JP2022013412A - Image formation apparatus, image formation control method and image formation program - Google Patents

Abstract

To prevent output of an abnormal image of an image formation apparatus.SOLUTION: An image formation apparatus sequentially performs writing and reading of printing information with respect to a plurality of storage units and supplies the printing information read from each storage unit to an image formation unit for printing on a sheet. At this time, a delay detection unit detects a writing delay of the printing information with respect to each storage unit. A control unit controls the image formation unit so as to discharge the sheet that has been fed when the delay detection unit detects the writing delay and stop the feeding of the sheet from a sheet feeding unit to suspend printing processing. With this configuration, such an inconvenience that an abnormal image is output can be prevented when the writing delay with respect to each storage unit occurs.SELECTED DRAWING: Figure 8

Description

The present invention relates to an image forming apparatus, an image forming control method, and an image forming program.

In order to increase the printing speed and improve productivity in a printing device, "processing to generate drawing data by an information processing device", "image processing to convert drawing data into print output data", and "image formation". The "transfer processing of print output data to the unit (engine)" needs to be performed in synchronization with the transfer of the paper to be printed.

Therefore, conventionally, a plurality of page buffer memories are provided in the data transfer path from the information processing device to the engine. Then, the process of writing the print output data generated by converting the drawing data to the page buffer and the process of reading the print output data from the page buffer memory and transferring the print output data at the timing requested by the engine are performed in parallel. As a result, continuous transfer of print output data is realized while absorbing the difference between the timing at which the information processing apparatus generates drawing data and the timing at which the engine requests transfer of print output data.

However, depending on the content of the print document or the content of the image processing, it takes time to generate the drawing data, and the image processing for converting the drawing data to the print output data takes time, so that the generation of the print output data is delayed. Sometimes. If the generation of print output data is delayed, the print output data is being written to the page buffer memory at the time when the engine requests the print data, or the print output data is not written to the page buffer memory at all. Occurs.

As a result, even though the printing paper is conveyed to the image forming position, the paper with defects in the printed image is output, or the blank paper is output, and the abnormal image is mixed in the print output result. Therefore, when the conventional printing device cannot transfer the print output data to the image forming unit (engine) in time, the conventional printing device notifies the user as an error and stops the printing operation to mix the abnormal image. Is being prevented.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2008-044172) discloses an image forming apparatus capable of detecting duplicate printing or the like without having a configuration for reading a print output result. This image forming apparatus compares the nth page of the raster data generated by the raster image processor unit with the (n-1) to (nm) pages of the preceding raster data. When raster data matching n pages is detected on the preceding page, it is determined that duplicate printing will occur, and error processing such as notification to the user and printing stop is performed. This makes it possible to prevent the occurrence of duplicate printing.

However, if an error occurs, there is a risk that paper on which a defective image is printed, or paper on which an abnormal image is printed, such as paper on which only one side is printed despite double-sided printing, may be output. There is.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus, an image forming control method, and an image forming program for preventing output of an abnormal image.

In order to solve the above-mentioned problems and achieve the object, the present invention sequentially writes and reads print information to a plurality of storage units, and prints the print information read from each storage unit to the image forming unit. An image forming device that supplies and prints on paper, a delay detection unit that detects the write delay of print information for each storage unit, and a paper that has already been fed when the delay detection unit detects a write delay. It has a control unit that interrupts the printing process by controlling the image forming unit so as to discharge the paper and stop the paper feeding from the paper feeding unit.

According to the present invention, there is an effect that the output of an abnormal image can be prevented.

FIG. 1 is a system configuration diagram of a printing system according to an embodiment. FIG. 2 is a block diagram of DFE. FIG. 3 is a block diagram of the image forming apparatus. FIG. 4 is a diagram schematically showing the configuration of the image forming portion. FIG. 5 is a block diagram of a printing system as a comparative example. FIG. 6 is a block diagram of the printing system of the embodiment. FIG. 7 is a diagram for explaining write / read control for the page buffer memory. FIG. 8 is a flowchart showing the flow of a write / read operation for the page buffer memory and a transfer abnormality determination operation. FIG. 9 is a diagram for explaining write / read control for the page buffer memory in the printing system of the second embodiment. FIG. 10 is a flowchart showing a flow of a write / read operation for the page buffer memory and a transfer abnormality determination operation in the printing system of the second embodiment. FIG. 11 is a flowchart for explaining the flow of the operation from the print stop operation to the print restart by the error notification.

