JPS6161860A - Printer control apparatus - Google Patents

Abstract

PURPOSE:To make it possible to have both of the function as a character printer and the function as an image printer in min. memory capacity, by forming the access address of pattern memory by the output data and rester number of page memory and selecting either one of output data of the page memory and the pattern memory. CONSTITUTION:At the time of the function as a character printer, the figure code transmitted from an external apparatus is converted to the internal code showing the stored address of figure pattern memory 4 corresponding to each figure code by a microcomputer 1 to be two-dimensionally arranged in page memory 3. When the output data corresponding to one page are gathered in the page memory 3, data corresponding to one line or one unit line are set to output memory 5 to start printing. At the time of the function as an image printer, image data are stored in the page memory 3 and, when the data corresponding to one page are stored, the data corresponding to one line is set to the output memory.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a printer control device for controlling a raster scan type printer.

Conventional printers generally include raster scan type printers such as digital copiers that use optical writing devices such as laser printers and dot array fluorescent tubes.

As a printer control device that controls video data generation, etc. of such a raster scan type printer, for example, 1
Data for a page is arranged two-dimensionally in the form of a figure code in the row and column directions, and the figure code is read out using the position information obtained by the raster synchronization signal during printing, and the figure pattern corresponding to the figure code is generated. There is a character map method in which graphic data is obtained by reading.

There is also a bitmap method in which graphic data for one page is developed two-dimensionally in the form of a dot image in a bitmap memory and output to a printer using raster synchronization (No. 0).

However, among such printer control devices, the former requires a small memory capacity and is capable of high-speed processing, but has disadvantages in that it is difficult to handle external image data and the degree of freedom in print position is small.

Also, the latter can handle image data from outside.

Although there is a high degree of freedom in the printing position, there are disadvantages in that the memory capacity is large and high-speed processing is difficult.

Purpose This invention has been made in view of the above points, and an object of the present invention is to enable both a character printer function and an image printer function to be provided with a minimum memory capacity.

Structure In order to achieve the above object, the present invention includes a page memory that stores printer data for at least one page, a pattern memory that stores one graphic pattern, and an access address of the pattern memory based on the output data of the page memory and a raster number. , and selection means for selecting output data of the page memory and pattern memory.

Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

FIG. 1 is a block diagram showing an example of a printer control device embodying the present invention.

A microcomputer (hereinafter referred to as "microcomputer") 1 includes a CPU, ROM, RAM, Ilo, etc., and controls the entire control device, controlling each part based on a program stored in an internal ROM.

The external interface 2 connects various external devices (not shown) such as an image processing device 2, a document processing device, and a business computer.
It is responsible for exchanging graphic code (including character code) data, image data, and control code data with the host system.

The page memory 3 is a memory that stores print data, and has a capacity that can store at least one page of print data.

The graphic pattern memory 4 is a memory that stores graphic patterns such as single character patterns, and is composed of a ROM that stores character patterns in advance or a RAM that downloads character patterns and the like from an external device when necessary.

The output memory (output buffer) 5 is a memory in which one line or one unit (described later) of output data is set during printing, and has a data capacity of two lines or two units. , used alternately for data input and output.

The output data read from the output memory 5 is output to a parallel-to-serial converter 12, which will be described later, and is also output to the graphic pattern memory 4 as address data.

A CG controller (CGC) 6 outputs position information obtained by counting raster synchronization signals from a raster scan type printer 7 such as a laser printer to the output memory 5 as address data, and also outputs raster numbers (line numbers, ) is output to the graphic pattern memory 4 as address data.

Therefore, this graphic pattern memory 4 is accessed with the output data of the output memory 5, that is, the address data generated from the output data and raster number of the page memory 6.

In other words, the CGC 6 constitutes an address generating means that generates an access address for the graphic pattern memory 4 based on the output data of the page memory B and the raster number.

The data selector 8 and the address selector S are selectors that control switching of data and addresses for the graphic pattern memory 4.

