JP4607838B2 - Image forming apparatus - Google Patents

Description

  According to the present invention, first image data after image processing is printed on a plurality of recording sheets by a printing unit, and second image data different from the first image data in parallel with the print recording of the first image data. The present invention relates to an image forming apparatus that performs image processing on an image processing unit.

  As a type of image forming apparatus, there is a so-called multi-access type model capable of reading another image data while printing and recording one image data. In a multi-access type copying machine, an improvement in processing speed is strongly desired, and image processing for printing and recording the first image data and image processing of the read second image data are executed in parallel. Some devices have two image processing units that are processing circuits.

  However, since an image processing unit that performs advanced image processing is expensive, it causes an increase in apparatus cost. Therefore, there is a demand for an image forming apparatus that includes only one image processing unit, that is low in cost and high in processing speed.

  In a multi-access type image forming apparatus, when one image data is composed of a plurality of pages, a plurality of recording sheets corresponding to each page are printed and recorded. In such a case, as one means for improving the processing speed, between the processing for one page and the processing for the next page, that is, print recording on one recording paper and printing recording on the next recording paper It is conceivable to use the space between papers. As a prior art that pays attention to such a gap between sheets, in an image forming apparatus capable of executing a plurality of jobs by interruption, a sheet interval is detected while one job is in progress, and a job that is not currently executed within that interval There is an image forming apparatus that executes it as an interrupt job if it can be executed (see Patent Document 1).

  Japanese Patent Application Laid-Open No. 2004-151867 merely discloses improving processing efficiency by executing an interrupt print job between sheets during normal print job execution. In the multi-access type image forming apparatus as described above, The problem of solving the problem of improving the processing efficiency by limiting the number of image processing units to one in order to reduce the image quality and enabling the printing and recording of one image data and the image processing of the other image data to be executed in parallel Is not disclosed at all.

JP 2004-173291 A

  The present inventors pay attention to the above-mentioned gap between sheets, and create a divided image data by dividing a sheet interval setting unit for setting a sheet interval for the first image data and a second image data for one original. An image forming apparatus is developed that includes an image dividing unit that controls the operation of the image processing unit so that the divided image data is processed between sheets.

  For example, a case where a scaling process of divided image data is performed is assumed. If it is 384 lines before the division, this is divided into 1/3 (128 lines), and if the magnification is changed by 150%, 192 lines are processed. In this image forming apparatus, DMA (Direct Memory Access) is set with the number of scaled lines as the ring memory depth of the data, and when DMA is completed (band end) to the address of the end of the band, the first image data In order to process the next page, the paper gap process is temporarily stopped.

  In this image forming apparatus, the image processing unit for performing the scaling process and the image assembling unit for assembling the divided images are controlled by the same single control unit. When each is controlled independently, it cannot be processed because the number of lines of the divided image data after scaling inputted from the image processing unit is unknown.

  An object of the present invention is to provide an image forming apparatus capable of smoothly cooperating with a transfer destination of image data and saving memory usage.

In the present invention, the first image data is image-processed by the image processing unit, the first image data after the image processing is printed on a plurality of recording sheets by the printing unit, and the first image data is printed and recorded in parallel. In the image forming apparatus that performs image processing on the second image data different from the first image data in the image processing unit,
An image data reading unit for reading image data formed on a document;
Paper that is an interval formed between recording papers on which the first image data is printed and recorded, and is an interval between a position where printing recording on the preceding recording paper ends and a position where printing recording on the following recording paper starts A paper interval setting section for setting the interval,
An image dividing unit that divides the second image data for one document read by the image data reading unit into a plurality of pieces to create divided image data;
A control unit that controls the operation of the image processing unit so as to electronically scale the divided image data between sheets;
When transferring the divided image data, a transfer destination of the divided image data, and a transfer control unit for outputting a completed signal indicating the completion of the transfer reaches the capacity required from the image rotation unit having a line boundary constraints Yes, and
The transfer control unit uses the ring memory depth of the divided image data after the electronic scaling process as the sum of the number of lines after the electronic scaling process and the number of processed lines of the image rotating unit, and the line required by the image rotating unit. An image forming apparatus that outputs a divided image data completion signal each time the number is counted .

