JP2001213012A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize most efficient continuous print performance even when print image data subjected to image compression is printed on consecutive pages. SOLUTION: Upon completion of a page of print image data, the number of pages N required for continuous printing on a sheet dependent on the type of a printer is determined. Information of the size of print image data (PageSize) is then acquired along with the information of the entire size of an image memory area (MemSize). A decision is then made whether MemSize >= PageSize*N is satisfied or no. If it is satisfied, a decision is made that continuous print performance can be achieved without requiring page compression and compression is not performed, otherwise the print page image is compressed. The compressed image data is decompressed and printed and the image data is printed as it is when it is not compressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printing apparatus,
In particular, the present invention relates to a printing apparatus that creates and prints an image in page units.

[0002]

2. Description of the Related Art Conventionally, a printing apparatus converts input print data into print image data that can be printed on paper by a printing unit (engine). Therefore, the printing apparatus requires a memory for storing the print image data. In particular, a page printer that creates print image data for each page requires a memory for storing at least one page of print image data.

Here, when a paper jam occurs, the page printer normally prints the page where the paper jam has occurred, and erases the print image data stored in the memory until the paper is discharged. Can not. That is, since the page printer has no storage area in the memory, the page printer (the next page) following the page in which the jam has occurred (the previous page) cannot be converted into print image data.

Therefore, a conventional printing apparatus, particularly a page printer, renders an image of a subsequent page until a previous page is discharged when a jam occurs while printing data having a plurality of pages. However, it is pointed out that a continuous speed cannot be obtained because of the inability to perform the operation.

[0005] Conventionally, there has been a demand for a printing apparatus to reduce the time required to finish printing all pages. That is, it is pointed out that the printing apparatus improves the printing efficiency.

Japanese Patent Application Laid-Open No. Hei 7-245885 discloses a conventional technique relating to a printing apparatus for compressing print image data in page units and improving the printing speed for printing data of a plurality of pages.

According to this conventional technique, a printing apparatus compresses all print image data and stores the data in a memory. This allows the printing apparatus to accept the (print) image data of the next page from the time when the (print) image data of the preceding page is compressed and written to the (compressed image) memory, (Printing) The receiving speed of image data is increased.

Thus, even if the recording paper (paper) is jammed in the image forming unit (printing unit), the (compressed image) memory already compresses the (print) image data of the next page. It is remembered. Therefore, this printing apparatus cannot convert the print data of the next page into the (print) image data because the (print) image data of the jammed page remains in the (compressed image) memory. It is no longer impossible to achieve continuous speed.

[0009]

However, according to the above prior art, the printing apparatus decompresses the print image data and then decompresses the print image data so that the printing unit can print it on paper. There must be. Since the compression process and the decompression process require time, the printing efficiency is reduced.

That is, according to the above prior art, a printing apparatus having only a memory capable of storing only one page of print image data has a smaller memory capacity than the compression time and the decompression time. Since the effect of the positive factor that the waiting for release is reduced is greater, the printing efficiency is improved.

However, a printing apparatus having a sufficiently large memory capacity can store a plurality of pages of print image data without compression. Therefore, according to the above-described related art, the compression processing and the decompression processing must be performed on the print image data of all pages, and the printing efficiency is reduced.

The size of one page of print image data varies depending on printing conditions such as paper size and resolution. For example, A4 size and 1200 DPI (dot
The print image data of (perinch) requires a capacity of about 17 Mbytes to store it. However, print image data of A4 size and 600 DPI resolution is about 4.3
If there is a capacity of M bytes, it is stored.

That is, a printing apparatus that requires a memory of 20 Mbytes can store one page for the 1200 dpi print image data and four pages for the 600 dpi print image data. As described above, depending on the printing conditions (in the case of print image data of 600 DPI according to the above example), the printing apparatus can store the print image data of a plurality of pages without compressing the print image data. There is also.

Therefore, according to the above prior art, the printing apparatus does not need to be performed (extra) depending on printing conditions.
Since the compression process and the decompression process must be performed, the printing efficiency is reduced.

