JP6627230B2 - Image forming apparatus, image forming system, and image forming control program - Google Patents

Description

  The present invention relates to an image forming apparatus, an image forming system, and an image forming control program. In particular, the present invention relates to a technique for efficiently executing image formation using long paper such as continuous paper or roll paper.

2. Description of the Related Art In an image forming apparatus such as a printer that forms an image based on image data, an image is generally formed on a sheet called a cut sheet cut to a predetermined fixed size such as A4 or B4.
On the other hand, in this type of image forming apparatus, it is also possible to form an image on continuous paper, called continuous paper or roll paper, having a longer paper length in the transport direction than paper of a standard size. In addition, such a long sheet is often used for the purpose of repeatedly printing a label in a sticker format such as an address, a serial number, and a product display.

In the image forming apparatus, most of the hardware such as an ASIC for controlling a memory and a buffer needs to change a hardware register setting and a look-up table by software when switching an image page.
During such hardware setting change, hardware such as ASIC cannot be operated. For this reason, a period in which an image cannot be output occurs. Here, in the case of an image forming apparatus using a cut sheet, a sheet interval exists between the cut sheet and the next cut sheet. Therefore, there is no problem if the software processing time, that is, the image output suspension period is within the inter-sheet time between the sheet and the next sheet.

  On the other hand, in the case of printing on long paper, there is no paper interval, and paper always exists in the image forming apparatus. The paper is conveyed at a constant linear speed. Therefore, the above-described software processing time cannot form an image on a sheet, and appears as a margin (image interval). Ultimately, the margins (image intervals) become waste, so it is required to minimize them.

  Here, the image interval can be reduced to zero if software processing for hardware such as an ASIC is unnecessary, or if hardware that can reserve the next page setting during output of the previous page is used. However, such hardware requires a great deal of cost because the hardware needs to be changed.

Some actual products have reduced the image interval to about 1 mm by reducing the processing time of software to solve this problem.
However, there has been no apparatus capable of realizing further reduction of the image interval on long paper with the conventional configuration without preparing dedicated hardware.

Further, when a look-up table having a large data size such as a gamma conversion table is rewritten, the processing time may be extended.
Various proposals have been made in the following patent documents and the like for control between images in an image forming apparatus using long paper.

JP 2006-116975 A

  In the above Patent Document 1, in an apparatus (inkjet printer) having a configuration that requires pre-output start processing and post-output completion processing, when outputting between images, pre-processing is performed on the first page and post-processing is performed on the last page. It describes that when an intermediate page crosses a head boundary at the time of page switching, one image connecting the previous and next pages is transmitted to the head.

However, this technique is to eliminate the space between the images of the process factors, but not to the space between the images generated by the software processing at the time of the page switching.
In other words, even if it is necessary to change the hardware register setting or look-up table by software at the time of image page switching, the conventional configuration can be used without the need for dedicated hardware. It is an object of the present invention to provide an image forming apparatus, an image forming system, and an image forming control program that can further reduce the image interval on a shaku sheet.

That is, in order to solve the above-described problem, an image forming apparatus, an image forming system, and an image forming control program in which one aspect of the present invention is reflected are configured as follows.
(1) An image forming apparatus for forming an image on continuous paper based on image data, comprising: a page memory for storing image data; a buffer for temporarily storing image data transferred from the page memory; And an image forming unit configured to execute image formation based on image data read from the printer.When transferring image data from the page memory to the buffer for each page, the transfer of each page is performed. In the meantime, transfer is performed during a page preparation process for register setting in the hardware controlling the page memory and the buffer for page switching and software preparation for changing the hardware setting of the look-up table. When reading image data from the buffer to the image forming unit, the first page With delaying the read start timing, so as to reduce than the page preparation processing time required time between the reading of each page to the image forming section from the page memory from the buffer to the page preparation process to the buffer.

(2) In the above (1), when image data is read from the buffer to the image forming unit, the reading of each page is set to be continuous.
(3) In the above (1) and (2), the timing to start reading the first page of the image data from the buffer to the image forming unit with a delay is determined according to the number of pages to be image-formed. Is determined by the accumulation of the page preparation processing time between each page.

