JP3267269B2 - Printing apparatus and printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus having a function of compressing and storing print data, and a printing method for temporarily storing print data and then performing printing in accordance with the print data.

[0002]

2. Description of the Related Art Recently, received printing data is stored in a printing apparatus used without printing, and actual printing is performed when an operation for instructing printing is performed on an operation panel. Those having a function are known.
In addition, this function is to prevent a printed matter whose output has been instructed using a host device installed at a remote place from being viewed by unspecified people other than the person who instructed the output. It is provided for the purpose.

[0003]

The printing apparatus as described above converts the received print data into a form as it is,
It is broadly classified into a method of compressing and saving in a form converted to an intermediate code, and a method of compressing and saving print data after expanding it into image data. The former type of printing apparatus generally has the advantage that the storage capacity required for compressing and storing print data is small, but since the conversion of compressed data to image data takes time corresponding to the content,
In this device, a normal print result cannot be obtained (an overrun error occurs). On the other hand, the latter type of printing device requires a
It has the advantage that no overrun error occurs because it hardly depends on the contents of the image data,
The apparatus requires a relatively large storage capacity to store the compressed data.

An object of the present invention is to provide an apparatus capable of compressing and storing image data for printing at a high compression rate and at a relatively high speed.

Another object of the present invention is to provide a printing method capable of compressing and storing image data for printing at a high compression rate and at a relatively high speed, and then performing printing in accordance with the image data. It is in.

[0006]

Means for Solving the Problems In order to solve the above problems, the printing apparatus and method of the present invention employ the following arrangement.

[0007]

[0008]

[0009]

[0010]

According to a first aspect of the present invention, there is provided a printing apparatus, comprising: a storage unit for storing compressed data; a printing unit for printing an image corresponding to the supplied image data on a sheet; Then, the image data is generated by decompressing the compressed data stored in the storage means and supplied to the printing means, and the image data is generated for each page unit data included in the received print data. Image data generating means for generating; first type compressed data generating means for generating first type compressed data for each page represented by print data by encoding each image data generated by the image data generating means; On the basis of the image data generated by the image data generating means, each of the second and subsequent pages represented by the print data is By comparing the image data relating to the page with the image data relating to the specific page for each unit data which is data of a predetermined size constituting each image data, one of the same contents included in the image data relating to the page concerned A start position information indicating a start position of a required replacement area, which is an area where the above unit data is continuous and an area where no unit data of the content exists in a corresponding portion of image data relating to a specific page, The second type compressed data including a plurality of element data composed of continuous number information indicating the number of unit data constituting the replacement area and replacement data indicating the contents of the unit data used in the required replacement area. A second-type compressed data creating means for creating, and a first-type compression for the first page created by the first-type compressed data creating means For each page after the second page, if the size of the type 1 compressed data is smaller than the size of the type 2 compressed data, the type 1 compressed data is included. ,
A storage unit for storing data including the second type of compressed data in the storage unit as compressed data relating to the print data. In other words, the printing apparatus according to the first aspect of the present invention, when the print data is a print of a plurality of pages and obtains a print having many portions in which each page has a common portion, creates the second type of compressed data. Utilizing the fact that the size of the second-type compressed data created by the means is smaller than the size of the first-type compressed data created by the first-type compressed data creating means, high compression of the image data for printing is performed. The device is designed to save the rate. Therefore, if this printing apparatus is used, print data of a printed matter having many portions where each page is common, for example, print data of a document created by spreadsheet software or print data of a standard document such as an invoice, The compression can be stored at a high compression rate and at a relatively high speed.

[0012]

[0013]

Further, a printing apparatus according to a second aspect of the present invention comprises:
Storage means for storing the compressed data, printing means for printing an image corresponding to the supplied image data on paper, and restoration of the compressed data stored in the storage means when a predetermined instruction is input Generating and supplying the printing data to the printing means, image data generating means for generating the first to n-th image data for each page unit of data included in the received print data, First-type compressed data creating means for creating first to n-th first-type compressed data for each page represented by print data by encoding each image data generated by the data generating means; and image data generating means Based on the image data generated in
Each page after the second page represented by the print data, and
For each k of 1 to n, the k-th image data of the page and the k-th image data of the specific page are compared for each unit data which is data of a predetermined size constituting each image data. Is an area where one or more unit data of the same content included in the k-th image data related to the page are continuous, and the unit data of the content exists in a corresponding portion of the k-th image data related to the specific page. Start position information indicating the start position of the required replacement area, which is a non-replacement area, continuous number information indicating the number of unit data forming the required replacement area, and the unit data used in the required replacement area. A k-th second element including a plurality of element data including replacement data indicating contents
A second kind compressed data creating means for creating kind compressed data;
It includes first to n-th compressed data of the first kind for the first page created by the compressed data creating means of the first kind. If the size of the k-th type compressed data is smaller than the size of the k-th type 2 compressed data, the k-th type compressed data is included. Otherwise, the k-th type 2nd type compressed data is included. Storage means for storing data including compressed data in the storage means as compressed data relating to print data.

The printing apparatus according to the second aspect has a configuration in which the process of creating compressed data is performed not in page units but in smaller data units (units of the first to n-th image data). Therefore, if this printing apparatus is used, print data of a printed matter having many portions where each page is common, for example, print data of a document created by spreadsheet software or print data of a standard document such as an invoice, The compression can be stored at a high compression rate and at a relatively high speed.

According to a third aspect of the present invention, there is provided a printing apparatus, comprising: storage means for storing compressed data; printing means for printing an image corresponding to the supplied image data on a sheet; Then, the image data is generated by decompressing the compressed data stored in the storage means and supplied to the printing means, and the image data is generated for each page unit data included in the received print data. Image data generating means for generating; first type compressed data generating means for generating first type compressed data for each page represented by print data by encoding each image data generated by the image data generating means; On the basis of the image data generated by the image data generating means, each of the second and subsequent pages represented by the print data is A second-type compressed data generating means for generating a second-type compressed data indicating a position and a content of a portion of the image data relating to the corresponding page different from the image data relating to the specific page; If the size of the first-type compressed data is smaller than the size of the second-type compressed data for each page after the second page, the first-type compressed data is included. Including one kind of compressed data,
Otherwise, the storage unit stores the data including the second type compressed data in the storage unit as compressed data relating to the print data, and the size of the second type compressed data created by the second type compressed data creation unit. Specific page determining means for determining a specific page so that the total is minimized.

Further, a printing apparatus according to a fourth aspect of the present invention includes:
Storage means for storing the compressed data, printing means for printing an image corresponding to the supplied image data on paper, and restoration of the compressed data stored in the storage means when a predetermined instruction is input Generating and supplying the printing data to the printing means, image data generating means for generating the first to n-th image data for each page unit of data included in the received print data, First-type compressed data creating means for creating first to n-th first-type compressed data for each page represented by print data by encoding each image data generated by the data generating means; and image data generating means Based on the image data generated in
For each page after the second page represented by the print data,
First to n-th second type compressed data indicating the position and content of a portion of the first to n-th image data relating to the corresponding page, respectively, which is different from the first to n-th image data relating to the specific page are created. A second-type compressed data generating unit; and first to n-th first-type compressed data for the first page generated by the first-type compressed data generating unit.
If the size of the k-th type 1 compressed data is smaller than the size of the k-th type 2 compressed data for each of k to n, the k-th type 1 compressed data is included and the k-th type 1 compressed data is not included. In this case, a storage unit for storing data including the k-th type 2 compressed data in the storage unit as compressed data relating to print data, and a first to a second format for each page created by the second type compressed data creating unit. specific page determining means for determining a specific page for each page such that the total size of n second-type compressed data is minimized.

As described above, each of the third and fourth printing apparatuses according to the present invention is designed so that the total size of the second type compressed data created by the second type compressed data creating means is minimized. The specific page determining means for determining the page, and the specific page for each page such that the total of the sizes of the first to n-th second type compressed data relating to each page generated by the second type compressed data generating means is minimized. A specific page determining means for determining is provided. Therefore, according to these printing apparatuses, although it takes more time to create compressed data, print data can be stored at a higher compression rate.

In realizing the printing apparatus according to the first or second aspect of the present invention, the specific page can be set as the previous page of the corresponding page or the first page. In addition, the second kind of compressed data created by the second kind compressed data creating means
The printing apparatus according to the first aspect of the present invention can be implemented by adding a specific page determining unit that determines a specific page so that the total size of the seed compressed data is minimized. Also, a specific page determining means for determining a specific page for each page such that the total of the sizes of the first to n-th compressed data of the second type for each page created by the compressed data of the second kind is minimized. In addition, the printing apparatus according to the second aspect of the present invention can be realized.

It should be noted that the printing apparatus according to each aspect of the present invention is realized.
User can instruct the user to execute printing on the spot.
Input a predetermined instruction to the generating and supplying means
It is desirable to add an instruction input panel for this.

In the printing method according to each aspect of the present invention,
Same as what is done in the printing device of each aspect of the present invention
Printing is performed according to the procedure.

[0022] Therefore,Of each aspect of the present inventionUsing a printing method
If you have a printed mark that has many common parts on each page
Printing data, for example, documents created with spreadsheet software
Print data and standard documents such as invoices
The print data can be compressed and stored at a high compression ratio.

[0023]

Embodiments of the present invention will be specifically described below with reference to the drawings.

First, an outline of the hardware configuration and operation of the printing apparatus according to the first to sixth embodiments of the present invention will be described.

FIG. 1 shows a hardware configuration of a printing apparatus according to each embodiment of the present invention. As illustrated, the printing apparatus according to each embodiment includes a communication control unit 11, a printing unit 12, an operation panel unit 13, a RAM 14, an HDD 15, and a main control unit 16.

The communication control unit 11 is a unit that receives print data transmitted from the host device and converts the received print data into data that can be processed by the main control unit 16. In the printing apparatus according to each embodiment, the communication control unit 11 having a function as a Centronics interface circuit and a network interface circuit is used. That is, the printing device (communication control unit 11) is connected to some host devices via the Centronics cable 21 and the LAN cable 22.

The printing unit 12 is a unit that actually performs printing on paper, and includes a printing unit that prints an image corresponding to the supplied image data on paper, a paper feeding mechanism that supplies paper to the printing unit, And a discharge mechanism for discharging printed paper. The printing unit 12 is a unit of a type that supplies one page of image data to a plurality of (Bmax) image data in band units.

The operation panel unit 13 is a unit for the main control unit 16 to receive various instructions from the user, and includes a touch screen and some buttons. RAM14
Is a memory used by the main control unit 16 as a work area. The HDD 15 is an auxiliary storage device used to store a compressed data file (details will be described later). The main control unit 16 is a unit including a CPU, a ROM in which a program that defines an operation procedure of the CPU is recorded, and the like.

Hereinafter, the overall operation of the printing apparatus according to each embodiment will be described with reference to FIG. FIG. 2 is a flowchart illustrating an overall operation procedure of the main control unit 16 included in the printing apparatus according to each embodiment after power is supplied.

As shown in the figure, when the power is turned on, the main control unit 16 generates various events (reception of print data by the communication control unit 11, input of an instruction to restore the compressed data file to the operation panel unit 13). Is monitored (step S001). When the communication control unit 11 detects that the print data has been received (step S002; data reception), the main control unit 13 determines whether the print data includes the storage instruction information (step S002). S004). The storage instruction information is information included in the print data by the printer driver of the host device. The storage instruction information includes data indicating that the storage instruction information is itself, and a user input when the print data is output. The password and the data name are included.

If the print data does not include the storage instruction information (step S004; NO),
If the print data is normal print data, the main control unit 13 controls the print unit 12 so that a printed matter corresponding to the print data is output (step S005). Then, step S0
01, and monitoring of occurrence of various events is started again. On the other hand, when the print data includes the save instruction information (step S004; YES), the main control unit 16
Executes a compression process (step S006) for creating a compressed data file based on print data.
At the time of this compression processing, the main control unit 16 associates the created compressed data file with the data of the HDD 1 in a form associated with the data name and the password included in the storage instruction information in the print data.
Store in 5. Thereafter, the main control unit 16 determines in step S
Returning to 001, monitoring of the occurrence of various events is started again.

When it is detected that a compressed data file restoration instruction has been input (step S002; restoration instruction input), the main control unit 16 decompresses the compressed data file and responds to the original print data. (Step S00)
Execute 3). Note that the main control unit 16 determines that a compressed data file restoration instruction has been input when the following series of operations are performed, and starts the restoration processing.

When a predetermined operation is performed on the operation panel unit 13, the main control unit 16 displays a list of data names of the compressed data files stored in the HDD 15 on the operation panel unit 13. Thereafter, when it is detected that an operation of selecting one data name from the list is performed, a message prompting the user to enter a password is displayed on the operation panel unit 13 and the password is received from the user. Only when the password input using the operation panel unit 13 matches the password stored in association with the selected data name, it is determined that a compressed data file restoration instruction input has been made. If it is determined that the restoration instruction has been input, the print start page Ps and the print end page Pe (≧ P
s) Acquire from the user information indicating whether or not to discard the compressed data file after printing. Then, the restoration process is started.