The data selector 10 and the address selector 11 are selectors that control data and Natres switching for the output memory 5.

Parallel-serial (p-s) converter 12 has one figure pattern memory 4
Or convert the parallel output data read from the output memory 5 into serial data (P → S conversion),
Output to printer as video data.

The printer interface 1!1 controls the transfer of control codes to and from the printer 7 and the exchange of Ready 4H and the like from the printer 7.

Next, page memory B will be explained with reference to FIG.

In this page memory B, if the data from the external device is image data, that image data is stored as is, and if it is graphic code (including character code) data, the microcomputer 1 corresponds to each graphic code data. The internal code is converted into an internal code indicating the storage address of the graphic pattern memory 4, and the internal code is two-dimensionally arranged according to the control code.

Pine pink in this page memory B will be described with reference to FIG. Here, we will discuss the case of a vertical mode in which the main scanning direction and the line direction match, but the same can be considered in the case of a horizontal mode in which the main scanning direction and character direction match, so the explanation will be omitted.

First, a general character map method is shown in FIG. 2(a), but this method cannot handle proportional fonts.

Therefore, mapping is performed here using the unit width (basic convergence) of the proportional font, as shown in FIG.

In this case, ■Unit U is 5 units as shown in the same figure (C).
Modification information such as character type, unit number, font type, presence or absence of angle lines, etc. requires about 16 bits in total, and one character is expressed by 1 to 8 units.

Next, the one-figure pattern memory 4 will be explained with reference to FIG.

The figure pattern stored in this figure pattern memory 4 is
As shown in Figure 3, for example, the pixel density is 240 dpi.
(dots/inch), 12cPI is 6LPI
The characters become a matrix of 24x40 dots. Also,
In a proportional font, when character spacing is expressed as an integral multiple of 1/60', 1/60' is the width of one unit U, which corresponds to 4 dots.

Therefore, the required capacity of page memory B mentioned above is A
Considering 4 sizes of printing paper, assuming that the longitudinal direction is 11 inches and 660 units can be printed, and the width direction can print up to 66 lines, 87120 bytes are required (However, ① units are assumed to be 2 bytes). Here, it is assumed that a 128-byte memory is used due to the structure of the memory element.

In addition, in the case of pixel density 240 dpi, main scanning 19201
-; If the entire effective range of A4 size is formed with 2640 sub-scanning lines and supported by bitmap memory, 633.6 Kbytes of memory will be required.

However, when considering an image printer as a hard copy device for a general CRT terminal, there is no practical problem even if the pixel density is reduced to half (120 dpi). It is thought that there is no practical problem in using it as a bitmap memory.

However, when a RAM is used as one graphic pattern memory element, the amount of page memory that is insufficient can be allocated to the graphic pattern memory element for use.

Next, the 'A Ic of data between each memory will be explained with reference to FIG.

The data read from the page memory 3 is temporarily stored in the output memory 5 for one row or one unit column.

At this time, the output data read from the output memory 5 by the C:GC 6 is transferred to the graphic pattern memory 4 as part of the access address, and the start address (character type, font type, unit number) of the graphic pattern memory 4 is is specified, and at the same time, the output (raster number) of the line counter 15 in the CGCG is output as the access address of the graphic pattern memory 4, and the line number in the unit is specified.

On the other hand, at this time, the dot counter 16 determines the number of dots in one line, and counts up the line counter (address counter) 17 when one line is completed.

The data read from the graphic pattern memory 4 is then transferred to a selection circuit 18 which is one selection means.

Further, data read from the output memory 5, that is, output data from the page memory 3, is transferred to the selection circuit 18 when transferred to the graphic pattern memory 4.

Therefore, this selection circuit 18 outputs the output from the output memory 5 in response to the CHR/IMG signal which instructs either the character/image to be output according to the setting results of the character printer function and the image printer function from the microcomputer 1. Either the data or the output data of the graphic pattern memory 4 is selected.

