JPH10823A - Print control device and method - Google Patents

Abstract

(57) [Summary] [Problem] To pay attention to the fact that printing of a normal document includes many blanks between lines, and efficiently compresses the blanks, thereby suppressing the amount of transfer data and achieving high speed. To be able to print. When a received data indicates that blank lines are continuous, a STOP signal (Low level signal) is output to an AND gate 293. Then, the expansion circuit 201 counts the LINE_END signal output each time one line is output from the engine I / F unit 109, and maintains the state for a period corresponding to a blank line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing control apparatus and method, and more particularly to a printing control apparatus and method for a printing apparatus for forming a visible image on a predetermined recording medium.

[0002]

2. Description of the Related Art In general, a printer receives print data written in a page description language from a host computer or the like, analyzes the print data, creates bitmap data, and prints the data in a printing unit. Is performed.

In this case, very complicated processing is required until the print data is analyzed and the bit map data is created, and this processing also requires a lot of time. In addition, there is also a problem that a large amount of memory is required because bitmap data is created.

As a method for solving this, it is conceivable that a host computer transfers image data. In this case, although the printer apparatus is released from processing such as analysis and bitmap development, the amount of data transferred from the host computer to the printer apparatus becomes very large, and the transfer requires much time. Problem. In particular, the printing resolution of recent printers has become extremely high, and this problem is no longer negligible.

[0005]

As a method for solving this problem, it is conceivable that a host computer transfers image data. In this case, although the printer apparatus is released from processing such as analysis and bitmap development, the amount of data transferred from the host computer to the printer apparatus becomes very large, and the transfer requires much time. Problem.
In particular, the printing resolution of recent printers has become extremely high, and this problem is no longer negligible.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and focuses on the fact that printing of a normal document includes many blank portions between lines. An object of the present invention is to provide a print control apparatus and method capable of suppressing the amount of transfer data and enabling high-speed printing by performing efficient compression.

In order to solve this problem, for example, a print control apparatus according to the present invention has the following configuration. That is, a print control device of a printing unit that receives pixel data compressed data from a higher-level device and decompresses the data to form a visible image on a predetermined recording medium, wherein the received data is compressed data in pixel units. There is a determining means for determining whether the data is compressed data in line units, and when it is determined that the compressed data is pixel-based compressed data, expands the pixel data according to the compressed data, and outputs the expanded data to the printing unit, When it is determined that the data is line-based compressed data, a control unit that creates line-based data in accordance with the compressed data and outputs the data to the printing unit.

[0008]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 7 shows a printer (L) according to the embodiment.
(BP) shows a sectional structural view. In FIG.
Reference numeral 0 denotes an LBP main body, which receives compressed format data supplied from an externally connected host computer,
The printing is performed according to it. However, like a normal printer, a mode is provided in which character information (character code) is received, a pattern is generated, and printing is performed in accordance with the pattern. These modes can be switched by setting using the operation panel 800 (where an LCD display and various setting switches are arranged). In some cases, it is also possible to input and store form information or macro instructions.

Reference numeral 701 denotes a printer control unit for controlling the entire LBP 700. This control unit 701
Is mainly for receiving print data in a compression format, performing decompression processing, etc., and converting the decompressed data (8 bits assigned to each pixel = 256 gradations) to a known PWM.
The new signal after the PWM conversion is output to the laser driver 702 as a video signal.

The laser driver 702 is a semiconductor laser 70
And a laser beam emitted from the semiconductor laser 703 in response to an input video signal.
04 is turned on and off. The laser light 704 is swung right and left by a rotary polygon mirror 705 to scan on an electrostatic drum 706. As a result, an electrostatic latent image such as a character is formed on the electrostatic drum 706. This latent image is stored in the electrostatic drum 706
After the image is developed by the peripheral developing unit 707, the image is transferred to a recording sheet.

A cut sheet is used as the recording paper, and the cut sheet recording paper is stored in a paper cassette 708 mounted on the LBP 700, taken into the apparatus by a paper feed roller 709 and delivery rollers 710 and 711, and It is supplied to the drum 706. Then, the toner image adhered on the electrostatic drum 706 by the developing device 707 is transferred to the conveyed recording paper. Thereafter, the recording paper is conveyed in the direction of the fixing device 712, where the toner is fixed, and finally discharged by the discharge roller 713 to the outside.

Next, a printer control unit 701 according to the embodiment will be described with reference to FIG.

