JPS6190231A - Laser beam hard copy printer - Google Patents

Abstract

PURPOSE:To use the paper efficiently by reading and printing the picture element signal for the sub-scan direction of the CRT since the time of picture element signal per one picture element becomes shorter as the resolution of CRT becomes higher. CONSTITUTION:When a microprocessor 10 recognizes that the reception of picture element signal is all completed from a vertical synchronizing counter 25, it commands a main controller 13 to start the printing process. A laser scanning start signal is outputted from the controller 13. The output of a dot counter 23 which counts the output of an oscillator 18 generating the pulse of the same length as one picture element of laser in the main scan direction and the output of a raster counter 24 which counts the number of scan in the sub-scan direction of laser give the read address to a picture element memory 15 through an address multiplexer 19. The 8-bit parallel data read from the picture element memory 15 is outputted to a multiplexer 16, and one bit is selected and outputted to video amplifier through a control circuit 7 as a video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a raster scan type C11, T display device hard copy device, and is particularly a laser beam printer type hard copy device suitable for those using a high resolution CRT. Regarding.

[Background of the invention]

Conventional devices, as described in Japanese Patent Publication No. 55-39030, are equipped with a buffer memory to store the luminance signals from the OR, T display device.However, as the resolution of CRT increases, the 17i The pixel contact time becomes shorter and the circuit for receiving pixels becomes expensive and technically difficult. Also,
B4. When making hard copies on A3 size paper or the like, in order to effectively use the paper, it is necessary to read out pixel signals in the CR, TQ sub-scanning directions and align the paper and CRT directions.

That is, if this is not done, the scanning directions of the printer (laser) and CRT will match, as shown in FIG. 2, and the screen and paper will not be aligned.

[Purpose of the invention]

It is an object of the present invention to provide a low cost, paper interface to high resolution raster scan CRT display devices.

An object of the present invention is to provide a laser printer type hard copy device that can be used effectively.

[Summary of the invention]

In CRT display devices, CR, T high snoring]7 With the increase in image resolution, l! l! Since the time per pixel of the jli element signal becomes shorter, by sampling and using it instead of using it continuously in the main scanning direction of the 4-beam,
If the time per pixel is increased, and if the laser scanning direction of the laser beam printer and the electron beam scanning direction of Cl ('r) match, paper cannot be used effectively.
By reading and printing pixel signals in the RT sub-scanning direction, paper can be used effectively.

[Embodiments of the invention]

FIG. 3 shows the operating principle of a laser beam printer, in which the pixel signals to be printed are Cl(, the data receiving device 7 which receives them from the T-display device 8, and the video signal output from the data receiving device 7). A laser diode 2 whose modulated emission is controlled by a video amplifier 1 that amplifies the light, a coupling lens 3 that aligns the emitted beam of the laser diode 2, and a deflection mirror 5 that is rotated by a scanner motor 4. An image is created by a graphics process.

The data receiving device 7 of such a laser beam printer generates pixel signals received from the CRT display device 8 and stored in accordance with the horizontal scanning position of the beam spot and the drum rotation position as a video signal.

FIG. 4 shows the configuration of the data receiving device 7. The microprocessor 10 operates according to the program written in the program memory 11. The main controller 13 performs sequence control, error detection, error display control, etc. of the laser beam printer, and notifies the microprocessor 10 via the main controller interface 12 that the printer is capable of printing. 10 microprocessor control signal interfaces 14
The ready signal and the busy signal inform the CR, T display device 8 that hard copy is possible.

The CR,T display device 8 outputs a print signal to the control signal interface 14 to request the start of the print job. When the CRT display unit 8 receives the busy signal, it outputs a horizontal synchronization signal.

The pixel signal is transmitted in synchronization with the data synchronization signal.

Pixel No. 1g, which is a serial data signal, is sent to the shift register 20.
is converted into 8-bit parallel data and stored in the pixel memory 15.
is memorized. The storage address of the pixel memory 15 is a horizontal synchronization counter 21 that counts the number of horizontal synchronization signals and a data counter 22 that counts the number of data synchronization signals.
and is input via the address multiplexer 19.

FIG. 5 shows the screen of the CRT display device 8. As shown in FIG. The transmission order of pixel signals output from Cf(,T display device 8) is shown below.