  (4) In the above (1) to (3), the timing to start reading the first page of the image data from the buffer to the image forming unit is delayed according to the number of pages to be image-formed. If the capacity of the image data required by determining the accumulation of the page preparation processing time between each page and delaying the read start timing exceeds the storage capacity of the buffer, the image formation is stopped. Alternatively, the user selects either the reduction of the number of pages for image formation.

(5) In the above (1) to (4), when a reference page preparation processing time serving as a reference is defined as the page preparation processing time, the time between transfer of each page from the page memory to the buffer is set. If the time does not match the reference page preparation processing time, the time between transfer of each page from the page memory to the buffer is made to match the reference page preparation processing time.

  (6) In the above (1) to (4), an image processing unit for performing image processing is provided, and the image processing unit performs main scanning on a plurality of images having different sizes in the sub-scanning direction in the image data. In the case where a plurality of images having different sizes in the sub-scanning direction are repeatedly formed in the sub-scanning direction, and the plurality of images are arranged in the sub-scanning direction, the images are not spaced in the sub-scanning direction. Generate data.

(7) In the above (1) to (6), the image forming unit receives the image data from the buffer and forms an image based on the image data while conveying the continuous paper .

According to the image forming apparatus, the image forming system, and the image forming control program in which one aspect of the present invention is reflected, the following effects can be obtained.
(1) When image data is transferred from the page memory to the buffer page by page when forming an image on continuous paper based on the image data , the page is switched for page switching between each page transfer. During the page preparation processing for register setting in the hardware controlling the memory and the buffer and the software preparation for changing the hardware setting of the look-up table, the transfer is temporarily stopped and the buffer is transferred to the image forming unit. When reading image data, the read start timing of the first page is delayed, and the time between reading of each page from the buffer to the image forming unit is set to the page preparation processing time required for the page preparation processing from the page memory to the buffer. To reduce it.

In other words, when it is necessary to change the hardware register setting or look-up table by software at the time of image page switching, the conventional configuration can be continuously used without preparing dedicated hardware. Further reduction of the image interval on paper can be realized.

(2) In the above (1), when reading image data from the buffer to the image forming unit, the reading of each page is set to be continuous. In other words, when it is necessary to change the hardware register setting or look-up table by software at the time of image page switching, the conventional configuration can be continuously used without preparing dedicated hardware. It is possible to make the images close to each other by setting the image interval on paper to zero.

  (3) In the above (1) and (2), the timing of delaying the reading start timing of the first page of image data from the buffer to the image forming unit is delayed according to the number of pages on which the image is formed. It is determined by the accumulation of the page preparation processing time between pages.

Thus, the data to be stored in the buffer is determined without waste while the image interval is reduced, and the delay of the start of image formation is controlled to a minimum.
(4) In the above (1) to (3), the timing for delaying the reading start timing of the first page of the image data from the buffer to the image forming unit is delayed according to the number of pages on which the image is formed. If the capacity of the image data required by determining the accumulation of the page preparation processing time between pages and delaying the read start timing exceeds the storage capacity of the buffer, the image formation is stopped or the number of pages to be formed is reduced. Choose one of the reductions. Thus, the data to be stored in the buffer is determined without waste according to the storage capacity of the buffer while the image interval is reduced, and the delay of the start of image formation is appropriately controlled. In addition, control does not fail.

(5) In the above (1) to (4), when a reference page preparation processing time serving as a reference is determined as the page preparation processing time, the time between transfer of each page from the page memory to the buffer is set as the reference time. If the time does not coincide with the page preparation processing time, the time between transfer of each page from the page memory to the buffer is made to coincide with the reference page preparation processing time.

In other words, when it is necessary to change the hardware register setting or look-up table by software at the time of image page switching, the conventional configuration can be continuously used without preparing dedicated hardware. The image interval on paper can be reduced to a certain state including zero.

  (6) In the above (1) to (4), a plurality of images having different sizes in the sub-scanning direction are arranged in the main scanning direction. When image formation is repeated, image data is generated without leaving an interval in the sub-scanning direction of each image. This makes it possible to form an image efficiently without generating blanks in the sub-scanning direction of the paper and generating no waste.

(7) In the above (1) to (6), the image forming unit that has received the image data from the buffer forms an image based on the image data while conveying the continuous paper .
That is, in a configuration in which image formation is performed while transporting continuous paper at a constant speed without stopping, it is necessary to change hardware register settings and look-up tables by software when switching pages of an image. In some cases, it is possible to further reduce the image interval on continuous paper without using dedicated hardware and with the conventional configuration.

