JPH11188931A - Image processor, image processing method and memory medium storing computer readable program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid time lag in band generation processing even when the writing data read out speed is low by providing a cache memory for caching a prescribed band of writing data through means for reading ahead each band of writing data stored at a memory section prior to start writing. SOLUTION: A data dividing section 208 divides a stored data in units of band and a data designated at a data read out section 209 is read out from an HD section 207. A cache managing section 210 read ahead a band data at the time of caching a data stored at the HD section 207 and makes a decision whether the data is cached in a primary cache 211 or a secondary cache 212. Consequently, the writing data can be read out efficiently using a cache memory of small capacity. According to the arrangement, such a situation as the band generating time is delayed depending on the reading time of writing data to cause print over can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and an image processing method for reading out drawing data stored in a predetermined storage unit and outputting print image data alternately developed through a plurality of band memories to a printing unit. The present invention relates to a processing method and a storage medium storing a computer-readable program.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus called a page printer such as a laser beam printer, image processing is performed by holding raster data of one page in a raster memory. Raster data as such an image processing device handles not only text but also all kinds of images from simple figures to images such as photographs.

Further, the resolution of these image forming apparatuses has been improved in recent years. For example, a resolution of 600 dpi, an A4 size, and a memory of 4 Mbytes for one page are required.
Thus, the resolution tends to increase more and more. Further, the gray scale conventionally represented by two gray scales (1 bit) per pixel is also changed from 16 gray scales (4 bits) to 256 gray scales (8 bits).
And require more and more raster memory.

[0004] In recent years, the number of cases of handling color has increased, and in the YMCK space, four planes have been required more than in the case of monochrome, and the volume has become much larger.

[0005] In order to suppress the increase in cost due to such an increase in memory, various memory saving techniques have been proposed. For example, instead of having a bitmap image for one page in the raster memory, the raster memory is divided into strip-shaped bands, and banding processing for performing processing in band units is performed. In the banding processing, data input in a page description language is once generated in band units as data called band-coded representation.

[0006] When the band-encoded representation is developed in a raster memory, raster data is generated. Two raster memories are prepared, raster data is developed in one raster memory, and video data is transferred (shipping) from the other raster memory to the printer engine. Processing is in progress.

For this reason, it is possible to print one page only by using a raster memory for two bands.

However, when rendering for the one page, during the parallel processing (between the other band and the end of the video transfer), the rasterized data must be developed from the band-encoded representation for one band. There was a condition that it should not. If this condition is not satisfied, the raster data must be transferred as a video signal to the printer engine before raster data development is completed, resulting in incomplete printing (overrun). Will be done.

As described above, in the band control, the paper transport speed of the printer engine is constant. Here, if the generation of the print image in band units cannot be made in time for the paper transport speed of the printer engine, an error called a print overrun occurs.

At present, an image generation system is used to retrieve data from a low-speed storage device (here, a low-speed storage device includes not only a storage device having a low read-down speed but also a device having many read errors and a low average read speed). In order to suppress the occurrence of print overrun because the band generation speed cannot keep up with the engine speed, a cache is once cached in a high-speed memory for processing.

[0011]

However, the above technique requires a large amount of storage for the cache memory area. In particular, there is a problem in that data such as an overlay, which covers one entire page, requires a storage device for one page, thereby increasing the device cost.

Further, if the above problem is dealt with by a low-speed access memory, there is also a problem that when data is taken out, the band generation speed cannot keep up with the engine speed and print overrun frequently occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a cache memory capable of accessing drawing data stored in a storage unit in units of bands at a high speed. And controlling the band generation processing for the band memory by reading out the data, avoids delaying the band generation processing time even when the reading speed of the drawing data read from the storage unit is low, resulting in a print overrun. It is an object of the present invention to provide an image processing apparatus and an image processing method capable of reliably avoiding the problem and a storage medium storing a computer-readable program.

[0014]

According to a first aspect of the present invention, a printing unit reads out drawing data stored in a predetermined storage unit and prints out print image data that is alternately developed through a plurality of band memories. Registering means for dividing drawing data in page units to be developed in the band memory into bands and registering the drawing data in the storage unit; and storing the storage unit before starting drawing in the band memory. And a cache memory for caching the drawing data for a predetermined band by the reading means.