1, reference numeral 101 denotes a host computer connected to the apparatus, 103 denotes a CPU for controlling a printer control unit 701, and 104 denotes an RO storing a control program of the CPU 103 and font data.
M and 105 denote host I / F circuits for interfacing with the host computer 101, and 106 denotes an RA
M and 107 are data decompression units for decompressing the compressed data, 108 is an arbiter for arbitrating access to the RAM 106 from the CPU 103 and the data decompression unit 107, 10
Reference numeral 9 denotes an engine I / F which interfaces with the printer engine shown in FIG. 7, and includes a PWM conversion processing circuit.

FIG. 2 shows a data decompression unit 1 according to this embodiment.
FIG. 7 is a block diagram illustrating a configuration of an engine I / F unit 07. In the figure, reference numeral 201 denotes a decompression circuit; 202, a flip-flop for holding decompressed parallel video data (in the embodiment, 8 bits per pixel, that is, data of 256 gradations is received and printed); A
ND gate.

The operation of the embodiment having the above configuration will be described below.

The host computer 101 sends compressed image data, for example, image data compressed according to the PackBits compression format. CPU10
3 receives the data in this format via the host interface circuit 105 and transfers it to the RAM 106 for storage. This reception operation is performed until the reception of the compressed image data for one page is completed. When the data of one page is stored, the data decompression unit 107 and the engine I / F unit 109 are activated.

The activated engine I / F unit 109
Instructs the printer engine to start feeding the paper in order to start conveying the paper.

In the data decompression unit 107, the RAM 10
6 is read out and decompressed and output to the flip-flop 202 in units of one pixel (= 8 bits). Since the / STOP signal of the AND gate 203 is normally at the H level, the data set in the flip-flop 202 is output to the engine I / F unit 109.
The engine I / F unit 109 temporarily stores the parallel video data in a register (not shown), reads out the parallel video data in bit units, performs a well-known PWM conversion process, and generates a pulse width signal depending on the density. VIDEO it
A laser driver 702 of the printer engine unit as a signal
Output to

Here, when the decompression circuit 201 performs decompression processing of, for example, a packbits data compression format, the RAM 10
No value of “80H (H means hexadecimal)” exists in the data corresponding to the command of the compressed data read from No. 6. Therefore, this "80H" is used, and the subsequent one byte means the number of blank lines. That is,
A new command “80H” + “line number value” is created and defined as a compression command for the white line. As a result, the following expansion is possible.

When the decompression circuit 201 detects the command "80H", it sets the STOP signal of the AND gate to the "L" level, and performs the decompression operation for the number of lines represented by one byte following the 80H. To stop. For this reason, the decompression circuit 201 counts the LINE END signal (this signal corresponds to a known BD signal from the printer engine unit) output from the engine I / F unit 1009 at the end of outputting one line of VIDEO data. ing. After finishing counting the set number of lines, the expansion circuit 201 sets the / STOP signal to "H" level and restarts the expansion operation.

With the above operation, it is possible to compress a white line such as a line interval by a command.

In the above description of the operation, the compressed data format is the pack bit data compression format. However, the same operation can be performed in other compression formats by defining a command for compressing a white line.

Here, packbits data compression applied to the embodiment will be described with reference to FIG.

In packbits compression, a 1-byte command is first followed by a data portion of at least 1 byte.

<Case where Same Pixel Data is Repeated> In this case, the first command is assigned data indicating the number of consecutive pixels, and its value is FFH (indicating that two identical pixels are present). ８１81H (indicating that there are 128 identical pixels). In the second byte,
The value of the pixel is stored (see FIG. 4A). 129
When a plurality of the same pixel data are continuous, a plurality of this command + data are prepared.

<When there is no repetition> In this case, 00H to 7FH is assigned to the first command. The meaning of these values indicates how many pixel data follows the command. However, the command 00H indicates that 1-byte pixel data continues, 01 indicates that 2-byte pixel data,..., 7FH indicates that 128-byte pixel data continues.

As described above, in the Packbits compression format,
Since 80H does not exist as a command, the number of blank lines can be defined using the 80H as in the above-described embodiment.
As a result, significant data compression is possible.

As described above, according to the present embodiment,
When receiving and printing compressed image data,
In particular, it is possible to increase the compression ratio for a blank portion between lines in a document or the like. Therefore, the amount of information to be transferred is reduced from the viewpoint of the host computer, and the same operation and effect as the speeding up of the printing process can be obtained.

In particular, in general compression, a blank line portion in a document is interpreted and compressed only as continuous white pixels, so that much encoded data is generated. According to the embodiment, the blank line portion can be compressed not in units of pixels but in units of lines, so that the compression efficiency is further increased.

The host computer may be running any OS (operating system), but at least the printer driver running on that OS needs to perform the above-described image compression. .