FIG. 1 is a configuration diagram illustrating a configuration of an image forming system according to an embodiment of the present invention. FIG. 1 is a configuration diagram illustrating a configuration of an image forming system according to an embodiment of the present invention. FIG. 1 is a configuration diagram illustrating a configuration of an image forming system according to an embodiment of the present invention. FIG. 4 is an explanatory diagram schematically showing a state of image formation. FIG. 4 is an explanatory diagram schematically showing a state of image formation. FIG. 3 is an explanatory diagram schematically illustrating a state of image formation according to the embodiment of the present invention. FIG. 3 is an explanatory diagram schematically illustrating a state of image formation according to the embodiment of the present invention. 5 is a flowchart illustrating an operation of the exemplary embodiment of the present invention. 5 is a flowchart illustrating an operation of the exemplary embodiment of the present invention. FIG. 3 is an explanatory diagram schematically illustrating a state of image formation according to the embodiment of the present invention.

Hereinafter, with reference to the drawings, an embodiment in which an image forming apparatus, an image forming system, and an image forming control program efficiently execute image forming using a roll of long paper will be described in detail.
The operation of the image forming apparatus 100 or the image forming system is an image forming control method. The control of the control unit 101 that controls the operations of the image forming apparatus 100 and the image forming system 1 is performed based on an image forming control program.

[Configuration of Image Forming System]
Here, a configuration example of the image forming system 1 in which the sheet feeding device 50, the image forming device 100, and the sheet discharging device 200 are set will be described in detail with reference to FIGS.
Note that the image forming system 1 in which the sheet feeding device 50, the image forming device 100, and the sheet discharging device 200 are set is an example of an image forming system, and another post-processing device (not shown) is connected thereto. Is also good.

  The paper feeding device 50 includes a control unit 51, a communication unit 52, a paper feeding unit 55, a paper feeding adjusting unit 56, a transporting unit 58, and a sensor 59. The control unit 51 controls each unit in the sheet feeding device 50 based on an instruction from the control unit 101 described later. The communication unit 52 communicates with another apparatus such as the image forming apparatus 100 that is set. The paper feed unit 55 feeds long paper from the paper roll toward the image forming apparatus 100. The paper feed adjustment unit 56 absorbs fluctuations in the transport speed while adjusting the tension and looseness of the paper fed from the paper feed unit 55. The transport section 58 transports the paper inside the paper feeding device 50. The sensor 59 detects various states regarding paper conveyance.

  The image forming apparatus 100 includes a control unit 101, a communication unit 102, a print controller 103, a storage unit 104, an operation display unit 105, an image forming / conveying unit 107, a sensor 109, a document reading unit 110, a RIP The processing unit 120 includes a processing unit 120, a data storage unit 130, an image processing unit 140, an image forming unit 150, and a fixing unit 160.

  The control unit 101 controls each unit in the image forming apparatus 100. The communication unit 102 communicates with another set device (such as an external device, the sheet feeding device 50, or the sheet discharging device 200). The print controller 103 receives job data described in a page description language from an external device and stores the job data as necessary. The storage unit 104 stores various settings. The operation display unit 105 accepts an operation input by a user and displays the status of the image forming apparatus 100. The image forming / conveying unit 107 conveys a sheet in the apparatus. The sensor 109 detects various states regarding image formation and paper conveyance. The document reading unit 110 reads a document image using an image sensor and generates document image data.

  The RIP processing unit 120 performs RIP processing on the job data before the RIP processing described in the page description language received by the print controller, and converts the job data into image data in a bitmap format capable of forming an image. The data storage unit 130 stores image data and various data when forming an image. The data storage unit 130 includes a read image memory that receives image data and a print image memory that outputs the received image data for image formation. The image processing unit 140 performs various image processing necessary for image formation. The image forming unit 150 forms an image on paper based on an image forming command and image data stored in a print image memory in the data storage unit 130. The fixing unit 160 stabilizes an image formed by the toner formed on the sheet with heat and pressure.