Hereinafter, the printing system according to the embodiment will be described with reference to the attached drawings.

[First Embodiment]
(System configuration)
FIG. 1 is a diagram showing a system configuration of the printing system of the first embodiment. As shown in FIG. 1, the printing system of the first embodiment includes one or a plurality of client personal computer devices (client PCs) 101, information processing devices (DFE: Digital Front End) 102, and image forming. It has a device 103. The client PC 101, DFE 102 and the image forming apparatus 103 are connected to each other via a predetermined communication cable or a predetermined network such as a LAN (Local Area Network).

(Client PC configuration)
The client PC 101 has a configuration of a normal personal computer device to which a display device such as a liquid crystal display and an input device such as a mouse device and a keyboard device are connected. That is, the client PC 101 has a storage unit such as a CPU (Center Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), and an SSD (Solid State Drive). The CPU operates based on the operation system program and the print control program stored in the storage unit, forms a print job such as an image desired to be printed by the user, and transmits the print job to the DFE 102.

(Structure of DFE)
FIG. 2 is a block diagram of DFE102. As shown in FIG. 2, the DFE 102 has a CPU 201, a ROM 202, a RAM 203, an HDD (or SSD) 204, an external interface (I / F) 205, and an image output interface (image output I / F) 206. There is. A client PC 101 is connected to the I / F 205. An image forming apparatus 103 is connected to the image output I / F 206.

Based on the print job acquired from the client PC 101, such a DFE 102 forms drawing data for each color plate by the RIP (Raster Image Processor) engine and transmits the drawing data to the image forming apparatus 103.

(Configuration of image forming apparatus)
FIG. 3 is a block diagram of the image forming apparatus 103. As shown in FIG. 3, the image forming apparatus 103 includes a CPU 301, a ROM 302, a RAM 303, an HDD (or SSD) 304, an external interface (I / F) 305, and an image processing unit 306 and an image forming unit 307. ing. DFE102 is connected to I / F305. A client PC 101 is connected to the DFE 102.

The image forming program is stored in the ROM 302. Based on the image forming program, the CPU 301 controls the image forming operation by the image processing unit 306 and the image forming unit 307 as described later.

The image processing unit 306 performs image correction processing according to the engine output characteristics on the drawing data acquired from the DFE 102, and also converts the drawing data into print output data that can be printed out by the image forming unit 307. The image forming unit 307 transfers and outputs an image or the like corresponding to the print output data generated by the image processing unit 306 to paper.

(Structure of image forming part)
FIG. 4 is a diagram schematically showing the configuration of the image forming unit 307. As shown in FIG. 4, the image forming unit 307 is a so-called tandem type image forming unit, and is a photoconductor drum 403Y, 403M, 403C, 403K of each color of yellow, magenta, cyan, and key plate (black). (Sometimes referred to as a photoconductor drum 403 as a whole).

The photoconductor drum 403 is fed from the paper feed tray 400, and the intermediate transfer belt 402 from the upstream side in the transport direction, on which an intermediate transfer image for transferring to the paper transported by the transport roller 401 is formed, is the intermediate transfer belt. Photoreceptor drums 403Y, 403M, 403C, and 403K are arranged in this order along 402.

An image of each color developed with the toner of each color is superimposed on the intermediate transfer belt 402 and transferred onto the surface of the photoconductor drum 403 of each color to form a full-color image. The full-color image formed on the intermediate transfer belt 402 is transferred onto the paper surface of the paper transported on the path by the function of the transfer roller 404 at the position closest to the paper transport path shown by the broken line in FIG. Will be done. The paper on which the image is formed on the paper surface is further conveyed, and the image is fixed (image formation) by the fixing roller 405.

In the case of double-sided printing, the paper on which the image is formed on the front surface of the paper is conveyed to the inversion path 407 in the transfer path, the front and back surfaces are inverted, and the paper is transferred to the position of the transfer roller 404 again to be conveyed to the back surface of the paper. Image formation is performed.

The paper on which the image is fixed (paper for which printing has been completed) is discharged to the output port 406-1 or the output port 406.2. When there are a plurality of paper ejection ports, the paper ejection ports for outputting paper may be switched according to the print job.

(Comparative example printing system)
Next, a printing system as a comparative example of the printing system of the first embodiment will be described. FIG. 5 is a block diagram of a printing system as a comparative example. As shown in FIG. 5, in the printing system as a comparative example, the image processing unit 306 of the image forming apparatus 103 has a printing processing order determination unit 501 and a color plate processing unit 502. Further, the image forming unit 307 has a transfer error detecting unit 508.