The printing apparatus according to the first to sixth embodiments uses the main control unit 1 at the time of compression processing and decompression processing in this flowchart.
Operation 6 (contents of program stored in ROM)
Are different. Hereinafter, the operation of the printing apparatus according to each embodiment will be described in detail focusing on the operation at the time of compression processing and restoration processing.

<First Embodiment> First, the structure of a compressed data file created by the printing apparatus according to the first embodiment will be described with reference to FIG.

As shown in FIG. 3A, the compressed data file 31 created by the printing apparatus according to the first embodiment includes management data and first to Mmax
Page compressed data # which is compressed data of page data (image data forming the first to M-th pages)
1 to Mmax.

As shown in FIG. 3B, the management data includes the number of compressed data Mmax, type flags # 2 to Mmax, and head position data # 1 to Mmax. The number of compressed data Mmax is
This is data indicating the number of page compressed data included in the compressed data file 31 (total number of pages of printed matter obtained by restoring the compressed data file 31). The head position data # 1 to Mmax are respectively the page compressed data #
1 to Mmax are represented by relative addresses from the beginning of the compressed data file 31. The type flag #M (M = 2 to Mmax) indicates that the page compression data #M
Is data indicating "0/1" as to which of the first-type page compressed data and the second-type page compressed data. In the compressed data file 31, the number of compressed data Mmax
, Mmax-1 bits in the data of "INT ((Mmax-2) / 8) +1" bytes are used as type flags # 2 to Mmax.

The first type page compressed data (page compressed data whose corresponding type flag is "0") is shown in FIG.
, Bmax pieces of normal compressed data # 1 to Bmax
Consists of The normal compressed data #B (B = 1 to Bmax) of the page compressed data #P which is the first type page compressed data is
This is compressed data created by encoding image data relating to the B-th band of the P-th page. That is, the first
The seed page compressed data is data that can independently restore the original image data of one page. As shown in FIG. 3A, the page compressed data # 1 for which the corresponding type flag is not prepared is also the first type page compressed data.

On the other hand, the compressed data of the second kind page is shown in FIG.
As shown in (d), Bmax differential compressed data # 1
~ Bmax. As shown in FIG. 3E, the differential compressed data is composed of the element data number Nmax and the Nmax element data composed of the position data and the replacement data. data#
P differential compressed data #B (B = 1 to Bmax) is obtained by converting the image data of the B-th band of the P-th page into the image data of the corresponding band of another page (the P-th page in this embodiment). And (compared in detail later) with compressed data. That is, the second-type page compressed data is data that cannot restore the original image data of one page by itself (image data of another page is required for restoration).

The operation of the printing apparatus during compression processing and decompression processing will be described in detail below. In the following, for convenience of description, the expression band compressed data D (P, B) is a general term for the normal compressed data #B for the Pth page and the differential compressed data #B for the Pth page included in the compressed data file 31. Will be used.

FIG. 4 shows a flowchart of a compression process performed in the printing apparatus. As described above with reference to FIG. 2, this compression process is executed when the received print data includes storage designation information including a data name and a password.

As shown in the figure, the main controller 1
6 is a variable M for counting the number of processed pages and a variable B for counting the number of processed bands.
Are set to "1" (step S10).
1).

Thereafter, the main controller 16 creates a band image #B, which is image data of the B-th band of the M-th page, on the RAM 14 based on the received print data (step S102). Next, the main control unit 16 encodes the created band image #B (in this embodiment, run-length encoding), so that the band compression data D (M (= 1) for the B-th band of the first page. ), B) to RA
It is created on M14 (step S103). Then, B
= Bmax is determined to determine whether or not the processing on the last band of the first page has been completed (step S104). If the processing on the last band has not been completed (step S104) ; NO)
, Add "1" to B (step S105). Then, the process returns to step S102 to start the processing for the next band.

When such processing is performed on the print data for one page, and the creation of the Bmax band compressed data is completed (step S104; YES),
The main controller 16 proceeds to step S <b> 106, and determines whether the print data for the next page has been received by the communication controller 11. If the print data for the next page has been received (step S106; YE)
In S), after adding "1" to M (step S107), a page compressed data creation process (step S108) for creating page compressed data #M is started.

FIGS. 5 and 6 show flow charts of page compressed data creation processing and differential compressed data creation processing executed at the time of page compressed data creation processing, respectively.

As shown in FIG. 5, at the time of the page compression data creation processing, the main control unit 16 first initializes a variable B to "1" (step S201). Then, step S2
Then, the process proceeds to step S 02, where the band image #B of the Mth page is created in the RAM 14 based on the received print data. Then, the differential compressed data creation processing (step S2
03) is started.

The differential compressed data creating process executed in this step is a process of creating differential compressed data #B relating to the band image #B of the Mth page, and uses the band image #B of the M-1 page as the reference image. And the band image #B of the Mth page is executed as a generated image.

Specifically, as shown in FIG. 6, at the time of differential compressed data creation processing, the main control unit 16 first sets “k” in a variable k for storing the unit data number of the unit data to be processed. 1 "and differential compressed data #B
Is set to "0" for a variable i for counting the number of element data included in (1) (step S301). The unit data number is information for identifying one unit data from the kmax unit data forming the band image. In the present apparatus, the unit data number at the head of the band image is "unit data number". 1 "is provided.

Thereafter, the main control unit 16 determines whether the unit data #k of the generated image (image data of the B-th band of the M-th page) and the unit image #k of the reference image (the image data of the B-th band of the (M-1) -th page). A comparison is made with the unit data #k (step S302). If they match (step S303; YES), “1” is added to k (step S306), and it is determined whether k is equal to or smaller than kmax (step S307).

On the other hand, when the unit data #k of the generated image does not match the unit data #k of the reference image (step S303; NO), the main control unit 16 adds "1" to i (step S303). Step S304). And k,
The unit data #k of the generated image is replaced with the position data # constituting the element data #i of the differential compressed data #B.
i, and stored as replacement data #i (step S30)
5). That is, the position data constituting the element data is data representing the position of one unit data of the generated image, and is data representing the position of the unit data whose content is different from the unit data of the corresponding position of the reference image. It has become. The replacement data forming the element data together with the position data is data indicating the contents of the unit data at the position indicated by the position data in the generated image.

Thereafter, the main controller 16 adds "1" to k (step S306), and then determines whether k is equal to or smaller than kmax (step S307). And k
Is less than or equal to kmax (step S307; YE
In step S), the process returns to step S302 to start processing for the next unit data. On the other hand, if k exceeds kmax (step S307; NO), that is, if the comparison of the unit data #kmax has been performed in step S302, the value of i at that time is replaced with the difference compressed data #
Stored as the number Nmax of element data of B (step S30)
8) Then, the differential compressed data creation processing ends.

After completion of the differential compressed data creation processing (FIG. 5, step S203), the main control unit 16 creates normal compressed data #B by encoding the band image #B (step S204). Note that the normal compressed data #B created in this step includes data representing its own size. Then, the reference image (band image #B of the (M-1) th page) on the RAM 14 is discarded (step S205). That is, the storage area used for storing the reference image is released so that it can be used for storing other data. Then, the main controller 16 proceeds to step S206, determines whether or not the processed band is the last band, and if not, adds “1” to B (step S206; NO) (step S206). S2
07), the processes of steps S202 to S206 are performed again.

When the processing for all bands of the M-th page is completed by repeating such processing (step S206; YES), that is, the difference compression data # 1 to Bmax and the normal compression data # 1 to Bmax When the creation is completed, the main control unit 16 executes steps S202 to S202.
Break out of loop 207. Then, step S208
The processing proceeds to calculate the total _{S D} of size of the differential compressed data # 1～Bmax created, and the total _{S RLE} size usually compressed data # 1～Bmax created.

Thereafter, the main controller 16 determines whether or not S _RLE < _SD holds between the calculated values (step S209). If S _RLE < _SD holds, (Step S209; YES), the normal compressed data # 1 to Bmax for the created M-th page are respectively converted to band compressed data (D (M, 1)) for the corresponding band of the page compressed data #M. ＤD (M, Bmax)) (step S210). Further, “0” is set to F (M) which is a variable for storing the type flag #M (step S211). That is, by setting F (M) to “0”, the page compressed data #M is set to the first type page compressed data (normal compressed data is selected as each band compressed data in the page compressed data #M). Is stored. Then, the unnecessary data (for example, differential compressed data # 1 to Bmax) is discarded (not shown), and the page compressed data creation processing ends.

On the other hand, if S _RLE < _SD is not satisfied (step S209; NO), the main control unit 16
The difference compressed data # 1 to Bmax for the Mth page created in step S203 are respectively converted to band compressed data (D (M, 1) to D (M, Bmax)) for the corresponding band of the page compressed data #M. (Step S212). The fact that each band compressed data in the compressed data #M is differential compression data is stored by setting F (M) to "1" (step S2).
13). Thereafter, the main control unit 16 discards unnecessary data (not shown), and ends the page compressed data creation processing.

After the end of the page compression data creation processing (FIG. 4: step S108), the main control unit 16 proceeds to step S1.
Return to 06. Then, it is determined whether there is a next page. If there is a next page (step S106; YES), steps S107 and S108 are executed again.

At the time of compression processing, the main control unit 16 repeats such processing, and when there are no more pages to be processed (step S106; NO), the main control unit 16 stores the compressed data file 31 based on the various data generated so far. HDD15
(Step S109). That is, the main control unit 16 recognizes the M value at that time as Mmax, and obtains the page compressed data #M (band compressed data D
Based on the size of (M, 1) to D (M, Bmax)) and the size of the management data as a function of the Mmax value, the top position data # 1
To Mmax. Then, Mmax, F (2) to F (Mma
x), top position data # 1 to Mmax, page compression data #
1 to Mmax, a compressed data file 31 having the configuration shown in FIG. 3 is created, and H is associated with the data name and password included in the storage instruction information.
Store in DD15. Then, the compression process ends.

That is, in this printing apparatus, for example, all five
A compressed data file 31 is created for the print data of the page in the procedure schematically shown in FIG. First, for the first page, only the first kind page compression data 40 ₁ made of ordinary compressed data are generated. Also,
For the P page of the second and subsequent pages, and the one page compression data 40 _P, and the two page compression data 41 _P consisting differential compression data is created consisting of ordinary compressed data. Then, the first one page compression data 40 _1, and page compressed data size of the smaller created for the second to fifth pages, page compression of any type for the second to fifth pages Type flags # 2 to 5 indicating whether data is used (in the illustrated case,
The compressed data file 31 is created by combining with management data including “1”, “0”, “1”, and “1”).

Next, a procedure for restoring the compressed data file 31 in the printing apparatus will be described with reference to FIGS. FIG. 8 is a flowchart of a restoration process performed in the printing apparatus. FIG. 9 is a flowchart of the differential compression page restoration process executed during the restoration process.
0 is a flowchart of the differential compressed data decompression process executed during the differential compressed page decompression process. As described above with reference to FIG. 2, in this restoration processing, the compressed data file 31 to be restored (printed) is specified, the print start page Ps, the print end page Pe (≧ Ps), the number of copies, the discard approval / disapproval instruction information Is executed after is given.

As shown in FIG. 8, at the start of the decompression processing, the main control unit 16 firstly manages the management data of the processing target compressed data file which is the compressed data file 31 instructed to be decompressed (printed), that is, compresses the data. The number of data Mmax, type flags # 2 to Mmax, and head position data # 1 to Mmax are acquired (step S401). In this step, the main control unit 16 stores the values of the type flags # 2 to Mmax as F (2) to F (Mmax), respectively.

Next, the main controller 16 sets "0" to F (1),
Ps is set to M (step S402). Thereafter, the main control unit 16 determines whether or not F (M) is “0” (step S403). If F (M) is not “0” (step S403; NO), "1" is subtracted from M (step S404). Then, the process returns to step S403, and it is determined whether or not F (M) = 0 holds for M whose value has been updated.

When F (Ps) = 0, or by executing step S404 one or more times, F (M) =
When M that satisfies 0 is found (step S403; YE)
S), the main control unit 16 performs a normal compressed page restoration process for the page compressed data #M (Step S405).
Execute

At the time of the normal compressed page decompression processing, the main control unit 16 sets the page compressed data #M (F (M) = 0) whose head position is indicated by the head position data #M. , Compressed data of the first type) is read and decoded. That is,
In the RAM 14, band images # 1 to B of the M-th page
Generate max. When Ps ≦ M ≦ Pe is satisfied, the main control unit 16 also performs a process of supplying the band images # 1 to Bmax obtained by decoding to the printing unit 12.

After executing the normal compressed page restoration process, the main control unit 16 determines whether M = Ps is satisfied (step S406). If M = Ps is not satisfied (step S406; NO), “1” is added to M (step S407). Then, the difference compression page restoration process (step S408), which is the process for the page compression data #M, is started.

As shown in FIG. 9, at the time of the differential compression page restoration process, the main control unit 16 first sets B to "1" (step S501). Then, using the band image #B of the (M−1) th page as a reference image, a difference compressed data restoration process for restoring the band compression data D (M, B) as the difference compression data (step S502).
To start.

As shown in FIG. 10, at the start of the differential compressed data decompression process, the main control unit 16
The number Nmax of element data of (M, B) is obtained (step S5).
51). When performing this step in the state of B = 1, the main control unit 16 recognizes the start position of D (M, 1) in the processing target compressed data file by the start position data #M. When this step is executed in the state of B ≠ 1, the data of a predetermined size stored at the next position of the already processed data in the processing target compressed data file is replaced with the data of D (M, B). It is recognized as the number of element data Nmax.