As described above, it cannot be said that the above-mentioned prior art shows a complete solution to the above problem. In particular, when no jam occurs, the printing apparatus has a lower printing efficiency than the printing apparatus not using the conventional technology, and thus the above problem is further exacerbated.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a printing apparatus that ensures continuous speed and improves printing efficiency even when a jam occurs.

[0017]

In order to achieve the above object, according to the present invention, there is provided a data compression means for compressing print image data and generating compressed data, and a method for compressing print image data and compressed data. A data storage unit for storing, a determination unit for determining whether to use the data compression unit, and a control unit for performing control without using the data compression unit when the determination unit determines not to use the data compression unit. It is characterized by having.

According to a second aspect of the present invention, in the apparatus according to the first aspect, the determining means determines that the data compression means is used when all pages of the print image data cannot be stored in the data storage means. It is characterized by being.

According to a third aspect of the present invention, in the device according to the first aspect, the determining means stores, in the data storage means, a capacity obtained by multiplying the data capacity of the first page of the print image data by the number of pages of the print image data. If you can't remember
It is characterized in that it is determined to use data compression means.

According to a fourth aspect of the present invention, in the apparatus according to the first aspect, the determining means multiplies the data capacity of the first page of the print image data by the number of pages of the print image data and a predetermined coefficient. When the data cannot be stored in the data storage means, it is determined that the data compression means is to be used, and the predetermined coefficient must be either double-sided printing or single-sided printing of the print image data. It is characterized by being determined by the above.

According to a fifth aspect of the present invention, in the apparatus according to any one of the first to fourth aspects, the determination means determines that the data compression means is not used when the print image data is data of only one page. It is characterized by that.

[0022]

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

FIG. 2 is a configuration diagram showing the configuration of the laser printer according to the embodiment of the present invention. According to FIG.
This laser printer has an image processing unit (controller)
1, a printing unit (engine) 2 and an operation unit (operation panel) 3.

An image processing unit (controller) 1 receives print data from a host device and print image data (Video
Data) is created and transferred to the printing unit (engine) 2.

The image processing unit (controller) 1 issues a print start control command to the printing unit (engine) 2. The image processing unit (controller) 1 monitors the status of the printing unit (engine) 2. As a result of this monitoring,
When an error has occurred in the printing unit (engine) 2, the image processing unit (controller) 1 notifies the operator of the error via the operation unit (operation panel) 3.

The printing unit (engine) 2 prints image data (Video) input from the image processing unit (controller) 1.
Data) is transferred to paper. The operation unit (operation panel) 3 receives information on the state of the laser printer from the image processing unit (controller) 1 and
indicate. The operation unit (operation panel) 3 receives various inputs from the operator and inputs them to the image processing unit (controller) 1. The operation unit (operation panel) 3 has a display unit for displaying the status of the laser printer and the like, and a switch unit for an operator to control the printer.

FIG. 1 is a configuration diagram showing the configuration of the image processing unit (controller) 1. According to FIG. 2, the image processing unit (controller) 1 includes a CPU 11, a program ROM
12, work RAM 13, font ROM 14, NVR
AM15, IC Card slot 16 Host I / F18, Ho
st Buffer 20, Panel I / F 21, Image memory 22,
Video I / F23, expansion unit 24, and Engine
I / F 25.

The CPU 11 controls the entire image processing unit (controller) 1 based on a program stored in the program ROM 12. The program ROM 12
A program for the CPU 11 to control the image processing unit (controller) 1 is stored.

The work RAM 13 is a memory for storing various information such as temporary information. Font ROM
Reference numeral 14 denotes a memory for storing character information. NVRAM
Reference numeral 15 denotes a nonvolatile memory that retains data even after the power of the laser printer is turned off. NVRAM15
Are used to hold setting information and the like of the laser printer.

The IC card slot 16 is a slot in which a removable memory card 17 is mounted. The memory card 17 includes one storing optional font data.

The host I / F 18 is an interface for connecting the laser printer to a host device 19. Host I / F 18 is a Centronics I / F,
There are types such as a network I / F, and a plurality of types of I / Fs may be provided. Host Buffer 20 is the host device 1
9 is a reception buffer for temporarily storing data received from the reception buffer 9. Panel I / F21 is an image processing unit (controller)
An interface unit 1 controls communication with an operation unit (operation panel) 3.