Or the present invention, the transfer control unit is characterized in that for transferring the image rotating unit is a transfer destination of the first image data and the second image data.

Further, the invention is characterized in that the inter-paper processing is temporarily stopped when an edge of a data valid signal output from an external chip is detected.

  In addition, the present invention is characterized in that the divided image data has a portion overlapping between adjacent divided image data.

  According to the present invention, when the image data reading unit reads the image data formed on the document, the sheet interval setting unit is the interval formed by the recording sheets on which the first image data is printed and recorded. A paper interval is set which is an interval between a position where the printing and recording of the recording paper to be finished ends and a position where the printing and recording of the subsequent recording paper starts.

  The second image data for one original read by the image data reading unit is divided into a plurality of pieces by the image dividing unit to create divided image data.

When transferring the divided image data, the transfer control unit outputs a completion signal indicating completion of transfer when the capacity required by the image rotation unit having the line boundary constraint, which is the transfer destination of the divided image data , is reached. At this time, the ring memory depth of the divided image data after the electronic scaling process is the sum of the number of lines after the electronic scaling process and the number of processed lines of the image rotation unit, and the number of lines required by the image rotation unit is counted. Each time a divided image data completion signal is output.

  As a result, it is possible to smoothly perform cooperation with a cooperation destination having a limited processing capacity and save memory usage within a limited time of paper-sheet processing.

According to or present invention, the transfer control unit not only the divided image data can be performed also transfer of the first image data.

According to or present invention, pausing the sheet between processing is performed when detecting an edge of the data valid signal output from the external chip. It is possible to share a single control unit between the paper interval process and the print process, thereby reducing the circuit scale.

  According to the invention, the divided image data has a portion that overlaps between adjacent divided image data. Thereby, peripheral pixels necessary for image processing of the divided image data can be included.

  FIG. 1 is a block diagram showing a simplified electrical configuration of an image forming apparatus 1 according to an embodiment of the present invention. An image forming apparatus 1 shown in FIG. 1 functions as a printer that is connected to a computer 5 and forms an image based on image data input from the computer 5, and a copying machine that copies image data formed on a document. It is a multifunctional machine that combines.

  The image forming apparatus 1 generally includes a controller unit 2, a scanner unit 3, and a printer unit 4 that is a printing unit.

  The scanner unit 3 includes a document placing unit on which a document on which an image is formed in advance is placed, and an optical scanning unit that optically scans an image of the document placed on the document placing unit and reads image data. The image data reading unit is configured. The document image data read by the scanner unit 3 is stored in an image memory 15 provided in the controller unit 2.

  The controller unit 2 includes a control unit 11, an operation unit 12 connected to the control unit 11, a storage unit 13, and a display unit 14, an image memory 15 connected to the control unit 11, an image dividing unit 16, and an image input unit. A unit 17, an image processing unit 18, an image output unit 19, an image assembly unit 20, an image buffer 21, and a laser control integrated circuit (laser control IC) 22.

  The control unit 11 is a processing circuit including a central processing unit (CPU), for example. The control unit 11 controls the overall operation of the image forming apparatus 1 and also controls the operation of each unit connected to the control unit 11.

  The storage unit 13 is configured by, for example, a read only memory (ROM), a random access memory (RAM), a nonvolatile memory, and the like, and a program for the control unit 11 to control the operation of the image forming apparatus 1 or between papers to be described later Table data used for setting the number of processing lines is stored.

  The operation unit 12 is also an input unit through which an operator of the image forming apparatus 1 inputs an operation command or an operation condition. For example, the operation unit 12 includes an input button, a touch panel, and the like which are set so as to be able to input each operation command. Prepare.

  The display unit 14 is configured by a liquid crystal display (LCD), for example. The display unit 14 displays the number of recording sheets to be printed and recorded in accordance with a display operation command from the control unit 11.

