used at present, and FIG. 2 is a schematic diagram of the above-mentioned cathode ray tube display device when the characters It L II are displayed on the screen. Cow #Tsubasa *The letter ``L'' appears on the screen on a cathode ray tube display device.
5 and 6 are block diagrams showing second and third embodiments of the cathode ray tube display device according to the present invention. 1 A- 1...・・・・・・・・・・・・・・・・・・・・・
・・・・・・Synchronization signal generator 2・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・Line address counter 3・・・・・・・・・・・・・・・・・・・・・
......Dot address counter 4...
・・・・・・・・・・・・・・・・・・・・・・・・
...Character code memory 5.41, 42.51・
...Character generator 6.44.52...
・・・・・・Shift register 7・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・ IH delay circuit 8.45・・・・・・・・・・・・・・・・・・・・・
Adder 10.20.30...Switch 43...
・・・・・・・・・・・・・・・・・・・・・Multiplexer patent applicant Sony Corporation representative Patent attorney Kodo Koike 1) Sakae Mura −

Claims (1)

[Claims] The video signal corresponding to one scanning line of the first field and the video signal of the first field one horizontal scanning period before are added together, and the video signal obtained by converting the level of the video signal into % is added to the video signal corresponding to one scanning line of the first field. A display device for a cathode ray tube, characterized in that a second field video signal corresponding to a scanning line is generated.