  The paper discharging device 200 includes a control unit 201, a communication unit 202, a cutting unit 203, a paper discharging adjusting unit 205, a conveying unit 206, a paper discharging unit 208, and a sensor 209. . The control unit 201 controls each unit in the paper discharge device 200 based on the control of the control unit 101. The communication unit 202 communicates with another apparatus such as the image forming apparatus 100 that is set. The cutting unit 203 cuts a long sheet at a predetermined position. The paper discharge adjustment unit 205 absorbs fluctuations in the transport speed while adjusting the tension of the paper discharged from the image forming apparatus 100. The transport unit 206 transports the paper in the paper discharge device 200. The paper discharge unit 208 discharges the long paper from the image forming apparatus 100 as a paper roll while winding the long paper into a roll shape. The sensor 209 detects various states regarding sheet conveyance.

  FIGS. 1 and 2 show a specific example in which a long sheet is handled as an image forming system including the sheet feeding device 50, the image forming device 100, and the sheet discharging device 200. Here, the long paper refers to a paper having a longer paper length in the transport direction than a standard size paper. Further, FIG. 2 illustrates an image forming unit 150 that forms an image in a plurality of colors, but is not limited thereto, and may be an image forming unit 150 that forms a monochrome image. Note that various structures are conceivable for sheet feeding, image formation, and sheet discharging, and FIGS. 1 and 2 show an example, and the present invention is not limited to the configuration and form shown in this specific example.

FIG. 3 shows a configuration of a portion that executes a characteristic operation of the present embodiment.
Here, the first processing unit 1000 includes a memory ASIC 1010 as a first processing control unit, and a page memory 1020 controlled by the memory ASIC 1010 to store image data. The second processing unit 2000 includes a print ASIC 2010 as a second processing control unit, and a buffer 2020 controlled by the print ASIC 2010 and temporarily storing image data. Further, the third processing unit 3000 is the image forming unit 150 in FIGS. 1 and 2 and includes an exposure unit 3030.

  Here, the first processing unit 1000 and the second processing unit 2000 may exist in the image data storage unit 130 in FIG. Further, the first processing unit 1000 may exist in the image data storage unit 130 in FIG. 1, and the second processing unit 2000 may exist in the image forming unit 150.

〔motion〕
Hereinafter, the operation will be described with reference to various explanatory diagrams after FIG.
[Prerequisite operation]
Here, a basic operation which is a premise of the present embodiment will be described with reference to a time chart of FIG. 4 and a storage state explanatory diagram of FIG. Note that this basic operation indicates an operation in a prerequisite state before applying the features of the present embodiment.

In the time chart of FIG. 4, VTOP is a signal that triggers the start of image formation output in the sub-scanning direction. This VTOP is input by software in the control unit 101 to hardware such as a memory ASIC in accordance with the timing of paper transport.
WVV is a hardware internal signal that becomes effective in conjunction with VTOP. The WVV is a hardware internal signal for transferring the image data on the page memory to the print ASIC. This WVV is effective only for a time corresponding to the sub-scanning length and the linear velocity of the image data. For example, if the linear speed at the time of paper conveyance in the image forming unit 150 is 315 mm / s and the sub-scanning length of the image is 315 mm, it is valid for just one second.

  PVV is a hardware internal signal that becomes valid after a delay from the VTOP by a specified value of the leading edge timing. This PVV is a hardware internal signal that enables image output from the print ASIC. This signal is valid only for a time corresponding to the image data sub-scanning length and the linear velocity. If the linear velocity at the time of paper conveyance in the image forming unit 150 is 315 mm / s and the sub-scanning length of the image is 315 mm, it is valid only for one second.

  Here, the image data must be present in the buffer in order for the PVV to be valid. For this reason, the PVV becomes valid in a state where it is delayed from the WVV by the specified value of the leading end timing. That is, the PVV cannot be turned on before the WVV. In other words, the tip timing does not become negative.

Here, the leading edge timing is an adjustment value for matching the timing of the leading edge of the image with the sheet to be conveyed, and can be arbitrarily designated to the print ASIC by software. Normally, the leading edge timing does not change during one job.
Hereinafter, the state at each timing will be described while comparing FIG. 4 with FIG.

a10: VTOP on.
a11: Data of the leading end of the image is stored in the buffer of the print ASIC. The print ASIC starts outputting from the leading edge of the image.
a12: The buffer of the print ASIC continues to receive image data while performing image formation output.

a13: The print ASIC buffer continuously outputs an image. During the page switching, the reception of the image data is stopped.
a14: The print ASIC buffer completes the image output of the first page and receives the image of the second page.

a21: The print ASIC buffer starts receiving the image data of the second page while starting the image output of the second page.
a23: The print ASIC buffer completes the image reception of the second page. The image output of the second page continues.