According to a second aspect of the present invention, there is provided an image processing apparatus for reading out drawing data stored in a predetermined storage unit and outputting print image data alternately developed through a plurality of band memories to the printing unit. Registration means for dividing the drawing data in page units for development in the band memory and registering the divided data in the storage unit, reading means for reading the drawing data of each band registered in the storage unit, A first cache memory for caching drawing data for an arbitrary band from a leading band pre-read by the reading unit before starting drawing to the band memory, and after the drawing data is cached in the first cache memory, A second cache memory for caching a predetermined band of drawing data of a subsequent band read by the reading unit; A control for controlling a cache in the first cache memory for drawing data of each band pre-read from the leading band by the reading means and a cache in the second cache memory for drawing data of each band subsequent to the leading band. Means.

According to a third aspect of the present invention, the control unit is configured to control the drawing data read in advance and cached in the first cache memory until the printing process of the number of pages designated by the printing unit is completed. It is not erased.

According to a fourth aspect of the present invention, the drawing data is predetermined overlay data.

In a fifth aspect according to the present invention, the storage section is a memory medium slower than a band generation speed for the band memory.

According to a sixth aspect of the present invention, the number of bands that can be cached in the second cache memory is equal to or greater than the number of bands that can be cached in the first cache memory.

According to a seventh aspect of the present invention, the first and second cache memories are storage media that can access the band memory at a speed higher than the band generation speed.

According to an eighth aspect of the present invention, there is provided an image processing method for reading out drawing data stored in a predetermined storage section and outputting print image data alternately developed through a plurality of band memories to the printing section. A registration step of dividing drawing data in page units for development in the band memory and registering the drawing data in the storage unit; and a leading band pre-read from the storage unit before starting drawing in the band memory. A first cache step of caching drawing data for an arbitrary band from a first cache memory in a first cache memory; and a subsequent cache readout by the storage unit after the drawing data is cached in the first cache memory. A second cache step of caching the band drawing data for a predetermined band in the second cache memory. That.

According to a ninth aspect of the present invention, there is provided a determining step for determining whether the data to be output to the printing section is the last page, and, when the determining step determines that the data is not the last page, A transition step of caching drawing data of a band subsequent to the arbitrary number of bands in the second cache memory without caching the arbitrary number of bands of drawing data from the first band in the first cache memory; And

According to a tenth aspect of the present invention, a computer reads out drawing data stored in a predetermined storage section and outputs print image data, which is alternately developed through a plurality of band memories, to the printing section. A storage medium storing a possible program, wherein a registration step of dividing drawing data in units of pages to be developed in the band memory into bands and registering the divided data in the storage unit; A first cache step of caching, in the first cache memory, drawing data of an arbitrary band from the first band read in advance from the storage unit in the first cache memory;
After the drawing data is cached in the first cache memory, caching the drawing data of the subsequent band read by the storage unit for a predetermined band in the second cache memory. Computer-readable program stored in a storage medium.

According to an eleventh aspect of the present invention, there is provided a judging step for judging whether or not the data to be output to the printing section is the last page, and when it is judged by the judging step that the data is not the last page, A transition step of caching drawing data of a band subsequent to the arbitrary number of bands in the second cache memory without caching the arbitrary number of bands of drawing data from the first band in the first cache memory; And a computer-readable program having the above is stored in a storage medium.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the configuration of the present embodiment, a laser beam printer suitable for applying the present embodiment will be described. The printer to which the present embodiment is applied is not limited to a laser beam printer and an ink jet printer, and it goes without saying that a printer of another printing method may be used.

FIG. 1 is a sectional view showing a configuration of an output device to which the present invention can be applied, for example, a case of a laser beam printer (LBP).

In the figure, reference numeral 1500 denotes an LBP main body, which includes print information (character codes, etc.), form information, microinstructions, etc. supplied from an externally connected host computer (host computer 201 shown in FIG. 2 described later). Is input and stored, and a corresponding character pattern, form pattern, or the like is created according to the information, and an image is formed on a recording medium such as recording paper. 1
Reference numeral 501 denotes an operation panel on which switches for scanning, an LED display, and the like are arranged. Reference numeral 1000 denotes a printer control unit, which controls the entire LBP body 1500 and analyzes character information and the like supplied from a host computer. The printer control unit 1000 mainly converts character information into a video signal having a corresponding character pattern and outputs the video signal to the laser driver 1502.

The laser driver 1502 is a semiconductor laser 1
A circuit for driving the laser beam 503 switches on / off a laser beam 1504 emitted from the semiconductor laser 1503 according to an input video signal. Laser light 15
Numeral 04 is swung right and left by a rotary polygon mirror 1505 to scan and expose an electrostatic drum 1506. As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 1506. This latent image is developed by a developing unit 1507 disposed around the electrostatic drum 1506,
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 1508 mounted on the LBP main body 1500, and is taken into the apparatus by a paper feed roller 1509 and transport rollers 1510 and 1511. And supplied to the electrostatic drum 1506.
The LBP body 1500 is provided with 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 system can be connected in addition to the built-in fonts.