The image memory 22 stores the program ROM 12
The print image data (Video data) created from the print data by the CPU 11 based on the program stored in the CPU 11 is stored in page units. The image memory 22
Stores print image data compressed by the CPU 11 based on the program stored in the program ROM 12 in page units. This print data compression processing may be performed by a compression unit (not shown).

The Video I / F 23 is an interface for transferring print image data (Video data) on the image memory 22 to the printing unit (engine) 2. The expansion unit 24 expands the compressed print image data in the image memory 22 and transfers the data to the Video I / F 23.

The Engine I / F 25 transmits a control command for controlling the printing unit (engine) 2 to the printing unit (engine).
Transfer to 2. The Engine I / F 25 takes in status information of the printing unit (engine) 2 from the printing unit (engine) 2.

Next, this laser printer is connected to the host device 1.
A series of printing operations for printing the print data received from the printer 9 on paper by the printing unit (engine) 2 will be described in detail with reference to FIG.

The print data input from the host device 19 is received by the Host I / F 18 and is temporarily stored in the host buffer.
20. The CPU 11 stores the program ROM 1
The print data is analyzed in accordance with the program stored in the printer 2 and print image data is created in accordance with an instruction from the host device 19. This program is called a command interpreter program.

The command interpreter program creates print image data in the image memory 22 from the host device 19 in accordance with printing conditions such as paper size, resolution, and single-sided / double-sided printing specified by a command or the like. When one page of print image data is created by this command interpreter program, the program ROM 12
The CPU 11 determines whether to compress the print image data according to a print control program for managing the print image stored in the print image data.

When the print control program determines to compress the print image data, the CPU 1
1 uses a compression program stored in the program ROM 12 to compress the print image data. The compressed print image data is stored in the image memory 22.

If the compression of the print image data by the compression program has been completed and the transfer operation of transferring the print image data of the previous page to the print unit (engine) 2 has been completed, the CPU 11 controls the Engine I / F 25 Then, a control command for instructing the start of printing is transmitted to the printing unit (engine) 2. Further, the CPU 11 makes settings for the decompression unit 24 to decompress the compressed print image data stored in the image memory 22. Then C
The PU 11 instructs the Video I / F 23 to perform a transfer process for transferring print image data to the printing unit (engine) 2. This is called print activation processing.

When the compression of the print image data is completed, the print image data of the previous page is sent to the printing unit (engine) 2.
If the transfer has not been completed, the image processing unit (controller)
After completing the print data transfer processing of the previous page, 1 performs print activation processing for this page. When the print image data is transferred to the printing unit (engine) 2, the printing unit (engine) 2 prints the data on paper.

When the print control program determines that the print image data is not compressed, the CPU 11
Sets the expansion unit 24 so that the print image data is not subjected to expansion processing and is passed through. Then, the CPU 11 performs the print activation process.

The CPU 11 keeps the image memory 2 until the printing section (engine) 2 finishes printing the print image data normally.
2 does not erase the print image data. Thereby, when a paper jam occurs in the printing unit (engine) 2,
The printing unit (engine) 2 can perform reprinting.

Since the command interpreter program operates as a task different from the print control program, if the image memory 22 has an area for creating one page of print image data, the print operation of the previous page is being executed. Even so, print image data can be created for the subsequent page.

As a result, the continuous printing performance of the printer can be maximized. This is because print image data for a plurality of pages must be created in advance in order to ensure the continuous printing performance of this printer to the maximum. That is, unless a print start command for the next page is issued before the discharge of the previous page is completed, the continuous printing performance of this printer is not exhibited.

In particular, in a printer having a long path from the paper feeding unit to the paper discharging unit, before the paper of the first page is completely discharged,
In some cases, a print start command for the third page or the fourth page must be issued. As described above, while printing the data of the first page, the print data of the subsequent page must be converted into print image data as necessary.

(First Operation Example) The first operation of the print control program for judging whether or not to compress print image data will be described in detail with reference to FIGS. 1 and 3.