  In the above description, the long paper continues to be conveyed in the image forming unit 150 during the page preparation processing between a14 and a21 in FIG. For this reason, as shown in “image formation” of a22 and a23 in FIG. 5, a blank (margin) area where no image is formed occurs between the pages between the image A and the image B in the sub-scanning direction.

[Operation of Embodiment]
Here, the characteristic operation of the present embodiment in which the above-described basic operation is improved will be described with reference to the time chart of FIG. 6 and the storage state explanatory diagram of FIG.
Since the PVV is a signal for controlling the image output, in order to prevent the margin on the image on the paper from being generated in the sub-scanning direction, the PVV in FIG. 6 may be kept valid.

In the present embodiment, the PVV invalid period is removed by using that the image data is stored in the buffer of the print ASIC at the point of time b11 when the PVV becomes valid and that the leading edge timing can be arbitrarily specified in units of pages from software. .
More specifically, the leading end timing amount is set large for the first page, and the leading end timing amount is reduced for each page by the page preparation processing time. By doing so, the PVV invalid period is removed while leaving the page preparation processing.

Hereinafter, the state at each timing will be described while comparing FIG. 6 with FIG. Note that a ** in FIGS. 4 and 5 described above and b ** in FIGS. 6 and 7 described below have the same numerical part.
b11: The data of the leading end of the image is stored in the buffer of the print ASIC. Output of the first page from the top of the image is started.

b13: The print ASIC buffer completes receiving the image of the first page, and stops receiving the image. The image output of the first page is continued.
b20: The buffer of the print ASIC starts receiving the image of the second page. The image output of the first page is continued.

b21 (b14): The buffer of the print ASIC continues to receive the image of the second page. The image output of the second page is started at the same time as the image output of the first page is completed (b14) (b21).
b23: The print ASIC buffer completes the image reception of the second page, and stops the image reception. The image output of the second page continues.

  In the above description, the WVV is turned off each time the page is switched, and the image reception of the print ASIC stops. Therefore, the data in the buffer in the print ASIC decreases every time the page is switched. Therefore, if the number of pages on which an image is formed is large, the leading end timing amount becomes negative in calculation, and a situation occurs in which image output cannot be continued. Therefore, in order to deal with the above problems, the buffer is secured as much as possible. However, considering the time for storing the image data in the buffer, it is desirable that the amount of data stored in the buffer be the minimum according to the number of copies and the image size. Further, the amount of decrease in the leading edge timing (the amount to advance the timing) is determined according to the time required for the page preparation processing (page preparation time × number of page switching). However, the page preparation processing itself is left, and only the timing of reading from the buffer is changed from the conventional one.

[Specific example of embodiment]
Here, a description will be given using specific numerical values.
-Image formation with four colors of YMCK.
The storage capacity of the print ASIC buffer is 256 MB (each color).
Since there is a time difference (inter-drum delay) from transfer of each color drum of the image forming unit 150 to the intermediate transfer member, K is the slowest from the buffer input to the buffer output.
・ The distance between the four color drums is 95mm × 3.
-The maximum writing width in the main scanning direction is set to 320 mm or 200 mm.
-The paper transport speed (linear speed) in the sub-scanning direction is 315 mm / s.
The page preparation processing time is 1/315 = 3.17 ms when the image interval in the sub-scanning direction is 1 mm.
・ Maximum value of the tip timing amount when the image width in the main scanning direction is 320 mm:
With 1200 dpi, 8 bit image data, one line of 320 mm is
320 / 25.4 × 1200 = 15120 (bytes).

The buffer is 256MB for each color,
Up to 256 × 1024 × 1024/15120 = 17753 lines can be stored.
If you convert 17753 lines to mm,
17753/1200 × 25.4 = 375.77 mm.