After obtaining the number of element data Nmax, the main control unit 1
6 sets “1” to a variable i (step S55)
2). If i ≦ Nmax is satisfied (step S553; YES), data of a predetermined size stored at the next position of the already processed data in the processing target compressed data file is read, thereby obtaining D (M,
The element data #i (position data #i and replacement data #i) of B) is obtained (step S554). Thereafter, the main control unit 16 writes the replacement data #i at the position indicated by the position data #i in the reference image on the RAM 14 (step S555). Then, “1” is added to i (step S556), and the process returns to step S553.

The main control unit 16 determines that such processing is i ≦ N
The difference compressed data restoration process is performed when i> Nmax is satisfied (step S553; NO), that is, when the generation of the band image #B of the Mth page is completed by rewriting the reference image. finish.

After the completion of the differential compressed data restoring process, the main control unit 16 determines whether or not Ps ≦ M ≦ Pe is satisfied (FIG. 9: step S503). And Ps ≦ M ≦ Pe
Is satisfied (step S503; YES), the band image #B is supplied to the printing unit 12 (step S504), and the process proceeds to step S505. On the other hand, P
If s ≦ M ≦ Pe is not satisfied (step S503;
In the case of NO), step S505 is directly executed.

In step S505, the main control unit 16
Determines whether the restored band image #B is related to the final band, and determines whether the band image #B is related to the final band (step S50).
5: NO), "1" is added to B (step S50).
6) Then, the process returns to step S502. Then, when the band image #B relates to the last band (step S505; YES), the differential compression page restoration processing ends.

Returning to FIG. 8, the description of the restoration processing will be continued. After the completion of the differential compression page restoration processing in step S408, the main control unit 16 returns to step S406, and M = P
It is determined whether or not s is satisfied. If M ≠ Ps (step S406; NO), steps S407 and S408 are executed again. That is, the main control unit 16 executes steps S407 and S408 for the number of times step S404 is executed. And M = Ps
Is satisfied (step S406; YES), the process proceeds to step S409.

In step S409, the main control unit 16
Determines whether M <Pe holds. If M <Pe is not satisfied (step S4)
09; NO), the restoration process ends. That is, P
If s = Pe, the Ps page is printed by the processing of step S405 or S408, and then a branch to “NO” is performed in step S409,
The restoration processing ends.

If M <Pe holds (step S
409; YES), the main control unit 16 adds “1” to M (step S410). Then, it is determined whether or not F (M) = 0, that is, whether the page compressed data #M is the first type page compressed data or the second type page compressed data (step S411). If it is the seed page compressed data (step S411; NO), the same differentially compressed page restoration processing as that performed in step S408 is executed on the page compressed data #M (step S412). Then, the process returns to step S409.

On the other hand, if F (M) = 0 holds (step S411; YES), that is, if the page compressed data #M is the first type page compressed data, the main control unit 16 The M-1 page data (band images # 1 to Mmax of the (M-1) th page) are discarded (step S4).
13). After that, the same normal compressed page decompression process as that performed in step S405 is performed on the page compressed data #M (step S414), and step S414 is performed.
Return to 409.

The main control section 16 repeats such processing at the time of restoration processing. Then, when M <Pe is not satisfied (step S409; NO), the restoration processing is terminated. Although not shown in the flowchart, step S
At 409, also when M = Mmax is satisfied (when Pe is set to a value equal to or greater than Mmax), the main control unit 16 branches to the “NO” side. Further, when branching to the “NO” side is performed in step S409, the main control unit 16 determines whether or not printing of the designated number of print copies has been completed. The processing from step S402 is executed again. On the other hand, if the printing of the designated number of copies has been completed, it is determined whether or not the discard permission / non-permission instruction information indicates that the compressed data file is to be discarded after printing. If the discard permission / instruction information indicates discard, the compressed data file 31 that has been processed is discarded (erased), the restoration process ends, and the discard permission / instruction information indicates discard. If not, the decompression process ends with the processed compressed data file 31 remaining in the HDD 15.

Hereinafter, a compressed data file 31 (page compressed data # 2, # 4, # 5) which is created from the print data of all five pages shown in FIG. As described above, the case where restoration of all pages is instructed and the case where restoration of fourth and fifth pages are instructed for compressed data files in which the first and third pages are the first-type page compressed data). The contents of the restoration processing will be described more specifically.

When restoration of all pages is instructed (Ps =
(1, Pe = 5), since F (Ps) = 0, a branch to the “YES” side is performed in step S403 executed first. As a result, normal compressed page restoration processing is performed on the page compressed data #M (M = 1), and band images # 1 to Bmax of the first page are generated on the RAM 14. In addition, since Ps ≦ M ≦ Pe holds, in step S405, the generated band images # 1 to B
The supply of max to the printing unit 12 (printing of the first page) is also performed.

In step S406 executed thereafter, M = Ps is established. Therefore, step S407,
The processing after step S409 is executed without executing S408.

Since M <Pe holds for the M value (= Ps = 1) at this time, a branch to the “YES” side is performed in step S409. And M is "2"
Is changed to In the next step S411, since F (2) is "1", a branch to the "NO" side is performed, and a differentially compressed page restoration process for the page compressed data # 2 is executed. In other words, according to the band compression data D (2, 1) to D (2, Bmax) which is the difference compression data, the RAM 1
Band images # 1 to Bmax for the first page on page 4
Is rewritten and the band image for the second page #
1 to Bmax are generated. Also, since Ps ≦ M ≦ Pe is satisfied, the printing unit 12 of the band images # 1 to Bmax
(Printing of the second page) is performed.

Thereafter, the processing from step S409 is performed again. And since M (= 2) <Pe,
M is changed to “3”, and step S411 is executed. In step S411, since F (3) = 0, "Y
A branch to the ES "side is performed, and as a result, the second page data is discarded, and the normal compressed page decompression process is performed on the page compressed data # 3. The second page data is discarded because the reference image is not required for the restoration of 3. The band compressed data D (3,1) to D (3, Bmax), which are the normal compressed data, are decoded. Band images # 1 to Bmax of three pages are generated, and Ps ≦
Since M ≦ Pe holds, in step S414, these band images are also supplied to the printing unit 12 (the third page is printed).

Thereafter, the processing from step S409 is performed again. And since M (= 3) <Pe,
M is changed to “4”. Then, since F (4) = 1, the difference compression page restoration process is performed on the page compression data # 4. That is, the band images # 1 to Bmax of the third page on the RAM 14 are rewritten to the band images # 1 to Bmax of the fourth page. Also, Ps ≦
Since M ≦ Pe holds, the generated band image #
Supply of 1 to Bmax to the printing unit 12 (4th page printing)
Is performed.

Thereafter, since 4 <Pe, M is set to “5”.
And step S411 is executed again. F
Since (5) = 1, differential compression page restoration processing is performed on the page compression data # 5, and band images # 1 to Bmax of the fifth page are generated and supplied to the printing unit. Then, since M <Pe does not hold, the restoration process ends.

On the other hand, when restoration (printing) of the fourth and fifth pages is instructed (Ps = 4, Pe = 5), the fourth and fifth pages are printed in the following procedure.

Since F (4) = 1, branching to the "NO" side is performed in step S403 executed first. That is, after M is changed to “3”, step S is performed again.
Step 403 is executed. In this step S403, F
(3) = 0, the branch to the “YES” side is performed,
The band images # 1 to Bmax of the third page are generated on the RAM 14 by the normal compressed page decompression process for the page compressed data # 3 which is the first type page compressed data. Since Ps ≦ M ≦ Pe does not hold, the normal compressed page restoration processing is executed without supplying the band images # 1 to Bmax to the printing unit 12.

In step S406 executed thereafter, since M = Ps is not established, a branch is made to the “NO” side. That is, the M value is changed to “4”, and the difference compressed page restoration
The band images # 1 to Bmax of the third page existing on the AM 14 are changed to the band images # 1 to Bm of the fourth page.
Rewritten as ax. In addition, since Ps ≦ M ≦ Pe is satisfied, the supply of the band images # 1 to Bmax to the printing unit 12 (the printing of the fourth page) is performed.

For the M value (= Ps = 4) at this time, M <Pe holds. Therefore, step S40
At 9, a branch is made to the "YES" side, and the value of M is changed to "5". Since F (5) is "1", the differential compression page restoration processing is executed. That is, the band compression data D (5, 1) to D (5, Bm
ax), the band images # 1 to Bmax for the fourth page on the RAM 14 are rewritten, and the band images # 1 to Bmax for the fifth page are generated. In addition, since Ps ≦ M ≦ Pe is satisfied, the supply of the band images # 1 to Bmax to the printing unit (the printing of the fifth page) is performed. Then, since M <Pe does not hold, the restoration process ends.

As described above, in the printing apparatus according to the present embodiment, normal compression for creating compressed data by run-length encoding on image data created from received print data, of,
Differential compression is performed in which data representing a difference from the corresponding image data of the previous page is created as compressed data. Then, the compressed data file 31 of the print data is created by using the compressed data having the smaller overall size.

If two consecutive pages (the P-1 page and the P page) represented by the print data to be processed have many common portions, each band of the P page is The total size of the differentially compressed data created in this way is smaller than the total size of the normal compressed data created for those bands. Therefore, according to this printing apparatus, a print data (for example, a document created by spreadsheet software,
Print data of a fixed document such as an invoice) can be compressed and stored at a higher compression ratio than the conventional device.

<Second Embodiment> FIG. 11 shows a second embodiment of the present invention.
2 shows a configuration of a compressed data file 32 created by the printing apparatus according to the embodiment. As shown in FIG. 11A, the compressed data file 32 is a compressed data file 3
1, the management data and the first to M-th data, respectively.
It is composed of page compressed data # 1 to Mmax which are compressed data of max page data (image data forming the first to Mth pages).

As shown in FIG. 11B, the management data of the compressed data file 32 has exactly the same configuration as the management data of the compressed data file 31. Although not shown, the compressed data file 32
The first type page compressed data used in the compressed data file 31 has the same configuration as the first type page compressed data used in the compressed data file 31.

As the type 2 page compression data, FIG.
As shown in (c), data composed of Bmax pieces of differentially compressed data is used as in the compressed data file 31 of the first embodiment. However, difference compressed data #B of page compressed data #P which is the second type page compressed data
(B = 1 to Bmax) is data created by comparing the image data of the B-th band of the P-th page with the image data of the first page.

Hereinafter, details of compression processing and decompression processing executed by the printing apparatus according to the second embodiment will be described. Note that the compression processing and decompression processing executed by the printing apparatus are similar to the compression processing and decompression processing executed by the printing apparatus according to the first embodiment. For this reason, a description will be given below of the compression processing and the decompression processing executed by the printing apparatus, focusing on portions having different contents. First, the operation of the printing apparatus according to the second embodiment during compression processing will be described.

In the printing apparatus, during the compression processing (see FIG. 4), the page compressed data creation processing of the procedure shown in FIG. 12 is executed. That is, when creating the page compression data for the M-th (≧ 2) page, the main control unit 16 in the printing apparatus according to the second embodiment first initializes the variable B to “1” (step S601). . Then, step S60
Then, the process proceeds to step S2, where the band image #B is created on the RAM 14 based on the received print data. And
A differential compressed data creation process (step S603) is performed with the band image #B as a processing target (generation image). The differential compressed data creation processing executed in this step is exactly the same processing as that already described with reference to FIG. However, in this step S603, the differential compressed data #B is created using the band image #M of the first page as the reference image.

After creating the differential compressed data #B in step S603, the main control unit 16
The normal compressed data #B is created by encoding B (step S604). Then, the generated image existing in the RAM 14 is discarded (step S605). That is, the reference image (band image #B of the first page)
Instead, the storage area used for storing the generated image (the band image #B of the Mth page) is released so that it can be used for storing other data. Thereafter, the main controller 16 proceeds to step S606, and determines whether or not B and Bmax match, thereby determining whether or not the processing for the final band (Bmax band) has been completed.

If the processing for the last band has not been completed (step S606; NO), the main control unit 16
Adds "1" to B (step S607). After that, the process returns to step S602 to perform processing for creating differential compressed data and normal compressed data for the next band.

At the time of page compression data creation processing, the main control unit 1
No. 6 repeats such processing. And B = Bmax
Holds (step S606; YES), that is, the difference compressed data # 1 to Bmax and the normal compressed data #
When the creation of 1 to Bmax is completed, step S602
The process exits the loop of steps S607 to S607 and proceeds to step S608. Then, it calculates a normal sum _{S RLE} size of the compressed data # 1～Bmax, a total _{S D} size of compressed difference data # 1~Bmax.

Thereafter, the main controller 16 determines whether or not S _RLE < _SD is satisfied between the calculated values (step S609). If S _RLE < _SD is satisfied (step S609) In step S609; YES), the normal compressed data #
1 to Bmax are respectively set to the band compression data (D (M, 1)) for the corresponding band of the page compression data #M.
ＤD (M, Bmax)) (step S61).
0). Further, “0” is set to F (M) which is a variable for storing the type flag #M (step S611).
Then, unnecessary data such as the differential compressed data # 1 to Bmax and the like are discarded (not shown), and the page compressed data creation processing ends.

