JPH09191406A - Output device and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an output device outputting data without deteriorating the dignity of printing and the like even if memories which can be used are not sufficient. SOLUTION: If printing information is inputted in a page buffer when printing information expressed by a page description language is transmitted from a host computer 3000 through an interface 21, a printer control unit 1001 analyzes printing information stored in the page buffer, generates an intermediate code and preserves it in an intermediate code memory. When a space does not exist in the intermediate code memory and the intermediate code expressing a binary image exists in the intermediate code memory, a closed area is divided into the block of 4×4. The number of black picture elements existing in the closed area of 4×4 is counted and an obtained counted value is converted into a prescribed code and the intermediate code memory is cleared. Printing can be executed without deteriorating printing dignity even if memories which can be used are not sufficient by analyzing the intermediate code and generating the printing image.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an output device.

[0002]

2. Description of the Related Art Conventionally, an output device such as a printer outputs a binary image in a bit image format.

[0003]

However, in the above-mentioned conventional example, since the binary image is handled as it is in the bit image format, if there is not enough available memory, for example, the resolution is reduced and output is performed. The problem is that the quality of printing is reduced.

Therefore, it is an object of the present invention to provide an output device for outputting without degrading the quality such as printing even when there is not enough available memory.

[0005]

In order to achieve the above object, an output device according to claim 1 of the present invention is an output device which outputs a binary image based on multivalued data, wherein
The value image is divided into predetermined closed areas, the pixel counting means for counting the number of black pixels in the closed areas, the code generation means for generating a predetermined code according to the count value, and the generated code It is characterized in that it is provided with a data storage means for storing in the memory and a data conversion means for converting the stored code into the predetermined multi-valued data.

According to a second aspect of the present invention, in the output device for outputting a binary image based on the dot pattern,
The binary image is divided into a predetermined closed area, the pixel counting means for counting the number of black pixels in the closed area, the code generating means for generating a predetermined code according to the counted value, and the generated code. It is characterized in that it is provided with a data storage means for storing the code in the memory and a data conversion means for converting the stored code into the predetermined dot pattern.

According to a third aspect of the present invention, in the output device according to the first or second aspect, the code generating means includes a histogram generating means for converting the count value into a histogram, and the histogram-converted total value. The feature is that the code is generated according to the bias of the numerical values.

According to a fourth aspect of the present invention, in the output device according to the first aspect, the data converting means stores the converted multi-valued data in a cache memory.

According to a fifth aspect of the present invention, in the output device according to the second aspect, the data conversion means stores the converted dot pattern in a cache memory.

According to a sixth aspect of the present invention, in the output method of outputting a binary image based on multi-valued data or dot patterns, the binary image is divided into predetermined closed areas, and black pixels in the closed areas are divided. Counting the number of the data, generating a predetermined code according to the count value, storing the generated code in a memory, and converting the stored code into the predetermined multi-valued data or dot pattern. Characterize.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an output device of the present invention will be described. The output device in this embodiment is applied to a laser beam printer (LBP).

[First Embodiment] FIG. 1 is a sectional view showing the arrangement of a laser beam printer. In the figure, 10
00 is an LBP main body, which is a workstation (WS) or a personal computer (P
The print information (character code, etc.) expressed in the control language (hereinafter referred to as page description language) peculiar to the printer sent from C) is received and stored, and the information is handled based on the information. A character pattern, a form pattern, or the like is created and an image is formed on a recording medium such as recording paper.

Reference numeral 1012 is an operation section in which operation switches and LED indicators are arranged, and 1001 is an LBP main body 1.
000 is a printer control unit that analyzes the overall control and character information supplied from the host computer. The printer control unit 1001 mainly converts character information into a video signal of a corresponding character pattern and outputs the video signal to a laser driver 1002.

The laser driver 1002 is a semiconductor laser 1
A laser light 1 emitted from the semiconductor laser 1003 according to an input video signal.
Switch 004 on and off.