When one page of print image data is created by the command interpreter program (step S11), the print control program determines that the printing unit (engine) 2 uses paper of a size to print the print image data. The number of pages (N) required for continuous printing is determined (step S12). Since the number of pages (N) required for the printing unit (engine) 2 to perform continuous printing is a numerical value unique to the printing unit (engine) 2, the program ROM 12 stores in advance the paper size and the number of pages (N ) Is stored.

This print control program is:
The size information (Page Size) of the print image data is obtained (step S13). This information is obtained as a variable from the command interpreter program.

Next, the print control program obtains overall size information (Mem Size) relating to the capacity of the image memory 22 (step S14). This information is stored in the image memory 22, the work RAM 13, the NVRAM 1
It is obtained from a memory management program that manages the memory in the image processing unit (controller) 1 such as the fifth.

The number of pages (N) required when performing continuous printing on paper of a size to print the print image data, and the size information (Page Size) of the print image data
) And the overall size information (Mem Size) regarding the capacity of the image memory 22, the print control program calculates the size of the print image data multiplied by the number of pages of the print image data. Judge whether it is less than the capacity of 22 (Mem Size> =
Page Size * N; Step S15).

When the capacity obtained by multiplying the size of the print image data by the number of pages of the print image data is equal to or smaller than the capacity of the image memory 22 (Mem Size> = Page Size *
N; step S15 / YES), the print control program determines that the print image data is not to be compressed, ends the process without compressing the print image data, and ends the process. This is because the image memory 22 can store print image data of all pages.

When the capacity obtained by multiplying the size of the print image data by the number of pages of the print image data is larger than the capacity of the image memory 22 (Mem Size <Page Size *).
N; step S15 / NO), the print control program determines to compress the print image data (step S16).

According to the above embodiment, the laser printer controls whether or not to compress the print image data in the image memory in consideration of the printing conditions such as the installed memory capacity, the printing paper size, and the printing resolution. Because of the above printing conditions,
In addition, it is possible to realize the optimum continuous printing performance for the laser printer.

(Second Operation Example) The second operation of the print control program for judging whether or not to compress print image data will be described in detail with reference to FIGS. 1 and 4.

When one page of print image data is created by the command interpreter program (step S21), the print control program determines whether this page requires printing on both sides (step S22).

If the page has to be printed on both sides (step S22 / YES), the print control program uses the data table for duplex printing stored in the program ROM 12 and the printing unit (engine) 2 uses this data table. The number of pages required when performing continuous printing on paper of a size to print the print image data is determined (N = the number of pages required for continuous printing in duplex printing; step S23).

If the page has to be printed on one side (step S22 / NO), the print control program has a data table for one-sided printing stored in the program ROM 12, and the printing unit (engine) 2 executes this process. The number of pages required when performing continuous printing on paper of the size to print the print image data is determined (N = the number of pages required for continuous printing in single-sided printing; step S24).

This print control program is:
The size information (Page Size) of the print image data is obtained (step S25). This information is obtained as a variable from the command interpreter program.

Next, the print control program obtains overall size information (Mem Size) relating to the capacity of the image memory 22 (step S26). This information is stored in the image memory 22, the work RAM 13, the NVRAM 1
It is obtained from a memory management program that manages the memory in the image processing unit (controller) 1 such as the fifth.

The number of pages (N) required when performing continuous printing on paper of a size to print the print image data, and the size information (Page Size) of the print image data
) And the overall size information (Mem Size) regarding the capacity of the image memory 22, the print control program calculates the size of the print image data multiplied by the number of pages of the print image data. Judge whether it is less than the capacity of 22 (Mem Size> =
Page Size * N; step S27).

When the capacity obtained by multiplying the size of the print image data by the number of pages of the print image data is equal to or smaller than the capacity of the image memory 22 (Mem Size> = Page Size *
N; step S27 / YES), the print control program determines that the print image data is not to be compressed, terminates the process without compressing the print image data. This is because the image memory 22 can store print image data of all pages.

When the capacity obtained by multiplying the size of the print image data by the number of pages of the print image data is larger than the capacity of the image memory 22 (Mem Size <Page Size *).
N; step S27 / NO), the print control program determines to compress the print image data (step S28).

