JP4962359B2 - Print control apparatus, print control method, and print control program - Google Patents

Description

The present invention relates to a print control apparatus, a print control method, and a print control program for controlling a printing apparatus including an ADF.

2. Description of the Related Art Conventionally, when copying a single page of a plurality of copies, there is known a printing apparatus that reads a document, stores image data indicating the document in a memory, and executes printing using the image data stored in the memory. (For example, Patent Document 1). There is also known a printing apparatus that includes an ADF (Auto Document Feeder) mechanism and has a function of reading a document of a plurality of pages and copying it to a plurality of copies (sort copy).
JP 2004-128895 A

In the conventional technique, when the sort copy function is realized using the ADF mechanism, the image data corresponding to a plurality of read pages cannot be efficiently stored in a limited size memory. Therefore, the maximum number of pages that can be sorted and copied at one time cannot be increased without increasing the size of the memory for storing image data.
If the image data is converted by some compression conversion method and stored in the memory, the number of pages that can be stored increases as compared with the case of storing in the memory without conversion. However, even if the same image data is converted by a different method, the size after conversion is different, and which method is used to convert the data size after conversion is the smallest depends on the characteristics of the image. In order for the printing apparatus to recognize the characteristics of an arbitrary document image placed on the document placement section, a method of reading the entire image once and grasping the characteristics of the image and converting it with an appropriate conversion method can be considered. As a result, the time from reading the original to completion of printing becomes longer.
The present invention has been made in view of the above problems. In a printing apparatus having an ADF mechanism and lacking memory resources, an image of a plurality of pages read can be obtained without increasing the time from reading of a document image to completion of printing. The object is to efficiently store corresponding data in a memory.

In order to achieve the above object, in the present invention, each of the first converted data and the second converted data obtained by converting the image data indicating the images of a plurality of pages by the first method and the second method for each page, Accumulated in each of a first memory area of a first size predetermined as the maximum size of the first conversion data and a second memory area of a second size predetermined as a size smaller than the first size Let When the size of the second conversion data exceeds the second size, the second conversion data is discarded and at least one remaining first memory area is secured in the memory, and the second conversion data When the size does not exceed the second size, the first conversion data is discarded and at least one remaining second memory area is secured in the memory. Thereafter, the first conversion data stored in the memory or /
The printing unit is caused to execute printing based on the second conversion data.

By repeating this method a plurality of times, conversion data corresponding to a plurality of pages of image data can be efficiently stored in the memory. That is, the first conversion data obtained by converting the image data indicating the image of the first page by the first method and the second conversion data converted by the second method are acquired and stored in different areas in the memory. If the second conversion data exceeds the second size as a threshold for determining whether or not to discard the second conversion data, the second conversion data is discarded and the first conversion data is left in the memory. A memory area for storing the first conversion data and the second conversion data is secured. Similarly, the first conversion data and the second conversion data on the second page are also stored in the memory area secured as described above. For example, if the second conversion data on the second page does not exceed the second size, this time, The first conversion data of the page is discarded and the second conversion data remains in the memory. The remaining second conversion data is a size that does not exceed the second size, and the second size is smaller than the first size. In this example, data indicating the image of two pages remaining in the memory at this time The size of the memory area used for storing (first conversion data on the first page and second conversion data on the second page) is used by storing the first conversion data on both the first page and the second page. Small compared to the size of the memory area. Here, “reservation” means that a memory area for storing the first conversion data or the second conversion data is allocated, and “release” described later means that the allocation is released. “Discard” means to make an area that can be overwritten with the conversion data of the next page.

By the way, the first size is the maximum size when image data is converted by the first method, and the first converted data does not exceed the first size (larger than the second size). On the other hand, the second conversion data may or may not exceed the second size. That is, the second conversion data may not exceed the second size, may exceed the second size and may not exceed the first size, and may further exceed the first size (second (Because there is a premise that the maximum size that conversion data can take is larger than the first size). Therefore, the size of the data (the first conversion data on the first page and the second conversion data on the second page) indicating the image of two pages remaining in the memory in the above example is the same for both the first page and the second page. There is a possibility that it will be smaller or larger than the case where it remains in the second conversion data. If there is a possibility of exceeding the first size when the image data of the first page is converted by the second method, the first conversion data converted by the first method that surely fits in the first size is stored. The data can be stored in a smaller memory area.
As described above, the conversion data can be reliably stored in the memory as conversion data of the second size or less when the conversion data can be reliably converted to the first size or less and also to the second size or less. By repeatedly accumulating and discarding data according to the method, it is possible to accumulate conversion data corresponding to more image data.