The laser beam 1004 is oscillated in the left-right direction by the rotary polygon mirror 1005 to scan the electrostatic drum 1006 for exposure. As a result, an electrostatic latent image having a character pattern is formed on the electrostatic drum 1006. This latent image is developed by a developing unit 1007 disposed around the electrostatic drum 1006 and then transferred to a recording sheet.

Cut sheets are used as the recording sheets, and the cut sheet recording sheets are stored in a sheet cassette 1008 mounted on the LBP main body 1000 and taken into the apparatus by a sheet feeding roller 1009, a conveying roller 1010 and a conveying roller 1011. And is supplied to the electrostatic drum 1006.

The LBP main body 1000 has at least one or more card slots (not shown) so that an optional font card and a control card (emulation card) having a different language can be connected in addition to the built-in fonts. .

FIG. 2 is a block diagram showing the configuration of the printer control system. The printer control system includes a printer control unit 1001 and a host computer 3000 connected to the printer control unit 1001 via a predetermined interface 21.

The host computer 3000 has a ROM 3
Has a CPU 1 for executing document processing in which graphics, images, characters, tables (including spreadsheets, etc.) are mixed based on a document processing program stored in the program ROM, and is connected to the system bus 4. Control each part as a whole.

The program ROM of the ROM 3 is the CPU 1
Of the control program, the font ROM of the ROM 3 stores font data used in the document processing, and the data ROM of the ROM 3 stores various data used in the document processing.

In the figure, reference numeral 2 is a RAM as a main memory of the CPU 1, which functions as a work area or the like.
A keyboard controller (KBC) 5 controls key inputs from the keyboard 9 and a pointing device (not shown). A CRT controller (CRTC) 6 controls the display of a CRT display (CRT) 10. A memory controller (MC) 7 controls access to an external memory 11 such as a hard disk (HD) or a floppy disk (FD) that stores a boot program, various applications, font data, user files, edit files, and the like. . A printer controller (PRTC) 8 is connected to the LBP main body 1000 via a predetermined interface 21,
A communication control process with the printer control unit 1001 is executed.

The CPU 1 executes, for example, an outline font rasterizing process on the display information RAM set on the RAM 2, and the WY on the CRT 10 is executed.
SIWYG is possible. Further, the CPU 1
Various windows registered based on commands designated by a mouse cursor (not shown) on T10 are opened, and various data processes are executed.

In the printer control unit 1001,
A printer CPU 12 generally controls access to each unit connected to the system bus 15 based on a control program stored in the program ROM of the ROM 13 or a control program stored in the external memory 14. Then, the image signal as output information is output to the printing unit (printer engine) 17 connected via the printing unit interface 16.

The program ROM of the ROM 13 is
The control program of the CPU 12 and the like are stored. ROM1
The font ROM 3 stores the font data and the like used when generating output information, and the data R of the ROM 13
In the case of a printer without an external memory 14 such as a hard disk, the OM stores information used on the host computer.

The CPU 12 is capable of communicating with the host computer 3000 via the input unit 18.
The host computer 3000 can be notified of information in the printer and the like.

Reference numeral 19 denotes an RA as a main memory of the CPU 12.
M, which functions as a work area or the like. The memory capacity can be expanded by an optional RAM connected to an expansion port (not shown). The RAM 19 is used as an output information expansion area, environment data storage area, NVRAM, and the like.

The external memory 14 such as the above-mentioned hard disk (HD) or IC card is a memory controller (M
C) Access is controlled by 20. The external memory 14 is connected as an option and stores font data, emulation programs, form data, and the like.
Reference numeral 18 denotes the above-described operation panel, on which operation switches and LED indicators are arranged.

The above-mentioned external memory is not limited to one, but at least one external memory is provided, and in addition to the built-in font, an optional font card and a plurality of external memories storing programs for interpreting printer control languages of different languages are connected. It may be configured to be possible. Further, an NVRAM (not shown) may be provided to store the printer mode setting information from the operation panel 1012.

