JPS5831590B2 - Brightness control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brightness control method for a display device, such as a character display device, and particularly to a brightness control method that can control the brightness and color of characters.

Conventionally, in brightness control for a single character, for example, in color display, a character code and a color specification code are sent as a pair from the center, separated by the controller of the display device, and the character code is stored in the character code register. , the color designation code is stored in the color designation register, and then the character pattern is read out from the character generator according to the character code, and the video signal of the character pattern is synchronized with the character code and outputted from the color designation register. Gate control was performed using designated signals to control the color of the CRT's cathode and characters in a desired color.

Another conventional example is to store a color designation code corresponding to each character pattern in a refresh memory that stores the patterns of all the characters to be displayed on one screen, and when refreshing, the character pattern and color designation code are read out and color display is performed. was being carried out.

However, even when there is no need to change the color pattern, when only the characters to be displayed are to be changed, the contents of the color specification code storage register or refresh memory are rewritten by specifying the color specification code together with the character code each time.

For this reason, the conventional method has the disadvantage that high-speed display cannot be performed.

Also, since a color is specified for each character, it would have been possible to display parts of the characters in different colors.

Furthermore, since character patterns and color designation codes are stored in the refresh memory, there is also the drawback that control is complicated.

The purpose of the present invention is to eliminate the disadvantages of the conventional method.
The first region is further divided into n2 Xm2 (n2≦nl 1m2≦m1
), the brightness control information string of the first area is stored in advance in a brightness control memory provided separately from the screen memory, with the second area as a unit; This is achieved by reading a brightness control information string from the brightness control memory and controlling the brightness in synchronization with refreshing the screen memory.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit block diagram for realizing the brightness control method according to the present invention, and 1 is a circuit block diagram for processing brightness input information sent from the center CNT according to a pre-stored program and outputting a memory address signal MAS and a brightness control system. A microcomputer that outputs information BI; 2 is a control unit that converts the brightness information BI from the microcomputer into a data string suitable for writing into the brightness control memo IJ3 and outputs it; 3 is a brightness control memory that stores brightness patterns: 4 is the address of the brightness control memory output from the microcomputer.
Address buffer for temporary storage: 5 is a refresh counter for refreshing the rewrite memory (screen memory); 6 is a gate circuit that passes either information from address buffer 4 or refresh counter 5; 7 is brightness control Address registers that store memory addresses: 9 is a multiplexer; 10 is a register.

A CRT screen (not shown) is made up of 1024 x 1024 pixels, and one character is made up of 32 x 32 pixels.

Therefore, considering the line spacing, 20 lines and 32 characters per line can be displayed on the screen, and characters can be displayed arbitrarily by refreshing the pattern information stored in the screen memory provided in correspondence with the pixels. Can be displayed.

Now, in the brightness control according to the present invention, <1024×1024 pixels are divided into a first region group consisting of 8×32 dots, and the first region is divided into a second region group consisting of 8.times.8 dots, and the luminance pattern is compressed and stored in advance using the second region as a unit.

FIG. 2 is a diagram showing the correspondence between brightness pattern display and pixels, and CR is an area (3
2×32 pixels), A1 to A1□.

are first regions each consisting of 8×32 pixels, 81
-B4 are second regions each consisting of 8×8 pixels.

Figure 3 is a diagram in which one screen is divided into the first area, A1
~A4096 is a symbol specifying the first area.

Referring back to FIG. 1, the present invention will be explained in detail.

Each of the brightness control memories 3 has 4096 addresses, each of which is composed of 8 bits, and the brightness pattern of the first area A1 in FIG. is the first area A2 in Figure 3.
The brightness pattern of the first area A33 in FIG. 3 is stored at the address 33, and the brightness pattern of the first area A4096 of FIG. 3 is stored at the address 4096.

Here, the brightness pattern of the first area means, in the example of color display, whether each of the four second areas that make up the first area is displayed in red, blue, or green. An 8-bit data string created by It is.

That is, if the entire first area A1 in FIG. 2 is represented in green, the brightness pattern becomes "11111111" and the first area A3
If all of 3 is represented in blue, the brightness pattern is "101010"
10'', and when displaying the first area A65 in red, the brightness pattern becomes 1''01010101'', and the second area B1.B3 of the first area A65 is displayed in red, B2 is green, B4
When expressed in blue, the brightness pattern is t011101
10” barrel.

Similarly, in the case of monochrome display, it goes without saying that the brightness pattern can be created based on brightness.

