JP5190332B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image based on input data input from an image processing apparatus.

In an image forming apparatus such as a conventional printer, in order to confirm what kind of formal image is actually printed, it is possible to easily guess the formally printed image, compared to the case of printing a formal image. Some prints are performed in a trial mode that consumes less medium such as ink and toner (see, for example, Patent Document 1).
Japanese Unexamined Patent Publication No. 7-323644 (paragraph “0017” to “0018”, FIG. 4)

  However, in the conventional technology described above, when performing formal printing (hereinafter referred to as “official printing”) after performing printing in the trial mode (hereinafter referred to as “trial printing”), Since the image is formed by different procedures between the image formation and the image formation in the formal printing, the image generated by the trial printing cannot be used in the formal printing and the original image has almost no difference, There is a problem in that it is necessary to perform image processing with a long processing time during formal printing.

  An object of the present invention is to solve such a problem, and an object thereof is to shorten an image processing time in formal printing after performing trial printing.

  Therefore, the present invention determines whether the attribute information of input data is a trial image formation instruction or a formal image formation instruction in an image forming apparatus that forms an image based on input data input from the image processing apparatus. Determining means for developing the input data into one or more blocks, and image generating means for generating first expanded data and second expanded data based on the first expanded data for each block; Storage means for storing the input data and the first development data, and input from the image processing apparatus, the attribute information is stored in the storage means, and the attribute information is a trial image formation instruction. Input data and comparison means for comparison are provided, and when the determination means determines that the test image formation instruction is given, the image generation means causes the first expansion data and the second expansion data to be compared. Generating the data and outputting the second decompressed data, and storing the first decompressed data in association with the input data and storing the first decompressed data. When the input data input by the means is compared with the input data stored in the storage means and it is detected that the data matches, the first expanded data stored in the storage means is output.

  The present invention as described above is advantageous in that the image processing time in formal printing after performing trial printing can be shortened.

  Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings.

FIG. 2 is an explanatory diagram showing a connection form of the image forming apparatus in the first embodiment.
In FIG. 2, reference numeral 100 denotes a printer as an image forming apparatus, and reference numeral 200 denotes a host computer as an image processing apparatus. The printer 100 and the host computer 200 are communicably connected via an interface cable 300.
The printer 100 forms an image according to input data (received print data) input from the host computer 200 and prints the image on a recording sheet.

FIG. 1 is a block diagram showing the configuration of the image forming apparatus in the first embodiment.
In FIG. 1, a printer 100 as an image forming apparatus includes a host interface 1, a printing mechanism unit 2, a reception buffer 3, a block extraction unit 4, a cache buffer 5, a data comparison unit 6, a PDL conversion unit 7, a draft conversion unit 8, A raster selection unit 9, a print mode determination unit 10, a raster buffer 11, a clock 15, and a draft selection unit 16 are included.

The host interface 1 controls communication with the host computer 200 via the interface cable 300.
The printing mechanism unit 2 controls a mechanism for transporting recording paper and a mechanism for printing characters, graphics, and the like on the recording paper.
The reception buffer 3 is a storage unit such as a memory that stores print data received by the host interface 1 from the host computer 200.

The block extraction unit 4 extracts PDL (Page Description Language) data as page description language data from print data stored in the reception buffer 3 in units of constituent blocks such as characters, rectangles, and lines.
The cache buffer 5 is a storage unit such as a memory that stores PDL data and raster data converted from the PDL data in association with each other. The cache buffer 5 includes a cache tag 12 that stores management information for associating PDL data and raster data, a PDL cache 13 that stores PDL data, and a raster cache 14 that stores raster data.

The data comparison unit 6 is a comparison unit that compares the PDL data extracted by the block extraction unit 4 with the PDL data stored in the PDL cache 13 of the cache buffer 5.
The PDL conversion unit 7 is an image generation unit that converts PDL data into raster data (first development data), and the draft conversion unit 8 prints the raster data to print image data (second development) for trial printing. Data generating means for converting to (data).

The raster selection unit 9 is selection means for selecting one of the raster data stored in the raster cache 14 of the cache buffer 5 and the raster data converted by the PDL conversion unit 7.
The print mode determination unit 10 determines whether the print instruction as attribute information included in the print data received from the host computer 200 is trial printing (trial image formation instruction) or formal printing (formal image formation instruction). It is the determination means to do.

The draft selection unit 16 is a selection unit that selects either raster data converted by the draft conversion unit 8 or raster data before conversion by the draft conversion unit 8 according to the determination of the print mode determination unit 10.
The raster buffer 11 is a storage unit that is initialized before generating print image data for each print unit, and synthesizes and stores the print image data for each constituent block.

The clock 15 is a time measuring means for measuring time.
The printer 100 configured as described above is controlled by a control unit such as a central processing unit (CPU) (not shown) based on a program (software) stored in a storage unit such as a memory or a magnetic disk (not shown).
Next, an outline of the operation of the printer 100 will be described below.

The host interface 1 of the printer 100 outputs print data 401 received from the host computer 200 via the host interface cable 300 and sequentially stores it in the reception buffer 3.
The block extraction unit 4 reads the print data from the reception buffer 3 as reception input data 402, decomposes it into constituent block units such as characters, rectangles, and lines, and inputs the block identifier 403 of the decomposed constituent block to the cache tag 12, The PDL data of the configuration block is input to the PDL cache 13 as the current PDL data 404, and is also input to the data comparison unit 6 and the PDL conversion unit 7.

The cache buffer 5 inputs a hit 405 that is valid when information matching the block identifier 403 is registered in the cache tag 12 to the data comparison unit 6.
Also, if the information matching the block identifier 403 is registered in the cache tag 12, the cache buffer 5 inputs the corresponding PDL data from the PDL cache 13 to the data comparison unit 6 as the saved PDL data 406 and the raster cache 14. The corresponding raster data is input to the raster selection unit 9 as saved raster data 407.

The data comparison unit 6 compares the current PDL data 404 with the stored PDL data 406 indicating that the input hit 405 is valid, indicates a match if they match, and stores a match result 408 indicating a mismatch otherwise. The data is input to the buffer 5, the PDL conversion unit 7, and the raster selection unit 9.
The PDL conversion unit 7 converts the current raster data 409 into current raster data 409 based on the current PDL data 404 when the matching result 408 indicates a mismatch, and inputs the current raster data 409 to the raster cache 14 and the raster selection unit 9.