In the case of interlacing, the first time Hl(1 le, Hl(2 le,...Hl(160
)■H3ω■,H3(2)■,... ...H1023(160)■ 2nd time I2(1ru, I2(2)■,...)I2(1
60) ■H4 (1) ■, H4 (2) ■, ... ... H1024 (160) ■ 16th I2 (1) ■, H2 ■■, ... I2 (16
0) ■H4 (1fu, H4■■, ......H1024 (160)■ Transfer one screen worth of data at odd and even times.

In the case of non-internose, the first Hl (1 residence, H1αm,...Hl (160)
■H2 (1 le, H2 ■■, ... ... H1024 (160) ■ 2nd time Same as the 1st time 16th time Hl (IX13), Hl (1) @, -H1 (
160)■H2■■, H2αfu,......H1024(160)■ Transfer one screen worth of data every odd or even number of times.

Pixel signals are transmitted according to the timing charts shown in FIGS. 6 and 7, and all pixel memos 17151c are stored.

Returning to FIG. 4 again, when the microprocessor 10 learns from the vertical synchronization counter 25 that counts the number of vertical synchronization signals that it has finished receiving all the pixel signals via the control signal interface 14, it sends the main controller interface. Main controller 1 via 12
3, outputs a command to start the printing process.

From the address multiplexer 19 to the pixel memory 15
The signals output to the horizontal synchronization counter 21 and data counter 22 are switched to the dot counter 23 and raster counter 24.

When a laser scanning start signal is output from the main controller 13, the output of the dot counter 23 which counts the output of the oscillator 18 which generates a pulse with a length of -J for one pixel in the main scanning direction of the laser, and the output of the laser sub-scanning signal are output. The output of the raster counter 24 that counts the number of scans in the scanning direction provides a read address to the pixel memory 15 via the address multiplexer 19.

The 8-bit parallel data read from the pixel memory 15 is output to the data multiplexer 16, and one pit is selected from the 8 bits and output as a video signal to the video amplifier 1 via the V-za control circuit 17. , the laser diode 2 emits modulated light.

As shown in FIG. 1, the scanning direction of the laser of the V-beam printer and the scanning direction of the electron beam of the CRT display device 8 are different, and as mentioned above, the pixel signals of one screen are transmitted from the upper left of the CRT display screen. Since they are not transmitted in the same order as the scanning of the electron beam, uai! memory 15
The address output to is not incremented by one address starting from address O.

Data counter 22 that counts the number of data synchronization signals
outputs HA3 to HA7, and outputs t-VAO to VA13 of the horizontal synchronization counter 21 that counts the number of horizontal synchronization signals.
, the output of the dot counter 23 that counts the number of pixels in the main scanning direction of the laser is DAO to DA9, and the output of the raster counter 24 that counts the number of pixels in the sub-scanning direction of the laser is R, AO to RAIO. The address signal outputted to the 1ili7 element memory 15 via the address signal 19 is as shown in FIG.

The addresses of the pixel memory 15 are AO-A17, Do-D
2 is a selection signal output to the data multiplexer 16. When a pixel signal is received from the CRT display device 8, the shift register 20 stores it in the pixel memory 15 8 bits at a time, so the DO-D2 is safe. In FIG. 8, the addition of N to AO to DA9 indicates that the logic is inverted.

〔Effect of the invention〕

According to the present invention, the data length per pixel can be increased even for pixel signals from a raster scan type CRT display device with low resolution, so that the cost of the interface circuit between the CRT display device and the hard copy device can be reduced. be able to.

Also, since the paper and CRT screen can be aligned in the same direction, paper can be used more effectively.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the paper and the CB and T screens when the scanning directions are changed according to the present invention, and Figure 2v is a diagram showing the relationship between the paper and the CILT screen when the scanning directions are made the same. The figure is a block diagram showing the configuration of the laser beam printer, FIG. 4 is a block diagram showing the configuration of the data receiving device, and FIG.
The RT screen, FIGS. 6 and 7 are timing charts of pixel signals, and FIG. 8 shows pixel memory addresses. 7... Data receiving device, 8... CRT display device, 15... Pixel memory, 19... Address multiplexer.

Claims (1)

[Claims] 1. In a hard copy device having means for receiving and storing pixel signals from a raster scan type CRT display device and a laser beam printer for recording an image on paper based on the stored pixel signals, It is characterized by providing means for receiving and storing pixel signals sampled and transmitted in the scanning direction, and means for reading out the pixel signals stored in this means in the sub-scanning direction of the CRT display device and applying them to the laser beam printer. Laser beam printer type hard copy device.