The color plate processing unit 502 includes a print output data generation unit 503, an output unit 504, and an output control unit 507. The output unit 504 has a first page buffer memory 505 and a second page buffer memory 506.

In such a printing system as a comparative example, when the DFE102 receives a print job of the client PC 101, it receives a print image size, an output paper size, a color plate used in the page, a resolution, a print surface, a print management page ID, and the like. Form a print request containing the information of. The print request is formed based on the print job information, and is print management information for notifying the paper type, image size, page management ID information, image processing, print processing content, etc. required for printing. This print request is supplied to the print processing order determination unit 501 of the image forming apparatus 103.

The print job includes characters, image data, layout information, information indicating a paper type for printing, a print command for designating print processing contents, and the like.

The print process order determination unit 501 determines the page order in which the print process is executed based on the print request, forms print information in which the print process order information is added to the print request information, and causes the image forming unit 307 to form print information. Notice. Further, the print processing order determination unit 501 requests print data from the DFE 102 according to the print processing order. This print data request is a data transfer request for performing the next required drawing data using the page management ID according to the execution order of the print process.

When the color plate processing unit 502 of the image forming apparatus 103 acquires drawing data (Y / M / C / K) from the DFE 102, the color plate processing unit 502 performs image processing for each output color plate that can be handled by the image forming unit 307. The color plate processing unit 502 has a plurality of processing functions corresponding to the number of output color plates of Y / M / C / K. The drawing data is print image data obtained by converting the character and image information of the print job into a raster image for each of the Y, M, C, and K color plates.

The print output data generation unit 503 corrects the drawing data for each color plate from the DFE 102 by gradation processing such as dither processing and gamma processing according to the output characteristics so that the image forming unit 307 can output the drawing data. Apply processing.

The output unit 504 temporarily stores the print output data for one page image-processed by the print output data generation unit 503, and transmits the print output data to the image forming unit 307 via the output control unit 507. At this time, the output unit 504 switches and uses the first page buffer memory 505 and the second page buffer memory 506 to write and read data. This makes it possible to continuously transfer print output data. The print output data is image data converted into a format that can be output by the image forming apparatus 103 by performing halftone dot processing and gamma correction processing on the drawing data for each color plate.

The print output data generation unit 503 of the image processing unit 306 converts the drawing data acquired in the order of the print processing into the print output data in the bitmap format that can be output by the image forming unit 307. In addition to this conversion process, the print output data generation unit 503 also performs correction processing such as color correction and image processing such as print position adjustment according to the output characteristics of the image forming unit 307 and the user's request.

Even if the print output data is on the same page, in the case of the image forming unit 307 in which the photoconductor drums 403Y, 403M, 403C, and 403K of each color are arranged in tandem as shown in FIG. 4, the print output data for the image forming unit 307 is The transfer will be performed at different timings for each color plate. Therefore, the print data request and the drawing data corresponding to the print data request are transferred for each color plate, and the image processing in the image processing unit 306 is also performed for each color plate.

The image processing unit 306 temporarily stores the print output data for each color plate corresponding to the print data size notified in the print information in the first page buffer memory 505 and the second page buffer memory 506 of the output unit 504. Then, the image processing unit 306 reads the print output data for each color plate from the first page buffer memory 505 or the second page buffer memory 506 at the timing required by the image forming unit 307, and the image forming unit 307. Transfer to.

At this time, the page buffer memory for two sides of the page buffer memory in which the data generated by the print output data generation unit 503 is written and the page buffer memory in which the data to be output to the image forming unit 307 is read is alternately switched. By using it as a toggle buffer memory, it supports continuous print output.

The print processing order determination unit 501 confirms the transfer status of the print data in the color plate processing 502 by the print data transfer status notification, and when the print output is completed normally, the output result indicating that the print output is completed normally. Send the notification to DFE102. The output result notification is a page management ID for notifying the DFE 102 of the color plate for which print output has been completed. Upon receiving this output result notification, the DEF 102 shifts to the next drawing data generation process. Further, the DFE 102 notifies the completion of the print output by transmitting the print output result including the page management ID to the client PC 101 of the host device.

Here, in order to maintain the printing speed and maintain productivity by continuous printing output, it is necessary to transfer the print output data to the image forming unit 307 without delaying the timing of forming an image on the conveyed paper. be.