The raster selection unit 9 selects the saved raster data 407 when the match result 408 indicates a match, selects the current raster data 409 when the match result 408 indicates a mismatch, and draft-converts the selected data as raster data 410. Input to the unit 8 and the draft selection unit 16.
The print mode determination unit 10 reads the received input data 402 from the reception buffer 3 to determine whether the print instruction from the host computer 200 is test print or formal print. If the print mode is test print, the test print mode 411 is validated. To.

The draft conversion unit 8 generates draft raster data 415 converted for trial printing from the input raster data 410 and inputs the draft raster data 415 to the draft selection unit 16.
The draft selection unit 16 outputs the draft raster data 415 input when the input test print mode 411 is valid as the print image data 412, and the raster data 410 input when the test print mode 411 is invalid. The print image data 412 is output and combined with the data in the raster buffer 11.

The printing mechanism unit 2 reads the print image data 413 from the raster buffer 11 and performs printing according to the print image data 413.
The clock 15 inputs the time 414 to the cache tag 12.
In this way, the printer 100 performs test printing or formal printing in accordance with the print instruction received from the host computer 200.

Next, the configuration of the cache buffer 5 will be described with reference to the explanatory diagram showing the configuration of the cache buffer in the first embodiment of FIG.
In FIG. 3, the cache buffer 5 includes the cache tag 12, the PDL cache 13, and the raster cache 14 as described above.
The cache tag 12 includes a plurality of entries (E1, E2,...) Having a block identifier F1, a PDL cache pointer F2, a raster cache pointer F3, a valid flag F4, a deletion enable flag F5, and update information F6 as one entry Ex. , En).

If there is an entry in the cache tag 12 where the block identifier F1 matches the input block identifier 403, the hit 405 becomes valid.
The PDL cache pointer F2 indicates the head position of the PDL data in the PDL cache 13 corresponding to the entry Ex, and the raster cache pointer F3 indicates the head position of the raster data in the raster cache 14 corresponding to the entry Ex.

The valid flag F4 indicates whether or not the entry Ex is a valid value, the deleteable flag F5 indicates whether or not the entry Ex is a deletion candidate, and the update information F6 indicates that the entry Ex has been updated Time 414 is shown.
The operation of the above-described configuration will be described in accordance with steps represented by S in the flowcharts showing the image forming process in the first embodiment shown in FIGS.

The operation of each part in each embodiment described below is controlled by a control means such as a central processing unit (not shown) based on a program (software) stored in a storage means such as a memory or a magnetic disk (not shown). .
First, an operation when the printer 100 is instructed by the host computer 200 for the first trial printing will be described.

S001: The printer 100 receives print data from the host computer 200.
S002: Upon receiving print data, the printer 100 initializes data in the raster buffer 11.
S003: The host interface 1 receives print data from the host computer 200 via the host interface cable 300 and stores it as print data 401 in the reception buffer 3.

S004: The host interface 1 continues to receive print data until reception of all print data from the host computer 200 is completed (S003), and sequentially stores it in the reception buffer 3. When reception of all print data is completed, the process proceeds to S005.
S005: Upon receiving all the print data, the print mode determination unit 10 reads the print data from the reception buffer 3 as reception input data 402, and extracts a print instruction from the host computer 200 included in the reception input data 402.

S006: The print mode determination unit 10 determines whether the print instruction is trial printing or formal printing. If it is determined to be trial printing, the process proceeds to S007. If it is determined to be formal printing, the process proceeds to S008. In this description, since this is the first test print, the process proceeds to S007.
S007: The print mode determination unit 10 validates the test print mode 411.

S009: The block extraction unit 4 extracts one piece of PDL data from the reception input data 402 of the reception buffer 3 in units of constituent blocks. In the present embodiment, the constituent blocks indicate units such as characters, rectangles, and lines, but may be area units divided at equal intervals, or may be text or image units, and the units of the constituent blocks are not limited. .
S010: The block extraction unit 4 outputs a block identifier 403 that identifies the extracted constituent block to the cache tag 12 of the cache buffer 5. The block identifier 403 is a numerical value or a character string that does not overlap among different constituent blocks.

  In this embodiment, for example, as shown in FIG. 7, the character “A” is combined with “F” indicating a 1-byte font, and the ASCII character code “0041” is combined into “F0041” as a block identifier 403. "L" indicating a line segment, "30" indicating an angle, and "90" indicating a line length are combined to form "L3090" as a block identifier 403, a rectangle is "B" indicating a rectangle, and "50" indicating a width. , “25” indicating the height is combined to make “B5025” the block identifier 403.

As described above, in this embodiment, the block identifier 403 is represented by a character string combining a graphic type and an identification code, but is not limited to this expression method.
S011: The block extraction unit 4 outputs the current PDL data 404, which is PDL data of the extracted configuration block, to the PDL cache 13, the data comparison unit 6, and the PDL conversion unit 7 of the cache buffer 5.

S012: The cache tag 12 of the cache buffer 5 validates the hit 405 if the valid flag F4 is valid and there is an entry Ex whose block identifier F1 matches the block identifier 403, and does not validate if it does not exist.
S013: In the first trial printing, since there is no entry Ex that matches the cache tag 12 of the cache buffer 5, the hit 405 is not valid, and the process proceeds to S014 (FIG. 5).

S014: The data comparison unit 6 in which the hit 405 is not valid makes the match determination 408 unmatched regardless of the saved PDL data 406 and the current PDL data 404.
S015: The PDL conversion unit 7 generates current raster data 409 from the current PDL data 404 and outputs it to the raster cache 14 and the raster selection unit 9 of the cache buffer 5.

S016: The raster selection unit 9 outputs the current raster data 409 as the raster data 410 because the match determination 408 does not match.
S017: It is determined whether or not the trial print mode 411 is valid. In this description, the process is shifted to S018 because it is determined to be valid.
S018: The cache tag 12 checks whether or not there is an entry Ex for which the validity flag F4 is invalid. If there is no entry Ex for which the valid flag F4 is invalid, the process proceeds to S019, and if present, the process proceeds to S024.