Now, when writing a brightness pattern, when the center CNT commands the start address, color information, and length of incorrect color of the brightness pattern, the microcomputer 1 stores the start address in the brightness control memory according to a pre-stored program. It is converted into an address and sent to the address buffer 5.

At the same time, the microcomputer sends color information and luminance length to the control section 2.

Now, the first address is (1, 1), the color information is green, and the brightness length is 3.
It is assumed to be 2 bits.

(1,1) indicates the position of the pixel in the left corner when the screen is divided into 1024×1024 pixels.

The control unit 2 determines the color information and its length, and first outputs a 6-bit data string.

Here, the first two bits of the above data string indicate a color code, and the third to sixth bits indicate which second area in the first area corresponds to the address specified by the address register 7. be.

That is, if we focus on the first area A1 in FIG. 2, the second area B1 in the area A1. B2. The positions of B3'' and B4 are respectively expressed as 1000.0100 and 0010°0001.

Therefore, when writing the luminance pattern in the first area A1, the data string becomes 111,000.

On the other hand, since the gate 6 operates to store the contents of the address buffer 4 in the address register 7 during the luminance pattern writing, the address register 7 contains 000...
...01 is set.

Similarly, the address register 7 is composed of a 12-pit binary counter, so the lower 5 bits are the first one in the X direction.
In the area coordinates, the upper 7 bits correspond to the coordinates of the first area in the Y direction.

However, first, the control unit 2 issues a READ command.

Contents of address 1 of brightness control memory (000000
00: is read out and input to the multiplexer 9.

At the same time, the control section 2 outputs the aforementioned data 111000 to the multiplexer 10.

The multiplexer 10 selects a second area B1 from the brightness pattern BS read from the memory 3 and the output from the control unit 2.
1" is set in the 100 bit position of the register corresponding to the 100th bit, that is, the 1st to 2nd bits, and the contents of the 3rd to 8th bits of the brightness pattern BS are set in the register 1003 to 8th bit.

Thereafter, a WRID command is issued from the control unit 2, and the contents of the register 10 (11000000) are stored at address 1.

As a result, the luminance of the second area B of the first area A1 (
green) is stored in memory 3.

Next, the control unit 2 issues a READ command and reads out the contents of address 1 (11000000) again.

At the same time, the control unit 2 outputs data 110100.

The multiplexer 10 operates in the same manner as described above to set bit positions of the register 10 corresponding to the second area B2, that is, 3 to 3.
61” in the 4th bit, 1 to 2.5 in register 10
~8 bits have brightness pattern BS (11000000)
The contents of bits 1 to 2 and 5 to 8 of are set respectively.

Thereafter, a WRITE command is issued from the control unit 2, and the contents of the register (11110000) are written to address 1.

Thereafter, the same operation is repeated, and 11111111 is written to the address 1 by the fourth WRITE command, and the writing of brightness green to the A1 area based on the command from the center is completed.

Incidentally, when the brightness pattern length command from the center is 32 bits or more, the same brightness writing can be performed by advancing the address in the address register by one.

Thereafter, the brightness patterns of the first areas A1 to A4096 can be written to the brightness control memory 3 in the same manner.

In other words, the brightness pattern is compressed to 1/64 of the capacity of the screen memory and stored.

Next, readout of the luminance pattern will be explained with reference to FIG.

Gate 6 in FIG. 1 operates to store an address in address register 7 based on the contents of refresh counter 5 except when writing.

Now, refresh counter 5 has a capacity of 1024 and has an X counter and a Y counter (10-bit binary counter).
The content always indicates the beam coordinate position in pixel units.

However, the coordinates of each pixel are converted into the coordinates of the first area and stored in the address register 7.

That is, the first area is divided into 32 pixels in the X direction, so the top 5 rows of the X-counter are divided, and in the Y direction, it is divided into 8 pixels, so the top 7 rows of the Y-counter. By storing the coordinates in parallel in the address register 7, coordinates in units of pixels can be converted and stored into coordinates in the first area.

FIG. 4 shows an embodiment for converting a luminance pattern into a pixel-by-pixel pattern, DECI to DEC4 are decoders;
AR, AB, AG are AND gates; SR, SB, S
G is a 32-bit shift register, WTP is a write timing pulse, and BS is an 8-bit brightness pattern signal.

1-2 bit signals BS1-BS of brightness pattern signal BS
2 is a 3 to 4 bit signal BS3 to B to the decoder DECI.
S4 sends 5 to 6 bit signals BS5 to decoder DEC2.
BS6 sends a 7- to 8-bit signal BS7 to the decoder DEC3.
~BS8 are respectively input to the decoder DEC4, and this
decoded with

If the input signal is "t00", "01" is sent to the output line lo.
(red) is the output line l.