[First Embodiment] FIG. 2 is a block diagram showing an example of an image processing apparatus according to a first embodiment of the present invention, in which a host computer and a printer can communicate via a predetermined communication medium. Corresponding to the case.

Referring to FIG. 1, reference numeral 201 denotes a host computer which outputs print information including print data and control data to a printing apparatus 202 via a predetermined communication medium (including a network and an interface).

The printing device 202 is roughly divided into a communication control unit 2
03, the formatter analysis unit 204, the drawing memory 205,
It comprises a printer engine unit 206 and an HD unit 207 composed of a hard disk.

A communication control unit 203 performs communication with the host computer 201 by a predetermined protocol. 20
Reference numeral 4 denotes a formatter analysis unit, and the host computer 2
The analysis processing of the print information received from 01 is performed. here,
A print image is created in the drawing memory 205 and sent to the printer engine unit 206.

The formatter analysis unit 204 includes a CPU, RA
M, ROM, etc.,
Is composed of a data division unit 208, a data read unit 209, a cache management unit 210, a primary cache 211, a secondary cache 212, and the like. Reference numeral 205 denotes a drawing memory which stores a print image created by the formatter analysis unit 204 and transfers the print image to the printer engine unit 206. The primary cache 211 is provided in the HD unit 20.
7 is used to cache data used by the second band of a plurality of pages.

On the other hand, the secondary cache 212
7 are cached in the primary cache 211.

In this embodiment, the band drawing process is performed, and the band memories for two bands are stored in the drawing memory 205.
Secured on top. When a print image is sent to the printer engine unit 206 having a print function for forming a print image as a permanent image, the image is transferred while alternately creating an image for each band. Here, if a print image is not created by the time of transfer, a print overrun occurs. The drawing memory 205 is configured by a RAM.

Reference numeral 207 denotes an HD unit, which comprises a hard disk. A data dividing unit 208 divides the data stored in the HD unit 207 including the hard disk and the stored data into band units to be processed.

A data reading unit 209 reads specified data from the HD unit 207. Reference numeral 210 denotes a cache management unit which prefetches band data when caching data stored in the HD unit 207,
It is determined whether the data is cached in the primary cache 211 or the secondary cache 212. If the data is for the first few bands, the data is stored in the primary cache 211, and the data after the band is stored in the secondary cache 212.
The primary cache 211 is not deleted until all pages have been printed.

In particular, in the case of overlay data including form data and the like, overlay data for the first few bands is stored in the primary cache 211, and overlay data after the band is stored in the secondary cache 212.

The overlay data stored in the primary cache 211 is not deleted until all pages have been printed.

FIG. 3 is a diagram showing the state of division and cache in the overlay data in the HD unit 207 shown in FIG. In the present embodiment, the size of one band is の of the size of a sheet, whereby the overlay data is divided into ８ and stored.

Here, the divided overlay data is called overlay data OD1 to OD8, respectively. The primary cache 212 is composed of a band cache for two bands, and the secondary cache 212 is composed of a band cache for three bands.
11, CA12 and the secondary cache are called band caches CA21, CA22 and CA23.

Hereinafter, the characteristic configuration of this embodiment will be described with reference to FIG.

The predetermined storage unit (H
D unit 207) is an image processing apparatus that reads out the drawing data stored in the memory unit and outputs print image data that is alternately developed through a plurality of band memories to a printing unit. A registration unit (data dividing unit 208) for dividing drawing data in units into bands and registering the drawing data in the storage unit; and a read-out unit that prefetches drawing data of each band registered in the storage unit before starting drawing in the band memory. Means (cache management unit 210) and a cache memory (primary cache 211 and secondary cache 212) for caching drawing data for a predetermined band by the reading means, so that the cache memory with a small memory capacity is developed in the band memory. Drawing data to be drawn can be efficiently read from the storage unit.