According to the above embodiment, the laser printer controls whether or not to compress the print image data in the image memory in consideration of the printing conditions such as the installed memory capacity, the printing paper size, and the printing resolution. Therefore, it is possible to realize continuous printing performance optimal for the above printing conditions.

Further, according to the above-described embodiment, the laser printer determines whether the printing image data must be printed on both sides or on one side as printing conditions. Printing conditions,
In addition, it is possible to realize the optimum continuous printing performance for the laser printer.

(Third Operation Example) Hereinafter, a second operation of the print control program for determining whether or not to compress print image data will be described in detail with reference to FIG. 1 and FIG.

When one page of print image data is created by the command interpreter program (step S31), the print control program determines whether print data is stored in the host buffer 20 (whether there is a subsequent page). A determination is made (step S32).

When print data is not stored in the host buffer 20 (when there is no subsequent page; step S
32 / NO), the print control program ends the process of determining whether to compress the print image data. If there is no subsequent page, all print image data is stored in the image memory 22.

When print data is stored in the host buffer 20 (when there is a subsequent page; step S32 /
YES), the print control program determines the number of pages (N) required when the printing unit (engine) 2 performs continuous printing on paper of a size to print the print image data (step S33). Since the number of pages (N) required for the printing unit (engine) 2 to perform continuous printing is a numerical value unique to the printing unit (engine) 2, the program ROM 12 stores in advance the paper size and the number of pages (N ) Is stored.

The number of pages (N) required for continuous printing on paper of a size to print the print image data is data for single-sided printing as shown in the second operation example. The data table to be used may be changed depending on whether the data is to be printed or to perform double-sided printing.

This print control program is:
The size information (Page Size) of the print image data is obtained (step S34). This information is obtained as a variable from the command interpreter program.

Next, the print control program obtains overall size information (Mem Size) relating to the capacity of the image memory 22 (step S35). This information is stored in the image memory 22, the work RAM 13, the NVRAM 1
It is obtained from a memory management program that manages the memory in the image processing unit (controller) 1 such as the fifth.

The number of pages (N) required for continuous printing on paper of a size to print the print image data and the size information (Page Size) of the print image data
) And the overall size information (Mem Size) regarding the capacity of the image memory 22, the print control program calculates the size of the print image data multiplied by the number of pages of the print image data. Judge whether it is less than the capacity of 22 (Mem Size> =
Page Size * N; Step S36).

When the capacity obtained by multiplying the size of the print image data by the number of pages of the print image data is equal to or less than the capacity of the image memory 22 (Mem Size> = Page Size *
N; step S36 / YES), the print control program determines that the print image data is not to be compressed, terminates the process without compressing the print image data. This is because the image memory 22 can store print image data of all pages.

When the capacity obtained by multiplying the size of the print image data by the number of pages of the print image data is larger than the capacity of the image memory 22 (Mem Size <Page Size *).
N; step S36 / NO), the print control program determines to compress this print image data (step S37).

According to the above embodiment, the laser printer controls whether or not to compress print image data in the image memory in consideration of printing conditions such as a mounted memory capacity, a printing paper size, and a printing resolution. Therefore, it is possible to realize continuous printing performance optimal for the above printing conditions.

Further, according to the above-described embodiment, since the print image data is not compressed when the data is a single page as the printing condition, this laser printer is also suitable for printing a single page of data. Printing performance can be realized.

[0077]

As is apparent from the above description, according to the first aspect of the present invention, data compression means for compressing print image data and creating compressed data, print image data,
And data storage means for storing compressed data, a determination means for determining whether to use the data compression means, and when the determination means determines not to use the data compression means,
By providing the control unit that performs control without using the data compression unit, it becomes possible to use or control the use of the print data compression unit, and it is possible to realize optimal continuous printing performance for the printing apparatus.

That is, when the printing process can be performed without using the print data compressing means, the printing apparatus does not compress the print image data. For this reason, the compression / decompression processing is omitted, but the printing efficiency is improved.