1, if "10" (blue), output line 11o, 11"
' (green), a logic "1" is output to the output line 11□.

Decoder DECI has shift registers SR and SB.

It corresponds to 1 to 8 bits of SG, and similarly decoder D
EC2-EC4 are each shift registers SR.

SG, SB 9-16 bits, 17-24 bits 25-
It supports 32 bits.

The shift register SR stores a red pixel-by-pixel pattern, the shift register SB stores a blue pixel-by-pixel pattern, and the shift register SG stores a green pixel-by-pixel pattern, and each of these patterns stores a character pattern. 1 in synchronization with the refresh operation of the screen memory to be stored.
Shifted bit by bit.

The outputs of the shift registers SR, SB, and SG are connected to one input terminal of the AND gates AR, AB, and AG, respectively, and the character video signal CvS read from the screen memory is input to the other input terminal of each AND gate. The outputs are respectively the cathode RK of the red electron gun, the cathode BK of the blue electron gun, and the cathode BK of the blue electron gun of the color cathode ray tube, and the color display of the given character.

Each output line l of decoders DEC1 to DEC4.

1 (red) corresponds to 1 to 8.9 of shift register SR, respectively.
Each output line 11o (blue) is connected to bits 1 to 8, 9 to 16, 17 to 24, and 25 to 32 of the shift register SH; The lines 11□ (green) are connected to bits 1 to 8.9 to 16.17 to 24 degrees and 25 to 32 degrees of the shift register SG, respectively.

However, if the brightness pattern signal SB is 01011011, the 1 to 16 bits of the shift register SR are set to '1', the others are tt Ojj, and the 17 to 16 bits of the shift register SB are set to '1'.
24 bits contain 1", the others are "0", and 25 to 32 bits of the shift register SG contain 1", the others are t.
It becomes tOty.

That is, the brightness pattern BS in units of the second area in the first area is converted into a brightness pattern in units of pixels and stored in the shift registers 5R-8G.

After that, each shift register is shifted one bit at a time in synchronization with the refresh, and if it is output, the AND gate AR-
The light is applied to each cathode via AG to display a desired color.

When the 32-bit shift is completed, the contents of the address register 7 in FIG. 1 are incremented by one step, and the luminance patterns stored at the address are sequentially output and set in the shift registers 5R-8G again.

Thereafter, it operates in the same manner, and characters can be displayed in color on the CRT in accordance with the brightness pattern stored in the brightness control memory.

As described above, according to the present invention, the brightness pattern (color, brightness) to be displayed is stored in advance in a brightness control memory provided separately from the screen memory, and the brightness pattern is output in synchronization with refresh. Allows fine-grained character brightness control that is fast and easy to control.

In addition, the brightness control memory is configured to store the brightness pattern compressed to 1/64 of the capacity of the screen memory, and when read out, converts it into a brightness pattern for each pixel, so the capacity of the brightness memory is extremely small. can.

[Brief explanation of the drawing]

FIG. 1 shows an example of the brightness control method according to the present invention, FIG. 2 shows the correspondence between brightness patterns and pixels, FIG. 3 shows one screen divided into a number of first areas, and FIG. The figure shows an example for converting a brightness pattern into a pixel-by-pixel pattern. In the figure, 1 is a microcomputer, 2 is a control unit, 3 is a brightness control memory, 4 is an address buffer, 5 is a refresh counter, 6 is a gate, 7 is an address register, BS
is the brightness pattern, A1-A4096 is the first area, DEC
1 to 4 are decoders, SR, and SB. SG is a shift register.

Claims (1)

[Claims] 1. The screen is divided into a first area consisting of n1×m1 pixels, and the first area is further divided into n2×m2 (n2≦n1.m
Luminance control information divided into a second area defined by pixels of 2≦m, ), and configured with the brightness control information string of the first area using the second area as a unit, and provided separately from the screen memory. A brightness control method characterized in that the brightness control information is compressed and stored in a memory in advance, and a brightness control information string is successively outputted from the brightness control memory in synchronization with refreshing of the screen memory to control the brightness of the screen. 2. The brightness control method according to claim 1, wherein m1 is the number of pixels in the X direction allocated to display one character. 3. The brightness control method according to claim 1, wherein the brightness control information of the second area means color. 4. The brightness control method according to claim 1, wherein the brightness control information of the second area means brightness.