That is, when an image is specified, this selection circuit 18 selects the output data of the output memory 5, that is, the output data of the page memory 3, and when a character is specified, the selection circuit 18 selects the output data of the figure pattern memory 4. is selected and output to the parallel-to-serial converter 12.

Next, the dot counter 15 and parallel-to-serial converter 12 will be explained with reference to FIG. 5.6 First, the relationship between the raster synchronization signal and print output will be explained with reference to FIG. Scanning has a raster gate (LGATE) signal as its valid period and a width clock (WCLK) signal as its clock, while sub-scanning has its valid period as a frame gate (FGATE) signal and its clock as a raster synchronization (Lsync) signal.

Note that the Lsync signal is assumed to be generated prior to the LGATE signal.

Returning to FIG. 5, the parallel/serial converter 12 consists of a shift register that can handle up to 16 bits.

Image data from the output memory 5 or graphic pattern data from the graphic pattern memory 4 are input.

In this case, 120 bytes of data (960 dots for images) for -main scanning lines are transferred to the output memory 5 from the page memory 3 by DMA transfer or transferred to the microcomputer 1 using the space between main scanning lines. Due to block transfer, data is stored one main scanning line at a time.

Note that the trailing edge of the LGATE signal is input to the microcomputer 1 as an interwoven signal, and when the image is
In order to achieve a pixel density of 0 dpi in the sub-scanning direction,
In odd-numbered interlinked data, the data in the output memory 5 is not updated and the same data is output as is.

In this way, image quality deteriorates because a 240 dpi printer is used as a 120 dpi printer, but it is also possible to add hardware measures such as one-dot interpolation for diagonally opposing dots.

When functioning as an image printer that outputs the data in page memory B as it is, 1 at several timings in both the horizontal and vertical scanning directions.
Expand the shape by outputting two pieces of data.

On the other hand, the clock selector 20 receives the WCLK signal and the IZ'2W signal obtained by dividing the WCLK signal by 172 (doubling the period).
CLK signal and CHR/IM from microcontroller 1.
One of the two is selected according to the G signal and output as a clock signal to the shift register (parallel-serial converter) 12 and dot counter controller 21.

As a result, when the 1/2WCLK signal is selected, the 16-bit data input to the shift register 12 is updated at a cycle of 32 clocks, and the 16-bit data input to the shift register 12 is updated at a cycle of 32 clocks.
20 dpi can be achieved.

Further, the dot counter controller 21 is set by the microcomputer 1 to operate as a hexadecimal counter before starting printing.

When the output of the 16-bit data is completed, the address counter 17 of the output memory 5 is counted up, and a load (LOAD) signal is output to the system register 12 to transfer the currently output data to the shift register 12. Let it load.

For example, for a character printer, if the height of the graphic pattern can be selected in 4-bit intervals, the parallel output of the graphic pattern memory B is 8 bits, and the height of the graphic is 28 bits.
When it is a dot, the figure address is stored in the figure pattern memory 4 at a cycle of 8-8-8-4, and the shift register 12 is
It outputs a LOAD signal to increment the address counter 17 of the output memory 5 by 1 at a cycle of 28 bits.

Note that the height of one figure pattern is set in advance by the microcomputer 1 before printing starts.
It shall be possible to set the

Next, the timing of each signal will be explained with reference to FIG.

The Lsync signal is generated one time before the L G A T E m, so it is a reset signal for the main scanning counter system.

Used for initial memory reading and creating shift register LOAD number.

Also, when the CG controller (CGC) 6 is operating, image data from the output memory 5 or figure pattern data from the figure pattern memory 4 is output to the printer, and when the CPU (microcomputer 1) is operating, it is output to the page memory filter. The read data is transferred to the output memory 5.

In this case, in the case of image data, 12
In the case of character data, it is necessary to transfer 1 unit column of data every 4 main scans in vertical mode, and 1 row of data every 28 to 40 main scans in horizontal mode. Yes, if all data cannot be transferred in one operation, it is divided into multiple transfers.

Next, the operation of this printer control device configured as described above will be briefly explained.