In the conversion data acquisition means, a document composed of a plurality of pages placed on the document placement unit is sequentially read page by page by the image reading unit, and the read image data is read by the image data conversion unit by the first method and the second method. It is only necessary that the first conversion data and the second conversion data, which are conversion data converted by the method, can be acquired for each page. The acquisition for each page means that conversion data corresponding to the page is acquired, and does not mean that the conversion data is acquired after conversion for one page is completed. In the image data converter, the image data for one page is converted in parallel by two types of conversion methods, and the image data acquisition means first conversion data and second conversion data corresponding to the conversion completed. And are acquired sequentially.
That is, the acquisition of the other conversion data is started before the acquisition of at least one of the conversion data is completed. This is to shorten the time from image reading to printing completion.

The memory according to the present invention has a capacity that is at least the size of the first size plus the second size. At least one first memory area (first size) and second memory area (second size) are secured in a state before starting the print control process by sort copy.

The conversion data accumulation control means only needs to be able to accumulate the first conversion data and the second conversion data acquired by the conversion data acquisition means in the first memory area and the second memory area, respectively. That is, the corresponding conversion data is accumulated in the first memory area or the second memory area. In addition, when it is found that the size of the second conversion data exceeds the second size while acquiring the second conversion data, the storage of the second conversion data is ended. That is, the second conversion data is not accumulated beyond the second memory area currently being accumulated. Similarly to the conversion data acquisition unit, the conversion data storage control unit starts to store the other conversion data before the acquisition of at least one conversion data is completed. This is because the time required to store the two types of stored data in the memory can be shortened as compared with the case where the storage of the other converted data is performed after the storage of one converted data is completed.

If the size of the second conversion data exceeds the second size, the memory area management means discards the second conversion data stored in the second memory area and secures at least one remaining first memory area In preparation for the accumulation of the first conversion data and the second conversion data for the next page. Also,
If the size of the second conversion data does not exceed the second size, discard the first conversion data stored in the first memory area, secure at least one remaining second memory area, and To prepare for the accumulation of the first conversion data and the second conversion data.

The print instructing unit only needs to allow the printing unit to perform printing based on the first conversion data and / or the second conversion data stored in the memory. That is, printing is executed using the conversion data remaining in the memory by repeatedly acquiring, storing, and discarding the conversion data by the conversion data acquisition means, the conversion data accumulation control means, and the memory area management means. If each of the acquired second conversion data for a plurality of pages exceeds the second size, the first conversion data remains in the memory and is used for printing. Also,
If each of the acquired second conversion data for multiple pages does not exceed the second size,
It is the second conversion data that remains in the memory and is used for printing. If some of the second conversion data for a plurality of pages has a page exceeding the second size and some pages do not exceed the page, pages stored as first conversion data and pages stored as second conversion data in the memory It means that and exist.

Furthermore, in the present invention, the memory may be composed of N (N is 2 or more) first memory areas and one second memory area reserved in advance. In that case, if the second conversion data does not exceed the second size and the remaining two or more first memory areas are secured, the memory area management means releases and releases one of the first memory areas. One second memory area may be secured in the allocated memory area. In addition, if the second conversion data exceeds the second size and no first memory area is secured and the memory area having the released first size exists in the memory, the first memory area is changed. One may be secured.
In this way, conversion data corresponding to N or more pages can be stored in the memory regardless of whether the image data for each page is stored as the first conversion data or the second conversion data. As a result, it is possible to ensure that the maximum number of original pages that can be sorted and copied at the same time is at least N, and it is possible to accumulate conversion data corresponding to as many pages as possible.

Furthermore, in the present invention, the print instructing unit may cause the printing unit to perform printing when either the first memory area or the second memory area cannot be secured.
In this way, it is possible to sort and copy a document composed of more pages. For example, when the memory is composed of N first memory areas and one second memory area as described above, an original of N + 1 pages or more is provided except that all pages are stored as first conversion data. Can be stored in memory at once and the stored pages can be printed.

