JPS60201386A - Display unit - 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 the Invention The present invention relates to a display device, such as a color graphics display, in which one pixel corresponds to a plurality of bits.

BACKGROUND TECHNOLOGY AND PROBLEMS The so-called graphics display is performed using a device as schematically shown in FIG. In the figure, addresses, data, and write/continue control signals from a drawing circuit (1) are stored in a graphics random access memory (RAM) (2).
1 and the desired graphics data is supplied to the RA
M (2) is written to each address. Furthermore, the address from the main control circuit (3) is supplied to the RAM (2), and the data at this address is successively output and supplied to the video signal conversion circuit (a), and the synchronization signal from the control circuit (3) is Signals and the like are supplied to a conversion circuit (4) to form a °ζ graphics video signal, which is output to an output terminal (5).

In such a display device, if the display is monochrome, l
l! +1 bit of data is sufficient.

FIG. 2 does not show the specific configuration of the device for this purpose, and here, in the drawing circuit (1), for example, as shown in FIG. 3, the memory addresses (
21), (22), . . . (2n) are accessed at the same time, and 1-bit data is written simultaneously in response to these accesses. Therefore, when rewriting only one pixel among these multiple pixels, in order to eliminate the influence on other pixels, read the data of each pixel once, rewrite only the necessary data of the successive data, Each data including this rewritten data is sent to each pixel address (21) ~
Write to (2n), read modify write (R
On the other hand, when displaying color graphics, one pixel is provided with a predetermined number of bits, so that, for example, 3 bits can display 23=8 colors. be done. In this case, data writing/rewriting, etc. is considered to have three aspects for each digit of the bit, and writing/rewriting is performed for each song.

Therefore, writing/rewriting time is required three times longer than in the case of single color described above. Furthermore, when displaying 28=256 colors using 8 bits, 8 times as much time is required, and the time required to form one screen becomes extremely long, resulting in a significant drop in so-called drawing speed.

On the other hand, in order to be able to write and rewrite the above-mentioned bits simultaneously in parallel, 3 times as much hardware would be required for 3 bits, and 8 times as much for 8 bits, making the circuit configuration extremely complicated. Realization is impossible.

Furthermore, in the display of color graphics, so-called tiling is performed in which two different colors are alternately displayed on adjacent pixels to produce a color that is a mixture of the two colors as a whole. According to this, 3 bits provides 82-64 colors, 8
It is possible to display approximately 60,000 colors (2562 bits).

However, in the past, such tiling had to be set sequentially for each pixel, which required an extremely large amount of time and effort.

OBJECTS OF THE INVENTION The present invention takes these points into account and provides a simple configuration that allows for the display of good color graphics.

Summary of the Invention The present invention provides a display device having a memory device in which a predetermined plurality of bits are associated with a tii element, a write control circuit that forms one bit of write data for one pixel, and a write control circuit that forms one bit of write data for one pixel; A register with the number of bits corresponding to the bit is provided,
The write data is gated by a write control signal from the write control circuit to perform the above II! This is a display device in which the output of the register is supplied to the write control terminal of the pixel, and the output of the register is supplied to the data terminal corresponding to a plurality of predetermined bits of the pixel. With this configuration, it is possible to display good color graphics.

In FIG. 4 of the embodiment, the drawing circuit (1) is a circuit for displaying the above-mentioned monochrome graphics. This drawing-1i (1
) is supplied with a potential of ζ"1" via a resistor, and each line is connected to a gate circuit (6).

In addition, a write/continuation control signal from the drawing circuit (11) is supplied to the gate circuit (6), and the gate circuit (6) is made conductive only in the write mode.Each line through this gate circuit (6) , respectively memory addresses (21) (22
) ... Connected to the write/continue output control terminal (2n).

Further, (71), (72)... (7n) are registers each having the same number of bits as the bit number of addresses (2i) to (2n), and these registers (71) to (7n)
) are connected to data inputs at addresses (21) to (2n), respectively.

In this device, each register (71) to
(7n) are set with desired color data, and all 0'' is output to each display data line of the drawing circuit (1), so that when the drawing circuit (1) enters the write mode, these "0" puts each address (21) to (2n) into write mode, and the data in registers (7z) to (7n) are written to addresses (21) to (2n).

Also, during rewriting, according to the RMW procedure, data of 0 and 1 are sequentially output from each display data line.The display data of the next necessary address is rewritten to 0''. Display data is output.When the write mode is entered in this state, the gate circuit (6)
"Display data is output with only the necessary addresses set to "0", and only those addresses are set to write mode.
Data from the register is written.

In this way, only the data at the necessary 'address' is rewritten. Note that the gate circuit (6) outputs “1” when not conducting.
” is output.

In this way, color graphics data is written and rewritten. According to the above-mentioned device, color graphics display data can be written using the conventional drawing circuit for car color graphics. It can be read and rewritten, and color graphics can be displayed with a simple configuration. Note that since it is only necessary to create registers for the number of addresses that are accessed at one time, the amount of hardware that is increased by this is small.

Furthermore, since all bits are written at the same time, the drawing speed does not decrease. Furthermore, since only desired addresses are rewritten during rewriting, other addresses accessed at the same time are not affected.

Furthermore, since a different color can be set for each pixel from each register, the above-mentioned tiling can be performed extremely easily.

Note that the register is not all pixels, but any decimal W
! One register may be provided in common for the A elements. In that case, for example, as shown in FIG.
If two registers (7a) and (7b) are connected alternately to every other address, this register (7a)
, (7b) can automatically perform tiling by setting different colors. Furthermore, by alternately inverting these depending on the vertical position, tiling in the vertical direction can also be performed automatically.

Effects of the Invention According to the present invention, it has become possible to display good color graphics with a simple configuration.

[Brief explanation of the drawing]

1 to 3 are diagrams for explaining a conventional device, FIG. 4 is a configuration diagram of one example of the present invention, and FIG. 5 is a configuration diagram of another example. +1) is a drawing circuit, (21), (22)... are memory addresses, (6) is a gate circuit, (71), (72)...
・ is a register. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a display device having a memory device in which one pixel corresponds to a predetermined plurality of bits, ll! ! A write control circuit that forms 1-bit write data in the i element and a register whose number of bits corresponds to the predetermined plurality of bits are provided, and the write data is written from the write control circuit. A display device in which a control signal is supplied to a write control terminal of the pixel by a gate signal, and an output of the register is supplied to a data terminal corresponding to a predetermined plurality of bits of the pixel.