However, the delay in the generation of the drawing data in the DFE 102 causes a delay in the transfer of the drawing data, and also causes a delay in the processing of the print output data generation unit 503, so that the print output data for the page buffer memories 505 and 506 is delayed. There may be a delay in writing and reading. If the transmission of print output data to the image forming unit 307 is delayed due to such a delay, or if the print output data cannot be transmitted to the image forming unit 307, an abnormal image such as a missing image or a blank sheet is output and printing is performed. Productivity is reduced.

In order to prevent such an inconvenience that an abnormal image is output, in the printing system of the comparative example, necessary print output data is transferred when the transfer error detection unit 508 of the image forming unit 307 executes the printing process. Detects whether or not it is done. The fact that the print output data is not transferred means that an abnormality (delay) has occurred in the image processing unit 306 or DFE102, which is an upstream device. Therefore, the transfer error detection unit 508 notifies the print processing order determination unit 501 of the image processing unit 306 of an error notification including an error occurrence and a page management ID indicating the color plate page in which the error occurred. Further, the transfer error detection unit 508 monitors the transfer state for each color plate, and notifies the image processing unit 306 for each color plate when an error is detected. At the same time, the transfer error detection unit 508 controls the stop of the printing operation of the image forming unit 307 in order to prevent the output of the abnormal image.

The print processing order determination unit 501 transmits to DFE102 the interruption information indicating the page in which printing has not been completed normally by the error notification and the print data transfer status notification from the transfer error detection unit 508. The print data transfer status notification is a status management signal that triggers the transition to the print process interruption process when it is determined that the transfer of the print output data is not in time for the transfer output process in the image forming unit. Based on the interruption information, the DFE 102 notifies the client PC 101 of the interruption processing result indicating the page for which printing has not been completed.

When continuing the print job instructed when an error occurs, the user selects and operates print continuation via the operation panel after resolving the error state of the device. When print continuation is selected, the DFE 102 generates a print request instructing to resume printing from the continuation of the page for which normal printing is completed and supplies it to the image forming apparatus 103. As a result, the printing process can be restarted from the continuation of the interrupted print job.

(Problems of comparative example)
In such a printing system as a comparative example, the transfer error detection unit 508 detects an error depending on whether or not the print output data required at the time of executing the printing process is transferred. However, in the printing system as a comparative example, it was difficult to identify the location causing the error in the upstream device. Therefore, when the print stop state is controlled due to the occurrence of an error, the user needs to confirm the content of the error, return the device to the printable state, and then restart the print process.

To return the device to a printable state from the state in which an error occurred, reset processing of the entire image processing system including the DFE 102 and the image forming apparatus 103, and once turning off the power of the main body of the image forming apparatus 103 and then turning it on again. There is a problem that the user's printing work is stopped (downtime) during that work.

(Operation of the printing system of the embodiment)
For this reason, in the case of the printing system of the first embodiment, whether or not the print output data is ready in time is not determined at the time of executing the printing process in the image forming unit 307, but the image processing in the previous stage. The determination is made in advance based on the transfer state of the print output data in the unit 306.

Specifically, in the printing system of the first embodiment, as shown in FIG. 6, in addition to the configuration of the above-mentioned comparative example, the DEF 102 includes a retransmission processing determination unit 520, and the image forming apparatus 103 transfers an image. It is equipped with a monitoring unit 509. The printing system of the first embodiment is not provided with the transfer error detection unit 508 provided in the image forming unit 307 of the comparative example.

The image transfer monitoring unit 509 includes a transfer status monitoring unit 510 (an example of a delay detection unit) and a transfer abnormality notification unit 511 (an example of a control unit). The transfer status monitoring unit 510 monitors the write / read status of the page buffer memories 505 and 506 based on the buffer control status notification supplied from the output unit 504. When a transfer abnormality such as a write delay or a read delay for each of the page buffer memories 505 and 506 is detected, the transfer abnormality notification unit 511 instructs the image forming unit 307 to suspend printing.

That is, the output unit 504 transmits a buffer control status notification indicating the write status of the print output data from the print output data generation unit 503 to the page buffer memories 505 and 506 to the image transfer monitoring unit 509. The buffer control status notification is information for monitoring the transfer status of the print output data, and is information indicating the write status and the read status for the page buffer memories 505 and 506.