Further, in the present invention, the first conversion data may be JPEG encoded data. The first method may be a conversion method other than JPEG encoding as long as the maximum size of the converted data can be specified.

Furthermore, in the present invention, the second conversion data may be run-length encoded data. The second method may be a conversion method other than run-length encoding as long as the maximum size of the converted data when images of the same resolution are converted can be larger than the maximum size of conversion by the first method.

Further, in the present invention, the second memory area may be secured in order from a smaller address in the memory, and the first memory area may be secured in order from a larger address in the memory. . In this configuration, when the size of the second conversion data that has been accumulated in the second memory area is less than the second size, the memory area management means creates a second memory area including an unused area in the second memory area. It may be ensured.
That is, in order to store the second conversion data from the (n + 1) th page in the second size memory area including the unused area of the second memory area reserved for storing the second conversion data of the nth page. Therefore, the second conversion data corresponding to more pages can be stored in order from the smallest memory address. This effect is more effective when the unused area in the second memory area is statistically larger than the unused area in the first memory area.

Further, as in the present invention, the first conversion data and the second conversion data corresponding to the image of the page are accumulated in the first memory area and the second memory area, respectively, and the size of the second conversion data is the second size. If it exceeds the size, the second conversion data is discarded and at least one remaining first memory area is secured in the memory. If the size of the second conversion data does not exceed the second size, the first conversion data is stored. A method for discarding and securing at least one remaining second memory area in the memory and causing the printing unit to execute printing based on the first conversion data and / or the second conversion data stored in the memory is a program. It is also applicable as a method. Also,
The printing apparatus, program, and method as described above may be implemented as a single printing apparatus or may be implemented by combining a plurality of apparatuses, and include various aspects. For example, it is possible to provide a printing apparatus, method, and program according to the present invention by cooperating a computer and a printing apparatus. Further, some changes may be made as appropriate, such as a part of software and a part of hardware. Furthermore, the invention is also established as a recording medium for a program for controlling the printing apparatus. Of course, the software recording medium may be a magnetic recording medium, a magneto-optical recording medium, or any recording medium to be developed in the future.

Here, embodiments of the present invention will be described in the following order.
(1) Multifunction printer configuration:
(2) Print control processing:
(2-1) Example of operation:
(3) Other embodiments:

(1) Multifunction printer configuration:
FIG. 1 is a block diagram showing a schematic configuration of a multifunction printer 10 including a print control apparatus according to the present invention. The multifunction printer 10 includes a RAM, a ROM,
A control unit 20 including a CPU or the like is provided, and a program recorded in the ROM is transferred to the control unit 20.
Can be done with. In this embodiment, the print control program 21 can be executed as one of the programs, and the print control program 21 performs control for reading a plurality of pages and printing a plurality of copies as one of the functions. A function to perform (sort copy function) is provided.

The multi-function printer 10 is provided with various buttons including a button for inputting the number of copies for sorting and a start button, and processing corresponding to the operation performed by the user is executed for these buttons. Is done. The image reading unit 40 includes an ADF unit that conveys a plurality of pages of documents stacked on a document placing unit (not shown) one page at a time, a line image sensor that optically reads the document conveyed by the ADF unit, and the like. The image data output from the line image sensor is temporarily stored in the line buffer 41. The image data stored in the line buffer 41 is, for example, data expressed in the RGB color system.

The image data conversion unit 42 converts the image data stored in the line buffer 41 using two types of conversion methods, JPEG and run length. JPEG encoding corresponds to the first method described in the claims, and run-length encoding corresponds to the second method described in the claims. Therefore, in this case, the first conversion data described in the claims is JPEG encoded data, and the second conversion data is run-length encoded data. The conversion of the image data by the two types of conversion methods by the image data conversion unit 42 is started at least before the image data for one page is completely stored in the line buffer 41. That is, the accumulation of the image data by the image reading unit 40 and the conversion of the image data by the image data conversion unit 42 are not performed sequentially but partially in parallel.

The print control program 21 uses the conversion data acquisition unit 2 to realize the sort copy function.
1a, conversion data buffer 22, conversion data accumulation control unit 21b, and memory area management unit 21c
And a print instruction unit 21d. The conversion data buffer 22 corresponds to the memory described in the claims. The conversion data acquisition unit 21a uses the JPEG converted by the image data conversion unit 42.
The control unit 20 is made to realize a function of acquiring encoded data and run-length encoded data.