An image processing apparatus for reading out drawing data stored in a predetermined storage unit (HD unit 207) and outputting print image data alternately developed through a plurality of band memories to a printing unit. A registration unit (data division unit 208) for dividing the drawing data in page units to be developed into the band memory and dividing the drawing data into bands, and registering the divided data in the storage unit;
A reading unit (cache management unit 210) for reading the drawing data of each band registered in the storage unit; and caching drawing data for an arbitrary band from the leading band pre-read by the reading unit before starting drawing to the band memory. After the drawing data is cached in the first cache memory (primary cache 211) and the first cache memory, a second band for caching a predetermined band of drawing data of a succeeding band read by the reading unit. A cache memory (secondary cache 212), a cache for the first cache memory for drawing data of each band read ahead from the first band by the reading means, and a second cache for drawing data of each band subsequent to the first band. Key to cache memory Control means (cache management unit 210) for controlling the drawing data, so that the drawing data divided and registered in band units in the storage unit is cached in the first and second cache memories having a small memory capacity. Thus, it is possible to reliably avoid a situation in which the band generation time is delayed depending on the speed at which the drawing data is read from the storage unit and print overrun occurs.

Further, the control means does not erase the pre-read and cached drawing data in the first cache memory until the printing process of the number of pages designated by the printing unit is completed. In the print processing using the, the time required to read the same drawing data from the storage section at the page break can be omitted, that is, the band generation processing start time at the beginning of each page after the first page can be shortened, and the continuous high-speed Printing processing becomes possible.

Further, since the drawing data is predetermined overlay data, it is possible to omit the time for reading the overlay data from the storage section at the page break in the printing process using the overlay data, and to reduce the band generation processing time. Can be significantly reduced.

Further, since the storage unit is a memory medium slower than the band generation speed for the band memory, various drawing data to be cached can be easily registered and managed.

Since the number of bands that can be cached in the second cache memory is equal to or greater than the number of bands that can be cached in the first cache memory, print overruns can be prevented even if the band generation processing time is short. It can be avoided reliably.

Further, since the first and second cache memories are storage media that can be accessed at a higher speed than the band generation speed for the band memory, the time from when the drawing data is read to when the band generation processing is started is reduced. Can be significantly reduced.

FIG. 4 is a flowchart showing a first data processing procedure in the image processing apparatus according to the present invention.
The data processing procedures of the cache management unit 210, the formatter analysis unit 204, and the printer engine unit 206 shown in FIG. 2 correspond to the respective data processing procedures. Note that (1) to (8) indicate each step in the cache management unit 210 illustrated in FIG.
1) to (19) are the formatter analyzer 20 shown in FIG.
4 show the steps, and (21) to (30) show the steps of the printer engine unit 206 shown in FIG.

The operation of the cache management unit 210, the formatter analysis unit 204, and the printer engine unit 206 in the printing apparatus during printing and their respective relationships will be described below with reference to FIG.

First, when the print data is analyzed, two bands are read from the overlay data OD1 to OD8 corresponding to the print data and stored in the band caches CA11 and CA12 of the primary cache 212 (1).

When printing by the printer engine unit 206 starts, a band cache C for band generation is generated.
The overlay data OD1 is read from A11, and a print image V1 is created in the band memory BM1 (11). At the same time, the overlay data OD3 is read from the HD unit 207 into the secondary cache band cache CA21 (2).

Next, when a print image is generated in the band memory BM1 secured on the drawing memory 205, the print image is transferred to the printer engine unit 206, and the sheet is conveyed (21), and printing is started (step 21). 22). At the same time, the next print image is created in the band memory BM2, and the overlay data OD2 is read from the band cache CA12 for the primary cache onto the band memory BM2 (12).

When the reading of the overlay data OD3 is completed, the overlay data OD4 is transferred from the HD unit 207 to the secondary cache band cache CA22.
(3).

Hereinafter, the reading of the overlay data from the HD unit 207 does not coincide with the timing of the creation of the print image or the reading from the cache, and the overlay data is read from the HD unit 207 (4) to (7) to determine whether it is the last page. (8), and if YES, the process is terminated, and if NO, the process returns to step (2).

However, since the read time of the pre-read band is earlier than the read time, the read from the cache does not catch up. Also, the band memory BM1,
HD unit 20 to cache not read into BM2
7, the reading from the HD unit 207 waits until the cache is read.

On the other hand, in step (12), the band memory B
When the print image V2 started to be created in M2 is completed, the print image is transferred to the printer engine unit 206 and printed (23). At the same time, a print image V3 is created in the band memory BM1, and at this time, the overlay data OD3 is read into the band memory BM1 from the secondary cache band cache CA21 (13).

The print image V is stored in the band memory BM1.
Upon completion of Step 3, the print image is transferred to the printer engine unit 206, and the print image V3 is printed (24).

At the same time, the overlay data OD4 is read from the secondary cache band cache CA22, and a print image V4 is created in the band memory BM2 (14).