On the other hand, if S _RLE < _SD is not satisfied (step S609; NO), the main control unit 16
The difference compression data # 1 to Bmax are stored as band compression data (D (M, 1) to D (M, Bmax)) for the corresponding band of the page compression data #M, respectively (step S612). Then, F (M) is set to "1" (step S613), unnecessary data (normal compressed data # 1 to Bmax, etc.) is discarded (not shown), and the page compressed data creation processing ends. I do.

Next, the procedure for restoring the compressed data file 32 in the printing apparatus will be described with reference to FIGS. FIG. 13 is a flowchart of a decompression process executed when decompression of the compressed data file 32 is instructed in the printing apparatus (see FIG. 2). FIG. It is a flowchart of a restoration process.

As shown in FIG. 13, when the restoration process starts,
The main control unit 16 first manages the management data of the processing target compressed data file which is the compressed data file 32 instructed to be restored (printed), that is, the number of compressed data Mmax, the type flags # 2 to Mmax, and the head position data # 1. ＭMmax is obtained (step S701). In this step, the main control unit 16 stores the values of the type flags # 2 to Mmax as F (2) to F (Mmax), respectively.

Next, the main controller 16 sets Ps in M (step S702), and determines whether Ps is "1" (step S704). If Ps is not “1” (step S704; NO), the main control unit 16
By decompressing the page compressed data # 1 whose head position is indicated by the head position data # 1, the first
RAM1 for band images # 1 to Mmax related to page
4 (step S705). Then, the process proceeds to step S708.

On the other hand, if Ps = 1 (step S
704; YES), the main control unit 16 performs the normal compression page restoration process on the page compression data # 1 (step S70).
Execute 6). The normal compressed page restoration processing executed in this step is the same as the processing executed in step S405. That is, the main control unit 16 determines in step S706 that the head position data #M (= Ps =
Each band compressed data of the page compressed data #M whose head position is indicated by 1) is read and decoded.
At this time, since Ps ≦ M ≦ Pe is satisfied, processing for supplying the band images # 1 to Bmax obtained by decoding to the printing unit 12 is also performed.

Normal compressed page restoration processing (step S70)
After the execution of 6), the main control unit 16 adds “1” to M (step S707), and proceeds to step S708. That is, the main control unit 16 restores (prints) the first page.
Is instructed (when Ps = 1), the first page is printed, M is set to "2", and the process proceeds to step S708. When restoration (printing) from the Ps page other than the first page is instructed, the M value is set to P
s, the Bmax band images for the first page are prepared on the RAM 14 and the process proceeds to step S708.
Proceed to.

In step S708, the main control unit 16
Determines whether M ≦ Pe holds. M ≦ Pe
Is satisfied (step S708; YES), it is further determined whether or not F (M) = 1 (whether or not the page compressed data #M is the second type page compressed data). (Step S709). If F (M) is not equal to 1 (Step S709; NO), Step S709
The same normal compressed data decompression process as that executed in 706 (step S710) is executed. Steps S709 to S711 are steps performed for M that satisfies Ps ≦ M ≦ Pe. Therefore, in the normal compression data decompression processing in step 710, band images # 1 to Bmax obtained by decoding are always used. Print unit 12
Is performed.

On the other hand, if F (M) = 1 (step S709; YES), that is, the page compressed data #M
Is the second type page compressed data, the main control unit 16
Starts the differential compressed page restoration process (step S711).

As shown in FIG. 14, at the time of the differential compressed page restoration processing, the main control unit 16 first sets B to “1” (step S801). Then, a copy of band image #B of the first page used as a reference image is copied to R
The data is created on the AM 14 (step S802), and the differential compression data restoration process (step S803) is executed. The differential compressed data decompression processing executed in this step is the same as the differential compressed data decompression processing (the flowchart shown in FIG. 10) executed by the printing apparatus according to the first embodiment.

After the completion of the differential compressed data restoration processing, the main control unit 16 supplies the band image #B to the printing unit 12 (Step S805). Thereafter, it is determined whether or not the processed band compressed data is the final band compressed data (step S806). When the band compression data is not related to the last band (step S806:
NO), the main control unit 16 adds "1" to B (step S807), returns to step S802, and performs processing for the next band compressed data. Then, the main control unit 16
When the processed band compressed data is the final band compressed data (step S806; YES), the differential compression page restoration process ends.

Returning to FIG. 13, the description of the restoration processing will be continued.
After the completion of the differential compression page restoration processing, the main control unit 16 proceeds to step S712, and discards the Mth page data (band images # 1 to Bmax related to the Mth page). That is, each type 2 page compressed data in the compressed data file 31 requires the image data of the previous page for the decompression, but each type 2 page compressed data in the compressed data file 32 created by the printing apparatus is used. The two-page compressed data does not require the image data of the previous page for its decompression (requires the image data of the first page). Therefore, the M-th page data is discarded.

After discarding the M-th page data, the main control unit 16
Adds “1” to M (step S713), and executes the processing from step S708 again. And M ≦ P
When e is not satisfied (step S708; NO)
Then, the restoration processing ends. This step S708
, When M = Mmax holds (Pe is M
main control unit 1).
6 branches to the "NO" side. Step S7
When the branch to the “NO” side is made at 08, the main control unit 16
Determines whether printing of the specified number of copies has been completed, and if not completed, determines in step S70
The processing from step 2 is executed again. When printing of the specified number of copies is completed, it is determined whether the discard approval / disapproval instruction information indicates that the compressed data file is to be discarded after printing, and the discard instruction is issued. If, the compressed data file that has been processed is discarded (erased), and then the decompression process is terminated.

Hereafter, the page compressed data # 2, 4, 5
It is the second kind page compressed data, and the page compressed data # 3
Is a compressed data file 3 which is the first kind page compressed data
The contents of the above-described restoration processing will be described more specifically by taking as an example a case where restoration of all pages is instructed and a case where restoration of fourth and fifth pages is instructed.

When restoration of all pages is instructed (Ps =
1, Pe = 5), since Ps = 1, step S7
At 04, a branch is made to the "YES" side. As a result, normal compressed page restoration processing is performed on the page compressed data #M (M = 1). That is, on the RAM 14, the first
The band images # 1 to Bmax of the page are generated, and are supplied to the printing unit 12 (the first page is printed).

After that, M is changed to “2”, and the processing after step S709 is executed.

Since M ≦ Pe holds for the M value (= 2) at this time, “YE” is determined in step S709.
A branch is made to the “S” side, and since F (2) is “1” (page compressed data # 2 is the second-type page compressed data), a branch is made to the “YES” side. , A differential compressed page restoration process is performed on the page compressed data # 2, that is, copies of the band images # 1 to Bmax relating to the first page on the RAM 14 are generated, and these are copied to the band compressed data D (2, 1) to Rewritten in accordance with D (2, Bmax), band images # 1 to Bmax for the second page are generated and supplied to the printing unit 12. Then, band images # 1 to Bmax for the second page are discarded. Thereafter, M is changed to “3”, and the processing from step S708 is performed again.

Since M (= 3) ≦ Pe, step S
At 708, a branch is made to the "YES" side. And
In step S709, "NO" because F (3) = 0.
Side, and the normal compressed page decompression process is executed, so that band images # 1 to Bmax for the third page are obtained.
Is generated on the RAM 14. Further, the generated band images # 1 to Bmax are supplied to the printing unit 12. Then, after the band images # 1 to Bmax relating to the third page are discarded, M is changed to “4”, and the processing from step S708 is performed again.

Steps S708 to S71 for M = 4
In 2, the same processing as that in steps S708 to S712 for M = 2 is performed on page compressed data # 4, which is the second type page compressed data. Also, in steps S708 to S712 for M = 5 that are performed thereafter, exactly the same processing as in steps S708 to S712 for M = 2 is performed on page compressed data # 5, which is the second type page compressed data. Then, in step S713 executed after discarding the fifth page data, M
Is changed to "6", so that a branch is made to the "NO" side in the following step S709, and the restoration processing is terminated.

On the other hand, when restoration (printing) of the fourth and fifth pages is instructed (Ps = 4, Pe = 5), the fourth and fifth pages are printed in the following procedure.

In this case, since Ps ≠ 1, branch to the “NO” side is performed in step S704. That is,
A band image for the first page on the RAM 14
1 to Mmax are generated, and step S70 is performed in a state where M = Ps.
Processing from step 8 is started.

Since M (= 4 = Ps) ≦ Pe is satisfied, a branch is made to the “YES” side in step S708.
Then, F (4) is “1” (page compressed data # 2).
Is the second-type page compressed data), so that step S7
At 09, a branch to the “YES” side is performed, and a differentially compressed page restoration process is performed on the page compressed data # 4. That is, copies of the band images # 1 to Bmax for the first page on the RAM 14 are generated. Then, they are the band compressed data D (4,1) to D (4, Bma
Rewritten according to (x), band images # 1 to Bmax for the fourth page are generated and supplied to the printing unit 12. Then, band image # 1 on the fourth page
After discarding Bmax, M is changed to “5”, and the processing from step S708 is performed again.

Steps S708 to S71 for M = 5
Even in the case of 2, the same processing as steps S708 to S712 for M = 4 is performed on page compressed data # 5, which is the second type page compressed data. Then, since M is changed to “6” in step S713 executed after the fifth page data is discarded, the subsequent step S709
The branch to the "NO" side is performed at the step S, and the restoration processing is terminated.

As described above, in the printing apparatus according to the present embodiment, the compressed data file 32 which can obtain the same print result as the received print data is required for printing according to the print data. As compressed data relating to the image data of the band for one page, a compressed data file 32 is created using differential compressed data representing a difference between the image data and the image data of the corresponding band of the first page.

If the first page and the P-th page represented by the print data to be processed have many common portions, the differential compressed data created for each band of the P-th page Is smaller than the total size of the normal compressed data created for those bands. Therefore, according to the printing apparatus, a document having many common portions in each page is printed (for example, printing of a document created by spreadsheet software or a standard document such as an invoice). ) Can be compressed and stored at a higher compression ratio than before.

The second type page compressed data of the compressed data file 32 created by the printing apparatus can be restored if there is image data of the first page. In other words, the printing apparatus is an apparatus capable of compressing and saving print data in such a manner that restoration from an intermediate page can be performed at a higher speed than the printing apparatus according to the first embodiment.

<Third Embodiment> FIG. 15 shows a third embodiment of the present invention.
2 shows a configuration of a compressed data file created by the printing apparatus according to the embodiment. As shown in FIG.
Similarly to the compressed data files 31 and 32, the compressed data file 33 created by the printing apparatus according to the third embodiment includes management data and first to Mmax
It is composed of page compressed data # 1 to Mmax which are compressed data of image data constituting a page.

As shown in FIG. 15B, the management data of the compressed data file 33 has exactly the same configuration as the management data of the compressed data files 31 and 32. Although not shown, the type 1 page compressed data used in the compressed data file 33 has the same configuration as the type 1 page compressed data used in the compressed data files 31 and 32. I have.

As shown schematically in FIG. 15C, the compressed data file 33 includes band flags # 1 to Bmax and Bmax pieces of band compressed data as second-type page compressed data. The band compressed data whose data is the corresponding band flag being “1” is differential compressed data, and the corresponding band flag is “0”.
The data whose band compression data is normally compressed data is used. The compressed data file 3
Each of the differential compressed data used for the third type (second type page compressed data), similar to the differential compressed data used for the compressed data file 31, converts the image data of the band of the target page into the corresponding band of the previous page. 3 (e), which is created by comparing with the image data of FIG.

Hereinafter, details of the compression processing and the decompression processing executed by the printing apparatus according to the third embodiment will be described. The compression processing and decompression processing executed by the printing apparatus are similar to the compression processing and decompression processing executed by the printing apparatus according to the first embodiment. For this reason, hereinafter, only the portions having different contents will be described.

In the printing apparatus, during the compression process (see FIG. 4), the page compressed data creation process of the procedure shown in FIG. 16 is executed.

That is, page compressed data #M (M ≧ M
When creating 2), the main control unit 16 first sets the type flag #M
Is set to "0" for a variable F (M) for storing the number of processed bands, and "1" is set for a variable B for counting the number of processed bands (step S901). After that, step S902
Then, a process of creating a band image #B of the Mth page on the RAM 14 based on the received print data is performed. Then, the differential compressed data creation processing (step S90)
Execute 3). The differential compressed data creation process executed in this step is exactly the same as that already described with reference to FIG.

After the completion of the differential compressed data creation processing, the main control unit 16 creates the normal compressed data #B by encoding the band image #B (step S904). And
The reference image (band image #B of the (M-1) th page) existing in the RAM 14 is discarded (step S9).
05).

Thereafter, the main control unit 16 proceeds to step S90.
And size _{S D} of the differential compressed data #B created in 3, the size S of the regular compressed data #B created in step S904
Compare with _RLE (step S906). S _RLE ≦
If _SD has been established (step S906; YE
S), the main controller 16 stores the normal compressed data #B as the band compressed data D (M, B) of the page compressed data #M (step S907). And the band flag #
“0” is set to BF (B) which is a variable for storing B (step S908). After that, the main control unit 16
Proceeds to step S911, and determines whether or not the processed band is the final band.