As the buffer control status notification, the "first write start detection notification" and the "first write completion detection notification" indicating the write status of the print data to the first page buffer memory 505 are supplied to the image transfer monitoring unit 509. To. Further, as the buffer control status notification, the "first read start detection notification" and the "first read completion detection notification" of the print data for the first page buffer memory 505 are supplied to the image transfer monitoring unit 509.

Further, as the buffer control status notification, the "second write start detection notification" and the "second write completion detection notification" indicating the write status of the print data to the second page buffer memory 506 are supplied to the image transfer monitoring unit 509. Will be done. Further, as the buffer control status notification, the "second read start detection notification" and the "second read completion detection notification" of the print data for the second page buffer memory 506 are supplied to the image transfer monitoring unit 509.

As an example, the image transfer monitoring unit 509 monitors the amount of data written or read from the page buffer memories 505 and 506 based on the data size information of the printed image indicated by the print request.

The output unit 504 starts writing data to the page buffer memories 505 and 506 on the first line with respect to the empty page buffer memory 505 or 506 based on the print image size information notified in the print request. When the image data for the main scan is written, the "first write start detection notification" or the "second write start detection notification" is transmitted to the image transfer monitoring unit 509.

Further, the output unit 504 will perform a "first write completion detection notification" or a "second write completion detection notification" when all the data for one page of the main scan and the sub scan are written in the page buffer memories 505 and 506. "Write completion detection notification" is transmitted to the image transfer monitoring unit 509.

Further, when the output unit 504 starts reading the print output data to be transferred from the first page buffer memory 505 or the second page buffer memory 506 to the image forming unit 307, the "first read start detection notification" is provided. Alternatively, a "second read start detection notification" is transmitted to the image transfer monitoring unit 509.

As an example, the output unit 504 monitors the amount of data read from the page buffer memories 505 and 506, respectively. Then, the output unit 504 detects the start of transfer when the image data for the main scan of the first line of the page buffer memories 505 and 506 is read and transferred.

Further, although it is an example, the output unit 504 completes the output of all the image data for one page of the main scan and the sub scan to the image forming unit 307, so that the buffer memories 505 and 506 become empty. At that time, the completion of reading is detected. Then, the output unit 504 transfers the "first read completion detection notification" or the "second read completion detection notification" to the image transfer monitoring unit 509.

The transfer status monitoring unit 510 recognizes the write status and the read status of the buffer memories 505 and 506 based on the buffer control status notification from the output unit 504. Then, when the transfer state monitoring unit 510 determines that the write state and read state of the buffer memories 505 and 506 are not in time for the print output timing of the image forming unit 307, the transfer abnormality notification unit 511 forms an image. Instruct unit 307 to suspend printing.

The interruption instruction is information for instructing the image forming unit 307 in association with the page management ID to specify the output destination of the page that has not been printed normally, stop the printing request that has not been started, and the like.

When the interruption instruction is supplied, the image forming unit 307 stops the print output operation and also stops the paper feeding operation of new paper from the paper feed tray 400. Further, the image forming unit 307 can print only the paper of the print page for which printing has been completed normally, the paper in which a part of the printed image is missing due to the stop of the print output operation, or the one-sided printing of double-sided printing. The completed paper is switched to a different paper ejection port 406-1 or paper ejection port 406.2 and ejected.

In the case of single-sided printing, the order is the print page order, but in the case of double-sided printing, the image forming unit 307 treats the pages where printing on both sides is completed as normal printing completed, and printing is completed only up to one side. For pages that are not printed or blank pages that have not been printed, paper ejection control is performed at a paper ejection destination (paper ejection port 406-1 or paper ejection port 406-2) that is different from normal printing. As a result, it is possible to prevent the inconvenience that incompletely printed paper is mixed in the normal printing result, and it is possible to facilitate the management of the normally output printing result.

Further, the print processing order determination unit 501 of the image processing unit 306 transmits the interruption information formed by associating the page that was normally printed out or the page that was not output by the interruption instruction with the page management ID to the DFE 102 of the host device. do. The retransmission processing determination unit 520 of the DFE 102 notifies the client PC 101 of the occurrence of the interruption processing and the interruption processing result. The client PC 101 recognizes the print completion page based on the interruption processing result, and notifies the user of the occurrence of the print interruption via the display unit (or the operation panel of the image forming apparatus 103 or the like).

When the user selects to resume the printing process via the client PC 101, the client PC 101 retransmits the print job from the page following the page on which printing is normally completed before the interruption, thereby performing the printing process. To continue.