FIG. 8 shows an operation processing procedure of the printer driver.

First, in step S21, the variable count
Is cleared to "0", and in the next step S22, print data is received from a higher-level device (for example, an application or an OS).

In step S23, a line of the image data corresponding to the received print data is checked, and it is determined whether or not the line is blank (for example, all are "00H"). If it is determined that the line is blank, the variable cou
nt is incremented by “1”, and the process returns to step S22.

On the other hand, if it is determined in step S23 that the line of interest is not a blank line, the flow advances to step S25 to determine whether or not the variable count at that time is "0".

If it is determined that the count is not "0", it means that the process of step S24 has been performed at least once, so the process proceeds to step S26, where the data of the blank line (the command starting with 80H and the number of lines) Is generated, and in step S27, it is output to the printer of the present embodiment, and the flow advances to step S28.

In step S25, count = 0
If it is determined that the process is performed, the process of steps S26 and S27 is skipped, and the process proceeds to step S28.

In step S28, pack bits compression processing is performed on the line of interest (non-blank line), and in step S29, processing for outputting it is performed. Then, unless it is determined in step S30 that the processing for one page is completed, the process returns to step S21 and the above processing is repeated.

Although the above processing has been described as a printer driver operating on the host computer, the processing may be provided in the OS itself or in the application itself.

[Explanation of Second Embodiment] FIG. 3 is a block diagram of the data decompression unit 107 and the engine I / F unit 109 in another embodiment. Referring to FIG.
Is an expansion circuit, 302 is a flip-flop, 303 is AN
D gate. FIG. 5 is a diagram showing a print result in the second embodiment, and the numbers shown on the right are characters or the number of lines occupied by line spaces. FIG. 6 shows a processing procedure (program) according to the second embodiment.

The operation of this embodiment will be described below.

When the host computer 101 compresses image data and outputs the image data to the printer, for example, when compressing an image as shown in FIG. 5, the host computer 101 compresses image data as shown in FIG. The number of lines in the blank line area is counted, and the data including the number of blocks and the total number of lines is added before the compressed data. Thereafter, the data is compressed in units of blocks in which characters are present, and the compressed data of each block is continuously transmitted. The compression method is not limited to the Packbits method, but may be any method. In short, it is only necessary that consistency is maintained between the host computer and the printer device.

The CPU 103 of the printer controls the operation of the decompression circuit 301 in accordance with control data indicating the number of blocks and the number of lines preceding the first received image data.

More specifically, the CPU 103 activates the data decompression unit 107 and the engine I / F unit 109, and a signal indicating that the engine I / F unit 109 has finished sending one line of data to the printer engine unit 110. LINE
Count the number of ENDs.

Referring to FIG. 5, when the LINE END signal is counted 200 times from the start of printing, the CP
U103 sets the / STOP signal to "L" level, stops the expansion circuit 301, and masks the AND gate 303. After counting the LINE END signal 100 times, the CPU 101 sets the / STOP signal to the “H” level, and sends out the video data to the engine I / F unit 109 again. By repeating this operation, white line data that does not exist as image data can be created.

If the host computer indicates the block where the dot exists to the printer, the host computer indirectly designates a blank line area, so that the blank portion need not be output. However, it will be necessary to specify the specific position of the block where each character image exists, for example, the coordinates of the upper left corner of the block.

The CPU 1 of the second embodiment described above
FIG. 6 summarizes the operation procedure of 03.
The decompression and the output of the video signal are performed by the data decompression unit 10.
7, the description is omitted below.

First, data is received in step S1, and stored in the RAM 106 in step S2. This operation is repeated until it is determined in the next step S3 that one page of data has been received.

When one page of data is received in this way, the process proceeds to step S4, where the head of the received data is analyzed.

As a result of this analysis, if it is determined that the received data is data other than image data, that is, data in a normal page description language format, a corresponding process is performed. Since this processing is not directly related to the second embodiment, the processing when it is determined that the data is image data will be described below.

In this case, the CPU 103 sets the / STOP signal in the data decompression unit 107 to LINE_EN
Control is performed by counting the D signal.

Since the dot starts from a certain area at first, the / STOP signal changes its logical output level to High.
It is.

Therefore, in step S8, the set number of lines is counted. Thereafter, the process proceeds to step S9,
The logic level of the / STOP signal is inverted, and step S10
Step S8 and subsequent steps are repeated until it is determined that the processing for all blocks is completed.

As described above, according to the second embodiment, the same operation and effect as those of the first embodiment can be obtained.

[Other Embodiments] Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), the present invention can be applied to an apparatus including one device. May be applied.