Here, when the distance between the drums of K is subtracted,
375.77−95 × 3 = 90.77 mm.
If this is converted to time, 90.77 / 315 = 0.288 seconds.
That is, the maximum value of the leading end timing amount when the image width is 320 mm is 0.288 seconds.
・ Maximum value of the tip timing amount when the image width in the main scanning direction is 200 mm:
In 1200 dpi, 8 bit image data, one line of 200 mm is
200 / 25.4 × 1200 = 9448 (bytes).

The buffer is 256MB for each color,
Up to 256 × 1024 × 1024/9448 = 28411 lines can be stored.
Converting 28411 lines to mm,
284111/1200 × 25.4 = 601.37 mm.

Here, when the distance between the drums of K is subtracted,
601.37−95 × 3 = 316.37 mm.
If this is converted into time, it will be 316.37 / 315 = 1.004 seconds.
That is, the maximum value of the tip timing amount when the image width is 200 mm is 1.004 seconds.
The number of pages where PVV = 0 when the image width in the main scanning direction is 320 mm:
288 / 3.17 = 90.85, and there are 91 pages because the interval between pages is 90 times.
The number of pages for which PVV = 0 when the image width in the main scanning direction is 200 mm:
1004 / 3.17 = 316.7, and the interval between pages is 316 times, which is 317 pages.

As described above, the maximum value of the tip timing amount changes according to the image width in the main scanning direction. For this reason, in an embodiment to be described later, the processing procedure takes into account the image width in the main scanning direction.
[Specific operation (1) of the embodiment]
Hereinafter, the operation (1) of the present embodiment will be described in detail with reference to the flowchart of FIG. Here, this flowchart is executed under the control of the control unit 101.

  Here, S: buffer capacity (byte), X: image width (mm), R: resolution (dpi), D: gradation (bit), L: linear velocity (mm / s), M: total number of copies, N : Total number of pages of one copy, Tb: Page preparation processing time (s), P: Number of page switching = M · N−1, A: One line data of image (byte), Tmax: Maximum timing amount of leading edge (s) = Defined as buffer-storable image length.

First, for the job to be executed, the control unit 101 calculates a required front end timing amount (required front end timing amount) Treq as Treq = P × Tb (step S101 in FIG. 8).
Further, the control unit 101 determines that A = (X / 25.4) × R × (D / 8) and Tmax = (S / A / R) × (25.4 / L) is calculated (step S102 in FIG. 8).

The control unit 101 compares the required tip timing amount Treq with the maximum tip timing amount Tmax (step S103 in FIG. 8).
If the required front-end timing amount Treq is larger than the maximum front-end timing amount Tmax (NO in step S103 in FIG. 8), the front-end timing amount becomes negative in calculation, and a situation occurs in which image output cannot be continued. Therefore, the control unit 101 displays on the operation display unit 105 a pop-up display screen for selecting whether to change the number of copies to satisfy Tmax ≧ Treq or to cancel the job execution, and prompt the user to make a selection (step S104 in FIG. 8). ).

If the user selects to stop job execution (NO in step S104 in FIG. 8), the control unit 101 stops image formation and ends (end in FIG. 8).
When Tmax ≧ Treq is satisfied (YES in step S103 in FIG. 8), or when the user changes the number of copies to satisfy Tmax ≧ Treq (YES in step S104 in FIG. 8), the control unit 101 The above Treq is set as the tip timing amount T (step S106 in FIG. 8).

Then, the control unit 101 executes image formation for the n (1 ≦ n ≦ N) page of the m (1 ≦ m ≦ M) section while setting the leading edge timing amount T = T−Tb for each page. (Steps S107 to SS113 in FIG. 8).
That is, the print ASIC 2010 reads the image data from the buffer 2020 and supplies the image data to the exposure unit 3030 while advancing the leading edge timing by the page preparation processing time for each page. As a result, as shown in FIG. 6, when reading image data from the buffer, reading of each page is continuous. In other words, even if it is necessary to change the hardware register setting or look-up table by software at the time of image page switching, the conventional configuration can be used without the need for dedicated hardware. It is possible to make the image close to each other by setting the image interval on the length paper to zero.

  Further, as described above, the timing (leading edge timing amount) for delaying the reading start timing of the first page of the image data from the buffer 2020 to the exposure unit 3030 when reading is delayed depends on the number of pages (M · N) on which the image is formed. Accordingly, it is determined by the accumulation of the time required for the page preparation processing time Tb between the pages. Thus, the data to be stored in the buffer is determined without waste while the image interval is reduced, and the delay of the start of image formation is controlled to a minimum.