S019: When there is no entry Ex for which the validity flag F4 is invalid in the cache tag 12, it is next checked whether or not there is an entry Ex for which the deletable flag F5 is valid for the cache tag 12.
S020: When there is an entry Ex for which the deleteable flag F5 is valid, the validity flag F4 of the entry Ex is invalidated.

S021: On the other hand, when there is no entry Ex for which the deleteable flag F5 is valid, the validity flag F4 of the entry Ex having the oldest update information F6 in the cache tag 12 is invalidated.
S022: When the valid flag F4 of a specific entry Ex is invalidated from the deletion possible flag F5 or the update information F6, the PDL data indicated by the PDL cache pointer F2 of the entry Ex is discarded.

S023: The raster data indicated by the raster cache pointer F3 of the entry Ex is discarded.
S024: Valid flag F4 of a specific entry Ex is invalidated, and PDL data and raster data associated with the entry Ex are discarded (S022, S023), or an entry in which the valid flag F4 is invalid in the cache tag 12 When the existence of Ex is confirmed (S018), the block identifier 403 is stored in the block identifier F1 of the entry Ex in which the validity flag F4 of the cache tag 12 is invalid, the validity flag F4 is validated, the deletion enable flag F5 is invalidated, The time 414 is stored in the update information F6 and updated.

S025: The current PDL data 404 is stored in the PDL cache 13, and the head position is stored in the PDL cache pointer F2 of the entry Ex.
S026: Further, the current raster data 409 is stored in the raster cache 14, the head position is stored in the raster cache pointer F3 of the entry Ex, and the process proceeds to S027 (FIG. 6).

  S027: The draft conversion unit 8 converts the raster data 410 into draft raster data 415 for draft printing in which the number of output pixels is reduced. The draft conversion unit 8 converts the draft raster data 415 for draft printing into, for example, thinning out effective pixels (dots), image reduction, invalidation or simplification of a fill, conversion from a color to a monochrome image, or reduction in resolution. Is mentioned.

S028: Since the trial print mode 411 is valid, the draft selection unit 16 selects the draft raster data 415 and outputs it as print image data 412.
S029: The output print image data 412 is combined with the raster data on the raster buffer 11.
S030: As described above, it is confirmed that the processing for one unit block is completed and all unit blocks are extracted. If there is a unit block that has not been extracted, the block extraction unit 4 repeats the block extraction (S009).

S031: When the extraction of all unit blocks is completed, the printing mechanism unit 2 reads the print image data 413 from the raster buffer 11, performs printing, and the printer 100 operates when a first test printing is instructed from the host computer 200. Exit.
Next, an operation when the printer 100 is instructed by the host computer 200 for the second trial printing with a partial correction will be described.

FIG. 8A shows the data for the first test print, and FIG. 8B shows the data for the second test print. As shown in FIG. 8, the data for the second trial printing is described as being different from the data for the first trial printing only in the thickness of the line segment.
First, the operation when the same characters and rectangles as in the first test print are extracted in the second test print will be described.

S001 to S012: Since this is the same as the first trial printing operation described above, the description thereof is omitted.
S013: In the second trial printing, since the cache tag 12 of the cache buffer 5 has an entry Ex that matches the block identifier 403, the hit 405 is valid, and the process proceeds to S033.

S033: The cache buffer 5 outputs the PDL data indicated by the PDL cache pointer F2 of the matched entry Ex to the data comparison unit 6 as saved PDL data 406.
S034: Further, the cache buffer 5 outputs the raster data indicated by the raster cache pointer F3 of the matched entry Ex to the raster selection unit 9 as saved raster data 407.

S035: The data comparison unit 6 compares the current PDL data 404 and the saved PDL data 406, and outputs a match result 408. Then, the process proceeds to S036 (FIG. 6).
S036: Since the PDL data of characters and rectangles is the same, the match result 408 is matched, and the process proceeds to S037.

S 037: When the coincidence result 408 coincides, the raster selecting unit 9 outputs the saved raster data 407 as the raster data 410.
S038: The cache buffer 5 checks whether the test print mode 411 is valid. In the case of this description, since it is valid, the process proceeds to S039.
S039: The cache tag 12 stores the time 414 in the update information F6 of the entry Ex in which the block identifier 403 and the block identifier F1 match.

Subsequent operations are the same as the operations in S027 to S031 in the first test printing, and thus description thereof is omitted.
Next, an operation when a line segment that differs only in thickness from the first test print is extracted in the second test print will be described.
In the present embodiment, as shown in FIG. 7, the block identifier is defined by the angle and the line length, so that the block identifier is the same even if the thickness is different.

S001 to S013, S033 to S035: Since they are similar to the above-described operations, the description thereof is omitted.
S036: The current PDL data 404 and the saved PDL data 406 do not match because of the comparison of the data comparison unit 6 and the matching result 408 does not match, and the process proceeds to S040.

S040: If the match result 408 does not match, the PDL conversion unit 7 generates current raster data 409 from the current PDL data 404 and outputs the current raster data 409 to the raster cache 14 and the raster selection unit 9 of the cache buffer 5.
S041: The raster selection unit 9 outputs current raster data 409 as raster data 410.

S042: The cache buffer 5 confirms whether or not the test print mode 411 is valid, and since it is valid in this description, the process proceeds to S043.
S043: The cache buffer 5 replaces the PDL data specified by the PDL cache pointer F2 of the entry Ex in which the block identifier 403 and the block identifier F1 match in the cache tag 12 with the current PDL data 404.

S044: Further, the cache buffer 5 replaces the raster data designated by the raster cache pointer F3 of the entry Ex in which the block identifier 403 and the block identifier F1 match in the cache tag 12 with the current raster data 409.
S045: Furthermore, the cache buffer 5 stores the time 414 in the update information F6 of the cache tag 12.

Subsequent operations are the same as the operations in S027 to S031 in the first test printing, and thus description thereof is omitted.
Next, an operation when the printer 100 is instructed by the host computer 200 for formal printing that is partly added to the second test printing will be described.
FIG. 9A shows data for the second trial printing, and FIG. 9B shows data for formal printing. As shown in FIG. 9, the data for formal printing will be described on the assumption that only the new character “Z” is added to the data for the second trial printing.

