JP3428817B2 - Print control device and method - Google Patents

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 that forms a visible image on a predetermined recording medium.

[0002]

2. Description of the Related Art Generally, 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 it in a printing section. Is performed.

In this case, a very complicated process is required until the print data is analyzed and the bit map data is created, and a lot of time is required in this process part. Further, there is also a problem that a large amount of memory is required in order to create bitmap data.

[0004]

[0005]

As a method for solving this, it is considered that the host computer transfers the image data. In this case, it is true that the printer side is relieved of the processing such as analysis and bitmap expansion, but this time, the amount of data transferred from the host computer to the printer side becomes very large, and the transfer requires a lot of time. There is a problem of doing.
In particular, the printing resolution of recent printers has become extremely high, and this problem can no longer be ignored.

The present invention has been made in view of the above problems, and printing with a blank portion such as a space between lines of a normal document.
Pack Bits data pressure, which is the existing compression method,
Effective use of non-default non-standard commands in compression method
Then, the blank part can be compressed efficiently , and
It is an object of the present invention to provide a print control apparatus and method capable of suppressing the amount of received compressed image data .

[0007]

To solve this problem, for example, a print control apparatus of the present invention has the following configuration. That is, it is compressed in the Packbits data compression format.
A multi-valued image data received from a higher-level device, expanded, and printed on a predetermined recording medium in a printing control device of a printing unit, which is compressed in the Packbits data compression format.
Of the command group included in the compressed image data
Identify default and nondefault commands in expressions
Identifying means and that the identifying command is a default command
If identified, the default command and subsequent data
Based on a pixel column extending means for extending the multi-level pixel column, before
If the identification means identifies the command as a non-default command,
If the data following the non-default command is blank,
The line is interpreted as data indicating that the line
The expansion of the pixel column expansion means is stopped for the number of times corresponding to the number.
And means .

[0008]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 7 shows a printer device (L
The cross-sectional structural drawing of BP) is shown. In the figure, 70
Reference numeral 0 is an LBP main body, which receives compressed data supplied from an externally connected host computer,
It is printed accordingly. However, like a normal printer, it also has a mode of receiving character information (character code), generating a pattern, and printing according to the pattern. These modes can be switched by setting on the operation panel 800 (LCD display and various setting switches are arranged). In some cases, it is also possible to input and store form information or macro commands.

A printer control unit 701 controls the entire LBP 700. This control unit 701
Mainly receives compressed print data, performs decompression processing, etc., and decompresses the resulting data (8 bits are assigned to each pixel = 256 gradations) to a known PWM.
The new issue after conversion and PWM conversion is output to the laser driver 702 as a video signal.

The laser driver 702 is a semiconductor laser 70.
Laser light 7 emitted from the semiconductor laser 703 according to the input video signal.
04 is switched on and off. The laser light 704 is swung in the left-right direction by the rotating polygon mirror 705 and scans the 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 an electrostatic drum 706.
After being developed by the surrounding developing unit 707, it is transferred to recording paper.

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, and is taken into the apparatus by a paper feed roller 709 and delivery rollers 710 and 711 to be electrostatically charged. 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. After that, the recording paper is conveyed toward the fixing device 712, the toner is fixed, and finally discharged by the discharge roller 713.

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

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

FIG. 2 shows the data decompression unit 1 in this embodiment.
7 is a block configuration diagram of 07 and an engine I / F unit 109. FIG. In the figure, 201 is a decompression circuit, 202 is a flip-flop for holding decompressed parallel video data (in the embodiment, 8 bits per pixel, that is, 256 gradation data is received and printed), and 203 is a flip-flop. A
It is an ND gate.

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

Compressed image data, for example, image data compressed in the Packbits compression format is sent from the host computer 101. CPU10
3 receives the data of this format via the host interface circuit 105, transfers it to the RAM 106 and stores it. Then, this receiving operation is performed until the reception of the compressed image data for one page is completed. When the data for one page is stored, the data decompression unit 107 and the engine I / F unit 109 are activated.

Engine I / F unit 109 which has been activated
Issues a paper feed start instruction to the printer engine in order to start conveyance of the paper.

In the data decompression unit 107, the RAM 10
The compressed data stored in 6 is read out, decompressed, and output to the flip-flop 202 in pixel units (= 8 bits). Since the AND gate 203 normally has the H / STOP signal 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 it out bit by bit from the register, and performs a known PWM conversion process to generate 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 in the Packbits data compression format, for example, the RAM 10
There is no value of "80H (H means hexadecimal number)" in the data corresponding to the command of the compressed data read from No. 6. Therefore, by utilizing this "80H", the following 1 byte means the number of blank lines. That is,
A new command "80H" + "value of the number of lines" is created, and this is defined as a compression command for the white line. As a result, the following extensions are possible.