Next, the operation of the printer having the above configuration will be described. FIG. 3 shows a host computer 3000.
6 is a flowchart showing a control processing procedure performed by the printer control unit 1001 when print information expressed in a page description language is sent from the printer via the interface 21.

First, it is determined whether or not print information is stored in the page buffer area of the RAM 19 (step S1).
0). If there is no print information in the page buffer,
Continuing to monitor the page buffer, if print information is stored in the page buffer, the print information stored in the page buffer is analyzed (step S11).

An intermediate code for printing a page is generated based on the analyzed print information, and is stored in an area (hereinafter referred to as an intermediate code memory) allocated for storing the intermediate code in the RAM 19 (step S12).

The intermediate code memory is monitored (step S1
3) If the intermediate code memory is not empty, it is determined whether or not the intermediate code representing the binary image exists in the intermediate code memory (step S14). If the intermediate code representing the binary image is present in the intermediate code memory, the process proceeds to step S15 and the subsequent steps.

In step S15, for example, the closed area of the binary image is divided into 4 × 4 blocks. The number of black pixels existing in the 4 × 4 closed area is counted (step S1).
6). Further, the obtained count value is converted into a predetermined code (step S17). Normally, 4 × 4 = 16 bits are required, but if the multivalued data (or dot pattern) is associated with each count value and then the count value is coded and stored, the count value is 0 to 15. So 0000-100
It can be expressed by 5 bits up to 00, and data can be reduced. These processing routines are effective when there are many image areas in one page.

On the other hand, if the intermediate code representing the binary image does not exist in the intermediate code memory in step S14, that is, if the compression process cannot be performed, the intermediate code created to free the intermediate code memory is analyzed (step S1.
8) Re-mapping the low-resolution print image creation memory for one page to create a low-resolution print image (step S19). When the intermediate code memory is opened (step S20), the process returns to step S13.

If the intermediate code memory is empty in step S13, it is determined whether or not the intermediate code for creating the print image for one page has been created (step S21). If the intermediate code cannot be created, step S10 is executed. Return to processing. On the other hand, if it can be created, the intermediate code for one page to be printed is analyzed (step S22). A print image is created based on the analyzed intermediate code (step S23).

At this time, the intermediate code is from step S15.
In the case where the intermediate code representing the image is created through the series of data compression processing shown in S17, the intermediate code to be converted into the corresponding multi-valued data (or dot pattern) in order to create the print image. Will be returned.

When returning to multi-valued data, the returned multi-valued data is stored in the cache memory, so that the speed can be increased when a print image is created again.

As described above, according to the printing apparatus of this embodiment, the amount of data can be reduced by handling the binary image, and the frequency of printing with reduced resolution can be reduced.

[Second Embodiment] FIG. 4 is a flowchart showing a control processing procedure performed by the printer control unit 1001 according to the second embodiment. The second embodiment is different from the first embodiment in the method of encoding the count value of black pixels in the data compression processing.

The same step number is assigned to the same step process as that of the first embodiment, and the description thereof is omitted. In step S17A, a histogram of count values is created. In step S17B, coding is performed in consideration of the frequency of each histogram-counted value.

FIG. 5 shows a closed area of 4 × 4 in step S17.
It is explanatory drawing which shows the process result when A and S17B are performed. A histogram is created by executing step S17A, and a short conversion code is assigned to a count value having a high frequency according to the frequency shown in the created histogram in step S17B, and a long code is assigned to a count value having a low frequency. By allocating, the data is generally compressed more efficiently than in the case of allocating codes of equal length.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading out a storage medium storing a program represented by software for achieving the present invention into a system or an apparatus, the system or the apparatus can enjoy the effects of the present invention.