First, the operation when the same characters, rectangles, and lines as those in the second trial printing are extracted in formal printing will be described.
S001 to S005: Since this is the same as the above-described second trial printing operation, the description thereof is omitted.
S006: The print mode determination unit 10 determines whether the print instruction is trial printing or formal printing. If it is determined to be official printing, the process proceeds to S008. In this description, since it is formal printing, the process proceeds to S008.

S008: The print mode determination unit 10 invalidates the test print mode 411.
S009 to S013, S033 to S037: The description is omitted because it is the same as the second trial printing operation.
S038: The cache buffer 5 checks whether the test print mode 411 is valid. In the case of this description, it is invalid, and the process proceeds to S046.

S046: The cache buffer 5 validates the deletion enable flag F5 of the entry Ex in which the block identifier 403 and the block identifier F1 match in the cache tag 12.
S047: Since the trial print mode 411 is invalid, the draft selection unit 16 outputs the raster data 410 as the print image data 412.
Subsequent operations are the same as the operations in S029 to S031 in the second trial printing, and thus the description thereof is omitted.

Next, an operation when a newly added character “Z” is extracted by formal printing will be described.
S001 to S016: Since this is the same as the operation in the first test printing, its description is omitted.
S017: It is determined whether or not the test print mode 411 is valid. In this description, it is determined invalid. Therefore, the process proceeds to S047 without adding data to the cache buffer 5.

S047: Since the trial print mode 411 is invalid, the draft selection unit 16 outputs the raster data 410 as the print image data 412.
Subsequent operations are the same as the operations in S029 to S031 in the second trial printing, and thus the description thereof is omitted.
As described above, the printer 100 stores all the same raster data in the test print in the cache buffer 5 in the test print, and in the test print, the raster data is converted into the raster data for the test print. In formal printing after trial printing, printing is performed using raster data stored in the cache buffer 5, so printing can be performed at high speed.

In addition, since the raster data whose cache hit frequency has decreased is deleted from the cache buffer 5, the cache hit rate can be improved.
In this embodiment, in the case of formal printing, data is not added to the cache buffer 5, but when there is an entry Ex with an invalid valid flag F4, the deletion enable flag F5 is validated and added. You may make it do.

  In this embodiment, the block identifier is compared in the comparison of the PDL data in S013. However, instead of this configuration, the block extraction unit 4 generates a hash value of the PDL data in units of configuration blocks. This hash value may be used as a comparison target. In this case, the generation of the hash value can be performed using, for example, the generation algorithm MD5.

  As described above, in the first embodiment, the same raster data as in formal printing is stored in the cache buffer in trial printing, and the raster data is converted into raster data for trial printing in trial printing. As a result, in formal printing after trial printing, printing is performed using raster data stored in the cache buffer, so that the effect of enabling high-speed printing is obtained.

  In addition, since the raster data whose cache hit frequency has decreased is deleted from the cache buffer, the cache hit rate can be improved.

The configuration of the second embodiment is different from the configuration of the printer as the image forming apparatus in the configuration of the first embodiment. The configuration of the printer 101 will be described.
FIG. 10 is a block diagram showing the configuration of the image forming apparatus in the second embodiment.
In FIG. 10, a printer 101 as an image forming apparatus includes a host interface 1, a printing mechanism unit 2, a reception buffer 3, a block extraction unit 4, a draft conversion unit 8, a printing mode determination unit 10, a raster buffer 11, a clock 15, a draft. A selection unit 16, a primary cache buffer 17, a secondary cache buffer 21, a primary data comparison unit 25, a secondary data comparison unit 26, a PDL conversion unit 27, a cache selection unit 28, and a raster selection unit 29 are configured.

The host interface 1, the print mechanism unit 2, the reception buffer 3, the block extraction unit 4, the draft conversion unit 8, the print mode determination unit 10, the raster buffer 11, the clock 15, and the draft selection unit 16 are the first embodiment described above. Since it is the same as an example, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
The primary cache buffer 17 is a storage unit such as a memory that stores the PDL data and raster data converted from the PDL data in association with each other, and the secondary cache buffer 21 is the raster data converted from the PDL data and the PDL data. Auxiliary storage means such as a memory for storing the information in association with each other.

The primary cache buffer 17 includes a primary cache tag 18 that stores management information for associating PDL data and raster data, a primary PDL cache 19 that stores PDL data, and a primary raster cache 20 that stores raster data. ing.
Similarly, the secondary cache buffer 21 also has a secondary cache tag 22 for storing management information for associating PDL data and raster data, a secondary PDL cache 23 for storing PDL data, and raster data (third development). Data) is stored in a secondary raster cache 24.

The primary data comparison unit 25 is a comparison unit that compares two PDL data, and the secondary data comparison unit 26 is an auxiliary comparison unit that compares the two PDL data.
The PDL conversion unit 27 is an image generation unit that converts PDL data into raster data.
The cache selection unit 28 and the raster selection unit 29 are selection means for selecting one of the two raster data.

The printer 101 configured as described above is controlled by a control unit such as a central processing unit (CPU) (not shown) based on a program (software) stored in a storage unit such as a memory or a magnetic disk (not shown).
Next, an outline of the operation of the printer 101 will be described below.
The host interface 1 of the printer 101 outputs print data 401 received from the host computer 200 via the host interface cable 300 and sequentially stores it in the reception buffer 3.

  The block extraction unit 4 reads the print data from the reception buffer 3 as reception input data 402, decomposes it into constituent block units such as characters, rectangles, and lines, and converts the block identifier 403 of the decomposed constituent block into the primary cache tag 18 and the secondary cache tag 18. The data is input to the cache tag 22, the PDL data of the constituent block is input to the primary PDL cache 19 as current PDL data 404, and is input to the primary data comparison unit 25 and the PDL conversion unit 27.

The primary cache buffer 17 inputs a primary hit 416 that becomes valid when information matching the block identifier 403 is registered in the primary cache tag 18 to the primary data comparison unit 25.
Further, the secondary cache buffer 21 inputs a secondary hit 419 that is valid when information matching the block identifier 403 is registered in the secondary cache tag 22 to the secondary data comparison unit 26.

  If the information matching the block identifier 403 is registered in the primary cache tag 18, the primary cache buffer 17 uses the corresponding PDL data from the primary PDL cache 19 as the primary storage PDL data 417 and the primary data comparison unit 25 and the secondary cache. The data is input to the secondary PDL cache 23 of the buffer 21 and the corresponding raster data from the primary raster cache 20 is input to the cache selection unit 28 and the secondary raster cache 24 of the secondary cache buffer 21 as primary storage raster data 418.

