CN1107596A

CN1107596A - Quick imaging method for Chinese character laser printer

Info

Publication number: CN1107596A
Application number: CN 94100156
Authority: CN
Inventors: 倪光南; 徐非; 刘洪�
Original assignee: LIANXIANG COMPUTER GROUP CO BEIJING
Current assignee: LIANXIANG COMPUTER GROUP CO BEIJING
Priority date: 1994-01-17
Filing date: 1994-01-17
Publication date: 1995-08-30

Abstract

The quick imaging method for Chinese-character laser printer features use of hardware for image processing. CPU reads command parameters of print file from parallel port and transmits the image informtion in file to quick imaging circuit, which shifts and developes each byte of image information according to command information. Processed bytes are aligned with output buffer, or calculated and then passed to output buffer. An image accelerating technique is used to make the image processing speed higher than transmission speed of host without change in software.

Description

Quick imaging method for Chinese character laser printer

The present invention relates to the fast imaging of Chinese character laser printer.

At present, most of laser printers are all as word processing.But because Chinese word library is not carried in nearly all laser printer inside, main frame can only change character into dot matrix, sends printer to by image packets.So nearly all Chinese software all adopts the image-driven mode to printer.Printer cpu is limited in one's ability after all, during especially a large amount of image data processing more apparent slowly.Usually laser printer is when printing western language, and speed can reach 8 pages/min, but when printing Chinese character, but can only reach 0.5 page/min.Among the present invention,, utilize hardware to participate in computing, make the performance of Chinese character laser printer that remarkable improvement arranged because of having adopted the fast imaging technology.

In the LJ3A of association Chinese character laser printer, most of softwares are all according to image mode driving laser printer, and the CPU of printer adopts following steps to carry out to the information processing of image usually:

1.CPU read in the command parameter of print file from the parallel port, comprise the position of image size, image resolution ratio and the image page of living in.

2.CPU reading in one by one with the byte from the parallel port is the picture coding of unit, and is shifted accordingly according to the data of acquired picture position information to each byte of reading in, and according to different print resolution the data of each bit is expanded again.

3. content corresponding in the byte after will handling and the output buffering is carried out or (OR) computing, and the gained result is that unit sends into output buffers again with the byte.

More than three steps go round and begin again, up to inserting just output buffers of whole page or leaf.Then, begin to print.

Above-mentioned Flame Image Process is almost all finished by CPU.This not only makes CPU, and over-burden, and software execution speed has limited the entire image print speed.

The fast imaging method that the purpose of this invention is to provide a kind of Chinese character laser printer.The entire image processing process is taken over by the fast imaging technology circuit.Therefore, the burden of CPU significantly alleviates.

Technical scheme of the present invention realizes by following mode:

2.CPU start the fast imaging technology circuit, and send above-mentioned information to the fast imaging technology circuit.

3. the image information of each byte that will read in from the parallel port automatically according to the command information that is obtained of fast imaging circuit is carried out displacement and expansion.

4. will carry out or (OR) computing through aliging with the output buffering after the fast imaging technical finesse, the gained result is that unit sends into the output buffering again with the byte.

More than four steps go round and begin again, until inserting just output buffers of whole page or leaf.Then, begin to print.

Below in conjunction with accompanying drawing the present invention is described in detail as follows:

Fig. 1 is the image processing process block scheme of laser printer in the prior art

Fig. 2 is the block scheme of the fast imaging processing procedure of Chinese character laser printer

Fig. 3 is the logic block-diagram of fast imaging technology circuit

Fig. 4 is fast imaging technology circuit figure

Confirming text when printer cpu is when sending with dot matrix way, at first remembers dot matrix resolution, image size and orientation, abandons the control to bus subsequently, carries out follow-up work by the fast imaging technology circuit.

Among Fig. 3, and, the handshake between string conversion portion and the parallel port is used to control the input of parallel port data.When also, during full 8 of the clock meter of string conversion, begin the input of next view data byte.