  Here, before the description of the remaining part of the controller unit 2, the paper gap will be described. FIG. 2 is a diagram showing a simplified mechanical configuration around the photosensitive drum 24 of the image forming apparatus 1. Around the photosensitive drum 24 included in the printing unit of the image forming apparatus 1, the photosensitive drum 24 is uniformly charged in order from the upstream side to the downstream side in the rotation direction indicated by the arrow 25. The illustrated charger, exposure means 26 for exposing the uniformly charged photosensitive drum 24 with light corresponding to image data to form an electrostatic latent image on the surface of the photosensitive drum 24, and the photosensitive drum 24. A developer is supplied to the surface of the toner to develop a toner image by developing the electrostatic latent image, and a toner image on the photosensitive drum 24 is applied by applying a reverse bias to the photosensitive drum 24. A transfer roller 27 for transferring onto the recording paper is provided. The recording paper on which the toner image is transferred and the recording paper after recording are conveyed in the direction of the arrow 29 by a plurality of conveyance rollers 28 provided on the conveyance path 30.

  The interval between the sheets is an interval formed by recording sheets on which the first image data is printed and recorded, and the position at which printing recording of the preceding first recording sheet 31 ends and the following second recording sheet 32 It is defined by the interval from the position where print recording starts. Strictly speaking, the interval between the sheets is set not on the conveyance path 30 of the first and second recording sheets 31 and 32 but on the photosensitive drum 24. That is, between the sheets, in the circumferential direction of the photosensitive drum 24, a position 33 where the last image data in the electrostatic latent image to be formed on the first recording paper 31 is scanned by the exposure unit 26, and further, the photosensitive drum When the position 24 rotates in the direction of the arrow 25 and reaches the position 33, the first image data of the electrostatic latent image is written by the exposure means 26 in order to form an image on the second recording paper 32. The time is a value obtained by dividing the distance by the rotational speed of the photosensitive drum 24.

  The timing is adjusted so that the conveyance interval between the first recording sheet 31 and the second recording sheet 32 on the conveyance path 30 matches the sheet interval set on the photosensitive drum 24. The timing adjustment is performed as follows. Two first and second detection sensors 35 and 36 for detecting the recording paper are provided along the conveyance path 30 so as to have a predetermined interval. The conveyance speed of the recording paper detected by the first and second detection sensors 35 and 36 and the detection result of the leading portion of the second recording paper 32 detected by the second detection sensor 36 are input to the control unit 11. The control unit 11 outputs an operation command to the drive system of the transport roller 28 and outputs an operation command to the drive system of the registration roller 37, and the image formation start position on the second recording paper 32, Control is performed so that the image writing start position 34 on the photosensitive drum 24 matches.

  Therefore, the control unit 11 that controls the formation position of the electrostatic latent image on the photosensitive drum 24 by the exposure unit 26 as part of the overall operation control of the image forming apparatus 1 is a sheet interval setting unit. In addition, the first and second detection sensors 35 and 36 are adjusted so that the interval between the plurality of recording sheets actually conveyed to the printing unit matches the interval between the sheets set on the photosensitive drum 24. The transport roller 28 and its drive system, the registration roller 37 and its drive system together with the control unit 11 constitute a paper gap adjustment unit.

Returning to FIG. 1 again, the configuration of the image forming apparatus 1 will be described.
The image memory 15 is a storage unit and is configured by, for example, a RAM. The image memory 15 stores image data of a document read by the scanner unit 3. The image memory 15 stores first image data that is exactly the image data that is to be printed and recorded, and the print waiting number that is the number of recording sheets to be printed and recorded.

  The image dividing unit 16 is second image data different from the first image data to be printed and recorded in accordance with an operation command from the control unit 11 based on the operation program, and is read by the scanner unit 3 and stored in the image memory 15. It is a processing circuit that executes the following image division processing on the second image data that has been performed.

  The image dividing unit 16 divides the second image data read from the image memory 15 and corresponding to one page of the original into a plurality of pieces, and generates divided image data. When dividing the second image data, the image dividing unit 16 uses the front position divided image in which the boundary portions corresponding to the data start portion and the data end portion of the divided image data generated by the division are located before the divided image data. The division is performed so that the boundary portion of the data and the boundary portion of the rear position divided image data positioned after the divided image data have overlapping portions of the image data.