[0043]

According to the output device of the first aspect of the present invention, when a binary image is output based on multivalued data, the binary image is divided into predetermined closed regions by the pixel counting means, The number of black pixels in the closed area is counted, a predetermined code is generated by the code generation means according to the count value, the generated code is stored in the memory by the data storage means, and the stored by the data conversion means. Since the generated code is converted into the predetermined multi-valued data, it can be output without degrading the quality such as printing even when the available memory is insufficient. Therefore, even with a memory having the same capacity as the conventional one, it is possible to reduce the resolution and reduce the frequency of printing, and it is possible to maintain high-quality printing quality.

According to the output device of the second aspect, when the binary image is output based on the dot pattern, the binary image is divided into predetermined closed regions by the pixel counting means, and the black pixels in the closed regions are divided. , The code generation means generates a predetermined code according to the counted value, the data storage means stores the generated code in a memory, and the data conversion means stores the stored code in a predetermined manner. Since the dot pattern is converted, it is possible to output without lowering the quality such as printing even when there is not enough available memory when outputting with the dot pattern.

According to the output device of the third aspect, the code generating means includes a histogram generating means for converting the count value into a histogram, and generates a code according to the bias of the histogram-ized count value. Therefore, depending on the frequency of the count value shown in the histogram, for example, assigning a short conversion code to a count value having a high frequency, and assigning a long code to a count value having a low frequency, the data is generally assigned in the same length. Can be compressed efficiently.

According to the output device of the fourth aspect, the data converting means stores the converted multi-valued data in the cache memory. Therefore, the multi-valued data stored in the cache memory is read out to increase the speed. Can be planned.

According to the output device of the fifth aspect, since the data conversion means stores the converted dot pattern in the cache memory, the speed can be increased by reading the dot pattern stored in the cache memory. You can

According to the sixth aspect of the output method, in the output method of outputting a binary image based on multi-valued data or a dot pattern, the binary image is divided into predetermined closed regions, and within the closed regions. The number of black pixels is counted, a predetermined code is generated according to the count value, the generated code is stored in a memory, and the stored code is converted into the predetermined multi-valued data or dot pattern. Therefore, even if the available memory is insufficient, it is possible to output without degrading the quality such as printing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a laser beam printer.

FIG. 2 is a block diagram showing a configuration of a printer control system.

FIG. 3 is a flowchart showing a control processing procedure performed by a printer control unit 1001 when print information expressed in a page description language is sent from a host computer 3000 via an interface 21.

FIG. 4 is a flowchart showing a control processing procedure performed by a printer control unit 1001 according to the second embodiment.

FIG. 5 shows steps S17A and S17B in a 4 × 4 closed region.
It is explanatory drawing which shows the process result at the time of performing.

[Explanation of symbols]

 12 CPU 13 ROM 19 RAM 1001 Printer control unit

Claims (6)

[Claims] 1. An output device for outputting a binary image based on multi-valued data, wherein the binary image is divided into predetermined closed regions, and pixel counting means for counting the number of black pixels in the closed regions, Code generation means for generating a predetermined code according to the count value, data storage means for storing the generated code in a memory, and data conversion means for converting the stored code into the predetermined multi-valued data. An output device comprising: 2. An output device for outputting a binary image based on a dot pattern, wherein the binary image is divided into predetermined closed regions, and pixel counting means for counting the number of black pixels in the closed regions, Code generation means for generating a predetermined code according to the count value, data storage means for storing the generated code in a memory, and data conversion means for converting the stored code into the predetermined dot pattern. An output device characterized by being provided. 3. The code generating means includes a histogram creating means for converting the count value into a histogram, and generates a code according to a bias of the histogram-ized count value. Claim 2
The output device described. 4. The output device according to claim 1, wherein the data conversion means stores the converted multi-valued data in a cache memory. 5. The output device according to claim 2, wherein the data conversion unit stores the converted dot pattern in a cache memory. 6. An output method for outputting a binary image based on multi-valued data or a dot pattern, dividing the binary image into predetermined closed regions, counting the number of black pixels in the closed regions, An output method, wherein a predetermined code is generated according to a count value, the generated code is stored in a memory, and the stored code is converted into the predetermined multi-valued data or dot pattern.