FIG. 2 is a schematic diagram showing the conversion data buffer 22. In FIG. 2, the area indicated by FIX indicates the first memory area, and the area indicated by RNL indicates the second memory area. The size (first size) of one first memory area is designed as the maximum size of JPEG encoded data when an image for one page is JPEG encoded. The size (second size) of one second memory area is smaller than the maximum size that run-length encoded data can take when an image for one page is run-length encoded, and smaller than the first size. Pre-designed as a size. Note that the run-length encoded data size may be within the second size.

The first size and the second size differ depending on the conditions such as the reading resolution and the compression rate for realizing the selected print quality, but the first size and the second size are uniquely determined under the same conditions. Is set. For example, when the first size is 5 megabytes under certain conditions, the second size is set to 1 megabyte.

The conversion data accumulation control unit 21b receives the JPEG acquired by the conversion data acquisition unit 21a.
This is a module that causes the control unit 20 to realize the function of storing the encoded data and the run-length encoded data in the first memory area and the second memory area, respectively. If the run-length encoded data is stored in the second memory area while being acquired, and if it is found that the run-length encoded data exceeds the second size, the storage ends. In other words, the run-length encoded data is not accumulated beyond the second memory area that is currently being accumulated, and the run-length encoded data that exceeds the second size is not accumulated in the memory.

In the conversion data acquisition unit 21a and the conversion data accumulation control unit 21b, JPEG encoded data and run-length encoded data output from the image data conversion unit 42 are sequentially acquired and stored. The acquisition and storage of the other is started before at least one of the acquisition and storage is completed. This is because the time required to store the two types of stored data in the memory can be shortened as compared with the case where the storage of the other converted data is performed after the storage of one converted data is completed.

If the size of the run-length encoded data exceeds the second size, the memory area management unit 21c discards the run-length encoded data stored in the second memory area, and at least the remaining one or more first memories This is a module that secures an area and causes the control unit 20 to realize a function for storing JPEG encoded data and run-length encoded data for the next page. If the run-length encoded data size does not exceed the second size, discard the JPEG encoded data stored in the first memory area and secure at least one remaining second memory area. This is a module for causing the control unit 20 to realize a function for storing JPEG encoded data and run length encoded data for the next page. Here, “reservation” means that a memory area for storing the first conversion data or the second conversion data is allocated, and “release” described later means that the allocation is released. “Discard” means to make an area that can be overwritten with the conversion data of the next page.

The print instruction unit 21d is a module that causes the control unit 20 to realize a function of causing the printing unit 43 to execute printing based on JPEG encoded data or / and run-length encoded data stored in the memory. That is, the JPEG encoded data remaining in the conversion data buffer 22 by repeating the acquisition, storage, and discarding of the conversion data by the conversion data acquisition unit 21a, the conversion data accumulation control unit 21b, and the memory area management unit 21c. / And causes the printing unit 43 to perform printing using the run-length encoded data.

The printing unit 43 includes a transport unit having a mechanism for transporting a print medium, a carriage that reciprocates in a direction perpendicular to the transport direction, an ink cartridge that is mounted on the carriage and contains ink of each color, and a print head. It is comprised as an ink-jet printer provided with. When receiving the print instruction from the print instruction unit 21d, the printing unit 43 decodes the JPEG encoded data and / or run-length encoded data stored in the converted data buffer 22, respectively, and CMYK or the like from the decoded image data. The printing is executed based on the print data generated through the color conversion process to the ink color system, the halftone process, the rearrangement process, and the like.
The configuration of the multifunction printer 10 has been described above.

(2) Print control processing:
Next, the print control process in the above configuration will be described. FIG. 3 is a flowchart showing the flow of the print control process. First, when a user sets the number of sort copies and gives a start instruction using a button or the like provided on the multi-function printer 10, the image reading unit 40 displays A.
Reading of the originals loaded on the DF is started, and the control unit 20 performs an initialization process before executing the process of the print control program 21. Specifically, in the present embodiment, the following description will be made assuming that N described in the claims is 5. Note that N may be an integer greater than or equal to 2, and of course is not limited to 5. The control unit 20 secures five first memory areas and one second memory area in the conversion data buffer 22 as shown in FIG. In FIG. 2, the upper address is smaller and the lower address is larger. Five first memory areas are secured in order from the smallest address, and one second memory area is secured from an address obtained by subtracting the second size from the entire size of the conversion data buffer 22. Also, by performing the initialization process, the control unit 20 causes the start address of the area for storing the JPEG encoded data corresponding to the first page image and the run-length encoded data corresponding to the first page image. Is set to the start address of the area for storing the. In FIG. 2A, pF and pR each mean a pointer that points to the head address.