On the other hand, if S _RLE ≦ _SD is not satisfied (step S906; NO), the main control unit 16
The difference compression data #B is stored as the band compression data D (M, B) of the page compression data #M (step S90).
9). Then, “1” is set to BF (M), and “1” is set to the variable F (M) for the type flag #M (step S910). The process advances to step S911 to determine whether the processed band is the final band.

If the processed band is not the final band (step S911; NO), the main control unit 16 adds "1" to B (step S912), and then performs the processing of steps S902 to S910 again. . Then, when completing the processing for all the bands of the M-th page (step S911; YES), the main control unit 16 ends the page compressed data creation processing.

[0133] Such page compressed data creation processing is performed as follows.
After repeating the process for each of the second and subsequent pages represented by the print data, the main control unit 16 in the printing apparatus performs a step corresponding to step S109 on the basis of the information obtained so far. A compressed data file 33 having the configuration shown in FIG. 15 is created. Specifically, D (M, 1) to D (M, M) are set as page compressed data #M where F (M) = 0.
Bmax) and band flags # 1 to Bmax as page compressed data #M where F (M) = 1.
Using data consisting of D (M, 1) to D (M, Bmax),
A compressed data file 33 is created.

That is, in the printing apparatuses according to the first and second embodiments, the type of band compression data to be included in the compression data files 31 and 32 is selected for each page from the second page onward. On the other hand, in this printing apparatus, as schematically shown in FIG. 17, the type of band compression data to be included in the compression data file 33 is selected for each band for each of the second and subsequent pages. You. For a page having a band for which differential compressed data has been selected, a band flag and second-type page compressed data 41 including differential compressed data and normal compressed data (or only differential compressed data) are used, For a page in which no band has been selected for which differential compressed data has been selected, a compressed data file 33 is created using first-type page compressed data 40 composed of only normal compressed data.

Next, the restoration processing in the printing apparatus will be described. In the printing apparatus, during the restoration process (see FIG. 8), the difference compressed page restoration process of the procedure shown in FIG. 18 is executed.

That is, at the time of the differential compression page restoration processing for the page compression data #M, the main control unit 16 in the printing apparatus according to the third embodiment firstly sets the band flag # 1 existing at the head of the page compression data #M. ~ Bmax (hereinafter BF
(1) to BF (Bmax)) (step S1000). Then, "1" is set to the variable B (step S1001), and whether or not BF (B) = 1 holds, that is, the band compression data D of the page compression data #M
It is determined whether (M, B) is differential compressed data or normal compressed data (step S1002).

If the band compressed data D (M, B) is differential compressed data (step S1002; YES), the main control unit 16 sets the (M-1) th band image #B
(This image already exists on the RAM 14)
Then, a differential compressed data decompression process (step S1005) is performed on D (M, B) with reference to. The differential compressed data decompression processing executed in this step is the same as that in FIG.
Is exactly the same as the process shown in the flowchart in FIG. That is, by the processing in step S1005, the band image #B of the (M-1) th page on the RAM 14 is rewritten to the band image #B of the Mth page.

On the other hand, if BF (B) = 1 is not satisfied (step S1002; NO), the main control unit 16
The band image #B on the M-1 page is discarded (step S1003). Then, the band image #B of the Mth page is created on the RAM 14 by decoding the band compression data D (M, B) which is the normal compression data (step S1004).

Step S1004 or step S10
After creating the band image #B of the Mth page in 05, the main control unit 16 determines whether or not Ps ≦ M ≦ Pe is satisfied (step S1006). And P
When s ≦ M ≦ Pe is satisfied (Step S1006;
If YES, the band image #B is supplied to the printing unit 12 (step S1007), and it is determined whether or not the band image #B relates to the last band (step S1008). On the other hand, when Ps ≦ M ≦ Pe is not satisfied (step S1006; NO), step S1008 is directly executed.

If band image #B does not relate to the final band (step S1008: N
To O), “1” is added to B (step S1009), and the process returns to step S1002 to complete the band image processing for the final band (step S100).
8; YES), the differential compression page restoration process ends.

As described above, in the printing apparatus according to the present embodiment, the compressed data file 33 that can obtain the same print result as the received print data is required for printing according to the print data. Compressed data file 3 including, as compressed data relating to image data of some bands, differential compressed data representing a difference between the image data and the image data of the corresponding band on the previous page.
3 is created.

When two consecutive pages (the P-1 page and the P page) represented by the print data to be processed have many common portions, each band of the P page is The total size of the differentially compressed data created in this way is smaller than the total size of the normal compressed data created for those bands. Further, even if the total size of the differentially compressed data is two pages that does not become smaller than the total size of the normal compressed data, by comparing the sizes of the differentially compressed data and the normal compressed data in band units,
Usually, there is a band in which the size of the differential compressed data is smaller. That is, the printing apparatus according to the present embodiment is an apparatus that often uses differential compression data as band compression data, compared to the printing apparatuses according to the first and second embodiments.

Therefore, if the printing apparatus is used, a print data (for example, a document created by spreadsheet software, a bill, etc. Print data of a fixed document) can be compressed and stored at a higher compression ratio than the conventional apparatus and the printing apparatuses according to the first and second embodiments.

<Fourth Embodiment> First, the structure of a compressed data file created by a printing apparatus according to a fourth embodiment will be described.

As shown in FIG. 19A, the compressed data file 34 created by the printing apparatus according to the fourth embodiment includes management data and page compressed data # 1 to Mma.
x. As shown in FIG. 19B, the management data includes the number of compressed data Mmax, type flags # 2 to Mmax, head position data # 1 to Mmax, and generated page numbers # 1 to Mmax.
And Number of compressed data Mma constituting management data
x, type flags # 2 to Mmax, head position data # 1 to Mma
x is the number of compressed data Mmax used in the management data of the compressed data files 31 to 33, the type flag # 2 to Mm
ax, which is the same as the head position data # 1 to Mmax. That is, the page compressed data # 1 in the compressed data file 34 and the page compressed data whose corresponding type flag is “0” are the first type page compressed data, and the corresponding type flag is “1”. Certain page compressed data is second-type page compressed data.

Generated page numbers # 1 to Mmax (hereinafter P
(1) to P (Mmax)) are data indicating the page numbers of the pages obtained by restoring the page compressed data # 1 to Mmax, respectively. The generated page number # 1 is also data indicating the page number of a page used as a reference when each type 2 page compressed data is created. That is, the compressed data file 3
4 are the compressed data of the image data of the P (1) th to P (Mmax) pages, respectively, and each of the second compressed data # 2 to Mmax included in the page compressed data # 2 to Mmax. The seed page compressed data is data composed of Bmax pieces of differential compressed data created on the basis of the image data of the corresponding band of the P (1) page, as shown in FIG. 19C. .

Hereinafter, the procedure for creating the compressed data file 34 in the printing apparatus will be described in detail.

FIG. 20 is a flowchart of a compression process performed in the printing apparatus according to the present embodiment. Note that, as already described with reference to FIG. 2, this compression processing is executed when the received print data includes storage designation information including a data name and a password.

As shown in the figure, during the compression processing, the main controller 1
6 is a variable M for counting the number of processed pages and a variable B for counting the number of processed bands.
Are set to "1" (step S110).
1).

Thereafter, the main controller 16 creates a band image #B which is image data of the B-th band of the M-th page based on the received print data (step S1).
102). Next, the main control unit 16 encodes the created band image #B (in this embodiment, run-length encoding), thereby generating the normal compressed data D of the Mth page.
_RLE (M, B) is created (step S1103). Thereafter, by determining whether or not B = Bmax is satisfied, it is determined whether or not the creation of the normal compressed data for the last band has been completed (step S1104). If the creation has not been completed (step S1104) S1104; NO)
, Add “1” to B (step S1105).
Then, the process returns to step S1102 to start creating normal compressed data for the next band.

By performing such processing for one page of print data, the band images # 1 to Bmax of the Mth page and the normal compressed data D _RLE (M, 1) to
When creation of D _RLE (M, Bmax) is completed (step S11
04; YES), the main control unit 16 determines the total size S of the created normal compressed data D _RLE (M, 1) to D _RLE (M, Bmax).
Calculate _RLE (M). The process advances to step S1107 to determine whether print data for the next page has been received. If print data for the next page has been received (step S1107; YES), “1” is added to M. Then, "1" is set to B (step S110).
8) After that, the process returns to step S1102.

When the processing for all print data supplied from the host device is completed (step S1107; N
O), the main control unit 16 performs steps S1102 to S110.
Exit loop 8 Then, a differential compressed data group creation process (step S1109) and a band compressed data selection process (step S1110) are sequentially executed.

FIGS. 21 and 22 show flowcharts of the differential compressed data group creation processing and the differential compressed data creation processing executed at the time of the differential compressed data group creation processing, respectively.

As shown in FIG. 21, at the start of the differential compressed data group creation processing, the main control unit 16 assigns the variables X and Y, which are the operands of the differential compressed data creation processing, to
“1” and “2” are set (step S1201), and “1” is set to a variable B which is also an operand of the differential compressed data creation processing (step S1202). Then, the difference compressed data creation processing (step S1203) is started.

As shown in FIG. 22, at the time of differential compressed data creation processing, the main control unit 16 first sets “1” as a variable k for storing a unit data number and sets a variable k for counting the number of element data. "0" is set to the variable i (step S1).
301). Next, the unit data #k of the band image #B of the X page and the unit data #k of the band image #B of the Y page are compared (step S1302).

When the unit data #k of the band image #B of the X page and the unit data #k of the band image #B of the Y page do not match (step S130)
3; NO), the main control unit 16 adds “1” to i (step S1304). Then, the k-th and unit data #k of the X-th page are converted into differential compressed data D (Y, X, B) (Y-th
Element data #i (positional data and replacement data) of differential compressed data in which band image #B of page X is restored using band image #B of page as a reference image
(Step S1305). Further, the unit data #k of the k-th page and the Y-th page are converted into differential compressed data D (X,
(Y, B) is stored as element data #i (step S1).
306). Then, “1” is added to k (step S
1307).

On the other hand, when unit data #k of band image #B on page X and unit data #k of band image #B on page Y match (step S130)
3; YES), the main control unit 16 performs steps S1304 to S1304.
Step S1307 is executed without executing S1306.

After changing the value of k in step S1307, the main control unit 16 determines that the value of k is
It is determined whether it is less than or equal to max (step S130)
8). If the value of k is equal to or less than kmax (step S1308; YES), the process returns to step S1302 to perform the processing for the next unit data.

The main control unit 16 repeats such a process for each unit data. When the value of k is not less than kmax (step S1308; NO), the main control unit 16 determines the value of i at that time by the difference. Compressed data D (X, Y, B), D
It is stored as the number Nmax of element data of (Y, X, B) (step S1309). Then, the differential compressed data creation processing ends.

The difference compressed data D (X, Y, B) and the difference compressed data creation processing (FIG. 21: step S1203)
After creating D (Y, X, B), the main control unit 16 determines that B = Bma
It is determined whether or not x is satisfied (step S120)
4). B is not Bmax (step S120)
4; NO), the main controller 16 adds “1” to B (step S1205). Then, step S1203
And executes the differential compressed data creation process for the updated B value.

By repeating steps S1203 to S1204, differentially compressed data D (X, Y, 1) to D (X, X
When the creation of (Y, Bmax) and D (Y, X, 1) to D (Y, X, Bmax) is completed (step S1204; YES), the main control unit 16 sets the D (X, Y, 1) to D (X, Y, Bmax) calculates the sum S _XY size, D (Y, X, 1 ) ~D (Y, X, Bmax) of the total S _YX size (step S1206). afterwards,
"1" is added to Y (step S1207), and Y becomes Mma
x is determined (step S120).
8). If Y has not exceeded Mmax (step S1208; NO), the process returns to step S1202, and the above-described series of processing is performed on the updated Y value.

On the other hand, if Y exceeds Mmax (step S1208; YES), the main control section 16 adds "1" to X and sets X + 1 (X is X after addition) to Y (X is added). Step S1209). Then, it is determined whether or not X <Mmax is satisfied (step S1210), and X <Mmax is determined.
If max is satisfied (step S1210; YE)
In S), the processing from step S1203 is executed again.

The main control unit 16 repeats such processing, and when X <Mmax is not satisfied (step S1).
(210; NO), the differential compression data group creation process ends. Then, the band compression data selection processing is started.

FIG. 23 shows a flowchart of the band compression data selection processing. As shown, at the start of the band compression data selection process, the main control unit 16 calculates ΣS _ij for each i of 1 to Mmax (step S1401). That is,
Mmax × (Mmax−) calculated in step S1206.
Based on 1) the S _ij, second to Nma created using a band image for the first page as a reference image
The total size of the second-type page compressed data for the x-page ΣS _1j , and the first, third to Nmax created using the band image for the second page as the reference image
Page and calculates the total size [sigma] s _2j like of the two page compression data for.