When the decompression circuit 201 finds the command "80H", it sets the STOP signal of the AND gate to the "L" level, and the decompression operation is performed for the period of the number of lines represented by 1 byte following 80H. To stop. Therefore, 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. When the set number of lines has been counted, the decompression circuit 201 sets the / STOP signal to "H" level and restarts the decompression operation.

With the above operation, it is possible to compress the white line between lines by a command.

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

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

In Packbits compression, it is composed of a command of 1 byte first and a data portion of at least 1 byte following the command.

<When the Same Pixel Data is Repeated> In this case, data indicating the number of consecutive pixels is assigned to the first command, and the value is FFH (indicating that two identical pixels exist). .About.81H (indicating that there are 128 identical pixels). In the second 1 byte,
The value of the pixel is stored (see FIG. 4A). 129
If the same pixel data or more continues, a plurality of this command + data are prepared.

<No Repeat> In this case, 00H to 7FH are assigned to the first command. The meaning of these values is how many pixel data follow the command. However, command 00H indicates that 1-byte pixel data follows, 01 indicates 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 embodiment,
As a result, significant data compression is possible.

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

In particular, in general compression, a large amount of encoded data was generated because a large amount of encoded data was generated because the white line pixels in a document were interpreted and compressed only as continuous white pixels. According to the embodiment, the blank line portion can be compressed line by line rather than pixel by pixel, so that the compression efficiency is further increased.

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

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

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

In step S23, the line of the image data corresponding to the received print data is checked to determine whether or not the line is blank (for example, all "00H"). If it is determined to be a blank line, 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 target line is not a blank line, the process proceeds to step S25, and it is determined 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. Therefore, the process proceeds to step S26 and the data of the blank line (command and line number starting at 80H Data) is generated, and is output to the printer device of the present embodiment in step S27, and the process proceeds to step S28.

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

In step S28, Packbits compression processing is performed on the line of interest (non-blank line), and in step S29, it is output. Then, unless it is determined in step S30 that the processing for one page has been 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 a host computer, it may be provided in the OS itself or in the application itself.

[Explanation of Second Embodiment] FIG. 3 is a block diagram of a data decompression unit 107 and an engine I / F unit 109 according to another embodiment. In the figure, 301
Is an expansion circuit, 302 is a flip-flop, and 303 is an AN
It is a D gate. Further, FIG. 5 is a diagram showing a printing result in the second embodiment, and the numeral shown on the right is a character or the number of lines occupied by line intervals. Further, FIG. 6 shows a processing procedure (program) in the second embodiment.

The operation of this embodiment will be described below.

When the host computer 101 compresses the image data and outputs it to the printer device, for example, when compressing an image as shown in FIG. 5, a block with a character and a line with no data between lines ( 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. After that, the data is compressed in units of blocks including characters, and the compressed data of each block is continuously transmitted. The compression method is not limited to the Packbits method and may be any method. In short, it suffices that the host computer and the printer device have consistency.

The CPU 103 of the printer device controls the operation of the decompression circuit 301 according to the control data indicating the number of blocks and the number of lines before the first received image data.

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 the "L" level to stop the expansion circuit 301 and mask the AND gate 303. Then, after counting the LINE END signal 100 times, the CPU 101 sets the / STOP signal to the "H" level, and again sends the video data to the engine I / F unit 109. By repeating this operation, it is possible to create white line data that does not exist as image data.

The host computer may indirectly specify the blank line area if the block in which the dot exists is indicated to the printer, so that it is not necessary to output the blank portion. However, it may be necessary to specify the particular location of the block in which each character image resides, for example the coordinates of the upper left corner of the block.

CPU 1 of the second embodiment described above
The operation procedure of No. 03 is summarized as shown in FIG.
The decompression and output of the video signal are performed by the data decompression unit 10.
7 is performed by hardware, the description thereof will be omitted below.

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

When the data for one page is thus received, the process proceeds to step S4, and the head portion of the received data is analyzed.

As a result of this analysis, when it is determined that the received data is data other than the image data, that is, the data in the 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 to be image data will be described below.

In this case, the CPU 103 changes the / STOP signal in the data decompression unit 107 to LINE_EN.
It is controlled by counting the D signal.

Since the dot is first started in the area where the dot exists, the / STOP signal changes its logical output level to High.
I am doing it.

Therefore, in step S8, the set number of lines is counted. After this, the process proceeds to step S9,
Invert the logic level of the / STOP signal, and execute step S10.
The processing from step S8 is repeated until it is determined that the processing has been completed for all blocks.

As described above, according to the second embodiment as well, it is possible to obtain the same effects as those of the first embodiment described above.