First, to explain when it functions as a character printer, graphic codes (including character codes) transferred from an external device are converted by the microcomputer 1 into internal codes that indicate the storage address of the graphic pattern memory 4 corresponding to each graphic code. and are arranged two-dimensionally in the page memory 3.

Then, when the output data for one page is completed in the page memory B, data for one row or one unit column is set in the output memory 5 and printing is started.

During the printing period, the alarm memory 5 and the graphic pattern memory 4 are time-divisionally controlled by the microcomputer 1 and the CGC 6 as shown in FIG.

First, the control period by the microcomputer 1 is the period required for resynchronizing the printer's main scanning and main scanning, and during this period, the output data for one line or one unit column to be printed next will be printed multiple times. The output memory 5 is divided into parts and stored little by little.

On the other hand, during the control period by CG(l), the output memory 5 and the graphic pattern memory 4 are removed from the control of the microcomputer 1 and placed under the control of the CGC 6 by the selectors 8 to 11.

Then, cacs accesses the internal code of the figure from the output memory 5 using the position information obtained by counting the raster synchronization signals from the printer 7 as an address, and uses the internal code as part of the storage address of the figure pattern memory 4. At the same time, the line number is stored in the figure pattern memory 4.
, (raster number) as the remainder of the address to obtain graphic pattern data.

The graphic pattern data thus read out from the graphic pattern memory 4 is transferred to the parallel/serial converter 12 via the selection circuit 18, converted into serial data, and output to the printer for printing.

Next, when functioning as an image printer, image data is stored in page memory B.

When one page's worth of data is stored, one line's worth of data is set in the output memory 5 in the same manner as described above.

Then, under the control of the CGC 6, the output memory 5
The output data is directly transferred as output data to the parallel-to-serial converter 12 via the selection circuit 18, where it is converted into serial data, and output to a printer for printing.

In this manner, this printer includes a page memory for storing printer data and a pattern memory for storing one graphic pattern, and generates an access address for the pattern memory based on the output data of the page memory and the raster number.

Either the output data of the page memory or the pattern memory is selected and output.

As a result, it is possible to have both a character printer function and an 11-pin image printer with a minimum memory capacity.

In other words, especially in small-sized computers, importance is placed on word processing functions, graphic functions, etc., and printers are also required to be compatible with these purposes.

In this case, the word processing function requires high speed and high print quality, but in graphic pot production, figures are often created on a computer's CRT and the exact image is made into a hard copy.

It does not necessarily require the same performance as a word processing function.

Therefore, by implementing the present invention, when a printer is used as a terminal for such a host system, it is possible to easily support graphic functions while maintaining high speed and high print quality as a character printer. .

Effects As explained above, according to the present invention, it is possible to have both a character printer function and an image printer function with a minimum memory capacity.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIGS. 2A to 2C are explanatory diagrams for explaining page memory mapping. FIGS. 3A and 3B are explanatory diagrams for explaining graphic patterns in a graphic pattern memory. FIG. 4 is a block diagram of main parts for explaining the flow of data between memories. FIG. 5 is a block diagram of the main parts of the dot counter and parallel-to-serial converter. FIG. 6 is an explanatory diagram for explaining the relationship between raster synchronization signals and print output, and FIG. 7 is a timing chart diagram for explaining control timing. 1...Microcomputer 3...Page memory 4...Graphic pattern memory 5
...Output memory 6...CG controller 7...Printer 12.
...Parallel-to-serial converter 18... Selection circuit η in Figure 2 (a) Sub-travel direction (b) Figure 3 (a) Fufufukofu Figure 4 Video data Figure 5 Figure 6 figure

Claims (1)

[Claims] 1 In a printer control device that controls a raster scan type printer, a page memory that stores print data for at least one page, a pattern memory that stores a graphic pattern, and output data of the page memory and a raster number A printer control device comprising: address generation means for generating an access address for the pattern memory; and selection means for selecting output data from the page memory and the pattern memory.