That is, the retransmission processing unit 520 determines, among the interrupted print jobs, the portion where continuous printing is executed (the page next to the page where printing is normally completed) based on the interruption information, and the interruption resulting in this determination result. The processing result is notified to the client PC 101. Therefore, the client PC 101 retransmits the print job for resuming printing from the page indicated by the interruption processing result. As a result, it is possible to continue printing from the place where printing is interrupted, not from the print job unit.

(Check operation of write completion timing for page buffer memory)
Next, the operation of checking the write completion timing for the page buffer memory will be described. When the transfer of the print output data to the image forming apparatus 103 is completed, whether or not the transfer of the next print data to the page buffer memories 505 and 506 is completed is checked by the transfer status monitoring unit of the image transfer monitoring unit 509. 510 checks.

The transfer status monitoring unit 510 determines a state in which the print output data is not ready in the page buffer memories 505 and 506 due to the transfer of drawing data or the processing of the print output data generation unit 503 being in time. Then, when a transfer abnormality is detected by the transfer status monitoring unit 510, the transfer abnormality notification unit 511 interrupts the printing process after the corresponding page and performs a purge process for switching the output destination of the incomplete print output result. , Suspend instructions are supplied to the image forming unit.

(Write / read control for page buffer memory)
Next, write / read control for each of the page buffer memories 505 and 506 will be described with reference to FIG. 7. The print output data P1 of the first page shown in FIG. 7A, which is generated based on the drawing data from DFE102, is written to the first page buffer memory 505 and printed on the next page (second page). The output data P2 is written to the second page buffer memory 506.

The image forming unit 307 forms an image based on the print output data P1 read from the first page buffer memory 505 as shown in FIG. 7B according to the printing order for print output (image formation). .. When the reading of the print output data P1 from the first page buffer memory 505 is completed, the DFE 102 transfers the drawing data of the print output data P3 to the image processing unit 306. The image processing unit 306 converts the drawing data into print output data P3 and writes it in the first page buffer 505 as shown in FIG. 7B.

When the print image corresponding to the print output data P1 is output from the image forming unit 307, the second page buffer memory 506 starts reading the print output data P2 of the second page as shown in FIG. 7 (c). Will be done. At the time of continuous printing, the print data is continuously transferred to the image forming unit 307 while switching the write control and the read control for the page buffer memories 505 and 506 in this way.

(Transfer error)
Next, the operation at the time of transfer abnormality will be described. The transfer abnormality of the print output data is determined at the timing of the completion of reading from the page buffer memories 505 and 506 and the completion of writing on the next page. In FIG. 7, an example will be described in which data transfer is normally completed on the third page, a delay occurs in the data transfer on the fourth page, and an abnormality is detected.

When the reading of the print output data P1 from the first page buffer memory 505 is completed, the writing of the print output data P3 is started in the first page buffer 505. While the print output data P3 is being written, the print output data P2 is read from the second page buffer memory 506 as the print output of the second page and output to the image forming apparatus 307.

When the reading of the print output data P2 from the second page buffer memory 506 is completed, the second reading completion detection notification is supplied to the image transfer monitoring unit 509 as shown in FIG. 7C. Before the second read completion detection notification is supplied to the image transfer monitoring unit 509, the first write completion detection notification occupies the fact that the writing of the print output data P3 to the first page buffer memory 505 is completed. When is occurring, the image transfer monitoring unit 509 determines normal operation.

On the other hand, after the reading of the print output data P2 from the second page buffer memory 506 is completed, the second page that is vacant while the print output data P3 is being printed out by the image forming unit 307. The print output data P4 shown in FIG. 7A is written to the buffer memory 506.

Here, if the transfer of drawing data from the DFE 102 or the image processing in the print output data generation unit 503 is delayed, the print output to the second page buffer 506 as shown in FIGS. 7 (c) and 7 (d). The completion of writing the data P4 will also be delayed. When the print output of the print output data P3 by the image forming unit 307 is completed and the reading of the first page buffer memory 505 is completed, the first reading completion detection notification indicating this is sent from the output unit 504 to the image transfer monitoring unit. It is supplied to 509. In the example of FIG. 7, when the first read completion detection notification is supplied to the image transfer monitoring unit 509, the second writing completion detection notification indicating that the writing of the print output data P4 is completed is the image transfer monitoring unit. Not supplied to 509. In this case, the image transfer monitoring unit 509 determines that the preparation of the print output data is delayed, as shown in FIG. 7 (e).