At this point, if the overlay data OD5 has been read into the secondary cache band cache CA23, the overlay data OD6 is transferred to the secondary cache band cache CA21 instead of the primary cache band cache CA11. It is read (5). Hereinafter, the data is not read into the primary cache but is cached in the used area of the secondary cache.

When the print image V4 is completed in the band memory BM2 in step (14), the print image is transferred to the printer engine unit 206, and the print image V4 is printed (25).

At the same time, the overlay data OD5 is read from the secondary cache band cache CA23, and a print image V5 is created in the band memory BM1 (1).
5).

When the print image V5 is completed in the band memory BM1 in step (15), the print image is transferred to the printer engine unit 206, and the print image V5 is printed (26).

At the same time, the overlay data OD6 is read from the secondary cache band cache CA21, and a print image V6 is created in the band memory BM2 (1).
6).

When the print image V6 is completed in the band memory BM2 in step (16), the print image is transferred to the printer engine unit 206, and the print image V6 is printed (27).

At the same time, the overlay data OD7 is read from the secondary cache band cache CA22, and a print image V7 is created in the band memory BM1 (1).
7).

When the print image V7 is completed in the band memory BM1 in step (17), the print image is transferred to the printer engine unit 206, and the print image V7 is printed (28).

At the same time, the overlay data OD8 is read from the secondary cache band cache CA23, and a print image V8 is created in the band memory BM2 (1).
8).

In step (18), when the print image V8 is completed in the band memory BM2, the print image is transferred to the printer engine unit 206, and the print image V8 is printed (29).

Next, the formatter analysis unit 204 determines whether or not the processing of the last page has been completed (19), and if NO, returns to step (11) and returns to YE.
If S, the process ends.

Similarly, the printer engine unit 206 determines whether or not the printing of the last page has been completed (30). If NO, the process returns to step (21) and returns to step (21).
If S, the process ends.

As a result, the cache management unit 210
When printing of a page and subsequent pages starts, two blocks of data have already been read into the primary cache 211 (because they have not been erased in the printing process of the first page), so there is no waiting for prefetching to the cache, that is, Since the process returns from step (8) to step (2) in FIG. 4, the creation of the print image V1 for the next page can be started immediately.

In the above-described embodiment, the band data to be pre-read is for two bands, which is the same as the capacity of the primary cache. However, the band data may be arbitrarily determined according to the relationship between the data reading speed of the hard disk and the band processing speed. For example, a total of 5 for 2 bands of primary cache and 3 bands of secondary cache
A look-ahead for the band may be performed.

FIG. 5 is a flowchart showing a second data processing procedure in the image processing apparatus according to the present invention.
This corresponds to the data division processing procedure by the data division unit 208 shown in FIG. Each of (1) to (5) indicates a step.

First, in step (1), the data to be divided is read, and it is determined whether the data is data based on a print command or data based on an image. If it is determined that the data is based on an image, the process proceeds to step (1). (4) Proceed to the subsequent steps.

On the other hand, if it is determined in step (1) that the data is print command data, the command is analyzed in step (2), and an image is created in step (3). Is used to divide the image into bands.

Next, in step (5), it is determined whether or not other data remains. If NO, the process returns to step (1), and if YES, the process ends.

In the present embodiment, the image data is once divided into image data and divided into bands. However, the command is analyzed and divided into a plurality of commands so that the print image generated in each band is contained. Thereby, division may be performed for each band.

FIG. 6 is a flowchart showing a third data processing procedure in the image processing apparatus according to the present invention.
This corresponds to the data management processing procedure of the cache management unit 210 shown in FIG. Note that (1) to (9) indicate each step.

When the information of the data to be cached is received from the formatter analysis unit 204 and the corresponding data is obtained through the data division unit 208, first, in step (1), it is determined whether or not the data is data up to the second band in the data. If the determination is NO, the process proceeds to step (5) and subsequent steps.

On the other hand, if it is determined in step (1) that the data is data up to the second band, the data is registered in the primary cache 211 in step (2). Next, in step (3), it is determined whether or not the second band has been cached (3). If NO, the process returns to step (1). If YES, the prefetching is completed in step (4). Is reported to the formatter analysis unit 204, and the process returns to step (1).

On the other hand, if NO is determined in step (1), that is, if the data is the third and subsequent bands, the process proceeds to step (5) to check whether the secondary cache 212 is open. If it is determined that the area has not been used, the process waits in step (6) until a used area is created.

On the other hand, if it is determined in step (5) that the used area has the secondary cache 212 open, then in step (7), if the used area is created, it is deleted. Next, if the secondary cache 212 is open or opened in step (6), step (8)
Then, the data is registered in the secondary cache 212. Then, in step (9), it is determined whether or not the data is completed. If the determination is YES, the process is terminated and NO
Is determined, the process returns to step (1) until the last band data, and the same processing is repeated.