Then, the i value that minimizes ΣS _ij is specified (step S1402), and the specified i value (hereinafter, referred to as Z) is set as a variable P (1) for storing the generated page number # 1. And generation page numbers # 2 to M
The variables P (2) to P (Mmax) for storing max are set to 1 to Mmax excluding Z, respectively (step S140).
3). Then, the normal compressed data # 1 to Bmax (D
_RLE (Z, 1) to D _RLE (Z, Bmax))
Band compressed data D (P (1), of page compressed data # 1
1) to D (P (1), Bmax) (step S1).
404).

Thereafter, the main control section 16 performs a process for determining the page compressed data # 2 to Mmax (step S14).
05 to S1411), and first, M is set to “2” (step S1405). Next, it is determined whether M ≦ Mmax is satisfied (step S1406), and M ≦ M is determined.
If max is satisfied (step S1406; YE)
In S), a P (M) value is set to j (step S140).
7). Then, the page compressed data (D _RLE (j, 1) to D
Size of data _RLE (j, Bmax)) S _RLE (j)
And S _RLE (j) between the size S _{zj of} page compressed data (data composed of D (Z, j, 1) to D (Z, j, Bmax)) using each band compressed data as differential compressed data. ) ≧ S _zj
It is determined whether or not is established (step S1408).

If S _RLE (j) ≧ S _zj is not satisfied (step S1408; NO), the main control unit 16
The normal compressed data # 1 to Bmax of the j-th page are converted to the band compressed data D (M, 1) to D (M, Bm) of the page compressed data #M.
ax) and set F (M) to “0” (step S1409). On the other hand, S _RLE (j) ≧ S _zj
Is satisfied (step S1408; YES),
The main control unit 16 transmits the differential compressed data D (Z, j, 1) to D (Z,
j, Bmax) as band compressed data D (M, 1) to D (M, Bmax) of page compressed data #M,
F (M) is set to "1" (step S1410).

After executing step S1409 or S1410 according to the magnitude relationship between S _RLE (j) and S _zj , main controller 16 adds “1” to M (step S1411).
Then, the processing from step S1406 is executed again. Then, when the processing for each of the M values of 2 to Mmax is completed (step S1406; NO), the band compression data selection processing ends.

After the band compression data creation processing (FIG. 20, step S1110) ends, the main control unit 16 stores the compressed data file 34 in the HDD based on the various data generated.
(Step S1111). Then, the compression process ends.

Hereinafter, the compressed data file 3 by the printing apparatus will be described by taking as an example the case where print data for five pages is received.
4 will be described more specifically.

In this case, since Mmax = 5, when the band compression data selection process is started, 20 (= 5)
× 4) A set of differentially compressed data and five sets of normal compressed data are created. In addition, the size S _{ij of} the second-type page compressed data configured using each set of differential compressed data is obtained. In step S1401, the sizes are divided into five groups according to the page of the image data used as the reference image, and the total size of the four second-type page compressed data belonging to each group is calculated. .

More specifically, this step S1401
Through the processes up to, for example, information as shown in FIGS. 24A and 24B is collected as information on the size. In FIG. 24A, the numerical values (1, 2, etc.) shown in the leftmost column are the page numbers of the image data used as the reference images (hereinafter, referred to as reference page numbers). The number shown on the top line is
This is the page number (generation page number) of the image data compared with the reference image. Then, a numerical value described in a place where the reference page number is X and the generated page number is Y is a second type page compression composed of D (X, Y, 1) to D (X, Y, Bmax). a size S _XY data, the numerical values are shown in the rightmost column is the total size of the two-page compressed data that is calculated in step S1401. Also, the numerical value shown in FIG.
6 is the size of the type 1 page compressed data calculated in step S6.

In the processing up to step S1401, FIG.
When the information as shown in (1) is collected, step S14
In 02, “3” whose total size is “110” is specified as the i value. In the following step S1403, the generated page numbers # 1 to Mmax are set to 3 (=
Z) 1,2,4,5. Then, in step S1404, it is stored that the normal compressed data # 1 to Bmax of the third page are used as each band compressed data of the page compressed data # 1.

In the loop of steps S1406 to S1411, for each j value of 1, 2, 4, and 5, S _RLE (j)
And S _3j are compared. In the case shown in FIG.
Only for j = 1, S _RLE (j) <S _3j holds. Therefore, only the page compressed data # 2 of the page compressed data # 2 to 5 is set as the first type page compressed data. Then, in step S1111, the compressed data file 34 having the configuration schematically shown in FIG. 25 is created based on the various information obtained as described above.

The operation of the printing apparatus during the restoration process will be described below.

FIG. 26 shows a flowchart of the restoration processing executed in the printing apparatus. As shown in the figure, at the start of the decompression processing, the main control unit 16 first manages the management data of the processing target compressed data file which is the compression data file 34 instructed to be decompressed (printed), that is, the number of compressed data Mmax,
Type flags # 2 to Mmax, head position data # 1 to Mma
x, generation page numbers # 1 to Mmax are acquired (step S1501). In this step, the main control unit 16
Indicates the values of the type flags # 2 to Mmax, respectively, as F (2)
To F (Mmax), and generated page numbers # 1 to Mmax
Are stored as P (1) to P (Mmax), respectively.

Next, the main controller 16 sets Ps as a variable P (step S1502). After that, Ps becomes P (1)
Is determined (step S1503)
If Ps does not match P (1) (step S1503; NO), page compressed data # 1 is restored (step S1504). That is, by decompressing the page compressed data # 1 whose head position is indicated by the head position data # 1, band images # 1 to Bmax for the P (1) th page are created on the RAM 14. Then, the process proceeds to step S1507.

On the other hand, if Ps = P (1) (step S1503; YES), the main control unit 16 executes a normal compressed page restoration process (step S1505) for the page compressed data # 1. The normal compressed page restoration process performed in this step is a process of restoring each band compression data in the designated page compression data #M and supplying the data to the printing unit 12.

After executing the normal compressed page restoration processing, the main control unit 16 adds “1” to P (step S1506).
Then, the process proceeds to step S1507.

In step S1507, the main control unit 1
Step 6 determines whether P ≦ Pe is satisfied. If P ≦ Pe is satisfied (step S150)
7; YES), it is determined whether or not P = P (1) (step S1508). If P = P (1) (step S1508; YES), the main control unit 16
The band image related to the P (1) th page existing on page 14 is supplied to the printing unit 12 (step S1509). Then, the process proceeds to step S1515. Step S1
The branch to the “YES” side is performed at 508 because Ps <
This is when the restoration process is executed in a state where Ps and Pe satisfying P (1) ≦ Pe are given.

On the other hand, if P = P (1) is not satisfied (step S1508; NO), the main control unit 16 specifies the compressed data number M whose generation page number is P (step S1508).
1510). Then, it is determined whether or not F (M) = 1 holds for the specified compressed data number M (step S).
1511). If F (M) is not 1 (step S1
(511; NO), the same normal compressed page restoration processing as that executed in step S1505 is executed on the page compressed data #M (step S1512). That is, in step S1512, the main control unit 16
Reads out and decodes each band compressed data of the page compressed data #M whose head position is indicated by the head position data #M, and supplies the band images # 1 to Bmax obtained by the decoding to the printing unit 12. I do. Then, the process proceeds to step S1514.

On the other hand, if F (M) = 1 (step S1511; YES), the main control unit 16 executes a differential compressed page restoration process (step S1513).

FIG. 27 shows a flowchart of the differential compression page restoration processing executed in step S1513. As shown in the figure, at the time of the differential compression page restoration processing, the main control unit 16 first sets “1” to the variable B (step S155).
1). Then, a copy of the band image #B of the page P (1) to be used as the reference image is created (step S
1552), and executes differential compression data decompression processing (step S1553) for the page compression data #M. The differential compressed data decompression processing executed in this step is exactly the same as the processing whose flowchart is shown in FIG.

After the band image #B for the M-th page is created by the differential compression data restoration processing, the main control unit 1
6 supplies the band image #B to the printing unit 12 (step S1555), and determines whether or not the band image #B relates to the last band (step S1).
556). When the band image #B is not related to the final band (step S1556: N
To O), “1” is added to B (step S1557), and the process returns to step S1552 to complete the band image processing for the last band (step S155).
6; YES), the differential compression page restoration process ends.

After the differential compressed page restoring process (FIG. 26: step S1513) ends, the main control unit 16 discards the Pth page data (each second type in the compressed data file 32 created by the printing apparatus). Page compressed data is
The restoration does not require the image data of the previous page). Thereafter, the main control unit 16 adds “1” to P (step S1515), and executes the processing from step S1507 again.

The main control section 16 repeats such processing at the time of restoration processing. Then, when P ≦ Pe is not satisfied (step S1507; NO), the restoration processing is ended.

As described above, in the printing apparatus according to the present embodiment, the compressed data file 34 from which a print result having the same content as the received print data is obtained, which is necessary for printing in accordance with the print data. The compressed data relating to the image data of the band for one page includes differential compressed data indicating the difference between the image data and the image data of the corresponding band of another page, and the size of the page compressed data composed of the differential compressed data The compressed data file 34 in which another page is selected so that the total of the compressed data files becomes smaller is created.

Therefore, if the printing apparatus is used, print data (for example, a document created by spreadsheet software or a fixed form document such as an invoice) for printing a document having many common portions is printed. ) Can be compressed and stored at a higher compression ratio than the conventional apparatus and the printing apparatus according to the second embodiment.

<Fifth Embodiment> FIG. 28 shows the configuration of a compressed data file 35 created by a printing apparatus according to a fifth embodiment. As illustrated, the compressed data file 35 created by the printing apparatus according to the fifth embodiment
Are management data and page compressed data # 1 to Mmax which are compressed data of image data of the first to Mmax pages.
max.

As shown in FIG. 28B, the management data includes the number of compressed data Mmax, the head position data # 1 to Mmax,
Reference page numbers # 2 to Mmax are included. Number of compressed data Mmax constituting management data, top position data # 1 to Mm
ax is the number Mmax of compressed data used in management data such as the compressed data file 31 and the head position data # 1 to Mm.
Same as ax.

Reference page numbers # 2 to Mmax (hereinafter R
(2) to R (Mmax)) are type flags # 2 to
This data has a function as Mmax and a function as a page number of image data used as a reference when creating the second type page compressed data included in the page compressed data # 2 to Mmax. More specifically, the page compressed data #M whose R (M) is "0" is the first-type page compressed data, and the page compressed data #M whose R (M) is not "0" is , As shown in FIG.
(M) Second type page compressed data composed of Bmax difference compressed data based on the page.

Hereinafter, a procedure for creating the compressed data file 35 in the printing apparatus will be described in detail. The compression processing performed by the printing apparatus is similar to the compression processing performed by the printing apparatus according to the fourth embodiment.
Therefore, hereinafter, the operation of the printing apparatus will be described focusing on the difference between the two.

In the printing apparatus, during the differential compressed data group creation processing (see FIG. 21), the differential compressed data creation processing in which step S1305 is omitted (see FIG. 22) is executed.

That is, the main controller 16 of the printing apparatus
For example, when the differential compressed data group creation processing for the print data of all five pages is completed, as shown in FIG.
Information on the size of Mmax × (Mmax−1) / 2 second-type page compressed data and information on the size of Mmax first-type page compressed data as shown in FIG. 29B are acquired. ing. Then, after the completion of the differential compressed data group creation processing, the main control unit 16 executes band compressed data selection processing whose flow chart is shown in FIG.

That is, at the time of band compression data selection processing,
The main control unit 16 first sets the first page of the normal compressed data #
It is stored that 1 to Bmax are to be the page compressed data # 1 (step S1601). Then, M is set to “2” (step S1602), and it is determined whether M ≦ Mmax is satisfied (step S1603). When M ≦ Mmax is satisfied (Step S1603; YES), the main control unit 16 specifies i that minimizes _SiM (Step S1604). When there are a plurality of i that minimize S _iM , the main control unit 16 _replaces i with the smaller value with S _{iM.
Specify iM} as the minimum i.

Then, for the specified i, S
_It is determined whether or not _RLE (M) ≧ _SiM is satisfied (step S1605), and if it is satisfied (step S160)
5; YES), the difference compressed data D (i, M, 1) to D (i, M, M) of the M-th page created based on the i-th page
Bmax) is stored as the page compressed data #M, and the reference page number #M is set as i (step S1).
607). On the other hand, when S _RLE (M) ≧ _SiM is not satisfied (step S1605; NO), the main control unit 16
Are the normal compressed data # 1 to Mmax (M
_RLE (M, 1) to D _RLE (M, Bmax)) are stored as page compressed data #M, and the reference page number #M is set to "0" (step S1607). That is, it stores that the page compressed data #M is the first type page compressed data.

Step S1606 or step S1
After the execution of Step 607, the main control unit 16 adds “1” to M (Step S1609). Then, step S160
Returning to 3, it is determined whether or not M ≦ Mmax is satisfied.

At the time of band compression data selection processing, the main control unit 1
No. 6 repeats such processing. And M ≦ Mmax
Is not satisfied (step S1603; NO)
Then, the band compression processing ends. Thereafter, a compressed data file 35 having the configuration shown in FIG. 28 is created based on the various information obtained so far, and the compression process ends.

That is, in this printing apparatus, the second-type page compressed data relating to the M-th page is stored in the first to M-1st pages.
It is created using each of the image data of the page as a reference image. And the second with the smallest size
Compressed data file 3 using seed page compressed data
5 is created.