When such a transfer abnormality is detected by the image transfer monitoring unit 509, the transfer abnormality notification unit 511 supplies an instruction to interrupt the printing process to the image forming unit 307. As a result, the print output of the print output data P4 and the image formation after the print output data P4 are stopped. The image forming unit 307 displays paper that has been printed on only one side even though double-sided printing is specified, and paper that has been fed into the transport path and cannot be returned to the paper feed tray. A paper ejection destination (paper ejection port 406-1 or paper ejection port 406.2) different from the normal printing result is specified and separated from the normal printing result. Further, the print processing order determination unit 501 supplies the interruption information indicating the page on which normal printing is completed and the page in which the processing is separated by the abnormality determination to the retransmission processing determination unit 520 of the DEF 102.

When the processing of the print job is completed and the transfer of the drawing data is completed, the print output data of the next page is not generated, so that it may be erroneously detected after the final page is printed. Therefore, the transfer status monitoring unit 510 determines the write completion detection for the page to which the print request is notified.

FIG. 8 is a flowchart showing the flow of the write / read operation for each of the page buffer memories 505 and 506 and the transfer abnormality determination operation. In each process of this flowchart, the CPU 301 controls the image processing unit 306, the image forming unit 307, and the like based on the image forming program stored in the storage unit such as the ROM 302 provided in the image forming apparatus 103. Will be executed.

In the flowchart of FIG. 8, in step S1, the transfer of the print output data from the output control unit 507 to the image forming unit 307 is started. When the transfer of the print output data is started, the transfer status monitoring unit 510 receives the first read completion detection notification (or the second read completion detection notification) supplied from the output unit 504. It is determined whether or not the reading of the print output data is completed from the page buffer memory 505 (or the second page buffer memory 506) (step S2).

When it is determined that the print output data has been read from the first page buffer memory 505 (or the second page buffer memory 506), the print processing order determination unit 501 determines that the next page is based on the print request from the DEF 102. It is determined whether or not there is a print request (step S3). If there is no print request for the next page (step S3: No), the entire process of the flowchart of FIG. 8 is terminated as it is.

On the other hand, when there is a print request for the next page (step S3: Yes), the transfer status monitoring unit 510 determines whether the page buffer memory for reading the print output data is the first page buffer memory 505. (Step S4).

When the page buffer memory for reading the print output data is not the first page buffer memory 505 (step S4: No), the process proceeds to step S8, and the transfer status monitoring unit 510 notifies the first write completion detection. It is determined whether or not the writing of the print output data of the next page to the first page buffer memory 505 is completed based on the presence or absence of the supply (step S8).

When the writing of the print output data of the next page to the first page buffer memory 505 is completed (step S8: Yes), the output unit 504 sets the page buffer memory to be read to the first page buffer memory 506. Switching control is performed (step S9). As a result, the process returns to step S1, and the print output data of the next page written in the first page buffer memory 506 is read out and supplied to the image forming unit 307.

On the other hand, the fact that the reading is not from the first page buffer memory 505 (step S4: No) means that the reading is from the second page buffer memory 506, and at this time, the first is empty. The fact that the writing of the print output data of the next page to the page buffer memory 505 of No. 1 is not completed (step S8: No) means that the writing delay to the first page buffer memory 505 has occurred. ..

Therefore, the transfer status monitoring unit 510 supplies an error notification indicating that the reception of the print output data has been delayed to the transfer abnormality notification unit 511 (step S6). When this error notification is supplied, the transfer abnormality notification unit 511 instructs the image forming unit 307 to suspend printing. As a result, printing is canceled (step S7).

On the other hand, if it is determined in step S4 that the print output data is read from the first page buffer memory 505 (step S4: Yes), the process proceeds to step S5. In step S5, the transfer status monitoring unit 510 determines whether or not the writing of the print output data of the next page to the second page buffer memory 506 is completed based on whether or not the second write completion detection notification is supplied. Determine.

When the writing of the print output data of the next page to the second page buffer memory 506 is completed (step S5: Yes), the output unit 504 sets the page buffer memory to be read to the second page buffer memory 506. Switching control is performed (step S9). As a result, the process returns to step S1, and the print output data of the next page read from the second page buffer memory 506 is transferred to the image forming unit 307.