In the present embodiment, since there are two pre-read bands, steps (3) to (4) are at the step positions in the drawing. This processing comes after step (8).

Hereinafter, the characteristic configuration of the present embodiment will be described with reference to FIGS.

The predetermined storage unit (H
D unit 207) to read out the drawing data stored in the memory unit and output print image data alternately developed through a plurality of band memories to the printing unit (printer engine 206). A storage medium storing a computer-readable program that reads out the drawing data stored in the printing unit and outputs print image data that is alternately developed through a plurality of band memories to a printing unit; A registration step (not shown) for dividing drawing data in page units for development into bands and registering the drawing data in the storage unit; and, before starting drawing in the band memory, an arbitrary band from a leading band pre-read from the storage unit. A first cache step of caching the drawing data in the first cache memory (step in FIG. 4) 1)) and after the drawing data is cached in the first cache memory, the drawing data of the subsequent band read by the storage unit is cached in the second cache memory for a predetermined band. Cache process (from step (2) in FIG. 4)
(7)), the drawing data divided and registered in the storage unit in band units can be cached in the first and second cache memories each having a small memory capacity. It is possible to reliably avoid a situation in which the band generation time is delayed depending on the data reading speed and print overrun occurs.

A determination step for determining whether or not the data to be output to the printing section is the last page, and if it is determined that the data is not the last page in the determination step, the next page and subsequent pages are transferred to the first cache memory. A transition step of caching drawing data of a band subsequent to the number of arbitrary bands in the second cache memory without caching drawing data of the number of arbitrary bands from the leading band (step (8) in FIG. 4). To (2)), it is possible to omit the time for reading the same drawing data from the storage unit at the page break in the printing process using the same drawing data. , The band generation processing start time can be shortened, and high-speed printing processing can be continuously performed.

Hereinafter, the configuration of a data processing program that can be read by a printing system to which the image processing apparatus according to the present invention can be applied will be described with reference to a memory map shown in FIG.

FIG. 7 is a diagram for explaining a memory map of a storage medium for storing various data processing programs that can be read by a printing system to which the image processing apparatus according to the present invention can be applied.

Although not shown, information for managing a group of programs stored in the storage medium, such as version information and a creator, is also stored, and information dependent on the OS or the like on the program reading side, such as a program, is stored. An icon or the like for identification display may also be stored.

Further, data dependent on various programs is also managed in the directory. In addition, a program for installing various programs on a computer or a program for decompressing a program to be installed when the program to be installed is compressed may be stored.

The functions shown in FIGS. 4, 5 and 6 in the present embodiment may be executed by a host computer by a program installed from the outside.
In this case, the present invention is applied even when a group of information including a program is supplied to the output device from a storage medium such as a CD-ROM, a flash memory, or an FD, or from an external storage medium via a network. Things.

As described above, the storage medium storing the program code of the software for realizing the functions of the above-described embodiment is supplied to the system or the apparatus, and the computer (or CPU or MP) of the system or the apparatus is supplied.
It goes without saying that the object of the present invention is also achieved when U) reads and executes the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

Examples of a storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and C
DR, magnetic tape, nonvolatile memory card, RO
M, EEPROM and 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. ) And the like perform 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 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, The CPU provided in the function expansion board or function expansion unit performs part or all of the actual processing,
It goes without saying that a case where the function of the above-described embodiment is realized by the processing is also included.

According to the above embodiment, the memory area used for the cache can be small, and the increase in cost can be suppressed. Further, by pre-reading data for several bands in advance so that band generation cannot catch up with data reading, it is possible to prevent print overrun from occurring.

Further, when the same data is used for two or more pages, in order to prevent the start of printing of the second and subsequent pages from being delayed due to the pre-reading time of the second and subsequent pages, the cached data of the first page is used from the beginning. By leaving several bands unerased, there is no delay in starting printing.

For data predicted to be used over a plurality of pages, such as overlay data, by caching unconditionally, without having to analyze a plurality of pages,
Analysis time can be saved, and when the same data is used over two or more pages, the first page is cached to prevent the start of printing of the second and subsequent pages from being delayed by the pre-reading time of the second and subsequent data. By not deleting several bands from the beginning of the data, it is possible to prevent the printing start from being delayed.

Further, when the size of the band is determined in advance, the division processing at the time of reading can be omitted, so that the printing speed can be improved.