  If the information matching the block identifier 403 is registered in the secondary cache tag 22, the secondary cache buffer 21 converts the corresponding PDL data from the secondary PDL cache 23 as the secondary storage PDL data 420 to the secondary data comparison unit. 26, and corresponding raster data from the secondary raster cache 24 is input to the cache selection unit 28 as secondary storage raster data 421.

When deleting the entry of the primary cache tag 18, the primary cache buffer 17 inputs to the secondary cache buffer 21 deletion information 424 that instructs to delete the entry having the same block identifier 403 of the secondary cache buffer 21.
The primary data comparison unit 25 indicates a match when the input primary hit 416 is valid and the current PDL data 404 and the primary storage PDL data 417 match and indicates a match, otherwise the primary match indicates a mismatch. The result 422 is input to the primary cache buffer 17, the PDL conversion unit 27, the cache selection unit 28, and the raster selection unit 29.

The secondary data comparison unit 26 indicates a match if the input secondary hit 419 is valid and the current PDL data 404 and the secondary storage PDL data 420 match and indicates a match, otherwise it indicates a mismatch. The secondary match result 423 shown is input to the PDL conversion unit 27 and the raster selection unit 29.
When the primary match result 422 indicates a mismatch, the PDL conversion unit 27 converts the current raster data 425 into current raster data 425 based on the current PDL data 404 and inputs the current raster data 425 to the primary raster cache 20 and the raster selection unit 29.

The cache selection unit 28 selects the primary storage raster data 418 when the primary match result 422 indicates a match, selects the secondary storage raster data 421 when the primary match result 422 indicates a mismatch, and stores the selected data. The data is input as raster data 426 to the raster conversion unit 29.
The raster selection unit 29 selects the saved raster data 426 when either the primary match result 422 or the secondary match result 423 indicates a match, and when both the primary match result 422 and the secondary match result 423 indicate a mismatch. The current raster data 425 is selected, and the selected data is input as the raster data 410 to the draft conversion unit 8 and the draft selection unit 16.

The print mode determination unit 10 reads the received input data 402 from the reception buffer 3 to determine whether the print instruction from the host computer 200 is test print or formal print. If the print mode is test print, the test print mode 411 is validated. To.
The draft conversion unit 8 generates draft raster data 415 converted for trial printing from the input raster data 410 and inputs the draft raster data 415 to the draft selection unit 16.

The draft selection unit 16 outputs the draft raster data 415 input when the input test print mode 411 is valid as the print image data 412, and the raster data 410 input when the test print mode 411 is invalid. The print image data 412 is output and combined with the data in the raster buffer 11.
The printing mechanism unit 2 reads the print image data 413 from the raster buffer 11 and performs printing according to the print image data 413.

The clock 15 inputs the time 414 to the primary cache tag 18.
In this way, the printer 101 performs trial printing or formal printing in accordance with the print instruction received from the host computer 200.
Next, the configuration of the primary cache buffer 17 and the secondary cache buffer 21 will be described. Since the configuration of the primary cache buffer 17 is the same as that of the cache buffer 5 of the first embodiment, its description is omitted.

FIG. 11 is an explanatory diagram showing the configuration of the secondary cache buffer in the second embodiment.
In FIG. 11, the secondary cache buffer 21 is composed of the secondary cache tag 22, the secondary PDL cache 23, and the secondary raster cache 24 as described above.
The secondary cache tag 22 includes a plurality of entries (E1, E2,..., En) having a block identifier F7, a PDL cache pointer F8, a raster cache pointer F9, and a valid flag F10 as one entry Ex.

If there is an entry in the secondary cache tag 22 where the block identifier F7 matches the input block identifier 403, the secondary hit 419 becomes valid.
The relationship between the entry of the primary cache tag 18 and the entry of the secondary cache tag 22 is the same as the block identifier 403 in both the primary cache tag 18 and the secondary cache tag 22, or the block identifier only in the primary cache tag 18 There are three types: the same as 403, or the same as the block identifier 403 in both the primary cache tag 18 and the secondary cache tag 22.

Therefore, if the primary hit 416 output by the primary cache buffer 17 is invalid, the secondary hit 419 is necessarily invalidated.
The PDL cache pointer F8 indicates the start position of the PDL data in the secondary PDL cache 23 corresponding to the entry Ex, and the raster cache pointer F9 indicates the start position of the raster data in the secondary raster cache 24 corresponding to the entry Ex. Yes.

The valid flag F10 indicates whether or not the entry Ex is a valid value.
The operation of the above-described configuration will be described in accordance with steps represented by S in the flowcharts showing the image forming process in the second embodiment shown in FIGS.
First, an operation when the printer 101 is instructed by the host computer 200 for the first trial printing will be described.

S101 to S109: Since they are the same as S001 to S009 in FIG. 4 of the first embodiment, description thereof is omitted.
S110: The block extraction unit 4 outputs a block identifier 403 that identifies the extracted constituent block to the primary cache tag 18 of the primary cache buffer 17. Note that the block identifier 403 is the same as in the first embodiment, and a description thereof will be omitted.

S111: The block extraction unit 4 converts the current PDL data 404, which is the PDL data of the extracted configuration block, into the primary PDL cache 19, the primary data comparison unit 25, the secondary data comparison unit 26, and the PDL conversion unit 27 of the primary cache buffer 17. Output to.
S112: The primary cache tag 18 of the primary cache buffer 17 validates the primary hit 416 if the valid flag F4 is valid and the entry Ex whose block identifier F1 matches the block identifier 403 is present, and valid otherwise. do not do.

S113: In the first test print, since there is no entry Ex that matches the primary cache tag 18 of the primary cache buffer 17, the primary hit 416 is not valid, and the process proceeds to S114 (FIG. 13).
S114: The primary data comparison unit 25 in which the primary hit 416 is not valid makes the primary match result 422 inconsistent regardless of the primary storage PDL data 417 and the current PDL data 404.