When image data starts to be accumulated in the line buffer 41 by the image reading unit 40, the image data conversion unit 42 sequentially starts JPEG encoding and run-length encoding based on the image data. Subsequently, the control unit 20 starts acquisition of JPEG encoded data and run-length encoded data generated by the image data conversion unit 42 by processing of the conversion data acquisition unit 21a (step S100).

Subsequently, the control unit 20 starts accumulation of JPEG encoded data in the first memory area by the process of the conversion data accumulation control unit 21b (step S105), and accumulation of run-length encoded data in the second memory area. Is started (step S110). Specifically, the pointer pF
JPEG encoded data starts to be accumulated from the address indicated by, and run-length encoded data starts to accumulate from the address indicated by the pointer pR.

Subsequently, the control unit 20 determines whether or not the size of the run-length encoded data exceeds the second size by the processing of the memory area management unit 21c (Step S115). Specifically, every time the run-length encoded data corresponding to the target page is acquired, the control unit 20 adds the data size already accumulated in the target page, and the second memory area stores the run-length encoded data. It is determined whether or not the run-length encoded data of the target page has been acquired even after the condition is satisfied. When the second memory area is full, that is, when the second size is exceeded, further acquisition and accumulation of run-length encoded data is stopped. The control unit 20 may cause the image data conversion unit 42 to interrupt the run-length encoding of the page. When it is determined in step S115 that the size of the run-length encoded data exceeds the second size, the control unit 20 discards the run-length encoded data stored in the second memory area by the processing of the memory area management unit 21c. (Step S120). In this case, J stored in the first memory area
The PEG encoded data is left without being discarded.

Subsequently, the control unit 20 determines whether at least one remaining first memory area can be secured by the processing of the memory area management unit 21c (step S125). If it can be secured, a first memory area and a second memory area for storing JPEG encoded data and run-length encoded data of the next page are respectively secured (step S130). Specifically, if one or more remaining first memory areas are already secured in step S125,
In step S130, the pointer pF indicating the area for storing the JPEG encoded data of the next page is set to the start address of the reserved first memory area, and the run-length encoded data of the next page is stored. The pointer pR indicating the area is set to the start address of the second memory area in which the run-length encoded data discarded in step S120 is stored. In step S125, if at least one remaining first memory area is not secured, it is determined whether it can be secured (whether there is a release area for the first size in the conversion data buffer 22). If it can be secured, a new first memory area is secured in step S130, the pointer pF is set at the head address of the first memory area, and the pointer pR is set in the same manner as described above.

If it is determined in step S115 that the run-length encoded data does not exceed the second size, the control unit 20 discards the JPEG encoded data stored in the first memory area by the processing of the memory area management unit 21c. (Step S135). In this case, the run-length encoded data stored in the second memory area is left without being discarded. Subsequently, the control unit 20 determines whether or not at least one remaining second memory area can be secured by the processing of the memory area management unit 21c (step S140). If it is possible to secure, JP on the next page
A first memory area and a second memory area for storing the EG encoded data and the run length encoded data are respectively secured (step S145). Specifically, step S1
The case where it is determined that it can be secured at 40 is, for example, a case where one or more remaining second memory areas are not secured but two or more remaining first memory areas are secured. In that case, in step S145, one of the first memory areas is released, and one second memory area is secured in the released memory area. Then, the pointer pR is set to the head address of the newly secured second memory area, and the pointer pF is set to the head address of the first memory area where the JPEG encoded data discarded in step S135 is stored. One first memory area was released to secure a new second memory area, but the remaining one including the first memory area where the JPEG encoded data discarded in step S135 was stored. The state secured above is still maintained.