[0104]

As described above, the first embodiment according to the present invention is described.
According to the invention, there is provided an image processing apparatus which reads out drawing data stored in a predetermined storage unit and outputs print image data alternately developed through a plurality of band memories to a printing unit, wherein the band memory Registering means for dividing drawing data in units of pages for development into bands and registering the drawing data in the storage unit, and reading out the drawing data of each band registered in the storage unit before starting drawing in the band memory. Means and a cache memory for caching the drawing data for a predetermined band by the reading means, the drawing data to be developed in the band memory can be efficiently read from the storage unit with a cache memory having a small memory capacity.

According to the second aspect of the present invention, there is provided an image processing apparatus which reads out drawing data stored in a predetermined storage unit and outputs print image data alternately developed through a plurality of band memories to a printing unit. Registering means for dividing drawing data in units of pages for development in the band memory into bands and registering the divided data in the storage unit; reading means for reading drawing data of each band registered in the storage unit; Means for caching drawing data for an arbitrary band from a leading band pre-read before starting drawing to the band memory for an arbitrary band; and, after the drawing data is cached in the first cache memory, to the readout. A second cache memory for caching a predetermined band of drawing data of a subsequent band read by the means, Control means for controlling a cache in the first cache memory for drawing data of each band read in advance from the leading band by the reading means and a cache in the second cache memory for drawing data of each band subsequent to the leading band; Therefore, the drawing data divided and registered in the storage unit in band units can be cached in the first and second cache memories having a small memory capacity, and the speed of reading the drawing data from the storage unit can be reduced. Accordingly, it is possible to reliably avoid a situation in which the band generation time is delayed and print overrun occurs.

According to the third aspect, the control means does not erase the drawing data read in advance and cached in the first cache memory until the printing process of the number of pages designated by the printing unit is completed. Therefore, in the printing process using the same drawing data, the time for reading the same drawing data from the storage unit at the page break can be omitted, that is, the band generation processing start time at the beginning of each page after the first page can be shortened. And high-speed printing can be continuously performed.

According to the fourth aspect, the drawing data is:
Since the predetermined overlay data is used, it is possible to omit the time for reading the overlay data from the storage unit at the page break in the printing process using the overlay data, and to greatly reduce the band generation processing time.

According to the fifth aspect, since the storage unit is a memory medium that is slower than the band generation speed for the band memory, it is possible to easily register and manage various drawing data to be cached.

According to the sixth aspect, the number of bands that can be cached in the second cache memory is equal to or larger than the number of bands that can be cached in the first cache memory. Also, the occurrence of print overrun can be reliably avoided.

According to the seventh aspect, the first and second cache memories are storage media that can be accessed faster than the band generation speed for the band memory.
The time from when the drawing data is read to when the band generation processing is started can be greatly reduced.

According to the eighth and tenth aspects, image processing for reading out drawing data stored in a predetermined storage section and outputting print image data alternately developed to the printing section via a plurality of band memories. A method for reading drawing data stored in a predetermined storage unit and outputting to a printing unit print image data that is alternately developed through a plurality of band memories. A medium, wherein a registration step of dividing drawing data in page units for development in the band memory into bands and registering the drawing data in the storage unit; and a head read ahead from the storage unit before starting drawing in the band memory. A first cache step of caching drawing data for an arbitrary band from a band in a first cache memory; After the drawing data is cached in the flash memory, a second cache step of caching the drawing data of the subsequent band read by the storage unit for a predetermined band in the second cache memory. Can be cached in the first and second cache memories each having a small memory capacity. The band generation time depends on the speed at which the drawing data is read from the storage unit. However, it is possible to reliably avoid a situation in which print overrun occurs due to delay.

According to the ninth and eleventh aspects of the present invention, a judging step of judging whether or not the data to be output to the printing section is the last page; Transition to cache the drawing data of the band following the arbitrary number of bands in the second cache memory without caching the arbitrary number of bands of the drawing data from the first band in the first cache memory. In the printing process using the same drawing data, the time for reading out the same drawing data from the storage unit at the page break can be omitted. That is, the band generation process at the top of each page after the first page The start time can be shortened, and high-speed printing can be continuously performed.

Accordingly, even when the reading speed of the drawing data read from the storage unit is low, it is possible to avoid a situation in which the band generation processing time is delayed and to surely avoid a situation in which a print overrun occurs. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an output device to which the present invention can be applied.

FIG. 2 is a block diagram illustrating an example of an image processing apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a state of division and cache in overlay data in an HD unit illustrated in FIG. 2;

FIG. 4 is a flowchart illustrating a first data processing procedure in the image processing apparatus according to the present invention.