If the primary hit 416 is invalid, the secondary hit 419 is also invalidated, and the secondary data comparison unit 26 makes the secondary match result 423 unmatched.
S115: Since both the primary match result 422 and the secondary match result 423 do not match, the PDL conversion unit 27 generates the current raster data 425 from the current PDL data 404, and the primary raster cache 20 and the raster of the primary cache buffer 17 The data is output to the selection unit 29.

S 116: The raster selection unit 29 outputs the current raster data 425 as the raster data 410 because both the primary match result 422 and the secondary match result 423 do not match.
S117: It is determined whether or not the test print mode 411 is valid. In this description, since it is determined to be valid, the process proceeds to S118.

S118: The primary cache tag 18 checks whether or not there is an entry Ex for which the valid flag F4 is invalid. If there is no entry Ex for which the valid flag F4 is invalid, the process proceeds to S119, and if present, the process proceeds to S129.
S119: When there is no entry Ex for which the valid flag F4 is invalid in the primary cache tag 18, it is next checked whether or not there is an entry Ex for which the deletable flag F5 is valid in the primary cache tag 18.

S120: When there is an entry Ex for which the deleteable flag F5 is valid, the validity flag F4 of the entry Ex is invalidated.
S121: On the other hand, if there is no entry Ex for which the deleteable flag F5 is valid, the validity flag F4 of the entry Ex having the oldest update information F6 in the primary cache tag 18 is invalidated.

S122: When the validity flag F4 of a specific entry Ex is invalidated from the deletion enable flag F5 or the update information F6, the PDL data indicated by the PDL cache pointer F2 of the entry Ex is discarded.
S123: Also, the raster data indicated by the raster cache pointer F3 of the entry Ex is discarded.

S124: The primary cache tag 18 outputs the deletion information 424 of the entry Ex in which the validity flag F4 is invalidated to the secondary cache tag 22.
S125: The secondary cache tag 22 checks whether or not there is an entry Ex that matches the deletion information 424. If there is no matching entry Ex, the process proceeds to S129, and if present, the process proceeds to S126.

S126: If there is an entry Ex that matches the deletion information 424, the secondary cache tag 22 changes the validity flag F10 of the matched entry Ex to invalid.
S127: When the valid flag F10 is invalidated, the PDL data indicated by the PDL cache pointer F8 of the entry Ex is discarded.
S128: Also, the raster data indicated by the raster cache pointer F9 of the entry Ex is discarded.

  S129: The validity flag F4 of the specific entry Ex of the primary cache tag 18 is invalidated, and the PDL data and raster data associated with the entry Ex are discarded (S127, S128), or the validity flag of the primary cache tag 18 When the existence of the entry Ex in which the validity flag F4 is invalid when the existence of the entry Ex in which F4 is invalid is confirmed (S118), the block identifier F1 of the entry Ex in which the validity flag F4 of the primary cache tag 18 is invalid. The block identifier 403 is stored, the validity flag F4 is validated, the deletion enable flag F5 is invalidated, and the time 414 is stored in the update information F6.

S130: The current PDL data 404 is stored in the primary PDL cache 19, and the head position is stored in the PDL cache pointer F2 of the entry Ex.
S131: Also, the current raster data 425 is stored in the primary raster cache 20, the head position is stored in the raster cache pointer F3 of the entry Ex, and the process proceeds to S132 (FIG. 15).

S132 to S136: Since they are the same as S027 to S031 in FIG. 6 of the first embodiment, description thereof is omitted.
As described above, the printer 101 ends the operation when the first trial printing is instructed from the host computer 200.
Next, an operation when the printer 101 is instructed by the host computer 200 for the second trial printing that is partially corrected will be described.

Similar to FIG. 8 of the first embodiment, the data for the second test print is described as being different from the data for the first test print only in the line segment thickness.
First, an operation in the case where characters, rectangles, and the like that have not changed from the first test print are extracted in the second test print will be described.
S101 to S112: Since this is the same as the first trial printing operation described above, the description thereof is omitted.

S113: In the second trial printing, since the primary cache tag 18 of the primary cache buffer 17 has an entry Ex that matches the block identifier 403, the primary hit 416 is valid, and the process proceeds to S138.
S138: The primary cache buffer 17 outputs the PDL data indicated by the PDL cache pointer F2 of the matched entry Ex as the primary storage PDL data 417 to the primary data comparison unit 25 and the secondary PDL cache 23.

S139: Further, the primary cache buffer 17 outputs the raster data indicated by the raster cache pointer F3 of the matched entry Ex as the primary storage raster data 418 to the cache selection unit 28 and the secondary raster cache 24.
S140: The primary data comparison unit 25 compares the current PDL data 404 with the primary storage PDL data 417, and outputs a primary match result 422. Then, the process proceeds to S141 in FIG.

S141: Since the PDL data of characters and rectangles is the same, the primary match result 422 is matched, and the process proceeds to S142.
S142: If the primary match result 422 matches, the cache selection unit 28 outputs the primary saved raster data 418 as saved raster data 426.
S143: The raster selection unit 29 outputs the saved raster data 426 as the raster data 410.

S144: The primary cache buffer 17 checks whether or not the test print mode 411 is valid. In the case of this description, since it is valid, the process proceeds to S145.
S145: The primary cache tag 18 stores the time 414 in the update information F6 of the entry Ex in which the block identifier 403 and the block identifier F1 match.
Subsequent operations are the same as the operations in S027 to S031 in the first test printing, and thus description thereof is omitted.

Next, an operation when a line segment that differs only in thickness from the first test print is extracted in the second test print will be described.
As in the first embodiment, as shown in FIG. 7, the block identifier is defined by the angle and the line length, so that the block identifier is the same even if the thickness is different.
S101 to S113, S138 to S140: Since they are similar to the above-described operation, the description thereof is omitted.

S141: Due to the comparison of the primary data comparison unit 25, the current PDL data 404 and the primary storage PDL data 417 do not match because the line segments are different, the primary match result 422 does not match, and the process proceeds to S146.
S146: If the primary match result 422 does not match, the secondary cache buffer 21 validates the secondary hit 419 if the valid flag F10 is valid and there is an entry Ex having the block identifier F7 that matches the block identifier 403.

