JPS63278851A - Magnification printing system of laser beam printer - Google Patents

Abstract

PURPOSE:To extract an arbitrary part from a bit map memory having a standard image stored therein at the time of printing to perform magnification printing, by magnifying the image data on the bit map memory when said image data is transferred to a printing part. CONSTITUTION:A data input part 2 receives the standard image data transferred from a host computer through a centronics interface or control data and other data and outputs the same to a bit map memory 3 by the indication of a CPU 1. The bit map memory 3 receives the standard image data from a data input part 2 and develops the said data on a bit map as the standard image data as it is to store the same and outputs this image data by a printing start control code order. A laser beam printer (LBP) printing part 4 receives the image data magnified on the basis of an magnification control code from the bit map memory 3 through a video interface and applies printing processing thereto as the magnified image output due to laser beam to output the same.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a page memory type laser beam printer, and in particular to a method for enlarging image data printing, and in general, enlarging printing for laser beam printers.

It is enlarged when image data is developed into a bitmap. Therefore, when it is enlarged twice vertically and horizontally.

Writing is performed in a memory area four times larger than the standard image data, and it takes more time than outputting the standard image data.

Furthermore, when several parts of the original image data held by the host are extracted and printed, it is necessary to transfer the image data of the parts to be printed each time from the host computer to the printer.

This invention has been made in view of the above-mentioned points, and an object of the present invention is to extract an arbitrary part from a bitmap memory in which a standard image is stored and print it in an enlarged manner at the time of printing.

In order to achieve the above object, the present invention provides a laser printer that has a bitmap memory and transfers data between the bitmap memory, a control section, and a printing section via a video interface. The image data on the memory is enlarged when it is transferred to the printing unit.

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

FIG. 1 is a basic block diagram showing an embodiment of the present invention.

This laser beam printer (hereinafter referred to as rLBPJ) includes a CPU 1 including a system ROM and a system RAM;
The basic configuration includes a data input section 2, a bitmap memory 3, and an LBP printing section.

The CPU 1 controls the LBP using a system ROM that stores programs for the CPU to perform arithmetic and control processing, and a system RAM that is its work area.

The data input section 2 receives standard image data, control data, and other data transferred from the host computer via the Centronics interface, and receives the data from the CPU.
1, the data is output to the bitmap memory 3.

The bitmap memory 3 receives standard image data from the data input section 2, develops and stores it as standard image data on a bitmap, and outputs this image data in response to a control code command to start printing.

The LBP printing section receives image data enlarged by an enlargement control code from the upper bitmap memory 3 via the video interface, prints it as an enlarged image output using a laser beam, and outputs it.

FIG. 2 is a block diagram showing the functions of FIG. 1.

A data input section 2 receives standard image data, control data, and other data transferred from a host computer via a Centronics interface, and outputs this to a data decoding section 5.

The data decoding section 5 determines whether the data received from the data input section 2 is a control code, character data, or image data, and transfers the data to the respective circuits.

The control code processing unit 6 receives the control code from the data decoding unit 5 and performs internal processing using this control code.

Character data/image data storage area 7.

It receives character data and image data from the data decoding section 5 and sequentially outputs them to the data expansion section 8.

The data development section 8 develops the data received from the character data/image data storage area 7 into an image on a bitmap memory.

If the control code received from the control code processing section 6 is a paper ejection instruction code, the paper ejection command code section 9 causes the print activation section 10 to start printing. If there is an enlargement specification at this time, the enlargement setting is made in the horizontal enlargement setting section 11 when printing is started.

On the other hand, data transfer from the bitmap memory 3 (character data/image data storage area 7, data development section 8) to the LBP printing section is performed by DMA (direct memory access), so an interrupt of DMA completion will cause the DMA to be transferred. DM of completion completion interrupt unit upper 2MA restart unit 13
A. A reboot is performed. When the vertical expansion setting unit 14 completes the vertical expansion setting, the number of lines is doubled and the same image data is transferred twice.

Next, the image data output method according to this embodiment will be explained with reference to FIG.

As shown in Fig. 3, in the standard image data output in (a), 1 bit of the bitmap memory and 1 bit of the output result are output.
The dots correspond one to one.

On the other hand, in (b) enlarged image data transfer, the height is doubled,
In the case of double horizontal expansion, one bit on the bitmap memory corresponds to a 2×2 dot in the output result. In FIG. 3, ■ is host image data, ■ is bitmap memory, and ■ is output data.

For example, in the case of an A-size printer, in (a) standard image data output, the contents of the bitmap memory are printed as they are on A4 paper. On the other hand, in b) enlarged image data output, any A in the bitmap memory is
It is possible to extract the 6-size portion and print the image data enlarged to A4 size.

When the print routine is called, addresses on the memory are specified using a map structure as shown in FIG.

Vertical direction by 5RG (segment register).

The horizontal printing start point is determined by ORG (offset register). The address value is 5RGX16+OR
G, the number of bytes per line in the print area, and the number of print lines are specified by the DX and CX registers.

The SRG is expressed as (number of lines)×(horizontal size)/16.

The control code for enlarged printing is X' IB 7E43 0
0 C71A m p XIX! Represented by ytyi.

m indicates the horizontal and vertical enlargement ratio in the copy mode.

0:IXl, 1:IX2, 2:2X1, 3:2x2. p
is the number of printed sheets e,

Next, the procedure for transferring data from the bitmap memory to the LBP printing section 4 will be explained with reference to the flowchart shown in FIG.

The interface (I/F) is a video I/F, and image data is transferred by DMA for each line of the bitmap.When the video I/F is driven, it is determined whether the mode is double horizontal mode or not. , if the mode is 2x horizontal mode, the 2x horizontal mode is set in the hardware.

In the normal mode, one word of data is output per one clock, whereas in the horizontal double mode, one word of data is output per two clocks, thereby performing horizontal expansion. Then, data for one line is transferred.

Next, it is determined whether or not the double-vertical mode is set, and if the double-vertical mode is set, double-vertical enlargement is performed by performing DMA transfer twice per line. Then continue this motion to the final line.

In this way, after standard image data is transferred from the host computer to the printer, enlargement in both vertical and horizontal directions is specified in the print start control code. the result,
You can extract any part of the image data, enlarge it, and print it.

Therefore, even for enlarged printing, the transfer time and memory capacity are the same as for conventional standard images.

Toyoto: As explained above, according to the present invention, standard image data that is not enlarged can be developed as it is on a bitmap memory, and any part thereof can be extracted and enlarged and printed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the basic configuration of a printing apparatus according to the present invention. FIG. 2 is a block diagram showing the functions of an embodiment of the present invention. FIG. 3 is an explanatory diagram of the output method of the present invention, FIG. 4 is an explanatory diagram of a bit map for enlarged transfer, and FIG. 5 is a flow diagram showing the data transfer procedure. 1... CPU (including system ROM and system RAM) 2... Data input section 3... Bit map memory 4... Laser printer 5... Data decoding section 6... Control code processing section 7 ...Character data/image data storage area 8...
・Data development section 9...Sheet discharge instruction code section 10.
...Print start section 11...Horizontal enlargement setting section 12
...DMA completion interrupt section 13...DMA restart section 14...vertical expansion setting section

Claims (1)

[Claims] 1. In a laser beam printer that has a bitmap memory and transfers data between the bitmap memory, a control unit, and a printing unit via a video interface, image data on the bitmap memory is transferred to the printing unit. An enlarged printing method for laser beam printers, which is characterized by enlarging the image at the same time.