FIG. 5 is a flowchart illustrating a second data processing procedure in the image processing apparatus according to the present invention.

FIG. 6 is a flowchart illustrating a third data processing procedure in the image processing apparatus according to the present invention.

FIG. 7 is a diagram illustrating a memory map of a storage medium that stores various data processing programs that can be read by a printing system to which the image processing apparatus according to the present invention can be applied.

[Explanation of symbols]

 201 Host Computer 202 Printing Device 203 Communication Control Unit 204 Formatter Analysis Unit 205 Drawing Memory 206 Printer Engine Unit 207 HD Unit 208 Data Division Unit 209 Data Read Unit 210 Cache Management Unit 211 Primary Cache 212 Secondary Cache

Claims (11)

[Claims] An image processing apparatus for reading drawing data stored in a predetermined storage unit and outputting print image data alternately developed through a plurality of band memories to a printing unit, wherein the band memory stores Registering means for dividing drawing data in page units for development into bands and registering the drawing data in the storage unit; and reading means for prefetching drawing data of each band registered in the storage unit before starting drawing in the band memory. An image processing apparatus comprising: a cache memory that caches drawing data for a predetermined band by the reading unit. 2. An image processing apparatus which reads out drawing data stored in a predetermined storage unit and outputs print image data alternately developed through a plurality of band memories to a printing unit. A registration unit that divides the drawing data in units of pages to be developed into bands and registers the drawing data in the storage unit; a reading unit that reads out the drawing data of each band registered in the storage unit; A first cache memory for caching drawing data for an arbitrary band from a leading band pre-read before drawing is started; and a subsequent cache read by the reading means after the drawing data is cached in the first cache memory. A second cache memory that caches band drawing data for a predetermined band; Control means for controlling a cache in the first cache memory for drawing data of each band read in advance from the leading band and a cache in the second cache memory for drawing data of each band subsequent to the leading band; An image processing apparatus characterized by the above-mentioned. 3. The method according to claim 1, wherein the control unit is configured to read in advance the first
3. The image processing apparatus according to claim 2, wherein the drawing data cached in the cache memory is not erased until the printing process of the number of pages specified by the printing unit is completed. 4. The image processing apparatus according to claim 1, wherein said drawing data is predetermined overlay data. 5. The image processing apparatus according to claim 1, wherein the storage unit is a memory medium that is slower than a band generation speed for the band memory. 6. The image processing apparatus according to claim 1, wherein the number of bands that can be cached in the second cache memory is equal to or larger than the number of bands that can be cached in the first cache memory. 7. The first and second cache memories,
2. A storage medium capable of accessing the band memory at a speed higher than a band generation speed.
Or the image processing apparatus according to 2. 8. An image processing method for reading drawing data stored in a predetermined storage unit and outputting print image data alternately developed through a plurality of band memories to a printing unit, the image processing method comprising: A registration step of dividing drawing data in page units for development into bands and registering the drawing data in the storage unit, and before starting drawing in the band memory, drawing data for an arbitrary band from a leading band pre-read from the storage unit. A first cache step of caching in the first cache memory; and, after the drawing data is cached in the first cache memory, drawing data of a subsequent band read by the storage unit for a predetermined band. A second cache step of caching for the second cache memory;
An image processing method comprising: 9. A determining step of determining whether the data to be output to the printing unit is the last page, and determining that the data is not the last page by the determining step.
After the next page, the drawing data of the band subsequent to the arbitrary band number is stored in the second cache memory without caching the arbitrary band number of drawing data from the first band in the first cache memory. 10. A cache transfer step.
The image processing method described in the above. 10. A storage medium storing a computer readable program for reading drawing data stored in a predetermined storage unit and outputting print image data alternately developed through a plurality of band memories to a printing unit. A registration step of dividing drawing data in page units for development in the band memory and registering the drawing data in the storage unit; and a leading band pre-read from the storage unit before starting drawing in the band memory. A first cache step of caching drawing data for an arbitrary band from the first cache memory into a first cache memory; and a subsequent cache data read from the storage unit after the drawing data is cached in the first cache memory. A second cache for caching band drawing data for a predetermined band in a second cache memory; Process
A storage medium storing a computer-readable program, comprising: 11. A determining step of determining whether data to be output to the printing unit is the last page; and determining that the data is not the last page by the determining step.
After the next page, the drawing data of the band subsequent to the arbitrary band number is stored in the second cache memory without caching the arbitrary band number of drawing data from the first band in the first cache memory. 2. A migrating step for caching.
0. A storage medium storing a computer-readable program according to item 0.