Even if a jam occurs,
Since the print image data after the page where the jam occurred is stored in a compressed or uncompressed form by the data storage means, the printing apparatus can start printing of the subsequent page. And it is possible to achieve continuous speed.

According to a second aspect of the present invention, in the apparatus of the first aspect, the judging means judges that the data compression means is used when all pages of the print image data cannot be stored in the data storage means. If it is possible to store all pages of print image data,
This printing device eliminates the time required for compression / decompression processing,
Printing efficiency is improved.

Even if a jam occurs,
Since there is a capacity to store the print image data after the page in which the jam occurred in the data storage unit in a compressed or uncompressed form, the printing apparatus can start printing of the subsequent page. It becomes possible, and it becomes possible to achieve continuous speed.

According to a third aspect of the present invention, in the device of the first aspect, the determining means stores, in the data storage means, a capacity obtained by multiplying the data capacity of the first page of the print image data by the number of pages of the print image data. If you can't remember
When all the pages of the print image data can be stored by determining that the data compression unit is used, the printing apparatus saves time required for compression / decompression processing and improves printing efficiency.

Even if a jam occurs,
Since there is a capacity to store the print image data after the page in which the jam occurred in the data storage unit in a compressed or uncompressed form, the printing apparatus can start printing of the subsequent page. It becomes possible, and it becomes possible to achieve continuous speed.

According to a fourth aspect of the present invention, in the apparatus of the first aspect, the judging means multiplies the data capacity of the first page of the print image data by the number of pages of the print image data and a predetermined coefficient. When the data cannot be stored in the data storage means, it is determined that the data compression means is to be used, and the predetermined coefficient must be either double-sided printing or single-sided printing of the print image data. With this setting, the printing apparatus can realize optimal continuous printing performance for the printing apparatus even if the print image data is data that must be printed on both sides.

According to a fifth aspect of the present invention, in the apparatus according to any one of the first to fourth aspects, the determination means determines that the data compression means is not used when the print image data is data of only one page. This eliminates the need for the printing apparatus to perform compression / expansion processing on only one page of data that does not require compression of print image data. Thus, the printing efficiency of the printing apparatus is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration of a controller of a laser printer according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of a laser printer according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating a first operation of the laser printer according to the embodiment of the present invention for determining whether to compress a print image.

FIG. 4 is a flowchart illustrating a second operation of the laser printer according to the embodiment of the present invention for determining whether to compress a print image.

FIG. 5 is a flowchart illustrating a third operation in which the laser printer according to the embodiment of the present invention determines whether to compress a print image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image processing part (controller) 2 Printing part (engine) 3 Operation part (operation panel) 11 CPU 12 Program ROM 13 Work RAM 14 Font ROM 15 NVRAM 16 IC Card slot 17 Memory card 18 HOST I / F 19 Host device 20 Host Buffer 21 Panel I / F 22 Image memory 23 Video I / F 24 Expansion unit 25 Engion I / F

Claims (5)

[Claims] 1. A data compression unit for compressing print image data to create compressed data; a data storage unit for storing the print image data and the compressed data; and determining whether to use the data compression unit. A printing apparatus comprising: a determination unit; and a control unit that performs control without using the data compression unit when the determination unit determines that the data compression unit is not used. 2. The image processing apparatus according to claim 1, wherein the determination unit determines that the data compression unit is to be used when all pages of the print image data cannot be stored in the data storage unit. Item 6. The printing device according to Item 1. 3. The method according to claim 1, wherein the determining unit determines that the data capacity of the first page of the print image data multiplied by the number of pages of the print image data cannot be stored in the data storage unit. 2. The printing apparatus according to claim 1, wherein it is determined that a data compression unit is used. 4. The data storage means stores a capacity obtained by multiplying a data capacity of a first page of the print image data by a number of pages of the print image data and a predetermined coefficient. If not, it is determined that the data compression unit is to be used, and the predetermined coefficient is determined depending on whether the print image data must be printed on both sides or printed on one side. The printing apparatus according to claim 1, wherein: 5. The apparatus according to claim 1, wherein the determining unit determines that the data compression unit is not used when the print image data is data of only one page. The printing device according to claim 1.