Another object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium. In particular, processing on the host computer side is realized in this manner.

In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

In the embodiment, a laser beam printer has been described as an example of a printer, but the present invention is not limited to this and can be applied to any type of printer.

Further, in the first embodiment, an example using the Packbits compression method has been described, but another compression method may be used. Therefore, the present invention is not limited by the above-described embodiment, and any changes can be made within the scope described in the claims.

[0063]

As described above, according to the present invention, when printing having a blank portion, such as between the lines of a normal document, the blank portion can be efficiently compressed and decompressed simply. Since it is sufficient to generate a blank portion in line units instead of blank dots, it is possible to increase the use efficiency of the memory.

[0064]

[Brief description of the drawings]

FIG. 1 is a block diagram of a printer device according to an embodiment.

FIG. 2 is a block diagram of a data decompression unit.

FIG. 3 is a block diagram of a data decompression unit according to a second embodiment.

FIG. 4 is a diagram showing a data format of PackBits compression.

FIG. 5 is a diagram for explaining an outline of printing in a second embodiment.

FIG. 6 is a flowchart illustrating a processing procedure according to the second embodiment.

FIG. 7 is a diagram illustrating an example of a cross-sectional structure of the printer device according to the embodiment.

FIG. 8 is a flowchart illustrating an operation processing procedure on the host computer side according to the first embodiment.

[Explanation of symbols]

 101 Host Computer 103 CPU 104 ROM 105 Host I / F Circuit 106 RAM 107 Data Decompression Unit 108 Arbiter 109 Engine I / F Unit 110 Printer Engine 201 Decompression Circuit 202 Flip-Flop 203 AND Gate

Claims (8)

[Claims] 1. A printing control apparatus for a printing unit for receiving pixel data compressed data from a host device and decompressing the data to form a visible image on a predetermined recording medium, wherein the received data is a pixel unit. Determining means for determining whether the data is compressed data or compressed data in line units; and, if it is determined that the data is compressed data in pixel units, decompresses the pixel data in accordance with the compressed data and sends it to the printing unit. Output, and if it is determined that the data is compressed data in line units, data is created in line units according to the compressed data,
And a control unit for outputting to the printing unit. 2. The apparatus according to claim 1, wherein said control means outputs blank data for a period corresponding to the number of corresponding lines when receiving the compressed data in line units.
A print control device according to the item. 3. A printing control method for a printing unit for receiving pixel data compressed data from a host device and decompressing the data to form a visible image on a predetermined recording medium, wherein the received data is a pixel unit. A judging step of judging whether the data is compressed data or compressed data in line units, and if it is judged that the data is compressed data in pixel units, decompresses the pixel data according to the compressed data and sends it to the printing unit. Output, and if it is determined that the data is compressed data in line units, data is created in line units according to the compressed data,
And a control step of outputting to the printing unit. 4. The method according to claim 3, wherein the control step outputs blank data for a period corresponding to the number of lines when receiving compressed data in line units.
The print control method described in the paragraph. 5. A print control method in an information processing apparatus for outputting compressed data in pixel data units and line units to a lower-level printing apparatus and printing the same, wherein a blank line is formed based on print data passed from a higher-level process. If there is one or more blank lines, the compressed data in units of lines is used for a portion corresponding to a continuous section, and the compressed data in pixels is used if it is not a blank line. Printing control method for outputting to a lower-level printing device. 6. A printing unit which receives a block in which all lines are white data and block information including the number of lines of each of compressed blocks in which image data exists, and prints a visible image on a predetermined recording medium by a printing unit. A first output unit that, when receiving a block including image data, decompresses the block based on the compressed data of the block and outputs the decompressed image data to a printing unit; When the information indicating the block of the white data is received, the decompression process is stopped for the printing unit for the number of lines corresponding to the block, and the data corresponding to the white data is output to the printing unit. 2. A printing control device comprising: a second output unit. 7. A printing method for receiving a block in which all lines are white data and block information including the number of lines of each of compressed blocks in which image data exists, and printing a visible image on a predetermined recording medium by a printing unit. A control method, comprising: when a block including image data is received, decompressing based on compressed data of the block, and outputting the decompressed image data to a printing unit; When the information indicating the block of the white data is received, the decompression process is stopped for the printing unit for the number of lines corresponding to the block, and the data corresponding to the white data is output to the printing unit. 2. A printing control method, comprising: 8. A print control device of a printing unit for receiving pixel data compressed data from a host device and decompressing the data to form a visible image on a predetermined recording medium, and decompresses the pixel data according to the compressed data. And a decompressed pixel data that is directly output to a printing unit.