S147: Since the entry Ex that matches the block identifier 403 exists only in the primary cache buffer 17 by the first trial printing, the secondary hit 419 becomes invalid, and the process proceeds to S153.
S153: Since both the primary match result 422 and the secondary match result 423 do not match, the PDL conversion unit 27 generates the current raster data 425 from the current PDL data 404, and the primary raster cache 20 and the raster of the primary cache buffer 17 The data is output to the selection unit 29.

S154: The raster selection unit 29 outputs the current raster data 425 as the raster data 410 because both the primary match result 422 and the secondary match result 423 do not match.
S155: The secondary cache buffer 21 confirms whether or not the test print mode 411 is valid, and since it is valid in this description, the process proceeds to S156 in FIG.

S156: The secondary cache buffer 21 stores the block identifier 403 in the block identifier F7 of the entry Ex in which the validity flag F10 of the secondary cache tag 22 is invalid, and validates the validity flag F10.
S157: The primary storage PDL data 417 is stored in the secondary PDL cache 23, and the head position is stored in the PDL cache pointer F8 of the entry Ex.

S158: The primary storage raster data 418 is stored in the secondary raster cache 24, and the head position is stored in the raster cache pointer F9 of the entry Ex.
S159: The primary cache buffer 17 replaces the PDL data specified by the PDL cache pointer F2 of the entry Ex in which the block identifier 403 and the block identifier F1 match with the primary cache tag 18 with the current PDL data 404.

S160: The primary cache buffer 17 replaces the raster data specified by the raster cache pointer F3 of the entry Ex in which the block identifier 403 and the block identifier F1 match with the primary cache tag 18 with the current raster data 409.
S161: Further, the primary cache buffer 17 stores the time 414 in the update information F6 of the primary cache tag 18.

Subsequent operations are the same as the operations in S132 to S136 in the first test printing, and thus the description thereof is omitted.
Next, a description will be given of an operation in the case where the formal printing is instructed by the host computer 200 in which a part of the printer 101 is added to the second trial printing and a part of the printer 101 is returned to the state of the first trial printing. To do.

FIG. 16A shows the data for the first test print, FIG. 16B shows the data for the second test print, and FIG. 16C shows the data for the official print. As shown in FIG. 16, the formal print data is described on the assumption that a new character “Z” is added to the second trial print data, and the thickness of the line segment is the same as that of the first trial print. To do.
S101 to S109: Since it is the same as S001 to S009 of the formal printing operation in FIG. 4 of the first embodiment, description thereof is omitted.

S110 to S113, S138 to 143: Since this is the same as the above-described second test printing operation, the description thereof is omitted.
S144: The primary cache buffer 17 checks whether or not the test print mode 411 is valid. In the case of this description, since it is invalid, the process proceeds to S162.
S162: The primary cache buffer 17 enables the deleteable flag F5 of the entry Ex in which the block identifier 403 and the block identifier F1 match with the primary cache tag 18, and proceeds to S163 in FIG.

S163: The draft selection unit 16 outputs the raster data 410 as the print image data 412 because the test print mode 411 is invalid.
Subsequent operations are the same as the operations in S134 to S136 in the second trial printing, and thus description thereof is omitted.
Next, an operation when a newly added character “Z” is extracted by formal printing will be described.

S101 to S116: Since this is the same as the operation in the first test printing, its description is omitted.
S117: It is determined whether or not the test print mode 411 is valid. In this description, it is determined invalid. Therefore, the process proceeds to S163 in FIG. 15 without adding data to the primary cache buffer 17.

S163: The draft selection unit 16 outputs the raster data 410 as the print image data 412 because the test print mode 411 is invalid.
In this embodiment, in the case of formal printing, data is not added to the primary cache buffer 17, but when there is an entry Ex in which the validity flag F4 is invalid, the deletion enable flag F5 is activated. You may make it add.

Next, the operation when the same line segment as that in the first test printing is extracted in the formal printing will be described.
S101 to S113, S138 to S141: Since the operations are the same as those in the case where characters, rectangles and the like that are not changed are extracted in the second test printing described above, the description thereof is omitted.
S146: As a result of the comparison by the primary data comparison unit 25, the current PDL data 404 and the primary storage PDL data 417 do not match because the line segments are different in thickness, and the primary match result 422 does not match.

The secondary cache buffer 21 validates the secondary hit 419 if the valid flag F10 is valid and there is an entry Ex having the block identifier F7 that matches the block identifier 403.
S147: Since the PDL data and raster data related to the line segment of the first test print are stored in the secondary cache buffer 21 by the second test print, the secondary hit 419 becomes valid, and the process proceeds to S148. To do.

S148: The secondary cache buffer 21 outputs the PDL data indicated by the PDL cache pointer F8 of the entry Ex having the block identifier F7 that matches the block identifier 403 as the secondary storage PDL data 420.
S149: Further, the secondary cache buffer 21 outputs the raster data indicated by the raster cache pointer F9 of the matched entry Ex as the secondary storage raster data 421.

S150: The secondary data comparison unit 26 compares the current PDL data 404 with the secondary storage PDL data 420, and outputs a secondary match result 423. Here, since the first test print line segment and the formal print line segment are the same, the secondary match result 423 is the same.
S151: The secondary match result 423 is matched, and the process proceeds to S152.
S152: Since the primary match result 422 does not match, the cache selection unit 28 outputs the secondary saved raster data 421 as the saved raster data 426, and the process proceeds to S143.

S143: The raster selection unit 29 outputs the saved raster data 426 as the raster data 410.
Subsequent operations are the same as S144, S162, S163, and S134 to S136 described above, and a description thereof will be omitted.
As described above, the printer 101 stores the past PDL data and raster data based on the PDL data in the secondary cache buffer when the PDL data is different in a plurality of test prints. Even if it is temporarily changed and then restored, it is printed at high speed because formal printing after trial printing uses raster data stored in the secondary cache buffer. Will be able to.

In addition, by using a plurality of storage numbers per block identifier, when there is an approximate constituent block with the same block identifier, the problem that the storage of the other constituent block is lost due to saving in one constituent block is solved. be able to.
In this embodiment, the secondary cache buffer 21 is added to the primary cache buffer 17. However, a tertiary cache buffer is provided for the secondary cache buffer 21, and steps S146 to S151 in FIG. By nesting the processing, it is possible to store PDL data and raster data by a multilevel cache.