  FIG. 3 is a diagram for explaining the outline of the division of the second image data by the image dividing unit 16. Hereinafter, the division of the second image data will be described with reference to FIG. In FIG. 3, the image dividing unit 16 equally divides the second image data to be formed on one sheet of recording paper into four parallel to the main operation direction, that is, the first to fourth divided image data. An example of equally dividing into A, B, C, and D will be described. Taking the second divided image data B, it is a boundary portion between the first divided image data A and the second divided image data B, which is the previous position divided image data, and the data start portion 51 of the second divided image data B includes The boundary portion between the third divided image data C and the second divided image data B, which is the rear position divided image data, so that the overlapping portion 52 of the image data with the first divided image data A is formed. The image dividing unit 16 divides the second image data so that an overlapping portion 54 of the image data with the third divided image data C is formed at the data end portion 53 of the second divided image data B.

  Similar to the second divided image data B, the remaining divided image data other than the second divided image data is also divided so as to have an image data portion that overlaps with the preceding and subsequent divided image data. However, overlapping portions of the image data are not formed in the data start portion and the data end portion of the entire second image data.

  The number of processing lines between sheets can be changed according to the number of pages waiting for printing of the first image data. In this case, when the number of pages waiting to be printed is small, the number of processing lines between papers is large (the number of divisions is small), and when the number of pages waiting for printing is large, the number of processing lines between papers is small (the number of divisions is large). To do. In this way, when the number of pages waiting to be printed is small, the print processing time of the first image itself is short. Therefore, even if there is a slight increase in the paper interval, the overall time is short. The waiting time of itself is short, and the image processing of the second image can be performed quickly. On the other hand, when the number of pages waiting to be printed is large, the interval between the sheets is shortened, so that the interval between sheets for printing a large number of pages can be used effectively, and the waiting time of the user waiting for printing the first image is not prolonged.

  Returning to FIG. 1, the second image data divided by the image dividing unit 16 is output to the image processing unit 18 by the operation of the image input unit 17.

  The image processing unit 18 performs image processing on the plurality of second image data divided by the image dividing unit 16 between sheets on which the first image data is printed and recorded in accordance with an operation command from the control unit 11. Here, examples of image processing include wrinkle processing, filter processing, scaling processing, and rotation processing.

  The divided image data subjected to the image processing in the image processing unit 18 is output to the image assembling unit 20 by the operation of the image output unit 19. The image assembling unit 20 is a processing circuit that reassembles the divided image data of the second image data divided by the image dividing unit 16 and processed by the image processing unit 18 into image data for one sheet of recording paper. The second image data assembled for one sheet of recording paper by the image assembling unit 20 is input from the image assembling unit 20 to the image buffer 21 which is a memory and stored. The second image data temporarily stored in the image buffer 21 is read from the image buffer 21 by the control unit 11 when the second image data is printed and recorded, and also operates in accordance with an operation command from the control unit 11. It is sent to the printer unit 4 by the control IC 22. The image rotation unit 23 performs rotation processing on the assembled image data and outputs it to the image buffer 21.

  The printer unit 4 of the image forming apparatus 1 includes a printer control unit 41 and a laser writing control unit 42. The laser writing control unit 42 is used for forming an image on the photosensitive drum 24 such as charging control of the photosensitive drum 24, writing control of the electrostatic latent image by the exposure unit, and control related to development of the electrostatic latent image. Perform motion control. Based on the operation command of the control unit 11, the printer control unit 41 performs operation control such as transfer of an image formed on the photosensitive drum 24 to a recording sheet and fixing of the image transferred to the recording sheet. The printer unit 4 charges the photosensitive drum 24 to a uniform potential, exposes the photosensitive drum 24 with light according to image data sent from the controller unit 2 to form an electrostatic latent image, and The latent image is developed and visualized as a toner image, and the toner image is transferred to recording paper and further fixed. That is, the printer unit 4 is a printing unit (printing operation execution unit).

  In the present invention, the image input unit 17, the image processing unit 18 and the image output unit 19 constitute an image processing unit 2a, and are controlled by the control unit 11 independently of other units at the software level.

  FIG. 4 is a block diagram showing the configuration of the image assembling unit 20 and the image rotating unit 23 in the present embodiment.