  If the required front-end timing amount Treq exceeds the maximum front-end timing amount (buffer storable image length) calculated from the storage capacity of the buffer, one of the stoppage of image formation or the reduction of the number of pages to be formed is performed. Is selected by the user. By doing so, the control does not break down while reducing the image interval.

[Specific operation (2) of the embodiment]
Hereinafter, the operation (2) of the present embodiment will be described in detail with reference to the flowchart of FIG. Here, this flowchart is executed under the control of the control unit 101. In addition, the same processing contents as those in the flowchart of FIG. 8 are denoted by the same step numbers, and redundant description will be omitted.

  The above operation (1) is based on the premise that the characteristic processing of this embodiment is applied to each page. However, it is not always necessary to carry out each page. Therefore, by applying the present embodiment only at the time of page switching in which a particularly time-consuming process occurs in the page preparation process, it is possible to make a time-consuming output setting change.

Here, the processing that takes a particularly long time is a processing that requires a page preparation processing time (non-standard page preparation processing time) longer than a normal reference page preparation processing time (reference page preparation processing time). However, the non-standard page preparation processing time is not limited to one type.
For example, there is an image processing parameter setting change. This corresponds to the necessity of setting data in units of kilobytes in a lookup table in hardware such as an ASIC. This may occur in a situation where two types of image data processed by different look-up tables or the like are to be printed by 100 meters.

The flowchart of the operation (2) in this case is as shown in FIG. Hereinafter, a description will be given focusing on points different from the operation (1) shown in FIG.
First, an expected page preparation processing time (expected page preparation processing time Temn) and a reference value (reference page preparation processing time) Tb of the page preparation processing time are calculated for all pages (m-part n pages) ( Step S100 in FIG. 9). The page preparation processing time when there is no change in the image processing parameters (for example, T11 of the first page of one copy) is set as the reference page preparation processing time Tb.

As the required front-end timing amount Treq, a total sum of all pages (1 to N for n and 1 to M for m, as m sections / n pages) is calculated for Temn-Tb.
In the embodiment of the operation (2), in the case where the page preparation processing time includes the reference page preparation processing time and the non-standard page preparation processing time different from the reference page preparation processing time, each of the data transfer from the memory to the buffer is performed. When the time between page transfer is the reference page preparation processing time, the time between reading of each page from the buffer to the image forming unit is set as the reference page preparation processing time, and each page from the memory to the buffer is stored. If the time between the transfer of the data is the non-standard page preparation processing time, the time between the reading of each page from the buffer to the image forming unit matches the non-standard page preparation processing time with the standard page preparation processing time. To increase or decrease.

  In other words, even if it is necessary to change the hardware register setting or look-up table by software at the time of image page switching, the conventional configuration can be used without the need for dedicated hardware. It is possible to reduce the image interval on the length paper to a certain state including zero.

[Specific operation (3) of the embodiment]
Hereinafter, operation (3) of the present embodiment will be described.
It is assumed that the image data includes a plurality of images. Here, a plurality of images having different sizes in the sub-scanning direction are arranged in the main scanning direction, and a plurality of images having different sizes in the sub-scanning direction are repeatedly formed in the sub-scanning direction. is there.

For example, FIG. 10A corresponds to an image in which a plurality of images are included in image data and a plurality of images having different sizes in the sub-scanning direction are arranged in the main scanning direction.
It is assumed that such image data of FIG. 10A is repeatedly formed in a sub-scanning direction using long paper.

When the present embodiment is not applied at all, there is a useless margin between images as shown in FIG.
When this embodiment is applied, no useless blank space occurs between images as shown in FIG. However, for small images having different sizes in the sub-scanning direction among the images included in the image data, a margin is generated even when the present embodiment is applied.

  Therefore, by the image processing of the image processing unit 140, for the images included in the image data, the images having different sizes in the sub-scanning direction are individually set such that the images are not spaced in the sub-scanning direction. Generate data. Then, as described in the above operation (1), image formation is performed so as not to leave an interval.

That is, by applying the embodiment of the operation (3), useless blank space is not generated between all the images as shown in FIG.
Here, two types of images having different sizes in the sub-scanning direction are used. However, even when there are three or more types of images, it is necessary to take measures so as not to generate a margin of each image. Is possible.

