JPS60254321A - Raster scanning type display device - Google Patents

Abstract

PURPOSE:To simplify the constitution of a color hard copy side by providing a display device with a rewritable LUT (look-up table) for three colors of Y, M and C in addition to an LUT for three colors of R, G and B. CONSTITUTION:The LUT for R, G, B which is constituted of a RAM is accessed by using color codes read out from a picture memory 3 as its addresses, the respective codes are converted into the luminance information of respective colors and the luminance information is converted into analog signals by a D/A convertor 5 and outputted to a CRT. The LUT for Y (yellow), M (magenta) and C (cyanine) is also prepared in the LUT13 and color codes from the picture memory 3 are used as the addresses of the LUT for Y, M, C, converted into the luminance information of Y, M, C and sent to a color hard copying device. Since the LUT13 is constituted of a RAM, the LUT13 can be connected to various color hard copying devices having the different number of display colors and a slow clock is prepared for the color hard copy, so that interface is easily attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a raster scanning display device having a look-up table (hereinafter referred to as LUT) connectable to a color hard copy device.

[Prior art and its drawbacks]

Equipped with an LUT that can be connected to a color hard copy device
In a raster scanning type display device, the video signal generation circuit has a RAM having a capacity of 2"X s'
Brightness information corresponding to each color code is controlled by software for the LU'l'' configured with The stored n-bit luminance information for each color is output, and once the information is synchronized, it is subjected to D/A conversion and then level conversion is performed.

Then, the generated video signals R (red), G (a), B
C blue) (hereinafter referred to as R, G, and B) are supplied to the ORT, the vertical copy device, and other devices.

Also, in color hard copy devices, R and G.

The B video signal is made high-speed and undergoes complex internal conversion,
Y (yellow) 1M (magenta) IC, which is the 6 primary colors of subtractive color mixing
(cyan) (hereinafter referred to as Y, M, O).

The disadvantage of conventional task scanning display devices is that the R of the video signal
. It is something that must be done.

Further, the operating clock frequency of the task scanning display device is generally a high frequency of several 10 MHz to several 100 MHz, and the video signal is also high speed, making it extremely difficult to interface with a color hard copy device.

[Purpose of the invention]

The present invention provides a task scanning type display device having an LUT that can be connected to a color hard copy device.
It consists of a 5-color LUT and a YMO 3-color RAM with a capacity that corresponds to the number of image memory planes and gradation, and the LUT can rewrite the brightness information of each color corresponding to each color code according to the gradation using software. By adding the 71-color hardcopy device and directly supplying its output to the color hardcopy device, the complicated internal conversion circuit of the color hardcopy device is unnecessary, and the circuit can be configured with fewer elements, allowing color hardcopy devices with different numbers of display colors to be used. The purpose is to enable connection with a copying device.

In addition, since each operation clock of a TESQ scan type display device is generally high-speed, an oscillation circuit for the color hard copy device is provided, and when copying starts, a low-speed clock for the color hard copy device is selected by the copy start signal. During color hard copy printing, all processing is carried out by the clock, and once the printing is finished, a frequency conversion circuit that makes it possible to switch back to high speed and lock, and the oscillation circuit for the hard copy machine mentioned above are added, and the color DESCRIPTION OF THE PREFERRED EMBODIMENTS [Structure of the Invention] Aiming to facilitate the interface with a hard copy device [Structure of the Invention] An embodiment of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a block diagram illustrating an embodiment of the present invention, and shows a video signal generation circuit of a task scanning type display device.

The above circuit consists of a shift register 12 which converts a color code 24 of m (number of planes in the image memory)) l (dots per plane transferred at a time) bits sequentially transferred from the image memory 3 into a color code 25 of m bits. and L
Color code 25 of the information bit indicated by UT counter 11
For this, brightness information 1.6 and 17, which can be changed by software and corresponds to the gradation, is written into the RAM and stored, and when read out, the color code 25 of each bit given from the image memory is used as an address. 2 town exports that output the stored luminance information 18.19 data.
L'T7T13 composed of a bit RAIIr, a latch 14 for synchronizing the data, and the R, G, B luminance information 20 of the output is converted into the R, G, B video signal 2.
It consists of a D/A conversion circuit 15 for converting into 1.

In FIG. 1, using the output value of the LUT counter 11 as an address, brightness information 16 and 17 of each color according to the gradation, which is data corresponding to each address, is written in advance to the LU'l'' 15 by software. .

Then, input the m x x bit color code 24 from the image memory 5, convert it into a dark bit color code 25 by the shift register 12, and output the brightness information 18.19 stored in the LUT 13 corresponding to this color code. , after inputting it to the latch 14 to synchronize each data,
The R, G, and B luminance information 20 is D/A converted by a CRT 6 D/A conversion circuit 15, and after further level conversion, the R, G, and B brightness information 20 is converted to R, G, and B luminance information.