In the present embodiment, the block identifiers are compared in the comparison of the PDL data in S113. Instead of this configuration, the block extraction unit 4 generates a hash value of the PDL data in units of the configuration blocks. As in the first embodiment, this hash value may be used as a comparison target.
As described above, in the second embodiment, in addition to the effects of the first embodiment, when the PDL data is different in a plurality of test prints, the second cache buffer is based on the past PDL data and the PDL data. By saving raster data, even if the block of print data is temporarily changed and then restored, it is saved in the secondary cache buffer for official printing after trial printing. Since printing is performed using the raster data, the effect of being able to print at high speed is obtained.

In addition, by using a plurality of storage numbers per block identifier, when there is an approximate constituent block with the same block identifier, the problem that the storage of the other constituent block is lost due to the storage of one constituent block is solved. The effect that it can be obtained.
In the first embodiment and the second embodiment, the present invention has been described as being applied to a printer as an image forming apparatus. However, the present invention is not limited to this and is applied to an image copying apparatus and an image recording apparatus. Is also possible.

1 is a block diagram illustrating a configuration of an image forming apparatus according to a first embodiment. Explanatory drawing which shows the connection form of the image forming apparatus in 1st Example Explanatory drawing which shows the structure of the cache buffer in 1st Example. Flowchart (1/3) showing image forming process in first embodiment Flowchart (2/3) showing image forming process in first embodiment Flowchart (3/3) showing image forming process in first embodiment Explanatory drawing of the block identifier in 1st Example Explanatory drawing of the first and second test printing results in the first embodiment Explanatory drawing of the second trial printing result and formal printing result in the first embodiment FIG. 2 is a block diagram illustrating a configuration of an image forming apparatus according to a second embodiment. Explanatory drawing which shows the structure of the secondary cache buffer in 2nd Example. Flowchart (1/4) showing image forming process in second embodiment. Flowchart (2/4) showing image forming process in the second embodiment Flowchart (3/4) showing image forming process in the second embodiment. Flowchart (4/4) showing image forming process in second embodiment. Explanatory drawing of the first and second trial printing results and the formal printing results in the second embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Host interface 2 Printing mechanism part 3 Reception buffer 4 Block extraction part 5 Cache buffer 6 Data comparison part 7, 27 PDL conversion part 8 Draft conversion part 9, 29 Raster selection part 10 Print mode determination part 11 Raster buffer 12 Cache tag 13 PDL Cache 14 Raster cache 16 Draft selector 17 Primary cache buffer 18 Primary cache tag 19 Primary PDL cache 20 Primary raster cache 21 Secondary cache buffer 22 Secondary cache tag 23 Secondary PDL cache 24 Secondary raster cache 25 Primary data comparator 26 Secondary data comparison unit 28 Cache selection unit 100, 101 Printer 200 Host computer 300 Interface cable

Claims (10)

In an image forming apparatus that forms an image based on input data input from an image processing apparatus,
Determining means for determining whether the attribute information of the input data is a test image formation instruction or a formal image formation instruction;
Image generating means for expanding the input data into one or more blocks, and generating first expanded data and second expanded data based on the first expanded data for each block;
Storage means for storing the input data and the first expanded data;
Input from the image processing apparatus, the attribute information is stored in the storage means, the input data of the formal image formation instruction, the attribute information is provided with the input data of the trial image formation instruction, and a comparison means for comparing,
When the determination means determines that it is a test image formation instruction, the image generation means generates first expansion data and second expansion data and outputs the second expansion data, and the storage means outputs the input data. Storing the first development data in association with
When the determination means determines that it is a formal image formation instruction, the comparison means compares the input data input with the input data stored in the storage means and detects that they match, and stores them in the storage means. An image forming apparatus that outputs the first development data. The image forming apparatus according to claim 1.
When the determination unit determines that it is a formal image formation instruction, the comparison unit compares the input data input to the input data stored in the storage unit and detects that they do not match. Generating image development data and outputting the first development data. The image forming apparatus according to claim 1 or 2,
When the determination means determines that it is a formal image formation instruction, if there is no input data stored in the storage means, the image generation means generates first development data from the input data and An image forming apparatus that outputs one development data. The image forming apparatus according to claim 1, 2 or 3,
The storage means has information indicating whether the stored first decompressed data is valid / invalid and deleteability;
When the determination means determines that it is a test image formation instruction, the storage means stores the first development data in association with the input data and the block and stores information indicating validity;
An image forming apparatus characterized in that, when the determination unit determines that it is a formal image formation instruction, if there is input data stored in the storage unit, the storage unit stores information indicating that deletion is possible. The image forming apparatus according to claim 4.
Equipped with a timekeeping means to keep time
The image forming apparatus, wherein the storage unit stores a time at which first development data is stored in association with the input data and the block. The image forming apparatus according to any one of claims 1 to 5,
The first development data is raster data,
2. The image forming apparatus according to claim 1, wherein the second development data is data obtained by reducing the number of pixels output from the first development data. The image forming apparatus according to claim 6.
The second expanded data is converted from the first expanded data by thinning out effective pixels, reduced image data, invalidated data, simplified data, and color image into a monochrome image. An image forming apparatus characterized in that any one of these data and data with reduced resolution or a combination thereof is used. The image forming apparatus according to any one of claims 1 to 7,
The image forming apparatus, wherein the block is divided into one of a character, a line segment, a rectangle, an image and a region, or a combination thereof. The image forming apparatus according to any one of claims 1 to 8,
Auxiliary storage means for storing the input data and the first decompressed data stored in the storage means;
An auxiliary comparison unit that is input from the image processing apparatus, the attribute information is stored in the auxiliary storage unit as input data of the formal image formation instruction, and the attribute information is compared with the input data of the test image formation instruction;
If the determination unit determines that the instruction is a test image formation instruction and the comparison unit compares the input data input to the input data stored in the storage unit and detects that they do not match, the determination unit stores the input data. Storing the input data and the first development data in the auxiliary storage means,
When the determination means determines that it is a formal image formation instruction, and the auxiliary comparison means compares the input data input with the input data stored in the auxiliary storage means and detects that they match, the auxiliary storage means An image forming apparatus characterized in that the first development data stored in is output. The image forming apparatus according to claim 9.
The image forming apparatus according to claim 1, wherein the auxiliary comparison unit performs comparison when the comparison unit does not match.

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