[Supplemental explanation]
In the above description of the operation, the image forming unit 150 forms an electrophotographic image, but the present invention is not limited to this. That is, the present embodiment can be applied to various types of image formation.

Further, the above embodiments can be applied to various apparatuses that receive image data from a buffer and form an image based on the image data while conveying long paper.
Here, image formation while transporting a long sheet means various methods for executing image formation without stopping the transport of the sheet. In such various types of image formation, it is possible to reduce the image interval and prevent unnecessary margins from being generated.

  Further, reducing the image interval includes not only making the image interval completely zero and bringing the image into close contact with each other, but also reducing the image interval while leaving a blank portion generated by the page preparation processing time.

50 paper feeding device 100 image forming device 200 paper discharging device

Claims (9)

An image forming apparatus that forms an image on continuous paper based on image data,
A page memory for storing image data,
A buffer for temporarily storing image data transferred from the page memory,
An image forming unit that performs image formation based on image data read from the buffer,
It is configured with
When transferring image data from the page memory to the buffer page by page, register transfer and look-up table in hardware for controlling the page memory and the buffer for page switching during transfer of each page The transfer is temporarily suspended during the page preparation process for software preparation for changing the hardware settings of
When reading image data from the buffer to the image forming unit, the read start timing of the first page is delayed, and the time between reading of each page from the buffer to the image forming unit is reduced from the page memory. To reduce the page preparation processing time required for the page preparation processing for the buffer,
An image forming apparatus comprising: When reading image data from the buffer to the image forming unit, read each page so as to be in a continuous state,
The image forming apparatus according to claim 1, wherein: The timing of delaying the read start timing of the first page of the image data from the buffer to the image forming unit is delayed according to the number of pages to be image-formed by accumulating the page preparation processing time between each page. It is determined,
The image forming apparatus according to claim 1, wherein: The timing for delaying the reading start timing of the first page of the image data from the buffer to the image forming unit is delayed by accumulating the page preparation processing time between each page according to the number of pages to be image-formed. Decide,
If the capacity of the image data required by delaying the read start timing exceeds the storage capacity of the buffer, either stop image formation or reduce the number of pages on which the image is formed is selected.
The image forming apparatus according to any one of claims 1 to 3, wherein: When the reference page preparation processing time as a reference is determined as the page preparation processing time,
If the time between the transfer of each page from the page memory to the buffer does not match the reference page preparation processing time, the time between the transfer of each page from the page memory to the buffer is the reference page To match the preparation time,
The image forming apparatus according to any one of claims 1 to 4, wherein: An image processing unit for performing image processing is provided,
The image processing unit,
The image included in the image data is obtained by arranging a plurality of images having different sizes in the sub-scanning direction in the main scanning direction, and repeating the plurality of images having different sizes in the sub-scanning direction in the sub-scanning direction. In the case of forming, generating image data in a state where no space is left in the sub-scanning direction of each image,
The image forming apparatus according to any one of claims 1 to 4, wherein: The image forming unit receives the image data from the buffer, and forms an image based on the image data while conveying the continuous paper.
The image forming apparatus according to any one of claims 1 to 6, wherein: A paper feeder that feeds continuous paper,
The image forming apparatus according to claim 1, wherein an image is formed on the continuous paper fed by the paper feeding device based on image data.
A paper discharging device for discharging the continuous paper on which an image is formed by the image forming apparatus;
An image forming system having: An image forming control program for controlling an image forming apparatus that forms an image on continuous paper based on image data,
The image forming apparatus includes:
A page memory for storing image data,
A buffer for temporarily storing image data transferred from the page memory,
An image forming unit that performs image formation based on the image data read from the buffer,
When transferring image data from the page memory to the buffer page by page, register transfer and look-up table in hardware for controlling the page memory and the buffer for page switching during transfer of each page The transfer is temporarily suspended during the page preparation process for software preparation for changing the hardware settings of
When reading image data from the buffer to the image forming unit, the read start timing of the first page is delayed, and the time between reading of each page from the buffer to the image forming unit is reduced from the page memory. Reduce the page preparation processing time required for the page preparation processing for the buffer,
An image forming control program for causing a computer of the image forming apparatus to function as described above.