Further, in the case where it is determined in step S140 that it can be secured, the remaining one or more second memory areas are not secured, but only the remaining one first memory area is secured and the second size. This is a case where the above release area exists in the conversion data buffer 22. In that case, in step S145, one second memory area is secured in the release area. And pointer pR
Is set to the start address of the newly secured second memory area, and the pointer pF is set to step S
In 135, the first address of the first memory area in which the JPEG encoded data discarded is set.
By repeating the above steps S100 to S115 through step S130, or from step S100 through step S115 to step S145, or both, the converted data buffer 22 stores the image data for each page in JPEG encoding. The data is accumulated as either data or run-length encoded data. Step S
If it is determined in 125 that at least one remaining memory area cannot be secured,
And when it is determined in step S140 that at least one remaining second memory area cannot be secured, "when either the first memory area or the second memory area cannot be secured" It corresponds to. Therefore, step S125 or step S1
If it is determined that the data cannot be secured at 40, the control unit 20 designates the JPEG encoded data and / or run-length encoded data stored in the converted data buffer 22 by the processing of the print instruction unit 21d to the user in page order. The number of copies is printed on the printing section.

(2-1) Example of operation:
A specific example of accumulation and destruction will be described with reference to FIG. As described above, FIG. 2A shows a state where the initialization process is performed before the conversion data of the first page is acquired. First, the JPEG encoded data of the first page starts to be accumulated in the memory area FIX [0] indicated by the pointer pF.
Similarly, the run-length encoded data of the first page is stored in the memory area RNL [
0] begins to accumulate. For example, if the run-length encoded data of the first page exceeds the second size (see FIG. 2B, S115: Y), the JPEG encoded data of the first page remains in FIX [0] without being discarded. The run-length encoded data stored in RNL [0] is discarded (S120). At this time, since at least one remaining first memory area has already been secured (S125: Y), the start address of the first memory area FIX [1] for storing the JPEG encoded data of the second page The pointer pF is set to (S130). The pointer pR is set to RNL [0] again. FIG. 2C shows this state.

Subsequently, in the state of FIG. 2C, acquisition and accumulation of JPEG encoded data and run length encoded data for the second page are started. That is, JPEG encoded data of the second page starts to be accumulated in FIX [1], and run-length encoded data of the second page starts to be accumulated in RNL [0]. If the run-length encoded data of the second page does not exceed the second size (see FIG. 2D, S
115: N), the run-length encoded data of the second page remains in RNL [0],
The JPEG encoded data stored in FIX [1] is discarded (S135). At this time, at least one second memory area is not secured, but at least two first memory areas are secured, so it is determined that at least one second memory area can be secured. (S140: Y). Therefore, FIX [4], which is one of the remaining two or more first memory areas and is secured at the position with the highest address, is released and newly released into the released memory area. One second memory area RNL [1] is secured. Then, the pointer pR is set to the start address of RNL [1] for storing the run-length encoded data of the third page. The pointer pF is set to FIX [1] again (S145). FIG. 4A shows this state.

Subsequently, assuming that the run-length encoded data on the third page does not exceed the second size, the converted data buffer 22 performs the same process as described above and the converted data buffer 22 at the time when the process of step S145 is completed.
The state shown in B is obtained. Subsequently, assuming that the run-length encoded data of the fourth page exceeds the second size, the converted data buffer 22 is in the state shown in FIG. 4C when the same processing as described above is performed and the processing in step S130 is completed. If the run-length encoded data of the fifth page exceeds the second size, it is determined in step S130 whether or not there is a release area for the first size in the converted data buffer 22, and in this case, it exists again. First memory area F
IX [3] is secured. FIG. 4D shows the state at this time.

Subsequently, assuming that the run-length encoded data of the sixth page exceeds the second size, step S
When 120 is completed, the state shown in FIG. 5A is obtained. That is, since the size of the release area is smaller than the first size, it is determined in step S125 that at least one remaining memory area cannot be secured. In step S150, the converted data buffer 22
The printing unit 43 is instructed to print the JPEG encoded data and run-length encoded data stored in the page in the page order for the number of copies designated by the user, and the printing unit 43 performs printing.