The output buffering is the unit storage with the byte.View data also is that unit is written into the byte.But the reference position of view data often is not the integral multiple of 8bits in each row, at this moment, need with this data shift with carry out computing again after aliging in relevant position during output cushions.This part by also, string conversion and string, and conversion is common realizes that the clock of change-over circuit is controlled by corresponding counting circuit.After computing is finished, send the DMA interrupt request, by dma controller transformation result is sent into the output buffering.

The startup of change-over circuit is controlled by CPU, stops to control automatically by tale.

Two clocks to change-over circuit are described in detail below:

And, the clock table of string conversion is shown SCLK, string, and the clock table of conversion be shown FCLK.They are that clock by circuit dominant frequency 16MHz carries out frequency division according to printer resolution and obtains.For the printer of 300DPI, FCLK is identical with the frequency of SCLK, and promptly the view data of each bit need not expansion.And for the printer of 150DPI, FCLK is 2: 1 with the ratio of the dominant frequency of SCLK, and promptly the image spreading of 1bit is two bit, becomes 4bit through after duplicating, and resolution reduces half than 300DPI.In like manner, for the 75DPI printer, the frequency ratio of FCLK and SCLK is 4: 1, i.e. the view data of 1bit expansion is 4 bit, becomes 1bits after duplicating, and makes resolution reduce half than 150DPI.

Embodiment: status register 273 shift counters 161, deserializer 164, parallel-to-serial converter 165, request of data device register uses the CPU80C188 internal counter.

The present invention compared with prior art has the following advantages:

1. printer speed is doubled, and when printing with image mode, every page only needs 1 minute.

2. system compatibility is good, and the Chinese character printing drive software need not any modification.

3. when carrying out the image processing, the CPU free time, expansion is convenient in system, carries out parallel processing.

Claims

1, a kind of fast imaging method of Chinese character laser printer, it is characterized in that: CPU reads in the command parameter of print file from the parallel port, the position that comprises image size, image resolution ratio and the image page of living in, and start the fast imaging technology circuit, send above-mentioned information to the fast imaging technology circuit; The fast imaging technology circuit is according to the command information that is obtained, and the image information that will read in each byte automatically from the parallel port is shifted and launches; To align with output buffer through the byte after the fast imaging technical finesse and carry out exclusive disjunction, the gained result is that unit sends into output buffers again with the byte; More than four steps go round and begin again, up to filling up just output buffers of whole page or leaf, then, begin to print; Confirming text when printer cpu is when sending with dot matrix way, at first remembers dot matrix resolution, image size and orientation, abandons the control to bus subsequently, carries out follow-up work by the fast imaging technology circuit.And, the handshake between string conversion portion and the parallel port is used to control the input of parallel port data.When also, during full 8 of the clock meter of string conversion, begin the input of next view data byte; Output buffering is the unit storage with the byte, and view data also is that unit is written into the byte, if the reference position of view data is not the integral multiple of the 8bits in each row, then need with this data shift with carry out computing again after aliging in relevant position during output cushions; This part by also, string conversion and string, and conversion is common realizes that the clock of change-over circuit is controlled by corresponding counting circuit; After computing is finished, send the DMA interrupt request, by dma controller transformation result is sent into output buffers; The startup of change-over circuit is controlled by CPU, stops to control automatically by total counter;

2, the fast imaging method of Chinese character laser printer according to claim 1 is characterized in that: also, the clock table of string conversion is shown SCLK, string, and the clock table of conversion be shown FCLK.They are that clock by circuit dominant frequency 16MHz carries out frequency division according to printer resolution and obtains.For the printer of 300DPI, FCLK is identical with the frequency of SCLK, and promptly the view data of each bit need not expansion.And for the printer of 150DPI, FCLK is 2: 1 with the ratio of the dominant frequency of SCLK, and promptly the image spreading of 1bit is two bits, becomes 4bit after row duplicates, and resolution reduces half than 300DPI, and the rest may be inferred.