  The image assembling unit 20 includes a data input unit 200 that receives image data input from the image input unit 17, a DMA control unit 201 that performs transfer control of image data using a DMA method, and a register unit 202 that stores parameters necessary for DMA control. including. The register unit 202 stores, as parameters, the number of band lines at the time of band linking and the requested number of lines, which is the number of lines requested by the image processing unit 2a to be linked. The DMA control unit 201 includes a line counter 201a that counts the number of lines of image data, and a determination circuit 201b that compares the count number of the line counter with the number of band lines or the number of requested lines to determine whether they match.

  The image rotation unit 23 includes a data input unit 230 that receives image data input from the image assembly unit 20, a DMA control unit 231 that performs transfer control of image data using a DMA method, and a register unit 232 that stores parameters necessary for DMA control. including.

  Here, as described above, it is assumed that the scaling processing of the divided image data is performed. When performing band cooperation, after the band end, the chain_end signal is notified to the cooperation destination, and the cooperation destination that receives the signal automatically starts DMA, but this cooperation destination has a line boundary constraint (for example, 128). Line), 64 lines exceeding the limit cannot be processed. In order to solve this problem, the ring memory depth of the image data after scaling is set to (number of lines after electronic scaling) + [number of processing lines of the link destination (multiple of the line boundary)] Every time the number of lines requested by the destination is counted, control is performed to notify the chain_end signal, which is the image data processing completion signal.The state is maintained during the pause of the inter-sheet processing, and the state before the suspension is resumed after the restart. Takes over and outputs the chain_end signal at the timing that matches the linkage destination.

  As a result, it is possible to smoothly perform cooperation with a cooperation destination having a line boundary constraint and save memory usage within a limited time of paper interval processing.

FIG. 5 is a flowchart showing image processing according to the present embodiment.
In step S1, it is determined whether an image processing start signal START1 is output. If it is output, the process proceeds to step S2, and if it is not output, it waits. The image processing start signal START1 is output for each page of the first image data to be printed.

  In step S2, print processing is performed on the page of the first image data. In step S3, it is determined whether the image processing start signal START2 is output. If it is output, the process proceeds to step S4. If it is not output, the process returns to step S2. The image processing start signal START2 is output for each divided image data of the second image data.

  In step S4, the divided image data is read. In step S5, it is determined whether or not the number of read lines has reached a predetermined number of lines desired by the other party. This determination is performed by the determination circuit 201b, and it is determined that the predetermined number of lines has been reached when the count number of the line counter 201a matches the required number of lines. If the predetermined number of lines has been reached, the process proceeds to step S6, and if not, the process proceeds to step S7.

  In step S6, a chain_end signal is output and the process returns to step S4. In step S7, it is determined whether the image assembly unit has reached the desired number of lines. If it has reached, the process proceeds to step S8, and if not, the process returns to step S4. In step S8, it is determined whether or not the read divided image data is the last block. If it is the final block, the process proceeds to step S9, and if it is not the final block, the process returns to step S4. In step S9, the depth of the ring memory is set and the process ends.

Next, another embodiment of the present invention will be described.
The configuration of the image assembling unit 20 is different from that of the above embodiment, and the other operations are performed in the same manner, and thus the description thereof is omitted.

  FIG. 6 is a block diagram showing the configuration of the image assembling unit 20 and the image rotating unit 23 in the present embodiment. The data input unit 200 of the image assembling unit 20 includes a valid signal detection unit 200a that detects an edge of a data valid signal input together with image data.

  The timing at which the inter-sheet processing is temporarily stopped is detected when the number of lines of the divided image data is counted up to the number of band lines. However, if the cooperation destination is an external chip and the number of lines of input image data is unknown due to electronic scaling, the pause timing cannot be detected based on the count of input image data.

  In the present embodiment, in addition to the temporary stop based on the count number of the input image data, the negated edge of the data valid signal input from the external chip is detected and temporarily stopped. In addition, it is possible to switch the pause detection between the normal processing and the paper interval processing.

  As a result, it is possible to share one DMA control unit during normal processing and during inter-sheet processing, thereby reducing circuit scale (cost). Here, the normal processing refers to processing by contacting data for one page rather than dividing and processing image data. In this case, the end of processing is detected by a line counter independent of the negation of the data valid signal. Also, during the paper interval processing, when there is no scaling, it is not necessary to refer to the data valid signal, so there are cases where the detection of the stop is switched by two types of methods.

