JPS5814889A - Crt graphic display system - 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 The present invention relates to a CRT graphic display, and relates to a method of time-sharing TV rask scanning and random scanning.

Conventionally, CRT graphic display systems can be roughly divided into TV rask scanning systems and random scanning systems.

The TV Rusk scanning method allows for the display of a large amount of data, that is, the ability to display multiple types of screens in a composite manner, but because of this scanning method, it is difficult to draw straight lines accurately and beautifully.

be. Particularly when drawing a nearly horizontal line segment, it is inevitable that it will look like a staircase.

On the other hand, the random scan method can display thin, beautiful characters and full straight lines, but there is a limit to the amount of display due to the two-hour refresh time and writing speed. Therefore, a method can be considered that takes full advantage of the advantages of both methods and allows the display to be performed in a time-sharing manner that takes advantage of the characteristics of each.

This method (commonly known as TVMix display) is sometimes used in air route control systems using radar. In other words, radar raw video′! ! T with f-TV scan converter
Radar data and map data that have been converted into V-video and separately processed by a computer are displayed in a time-division manner using a random scanning method. Figure 1 fa) and Figure 2 (a) are
Show me this reed.

In addition to the radar video being displayed using the TV register scanning method, symbols such as AB, mouth, and one spacing are superimposed and displayed using the random scanning method. Figure 2 (a) shows the time relationship, and the random scan has a 60Hz period (
Refresh) is performed using only a small amount of time shown in the shaded area.

That is, in such a time division display method, Tv
In order to secure the time for register scanning, there is always insufficient time for random scanning, which has the drawback that the amount of data that can be displayed by random scanning is limited.

The invention is to automatically cut a portion of the top and bottom of the TV register scan and give priority to the entire random scan display when the amount of random scan display data increases in the TV register scan and random scan time division graphic display. All methods are provided.

Generally, on the Tv register screen display screen, even the upper (hatched area) has little effect. When calculating specifically, TV
Even if the scan is cut by 10% each (total 20%), only about 10 qb of the radar display screen (circular shaded area) will be cut in total.

The present invention makes full use of this fact and constantly monitors the amount of data required for random scan display, and if the amount of data increases, the TV
The purpose of this invention is to provide a time-division display system that automatically cuts only the required time from the top and bottom of the entire register check.

The gist of the present invention will be fully explained with reference to FIG. Figure 2(a)
represents the timing when a random scan time of ΔT is introduced into a TV register having 60 tlz field interlace scanning. tn(St)'a(Ei) and tn
(S2) and tn(Ez) respectively indicate the beginning and end of the raster scan corresponding to @1 figure (a). Suffix 1.2
indicates even-odd fields of intermittent scanning. Now, the amount of random scan display has increased, and the random scan time is set to 2nd.
As shown in Figure (b), if ΔT has to be increased to ΔT1, the random display that exceeds ΔTi at first will be transferred from the input field to the TV register by ΔT'-ΔT→ within the TV register display time. , it is desirable to cut it evenly at the bottom.

That is, the present invention is characterized in that it constantly monitors the time required for random scan to give priority to random scan display while minimizing the influence on TV register scanning.

Next, examples of the present invention will be described. It is assumed that the number of raster horizontal scanning lines is 945, the number of effective horizontal scanning lines is 800, and the intermittent scanning Kanakura 60Hz scanning method is used. In this case, in FIG. 2, it becomes 2.56 m5. (In fact, Flyno (2.5 m during ΔT with time remaining) 8
An example of a method for automatically increasing the random scan time from ΔT in Figure 2 to ΔT° in order to increase the display amount is shown in the block diagram in Figure 3 and the timing in Figure 4. This will be explained using figures. If the display amount decreases, the random scan time automatically returns from ΔT″ to ΔT.

In FIG. 3, the timing pulse generator 11 generates a pulse 102 at a horizontal scanning interval H (a in FIG. 4) and a clock pulse 101 twice as fast as the horizontal scanning interval H (a in FIG. 4). The field counter 12 counts all the clock pulses 101 and produces field pulses 103 (b) f in FIG. 4 every 945. At field pulse 103, raster end counter 13 starts counting clock pulses 101, typically 800 (
400H phase) Count and raster end pulse 104
(C in FIG. 4) 'jFr is generated and the random scan time register 16t is turned on. This register-on signal 109 (g in Figure i!4) completely permits the random scan control section 17 to perform random scanning on the CRT monitor section 31. When the random scan is completed, the random scan control unit 17 returns the refresh end signal 108 (d in FIG. 4) to the t-random scan time register 16 and resets it. This register on signal 109 is supplied to the random scan time counter 14, and the horizontal scan pulse H102k
It is counted and compared with a preset random scan time value of 72.5H, and if it is smaller, it is left as 72.5H. (When there is τ in Figure 4) If the amount of display due to random scanning is large and the random scan time exceeds 72.5Hk, (when τ in Figure 4)
The random scan time register is shown in Figure 4 d',
As shown in e, the refresh end 108 signal is synchronized with the clock pulse 101, and based on this, the random scan time counter calculates the extra required ft random scan time (ΔT1 - ΔT in Figure 84)? , horizontal scanning pulse H102
quantize and measure. The % value 106 of this measurement value is subtracted from the initial setting raster scan H count value 105 (400H, 800 clock pulses) using the subtracter, and the result 107 is the raster end pulse 104 generation time of the raster end counter 13. Control. C' in FIG. 4 shows that the timing of normal C has changed due to the increase in random scanning display. ΔT? <ΔT, the timing automatically becomes C timing.

The purpose of quantizing to (ΔT'-Δ'I'')=iH is to simplify the control process.

Vertical scanning signal generator 2 based on field pulse 103
1 is based on the vertical scanning sawtooth wave 111ffi and the horizontal scanning pulse H102, and while fully controlling the even-odd field counter 22, the horizontal scanning signal generating section 23 generates the horizontal scanning sawtooth wave 112. The raster scanning permission signal 113 (reverse waveform of FIG. 4g) is controlled by the gate 24 and supplied to the CRT monitor section 31 (121, 12
2) Raster scanning is performed.

The random scan display amount is determined by a command from the input unit 32.
The computer 33 fully controls the rift Vtsche capacity of the random scan control section 17 and determines it.

As explained above, the present invention is configured to automatically reduce the total raster scan display time according to the amount of random scan display, thereby converting the random scan display that allows accurate display into the raster scan display. This has the effect of making it possible to give priority to

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of time-sharing Tv register scanning display and random scanning display on a CRT, FIG. 2 is a timing diagram of the time-sharing display, and FIG. 3 is an embodiment of the present invention. FIG. 4, a block diagram illustrating an example, is a diagram representing an explanatory timing diagram in one embodiment of the present invention. 11...timing pulse generator, 12...
...Field counter, 13...Raster end counter, 14...Random scan time counter, 15...Subtractor, 16...
- Random scan register, 17...Random scan control section, 21...Vertical scanning signal generation section, 22...Even-odd field counter, 23.
...Horizontal scanning signal generation unit, 24...Gate, 31...CRT monitor section, 32...
・Enter 9- Blade part, 33... Computer.
, -111,10- 2 pieces Ez E/ 4 pieces! Half 4 figures

Claims (1)

[Claims] Time-sharing combination of TV rask scanning and random scanning, C
In the RT graphic display method, the time required to display the random scanning display data is constantly monitored, and when this time exceeds a predetermined amount, the time required to display the random scanning display data is automatically set at the beginning and end of the TV scanning time. This CRT graphic display system is characterized by cutting out part of the Tv rask scanning display and giving priority to the random scanning display.