As described above, even if image data for each page is stored as either JPEG encoded data or run-length encoded data, data corresponding to five or more pages can be stored in the memory. As a result, it can be ensured that the maximum number of original pages that can be sorted and copied at a time is at least five. Further, for example, when a page containing a wide range of photographic images is run-length encoded, there is a high possibility that the size will be larger than when JPEG encoding is performed. Also, for pages that do not contain photographic images and have many blank areas, it is more likely that the run-length encoding will be smaller than the JPEG encoding. In addition, the run length encoding and decoding has a shorter processing time than the time required for JPEG encoding and decoding (provided that the processing device has equivalent performance). In addition, since run-length encoding is lossless compression, image quality does not deteriorate. Therefore, when the length is equal to or smaller than the second size by the run length encoding, it is better to accumulate the run length encoded data in the converted data buffer 22.
It is also desirable from the viewpoint of processing time, size required for accumulation, and image quality. However, run-length encoded data is not always smaller than the second size. It may exceed the second size and further exceed the first size. In this embodiment, in order to shorten the time from image reading to printing completion as much as possible, image reading, image data accumulation, image data conversion, and conversion data accumulation are performed in parallel as much as possible, and image reading is performed on the same page. Since it is not repeated, the controller 2 determines whether or not the run-length encoded data exceeds the second size before accumulation.
0 can not grasp. For this reason, two types of conversion data are accumulated, and if the run-length encoded data exceeds the second size, the JPEG encoded data stored in parallel is left. If the run-length encoded data is equal to or smaller than the second size, the run-length encoded data is left. By repeating such processing, conversion data corresponding to image data can be efficiently stored in the conversion data buffer 22 without waste.

If the run-length encoded data of the sixth page does not exceed the second size, step S
When the processing of 135 is finished, the state shown in FIG. 5B is obtained. In step S140, it is determined that the second memory area can be secured, and in step S145, RNL [3] is secured in the release area. The remaining one or more second memory areas are not secured, but only the remaining one first memory area is secured, and the released memory area of the second size or larger is the converted data buffer 22.
It is because it exists. FIG. 5C shows a state in which the process of step S145 is finished.
If the run-length encoded data on the seventh and eighth pages does not exceed the second size, conversion data for nine pages can be stored.

(3) Other embodiments:
The above embodiment is an example for carrying out the present invention, and various other embodiments can be adopted without departing from the gist of the present invention. For example, in the initialization process, N (
N is not less than 2) and it is not necessary to secure one first memory area and one second memory area.
As shown in A, it is only necessary to secure at least one first memory area and one second memory area. Then, the first memory area and the second memory area for the next page may be secured according to the size of the release area.

Further, in the present invention, as shown in FIG. 6B, the second memory area may be allocated in order from the smaller address in the converted data buffer 22, and the first memory area is larger in the converted data buffer 22. The addresses may be secured in order. In this configuration, when the size of the second conversion data that has been accumulated in the second memory area is less than the second size, the memory area management means creates a second memory area including an unused area in the second memory area. It may be ensured.
That is, the run-length encoded data for the (n + 1) th and subsequent pages is stored in the second size memory area including the unused area of the second memory area reserved for storing the n-th page run-length encoded data. Is secured as a second memory area (FIG. 6C shows an example where n = 1). For this reason, run-length encoded data corresponding to more pages can be stored in order from the smallest memory address. This effect is more effective when the unused area in the second memory area is statistically larger than the unused area in the first memory area. In the case of FIG. 6A, the memory area of the first size including the unused area of the first memory area reserved for storing the JPEG encoded data of the n-th page is represented as J + 1 and the following pages.
You may make it ensure as a 1st memory area for accumulating PEG encoding data.

The printing unit 43 may be configured with a laser printer.
Furthermore, in the above-described embodiment, the configuration in which printing is executed when either the first memory area or the second memory area cannot be secured has been described. However, run-length encoded data or JPEG encoded data is provided for each page. The designated number of copies may be printed for each page when it is determined which one to leave.
Furthermore, in the above-described embodiment, the example in which the conversion data converted by the two types of conversion methods is stored in the memory has been described. However, three or more types of conversion data are stored in the memory, and one type of the conversion data is stored in the memory. You may make it accumulate | store.

It is a block diagram which shows the structure of a multifunction printer. (2A) to (2D) are schematic diagrams showing a conceptual internal structure of a conversion data buffer. 6 is a flowchart illustrating print control processing. (4A) to (4D) are schematic diagrams showing the conceptual internal structure of the converted data buffer. (5A) to (5C) are schematic diagrams showing the conceptual internal structure of the converted data buffer. (6A)-(6C) are schematic diagrams showing the conceptual internal structure of the converted data buffer.