FIG. 7 is a flowchart showing image processing of the present embodiment.
In step S11, it is determined whether the image processing start signal START1 is output. If it is output, the process proceeds to step S12. If it is not output, the process waits.

  In step S12, a printing process is performed on the page of the first image data. In step S13, it is determined whether the image processing start signal START2 is output. If it is output, the process proceeds to step S14. If it is not output, the process returns to step S2.

  In step S14, the divided image data is read. In step S15, it is determined whether a negated edge of the data valid signal has been detected. This determination is performed by the valid signal detection unit 200a, and a negated edge is detected from both edges (asserted and negated) of the data valid signal. If a negated edge is detected, the process proceeds to step S16, and if not detected, the process returns to step S14. In step S16, it is determined whether the number of read lines has reached a predetermined number of lines desired by the other party. If it has reached, the process proceeds to step S17, and if not, the process returns to step S11. In step S17, a chain_end signal is output and the process returns to step S11.

1 is a block diagram showing a simplified electrical configuration of an image forming apparatus 1 according to an embodiment of the present invention. 2 is a diagram showing a simplified mechanical configuration around a photosensitive drum 24 of the image forming apparatus 1. FIG. It is a figure explaining the outline | summary of the division | segmentation of the 2nd image data by the image division part. FIG. 3 is a block diagram illustrating configurations of an image assembly unit 20 and an image rotation unit 23 in the present embodiment. It is a flowchart which shows the image processing of this embodiment. FIG. 3 is a block diagram illustrating configurations of an image assembly unit 20 and an image rotation unit 23 in the present embodiment. It is a flowchart which shows the image processing of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Controller part 2a Image processing unit 3 Scanner part 4 Printer part 11 Control part 12 Operation part 13 Storage part 14 Display part 15 Image memory 16 Image division part 17 Image input part 18 Image processing part 19 Image output part 20 Image Assembly unit 21 Image buffer 22 Laser control IC
DESCRIPTION OF SYMBOLS 23 Image rotation part 24 Photosensitive drum 26 Exposure means 27 Transfer roller 28 Conveyance roller 35,36 Detection sensor 37 Registration roller 41 Printer control part 42 Laser writing control part 200 Data input part 200a Effective signal detection part 201,231 DMA control part 201a Line counter 201b Determination circuit 202, 232 Register unit 230 Rotation processing unit

Claims (4)

The first image data is subjected to image processing by the image processing unit, and the first image data after the image processing is printed on a plurality of recording sheets by the printing unit, and the first image data is printed in parallel with the first image data. In the image forming apparatus that performs image processing on the second image data different from the image data by the image processing unit,
An image data reading unit for reading image data formed on a document;
Paper that is an interval formed between recording sheets on which the first image data is printed and recorded, and is an interval between a position at which printing recording of the preceding recording paper ends and a position at which printing recording of the subsequent recording paper starts A paper interval setting section for setting the interval,
An image dividing unit that divides the second image data for one document read by the image data reading unit into a plurality of pieces to create divided image data;
A control unit that controls the operation of the image processing unit so as to electronically scale the divided image data between sheets;
When transferring the divided image data, a transfer destination of the divided image data, and a transfer control unit for outputting a completed signal indicating the completion of the transfer reaches the capacity required from the image rotation unit having a line boundary constraints Yes, and
The transfer control unit uses the ring memory depth of the divided image data after the electronic scaling process as the sum of the number of lines after the electronic scaling process and the number of processed lines of the image rotating unit, and the line required by the image rotating unit. An image forming apparatus that outputs a completion signal of divided image data each time the number is counted . The image forming apparatus according to claim 1, wherein the transfer control unit transfers the first image data and the second image data to an image rotation unit that is a transfer destination . The image forming apparatus according to claim 1, wherein the paper interval process is temporarily stopped when an edge of a data valid signal output from an external chip is detected.   The image forming apparatus according to claim 1, wherein the divided image data includes a portion that overlaps adjacent divided image data.

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