More specifically, for example, when the total number of pages of the received print data is “5” and the information collected regarding the size is as shown in FIG. 29, the main control unit 16 Since the size (“20”) of the second type page compressed data of the second page is smaller than the size (“40”) of the first type page compressed data of the second page, the second page Select the second-type page compressed data based on one page. Also, among the two second type page compressed data related to the third page, the size of the second type page compressed data based on the second page (“2
0 ”) is smaller than the size of the second-type page compressed data (“ 50 ”) based on the first page, and the size“ 20 ”is the size of the first-type page compressed data of the third page. Since the size is smaller than “30”, the second type page compressed data based on the second page is selected as the page compressed data # 3.

[0201] The size ("10") of the type 2 page compressed data based on the third page is the smallest among the three type 2 page compressed data related to the fourth page. In addition, the size is smaller than the size ("50") of the type 1 page compressed data for the fourth page. Therefore, the main control unit 16 sets the page compression data # 4 as
The second type page compressed data based on the third page is selected.

[0202] The four second-type page compressed data relating to the fifth page have a size "30" smaller than the size ("40") of the first-type page compressed data relating to the fifth page. 2nd type page compressed data is 2
There are two. For this reason, the smaller i value is specified, and the page compression data # 5 is set to the second page based on the first page.
Select seed page compressed data.

Then, as shown in FIG. 31, the main control unit 16 creates a compressed data file 35 including information on the selected page compressed data and the selected page compressed data itself.

The procedure for restoring the compressed data file 35 in the printing apparatus will be described below with reference to FIGS. FIG. 32 is a flowchart of a restoration process executed in the printing apparatus, and FIG. 33 is a flowchart of a differential compression page restoration process executed at the time of the restoration process.

As shown in FIG. 32, at the time of the decompression processing, the main control unit 16 manages the management data (that is, the number of compressed data Mmax, the head position data # 1
To Mmax, reference page numbers # 2 to Mmax) (step S1701). In this step, the main control unit 16 acquires the values of the reference page numbers # 2 to Mmax as R (2) to R (Mmax), respectively.

Then, the main controller 16 sets R (1) to “0” and sets M to “1” (step S1702). Next, it is determined whether or not R (M) = 1 (step S1703). If R (M) is not equal to 1 (step S1703; NO), the normal compressed page restoration process for the page compressed data #M ( Step S1
704). During this normal compressed page restoration process,
The main control unit 16 decodes the page compressed data #M in which each band compressed data is normal compressed data, and generates band images # 1 to Bmax on the RAM 14. Also, Ps ≦
If M ≦ Pe is satisfied, the created band images # 1 to Bmax are supplied to the printing unit 12.

On the other hand, if R (M) = 1 (step S1703; YES), the main control unit 16 executes the differential compression page restoration process for the page compression data #M (step S1703).
1705).

As shown in FIG. 33, at the time of the differential compression page restoration processing, the main control unit 16 first sets B to "1" (step S1801). Thereafter, a copy of the band image #B of the R (M) page to be used as the reference image is created on the RAM 14 (step S1802),
A differential compressed data restoration process (step S1803) is executed. The differential compressed data decompression process executed in this step is a differential compressed data decompression process executed by the printing apparatus according to the first embodiment (a flowchart shown in FIG. 10).
Is the same as

After the completion of the differential compression data restoration processing, the main control unit 16 determines whether or not Ps ≦ M ≦ Pe is satisfied (step S1804). Then, only when the condition is satisfied (step S1804; YES), the band image #B is supplied to the printing unit 12 (step S180).
5). Thereafter, it is determined whether or not the processed band compressed data is the final band compressed data (step S180).
6) If it does not relate to the final band (step S1806: NO), “1” is added to B (step S1807), and the process returns to step S1802. If the processed band compressed data is the final band compressed data (step S180)
6; YES), the differential compression page restoration process ends.

After the differential compressed page restoring process or the normal compressed page restoring process is completed, the main control unit 16 sets M to “1”.
Is added (step S1706). Then, M ≦ Pe
It is determined whether or not is established (step S1707).
If the condition is satisfied, step S1703 is performed again.
Execute the process from.

Then, when M ≦ Pe is not satisfied (step S1707; NO), the restoration processing ends.

As described above, in the printing apparatus according to the present embodiment, the compressed data file 35 from which a print result having the same content as the received print data is obtained is used as a reference so as to reduce the size. A compressed data file 35 including the type 2 page compressed data whose pages are individually selected is created.

Therefore, if the present printing apparatus is used, a document in which each page has many common portions will be printed (for example, a document created by spreadsheet software or a fixed form such as a bill). Document print data) can be compressed and stored at a higher compression ratio than the conventional device and the printing device according to another embodiment.

<Sixth Embodiment> FIG. 34 shows the structure of differential compressed data used for a compressed data file created by a printing apparatus according to a sixth embodiment. As is apparent from the figure, the compressed data file created by the printing apparatus is composed of the element data number Nmax and Nmax element data composed of replacement start position data, replacement number data and replacement data, respectively. In this case, the compressed difference data is used.

Hereinafter, the meaning of each data constituting the element data will be described by describing the compression / decompression operation of the printing apparatus. Since the overall operation of the printing apparatus is the same as that of the printing apparatus according to the first embodiment, the following description of the printing apparatus will focus on the parts that operate differently.

FIGS. 35 and 36 show flowcharts of differential compressed data creation processing executed by the printing apparatus.

As shown in FIG. 35, at the time of differential compressed data creation processing, the main control unit 16 sets “1” as a variable k for storing a unit data number and a variable i for storing the number of element data. Is set to "0", and "0" is set to a variable L for storing replacement number data (step S2101). Then, the unit data #k of the band image #B of the Mth page
(Hereinafter also referred to as D) and the unit data #k of the reference image are compared (step S2102).

If the two match (step S21)
03; YES), the main control unit 16 adds “1” to k (step S2110). Then, it is determined whether or not k is equal to or smaller than kmax. If k is equal to or smaller than kmax (step S2111; YES), step S2102 is performed.
The process from is executed again.

If D and unit data #k of the reference image do not match (step S2103; NO),
The main control unit 16 determines whether or not L is “0” (Step S2104). If L is “0” (step S2104; YES), the main control unit 16 sets k to ks, “1” to L, D to Dold, and kold to kold (step S2109), Proceed to step S2110.

On the other hand, if L is not "0" (step S2104; NO), the main control unit 16 determines whether D = Dold and k = kold + 1 hold (step S2105). . If the condition is satisfied (step S2105; YES), “1” is added to L and k is set to kold (step S2106). Then, the process proceeds to step S2110.

If either (or both) of D = Dold and k = kold + 1 are not satisfied (step S2
105; NO), the main control unit 16 adds “1” to the variable i (step S2107). Then, the values of ks, L, and Dold at that time are stored as respective elements of the replacement data #i (step S2108), and step S210 is performed.
9 is executed.

The main control section 16 repeats such processing until the processing for all the unit data in the band image #B is completed. Then, when the processing for all unit data is completed (step S2111; NO), it is determined whether or not L = 0 as shown in FIG. 33 (step S2112). If L = 0 is not satisfied (step S2112; NO), the main control unit 16
Is added (step S2113), and ks, L,
Dold is stored as each element of the element data #i (replacement start position data, replacement number data, replacement data) (step S2114). Then, the value of i is converted to differential compressed data #
Stored as the number of element data Mmax of B (step S211)
5) Then, the differential compressed data creation processing ends. On the other hand, L
If = 0 (step S2112; YES), the main control unit 16 executes step S2115 without changing the i value or the like, and ends the differential compressed data creation processing.

The processing in steps S2112 to S2114 is performed when the last unit data of band image #B is different from the corresponding unit data of the reference image.
This is a process that is performed to include element data relating to the unit data in the differential compression data.

That is, at the time of differential compressed data creation processing in the printing apparatus according to the present embodiment, the band image #
B is searched for a portion composed of continuous unit data having the same content from a portion different from the reference image, and information indicating the head element data of each such portion (replacement start position data ks ), The number of unit data constituting the part (replacement number data L), and the content of the unit data constituting the part (replacement data D), the difference compression data including the element data is created. .

The differential compressed data created in this manner is restored by the differential compressed data restoring process shown in FIG.

That is, the main controller 16 first obtains the element data number Nmax of the differential compressed data #B (step S2201). Next, "1" is set to a variable i for storing the element data number (step S2202),
It is determined whether the value of i is equal to or less than Nmax (step S2203). When the value of i is equal to or smaller than Nmax (step S2203; YES), the main control unit 16 extracts the element data #i of the normal compressed data #B (replacement position data ks, replacement number data L) from the processing target compressed data file. , Replacement data D) (step S2204).

Thereafter, the main control section 16 replaces the continuous L unit data starting from the position indicated by ks of the reference image stored in the RAM 14 with the replacement data D.
(Step S2205). Thereafter, "1" is added to i (step S2206), and the process returns to step S2203 to compare the changed value of i with Nmax. If i ≦ Nmax is satisfied (step S2203; YES), steps S404 to S4
06 is executed again, and if i ≦ Nmax is not satisfied (step S2203; NO), that is, when the processing on all the element data of the differential compressed data #B is completed, the differential compressed data restoring processing is performed. To end.

Now, the size of one element data in the compressed data file created by the printing apparatus is the same as the size of the compressed data file 3 including the continuous number data.
1 is larger than the size of the element data. However, if the continuous number data is q (≧ 2),
A portion represented by q element data in the compressed data file 31 is represented by one element data in the compressed data file created by the present apparatus. Therefore, if the band image #B contains a part that is different from the reference image and is composed of continuous unit data having the same content at a certain rate or more, the compressed data file Is a smaller file. The image data of a document created by spreadsheet software or a fixed document such as an invoice usually includes many such portions. For this reason, by using this printing apparatus, print data can be compressed and stored at a higher compression ratio than the printing apparatus according to the first embodiment.

<Modifications> The printer of each embodiment can perform various modifications. For example, the printing apparatuses of the second to fifth embodiments can be modified so that the differentially compressed data having the configuration used in the printing apparatus of the sixth embodiment is used. Further, the technology (using data that can mix differentially compressed data and normal compressed data as page compressed data) used in the printing apparatus according to the third embodiment is described in each of the other embodiments. It can also be applied to printing devices.

Although the printing apparatus of each embodiment creates one file as a compression result, the apparatus may be configured so that a file is created for each page. Furthermore, although the printing apparatus of each embodiment is an apparatus that uses run-length encoding to create normal compressed data, normal printing data may be created by another encoding procedure. That is natural.

Although the printing apparatus of each embodiment is an apparatus for creating a compressed data file when print data including information is received, the printing apparatus includes information for instructing printing of a plurality of copies. Upon receiving the data, the apparatus may be configured such that a compressed data file is created, and the second and subsequent copies are output by restoring the compressed data file. Further, the printing apparatus may be configured to create a compressed data file when print data is received from a specific host device.

[0232]

According to the printing apparatus and method of the present invention, image data for printing can be compressed and stored at a high compression rate and at a relatively high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a hardware configuration of a printing apparatus according to each embodiment.

FIG. 2 is a flowchart illustrating an overall operation procedure of the printing apparatus according to each embodiment.

FIG. 3 is an explanatory diagram of a compressed data file created by the printing apparatus according to the first embodiment.

FIG. 4 is a flowchart of a compression process performed in the printing apparatus according to the first embodiment.

FIG. 5 is a flowchart of a page compressed data creation process executed in the printing apparatus according to the first embodiment.

FIG. 6 is a flowchart of differential compressed data creation processing executed in the printing apparatus according to the first embodiment.

FIG. 7 is an explanatory diagram of a compressed data file created in the printing apparatus according to the first embodiment.

FIG. 8 is a flowchart of a restoration process executed in the printing apparatus according to the first embodiment.

FIG. 9 is a flowchart of differential compressed page restoration processing executed in the printing apparatus according to the first embodiment.

FIG. 10 is a flowchart of differential compressed data restoration processing executed in the printing apparatus according to the first embodiment.

FIG. 11 is an explanatory diagram of a compressed data file created by a printing device according to a second embodiment.

FIG. 12 is a flowchart of page compressed data creation processing executed in the printing apparatus according to the second embodiment.

FIG. 13 is an explanatory diagram of a restoration process executed in the printing apparatus according to the second embodiment.

FIG. 14 is a flowchart of a restoration process executed in the printing apparatus according to the second embodiment.

FIG. 15 is an explanatory diagram of a compressed data file created by the printing device according to the third embodiment.

FIG. 16 is a flowchart of page compressed data creation processing executed in the printing apparatus according to the third embodiment.

FIG. 17 is a diagram illustrating an example of a compressed data file created by a printing apparatus according to a third embodiment.

FIG. 18 is a flowchart of differential compressed page restoration processing executed in the printing apparatus according to the third embodiment.

FIG. 19 is an explanatory diagram of a compressed data file created by a printing device according to a fourth embodiment.

FIG. 20 is an explanatory diagram of a compression process performed in the printing apparatus according to the fourth embodiment.

FIG. 21 is an explanatory diagram of a differential compressed data group creation process executed in the printing apparatus according to the fourth embodiment.

FIG. 22 is an explanatory diagram of differential compressed data creation processing executed in the printing apparatus according to the fourth embodiment.