Explanation of symbols

10: Multi-function printer, 20: Control unit, 21: Print control program, 2
1a: conversion data acquisition unit, 21b: conversion data accumulation control unit, 21c: memory area management unit,
21d: print instruction section, 22: conversion data buffer, 40: image reading section, 41: line buffer, 42: image data conversion section, 43: printing section, FIX: first memory area, RNL: second memory area.

Claims (8)

Conversion data acquisition means for acquiring each of the first conversion data and the second conversion data obtained by converting image data indicating images of a plurality of pages for each page by the first method and the second method;
At least a first memory area of a first size that is predetermined as the maximum size of the first conversion data and a second memory area of a second size that is predetermined as a size smaller than the first size, respectively. One or more reserved memory,
Conversion data storage control means for storing each of the first conversion data and the second conversion data in each of the first memory area and the second memory area;
When the size of the second conversion data exceeds the second size, the second conversion data is discarded and at least one remaining first memory area is secured in the memory, and the size of the second conversion data Memory area management means for discarding the first conversion data and securing at least one remaining second memory area in the memory if the second size does not exceed the second size,
The first conversion data also stored in the memory and print instruction means to execute printing on a printing unit based on the second converted data,
A printing control apparatus comprising: The memory is composed of N (N is 2 or more) first memory areas and one second memory area reserved in advance.
The memory area management means discards the first conversion data when the second conversion data does not exceed the second size, and if one or more of the remaining first memory areas are secured, The first memory area is released, one second memory area is secured in the released memory area, and when the second conversion data exceeds the second size, the second conversion data is discarded and the first memory is discarded. If no remaining area is secured and there is a memory area of the first size released in the memory, the first memory area is secured.
The print control apparatus according to claim 1. The print instructing unit causes the printing unit to perform printing when either the first memory area or the second memory area cannot be secured;
The print control apparatus according to claim 1. The first conversion data is JPEG encoded data.
The printing control apparatus according to any one of claims 1 to 3. The second transformed data is run-length encoded data.
The printing control apparatus in any one of Claims 1-4. The second memory area is secured in order from a smaller address in the memory,
The first memory area is secured in order from a larger address in the memory,
The memory area management means includes the second memory including an unused area in the second memory area when the size of the second conversion data accumulated in the second memory area is less than the second size. Secure space,
The printing control apparatus according to claim 1. A conversion data acquisition step of acquiring each of the first conversion data and the second conversion data obtained by converting the image data indicating the images of a plurality of pages by the first method and the second method for each page;
At least a first memory area of a first size that is predetermined as the maximum size of the first conversion data and a second memory area of a second size that is predetermined as a size smaller than the first size, respectively. Each of the first and second memory areas secured in order from a larger address in the memory and the second memory area secured in order from a smaller address in the memory. A conversion data accumulation control step of accumulating each of the first conversion data and the second conversion data;
When the size of the second conversion data exceeds the second size, the second conversion data is discarded and at least one remaining first memory area is secured in the memory, and the size of the second conversion data A memory area management step of discarding the first conversion data and securing at least one second memory area including an unused area in the second memory area in the memory when the second size is less than the second size When,
When either of the first memory area or the second memory area can not be secured, the first conversion data also stored in the memory and print instruction step to execute the printing on the printing unit based on the second converted data ,
A printing control method. A conversion data acquisition function for acquiring each of the first conversion data and the second conversion data obtained by converting the image data indicating the images of a plurality of pages by the first method and the second method for each page;
At least a first memory area of a first size that is predetermined as the maximum size of the first conversion data and a second memory area of a second size that is predetermined as a size smaller than the first size, respectively. Each of the first and second memory areas secured in order from a larger address in the memory and the second memory area secured in order from a smaller address in the memory. A conversion data accumulation control function for accumulating each of the first conversion data and the second conversion data;
When the size of the second conversion data exceeds the second size, the second conversion data is discarded and at least one remaining first memory area is secured in the memory, and the size of the second conversion data If the memory size is less than the second size, the first conversion data is discarded, and at least one remaining second memory area including an unused area in the second memory area is secured in the memory. When,
When either of the first memory area or the second memory area can not be secured, the first conversion data also stored in the memory and the print instruction function to execute printing in the printing section based on the second conversion data ,
A print control program that causes a computer to realize

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