[Other Embodiments] Incidentally, even when 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.), it can be applied to an apparatus including one device. You may apply.

Another object of the present invention is to supply 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 supply a computer (or CPU) of the system or apparatus.
It is needless to say that it can be achieved by reading and executing the program code stored in the storage medium. In particular, the processing on the host computer side is realized in this way.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, 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, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD
-R, magnetic tape, non-volatile memory card, ROM, etc. can be used.

Further, not only the functions of the above-described embodiments are realized by executing the program code read by the computer, but also the OS (operating system) running on the computer based on the instructions of the program code. It is needless to say that this also includes a case where the above) performs a part or all of the actual processing and the processing realizes the functions of the above-described embodiments.

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

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

Furthermore, in the first embodiment, an example in which the Packbits compression method is used has been described, but other compression methods may be used. Therefore, the present invention is not limited to the above-described embodiment, and any modifications can be made within the scope described in the claims.

[0063]

As described above, according to the present invention, when printing a blank portion such as a space between lines of a normal document,
The existing compression method, Packbits data compression method
Non-default Non-default commands can be effectively used to efficiently compress the blank area, and the compressed image from the host device
It is possible to suppress the amount of data received .

[0064]

[Brief description of drawings]

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

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

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

FIG. 6 is a flowchart showing a processing procedure in 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 showing an operation processing procedure on the host computer side in 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 110 printer engine 201 Expansion circuit 202 flip flops 203 AND gate

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 5/30 G06F 3/12

Claims (6)

(57) [Claims] 1. Compressed in Packbits data compression format
A multi-valued image data received from a higher-level device, expanded, and printed on a predetermined recording medium in a printing control device of a printing unit, which is said to have been compressed in the Packbits data compression format.
Of the command group included in the reduced image data, the
To distinguish between default commands that are
Identification means, and if the identification means identifies a default command.
, Based on the default command and the data that follows.
Pixel column decompression means for decompressing to a value pixel row, and the predetermined non-default command by the identification means
Data that follows the non-default command, if identified
Is interpreted as data indicating that the number of blank lines is
Then, while the number of lines is equivalent,
And a means for stopping the length . 2. Reception of compressed image data from the host device
It is characterized in that transmission and decompression are performed in page units.
The print control device according to claim 1. 3. Further expanded by the pixel row expansion means
Temporary storage means for temporarily storing image data pixel by pixel
The image data set in the temporary storage means in order.
Next, the data is output to the printing unit.
Print control device installed. 4. Compressed in Packbits data compression format
Is a print control method for a printing unit that receives multi-valued image data from a higher-level device, decompresses it , and prints it on a predetermined recording medium, which is said to be compressed in the Packbits data compression format.
Of the command group included in the reduced image data, the
To distinguish between default commands that are
Identification process, and if the identification process identifies a default command.
Image based on the default command and the data that follows.
The pixel row decompression step of decompressing into a prime row, and the predetermined non-default command by the identification step
Data that follows the non-default command, if identified
Is interpreted as data indicating that the number of blank lines is
Then, while the number of lines is equivalent, the extension in the pixel column extension step is performed.
And a step of stopping the length, the printing control method. 5. Multi-valued pixel data is packed bit data pressure.
It is a print control method in an information processing apparatus that compresses by a compression method and outputs to a lower printing apparatus for printing, which is sequentially generated based on print data passed from a higher processing.
Multi-valued line it is determined whether or not a blank line to be
It is determined that there is a multivalued blank line in the discrimination step and the discrimination step.
If turned off, count the number of consecutive blank lines
However, the specified non-default commands and the Packbits compression method
And compressed data of the data showing the number of lines counted
There is no multivalued blank line in the first generation step to be performed and the discrimination step.
If it is determined that the multi-valued pixel data of the line
Compressed data using the default command of the Packbits compression method.
Under a second generation step of generating over data, the first, the compressed data generated by the second generating step
And a step of outputting to a printing device at a higher rank . 6. A multi-valued pixel data is packed bit data pressure.
Compress by the compression method and output to the lower printer to print.
An information processing device, which is sequentially generated based on the print data passed from the higher-level processing.
Whether the multi-valued line that is displayed is a blank line
It is determined that there is a multivalued blank line in the discrimination means and the discrimination means.
If turned off, count the number of consecutive blank lines
However, the specified non-default commands and the Packbits compression method
And compressed data of the data showing the number of lines counted
There is no multi-valued blank line in the first generating means to be formed and the judging means.
If it is determined that the multi-valued pixel data of the line
Compression de using the default command in PackBits compression method
A second generation unit for generating data and a compressed data generated by the first and second generation units.
It is characterized in that it comprises a means for outputting the position of the printing device
Information processing equipment.