FIG. 23 is a flowchart of band compression data selection processing executed in the printing apparatus according to the fourth embodiment.

FIG. 24 is a diagram illustrating a compression process performed in the printing apparatus according to the fourth embodiment.

FIG. 25 is a diagram illustrating an example of a compressed data file created by a printing apparatus according to a fourth embodiment.

FIG. 26 is a flowchart of a restoration process executed in the printing apparatus according to the fourth embodiment.

FIG. 27 is a flowchart of differential compressed page restoration processing executed in the printing apparatus according to the fourth embodiment.

FIG. 28 is an explanatory diagram of a compressed data file created by the printing device according to the fifth embodiment.

FIG. 29 is a diagram illustrating a compression process performed in the printing apparatus according to the fifth embodiment.

FIG. 30 is a flowchart of band compression data selection processing executed at the time of compression processing of the printing apparatus according to the fifth embodiment.

FIG. 31 is a diagram illustrating an example of a compressed data file created by a printing apparatus according to a fifth embodiment.

FIG. 32 is a flowchart of a restoration process executed in the printing apparatus according to the fifth embodiment.

FIG. 33 is a flowchart of differential compressed data restoration processing executed in the printing apparatus according to the fifth embodiment.

FIG. 34 is an explanatory diagram of differential compressed data included in a compressed data file created in the printing device according to the sixth embodiment.

FIG. 35 is a flowchart of differential compressed data creation processing executed in the printing apparatus according to the sixth embodiment.

FIG. 36 is a flowchart following FIG. 35 of differential compressed data creation processing executed in the printing apparatus according to the sixth embodiment.

FIG. 37 is a flowchart of differential compressed data restoration processing executed in the printing apparatus according to the sixth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Communication control part 12 Printing part 13 Operation panel part 14 RAM 15 HDD 16 Main control part 21 Centronics cable 22 LAN cable 31-35 Compressed data file 40 Type 1 page compressed data 41 Type 2 page compressed data

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-7-148997 (JP, A) JP-A-6-332667 (JP, A) JP-A-4-4672 (JP, A) JP-A-4- 126466 (JP, A) JP-A-9-116907 (JP, A) JP-A-8-204967 (JP, A) JP-A-6-169407 (JP, A) JP-A-3-112266 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/41-1/419

Claims (17)

(57) [Claims] A storage unit configured to store compressed data; a printing unit configured to print an image corresponding to the supplied image data on a sheet; and a storage unit configured to store the compressed data in a storage unit when a predetermined instruction is input. Generating and supplying means for generating image data by restoring the compressed data thus obtained and supplying the image data to the printing means; image data generating means for generating image data for each page unit of data included in the received print data; First-type compressed data generating means for generating first-type compressed data for each page represented by the print data by encoding each image data generated by the image data generating means; and generating the first-type compressed data by the image data generating means. For each of the second and subsequent pages represented by the print data, the page And image data concerning
By comparing the image data relating to a specific page with each unit data which is data of a predetermined size constituting each image data, one or more unit data having the same contents included in the image data relating to the page are compared. Start position information indicating the start position of the required replacement area, which is a continuous area and corresponding to the image data relating to the specific page, where the unit data of the content does not exist, and forms the required replacement area. A second type of compressed data including a plurality of element data including continuous number information indicating the number of unit data being replaced and replacement data indicating the contents of the unit data used in the replacement required area;
A first-type compressed data generating unit; and a first-type compressed data for the first page generated by the first-type compressed data generating unit. If the size of the compressed data is smaller than the size of the compressed data of two types, the data including the compressed data of the first type is stored. If not, the data including the compressed data of the second type is stored in the storage unit as compressed data related to the print data. A printing apparatus comprising: a storage unit. 2. A storage unit for storing compressed data, a printing unit for printing an image corresponding to the supplied image data on a sheet, and a storage unit for storing a predetermined instruction when a predetermined instruction is input. Generating and supplying means for generating image data by restoring the compressed data thus obtained and supplying the image data to the printing means; and an image for generating first to n-th image data for each page unit of data included in the received print data Data generation means; and first-type compressed data for creating first to n-th first-type compressed data for each page represented by the print data by encoding each image data generated by the image data generating means. Creating means; and second and subsequent pages represented by the print data based on the image data generated by the image data generating means. Each page, as well as, for each k in the 1 to n, the k-th image data for the page, the k for a particular page
By comparing the image data with the unit data which is data of a predetermined size constituting each image data, one or more unit data of the same content included in the k-th image data related to the page is continuously output. Position information indicating the start position of the required replacement area, which is an area where the unit data of the content does not exist, in the corresponding portion of the k-th image data relating to the specific page; The k-th compressed data of the second type including a plurality of element data including continuous number information indicating the number of unit data constituting the unit and replacement data indicating the contents of the unit data used in the required replacement area is stored. A second-type compressed data creating unit to be created; and first to n-th first-type compressed data related to the first page created by the first-type compressed data creating unit. , For each page from the second page onward, if the size of the k-th type 1 compressed data is smaller than the size of the k-th type 2 compressed data for each of k of 1 to n, The first of k
Seed compressed data, otherwise the k-th second
A printing apparatus comprising: a storage unit configured to store data including seed compressed data in the storage unit as compressed data related to the print data. 3. A storage unit for storing compressed data, a printing unit for printing an image corresponding to the supplied image data on a sheet, and storing in the storage unit when a predetermined instruction is input. Generating and supplying means for generating image data by restoring the compressed data thus obtained and supplying the image data to the printing means; image data generating means for generating image data for each page unit of data included in the received print data; First-type compressed data generating means for generating first-type compressed data for each page represented by the print data by encoding each image data generated by the image data generating means; and generating the first-type compressed data by the image data generating means. Based on the obtained image data, for each of the second and subsequent pages represented by the print data, A second-type compressed data creating unit that creates a second-type compressed data indicating a position and a content of a portion of the image data corresponding to the different page from the image data related to the specific page; If the size of the first-type compressed data is smaller than the size of the second-type compressed data for each page after the second page, the first-type compressed data is included. A storage unit for storing the data including the compressed data, otherwise the data including the second type of compressed data in the storage unit as compressed data relating to the print data; Second
A specific page determining unit that determines the specific page so that the total size of the seed compressed data is minimized. 4. A storage unit for storing compressed data, a printing unit for printing an image corresponding to the supplied image data on a sheet, and storing in the storage unit when a predetermined instruction is input. Generating and supplying means for generating image data by restoring the compressed data thus obtained and supplying the image data to the printing means; and an image for generating first to n-th image data for each page unit of data included in the received print data Data generating means; and first-type compressed data for generating first to n-th first-type compressed data for each page represented by the print data by encoding each image data generated by the image data generating means. Creating means; and second and subsequent pages represented by the print data based on the image data generated by the image data generating means. For each page, the first to n-th second data indicating the position and content of a portion of the first to n-th image data related to the corresponding page different from the first to n-th image data related to the specific page, respectively A second-type compressed data generating unit for generating the first-type compressed data; a first to n-th first-type compressed data relating to the first page generated by the first-type compressed data generating unit; For each page, for each k of 1 to n, if the size of the k-th type 1 compressed data is smaller than the size of the k-th type 2 compressed data, the k-th first type compressed data
Seed compressed data, otherwise the k-th second
Storage means for storing data including the type-compressed data in the storage means as compressed data for the print data; and first to n-th second-type compression for each page created by the second-type compressed data creation means A printing apparatus comprising: a specific page determining unit that determines the specific page for each page so that the total size of the data is minimized. Wherein said specific page, claim 1 or claim wherein said a front page of the corresponding page
3. The printing device according to 2 . 6. The printing apparatus according to claim 1, wherein the specific page is a first page. 7. The apparatus according to claim 1, further comprising a specific page determining unit that determines the specific page such that the total size of the second type compressed data created by the second type compressed data creating unit is minimized. The printing apparatus according to claim 1, wherein 8. The specific page is determined for each page such that the total size of the first to n-th compressed data of the second type for each page created by the compressed data of the second kind is minimized. 3. The printing apparatus according to claim 2 , further comprising a specific page determination unit. In wherein said product supply means, an instruction input panel for inputting the predetermined instruction, further, claims 1, characterized in that it comprises a printing device according to claim 8. 10. A printing step for printing an image corresponding to the supplied image data on paper, and, when a predetermined instruction is input, decompressing the compressed data stored in the storage device to convert the image data. A generating / supplying step of generating and supplying to the printing step; an image data generating step of generating image data for each page unit data included in the received print data; and each image data generated by the image data generating step A first-type compressed data creating step of creating first-type compressed data for each page represented by the print data by encoding the print data; and the print data represents based on the image data generated in the image data generating step. For each page after the second page, And an image data related to image data with a particular page, by comparing for each unit data is data of a predetermined size comprising each image data included in the image data relating to the page, one of the same content more Start position information indicating a start position of a replacement required area, which is an area where unit data is continuous and where no unit data of the content exists in a corresponding portion of the image data relating to the specific page; Creates second-type compressed data including a plurality of element data including continuous number information indicating the number of unit data constituting an area and replacement data indicating the contents of the unit data used in the required replacement area. A second type compressed data creating step, and a first type compression related to the first page created in the first type compressed data creating step For each page after the second page, if the size of the type 1 compressed data is smaller than the size of the type 2 compressed data, the type 1 compressed data is included. And storing the data including the second type of compressed data in the storage device as compressed data relating to the print data. 11. A printing step for printing an image corresponding to the supplied image data on a sheet, and, when a predetermined instruction is input, restoring the compressed data stored in the storage device to convert the image data. A generating / supplying step for generating and supplying the data to the printing step; an image data generating step for generating first to n-th image data for each page data included in the received print data; A first-type compressed data creating step of creating first to n-th first-type compressed data for each page represented by the print data by encoding each of the image data thus generated; Each of the second and subsequent pages represented by the print data, Each time, comparing for each k in the 1 to n, the k-th image data for the page, and a k-th image data for a particular page, for each unit data is data of a predetermined size constituting each image data Accordingly, one or more unit data of the same content included in the k-th image data related to the page is a continuous area, and the corresponding portion of the k-th image data related to the specific page includes the unit data of the content. , The start position information indicating the start position of the replacement required area, which is an area where no replacement exists, the continuous number information indicating the number of unit data forming the required replacement area, and the A second k-th type of compressed data including a plurality of element data including replacement data indicating the contents of unit data;
A first compressed data creating step; and first to n-th first kind compressed data related to the first page created in the first kind compressed data creating step. If the size of the k-th type 1 compressed data is smaller than the size of the k-th type 2 compressed data,
, And if not, the k-th type
Storing the data including the second type of compressed data as compressed data relating to the print data in the storage device. 12. A printing step of printing an image corresponding to the supplied image data on a sheet, and, when a predetermined instruction is input, decompressing the compressed data stored in the storage device to convert the image data. A generating / supplying step for generating and supplying to the printing step; an image data generating step for generating image data for each page unit data included in the received print data; and each image data generated in the image data generating step A first-type compressed data creating step of creating first-type compressed data for each page represented by the print data by encoding the print data; and the print data represents based on the image data generated in the image data generating step. For each page after the second page, the corresponding page Type compressed data creating step of creating type 2 compressed data indicating the position and content of a portion of the image data related to a specific page different from the image data related to the specific page; If the size of the first-type compressed data is smaller than the size of the second-type compressed data for each of the second and subsequent pages, the first-type compressed data is included. If not, a storing step of storing data including the second type compressed data in the storage device as compressed data relating to the print data; and a second type generated by the second type compressed data generating step. A specific page determining step of determining the specific page such that the total size of the compressed data is minimized. Print how. 13. A printing step of printing an image corresponding to the supplied image data on a sheet, and, when a predetermined instruction is input, decompressing the compressed data stored in the storage device to convert the image data. A generating / supplying step for generating and supplying the data to the printing step; an image data generating step for generating first to n-th image data for each page data included in the received print data; A first-type compressed data creating step of creating first to n-th first-type compressed data for each page represented by the print data by encoding each of the image data thus generated; Based on the image data, the second and subsequent pages represented by the print data And a first to n-th second type compressed data indicating a position and a content of a portion of the first to n-th image data related to the corresponding page different from the first to n-th image data related to the specific page, respectively. , And first to n-th first-type compressed data relating to the first page created in the first-type compressed data creation step, and for each page after the second page For each k of 1 to n, if the size of the k-th type 1 compressed data is smaller than the size of the k-th type 2 compressed data,
, And if not, the k-th type
Storing the data including the second-type compressed data in the storage device as compressed data relating to the print data; and storing the first to n-th data relating to each page created by the second-type compressed data creating step. A specific page determining step of determining the specific page for each page so that the total size of the two types of compressed data is minimized. 14. The method according to claim 10 , wherein the specific page is a page preceding the corresponding page.
The printing method according to claim 11 . 15. The printing method according to claim 10 , wherein the specific page is a first page. 16. A specific page determining step of determining the specific page such that the total size of the second-type compressed data created in the second-type compressed data creating step is minimized. Claim 10
The printing method described. 17. The specific page is determined for each page such that the total size of the first to n-th second type compressed data for each page generated in the second type compressed data generating step is minimized. The printing method according to claim 11 , further comprising a specific page determination step.