B is supplied as the video signal 21 to 0RT6, and Y, M
, O is directly supplied to the color hard copy device 7 as a digital signal.

FIG. 2 is a block diagram illustrating another embodiment of the present invention, and shows a task scanning type display device.

The above device includes a host computer 8. A control unit 1 includes a processor that communicates with the tablet 9I keyboard 10, etc., a processor that generates the coordinate values of the line segment and controls the operations of each part, and calculates the slope, length, etc. of the line segment based on the coordinate values of the line segment, etc. A straight line/character generating circuit 2 that generates nine straight characters by performing DDA calculation, an image memory 5 that stores the address information of one character of the straight line, and a color hood that sequentially inputs color hoods from the image memory 5. The brightness information corresponding to the color code is output from the LUT 13 in FIG.
In addition, the R, G, and B video signals 21 are D/D in FIG.
5. A video signal generation circuit 4 which is converted into an analog signal by the A conversion circuit 15; and an oscillation circuit 5 for CR1 display and color hard copy device for supplying operating clocks to each block; α, and a frequency conversion circuit 23 which switches between the two types of clocks using a copy start signal and supplies each block as a 48% clock.

The operation of the frequency conversion circuit 23 is performed when the copy start signal is “
In other words, if the information on the σRT screen is not printed on the color hard copy device 7, the OR of the oscillation circuit 5α
Divide the frequency of the very high-speed lock φG for T display into the necessary frequency, supply several clocks with different frequencies to each block, and generate a 1 copy 1 start signal or "H", that is, the color hard copy device 7. When starting printing, the relatively slow clock φH for the color hard copy device 7 of the oscillation circuit 5α is selected and supplied to each block as φSs.

Then, at the end of printing, the copy start signal &Y becomes "L", so φG is selected again, and 48% of the frequency of φG is supplied to each block.

〔Effect of the invention〕

As described above, according to the present invention, in a task scanning display device having an LUT that can be connected to a color hard copy device, Y +
Brightness information corresponding to the gradation of each color is rewritten by software according to the gradation of the color notebook copying device for each color code.

Add a LUT consisting of possible RAM, and its Y,
By supplying the LUT output of M, 03 colors to a color hard copy device, the R,
The extremely complex circuit with a large number of elements on the color hard copy device side, which converts G and B video signals into Y, M and O digital signals according to the gradation, is simplified on the rask scanning display device side. Moreover, it can be configured with a circuit with a small number of elements, and can be connected to color copying devices with various numbers of display colors.

In general, the operating clock of each part of a Tesque scanning display device is very high speed, so when printing a color note copy, a frequency conversion circuit and color converter circuit that uses a copy start signal to switch from a high speed clock for graphics to a relatively slow clock for color hard copy devices. By adding an oscillation circuit for the hard copy device, the interface with the color hard copy device can be facilitated, and the number of elements in the interface circuit on the color hard copy device side can also be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a video signal generation circuit of a TESK scan type display device showing an embodiment of the present invention, FIG. 2 is a block diagram of a TESK scan type display device showing another embodiment of the invention, and FIG. 4 is an explanatory diagram of an example of an LUT input Cadeka data format controlled by software, and FIG. 4 is an explanatory diagram showing the internal structure of the LUT. 1...Control unit 2...Line/character generation circuit 5...Image memory 4...Video signal generation circuit 5...Oscillation circuit 5α...Oscillation circuit 5 consisting of two types, one for color hard copy device and one for ORT display 6...0RT 7...Force 2-Hard copy device 8...
Host computer 9...Tablet 10;Keyboard 11...LUT counter 12...Shift register 15...Lookup table 14...Latch 15...D/A conversion circuit 16... ...Brightness information ("r G* B)17...
Brightness information (Y, M, 0) 18...LUT output signal (RIG, B) 19...L
UT output signal (Y, M, 0) 20...R, G, B luminance information -θ 21...R, G, B video signal 22...Y, M, O luminance information 23. ...Frequency conversion circuit 24...m x x bit color hood 25...
Color hood of KABIT Applicant: Seiko Electronic Industries Co., Ltd. Representative Patent attorney: Tsutomu Mogami Figure 3 Figure 4, χ is the number 91

Claims (1)

[Claims] (1) An image memory that stores color codes, and pre-stored R (red) ( ) (green) B (blue A look-up table consisting of a RAM that outputs the brightness information of the three colors, a D/A converter that converts the brightness information of the three colors from digital signals to analog signals, and a clock that is supplied to all of the above circuits. It consists of a raster scanning type display device having an oscillation circuit for
A raster scanning type display device having a color hard copy output, characterized by an additional RAM for a color hard copy device (cyan). (2. Rask scanning type according to claim 1 - In a display device, a frequency conversion circuit that makes it possible to switch between a clock for a CRT display and a clock for a color hard copy device, and an oscillation for a color notebook copy device) A raster scanning display device characterized by the addition of a circuit.