On the other hand, at the time of reading the print output data to the first page buffer memory 505 (step S4: Yes), the writing of the print output data of the next page to the second page buffer memory 506 is not completed. (Step S5: No), it means that there is a delay in writing the print output data of the next page to the second page buffer memory 506. Therefore, the transfer status monitoring unit 510 supplies an error notification indicating that the reception of the print output data has been delayed to the transfer abnormality notification unit 511 (step S6). When this error notification is supplied, the transfer abnormality notification unit 511 instructs the image forming unit 307 to suspend printing. As a result, printing is canceled (step S7).

(Print stop operation and print restart operation)
Next, the operation from the print stop operation to the print restart operation by the error notification will be described with reference to the flowchart of FIG. In each process of the flowchart of FIG. 11, the CPU 301 controls the image processing unit 306, the image forming unit 307, and the like based on the image forming program stored in the storage unit such as the ROM 302 provided in the image forming apparatus 103. It is executed by doing.

In the flowchart of FIG. 11, when the continuous execution of the print process is selected and the print operation is interrupted because the print output data is not prepared in time (step S21: transfer error detection), the client PC 101, DFE 102 and the image formation are formed. The device 103 is. The print cancellation process based on the interruption information is performed (step S22).

When the print cancellation process is completed (step S23: Yes) and the automatic print restart process is selected and operated by the user via the client PC (step S24: Yes), the client PC 101 has a ROM, RAM, HDD, or the like. Printing restart information including page information for which normal printing has been completed is stored in the storage unit (step S25).

Next, the client PC 101, DFE 102 and the image forming apparatus 103. After the print cancellation process based on the interruption information, self-diagnosis is executed respectively (step S26). The content of the self-diagnosis is the content executed when the power of each unit is turned on, or the operation content equivalent thereto, and the content of the inspection is such that the operation of the unit can be guaranteed.

When it is determined from the execution result of such self-diagnosis that the printing process can be continued (step S27: Yes, step S28: Yes), the client PC 101 and DFE 102 print following the normal printing result based on the printing restart information. The operation is restarted, and the printing process is continuously executed (step S29).

Further, the client PC 101 and DFE 102 display information indicating that printing is interrupted and restarted, a print job in which the interruption has occurred, and information on the generated page on the screen of the client PC 101, or on the operation panel of the DFE 102 or the image forming apparatus 103. Display (step S30). The user can confirm the print result later by the information notification of the interruption / restart location.

On the other hand, when it is determined by the self-diagnosis that it is difficult to restart printing (step S28: No), the client PC 101, DFE 102 and the image forming apparatus 103. Perform a hardware reset process (initialization process) (step S31, step S32). As a result, the client PC 101, DFE 102, and the image forming apparatus 103 can execute initialization without turning the power on and off, respectively, and can try to eliminate the error state.

When executing the hardware reset process, it is confirmed whether or not the print restart information is stored in the storage unit in the device startup process after the reset (step S33, step S34), and the print restart information is stored. When stored in the unit (step S34: Yes), the printing operation following the normal printing is restarted and the printing process is continued (step S29).

On the other hand, when the print restart information is not stored in the storage unit (step S34: No), the user is notified of the print interruption via the display unit of the client PC 101, the operation panel of the image forming unit 103, or the like. (Step S35).

As described above, in the printing system of the first embodiment, the printing process can be continuously executed without the user selecting to restart the printing process. Therefore, the downtime of the printing system can be reduced.

(Effect of the first embodiment)
As is clear from the above description, in the printing system of the first embodiment, the image forming unit 307 does not determine whether or not the print output data is ready in time, but the print output data. At the time of transfer, the image processing unit 306 in the previous stage determines in advance. Specifically, the transfer status monitoring unit 510 monitors the write status and the read status of the page buffer memories 505 and 506 based on the buffer control status notification supplied from the output unit. Then, when the transfer status monitoring unit 510 determines that the print output timing of the image forming unit 307 is not in time, the transfer abnormality notification unit 511 gives an instruction to interrupt printing to the image forming unit 307.

When the interruption instruction is supplied, the image forming unit 307 stops the print output operation and also stops the paper feeding operation of new paper from the paper feed tray 400. At the same time, the paper for which normal printing has been completed is ejected to the paper ejection port for the paper for which normal printing has been completed, and the page where the image is missing due to the stop of the print output operation, and only one side of double-sided printing. Paper for incomplete pages, such as pages that have not been printed, is ejected to the paper ejection slot of this incomplete page.

Further, the image processing unit 306 notifies the client PC via the DEF 102 of the information of the page for which normal printing is completed as interruption information. The client PC 101 notifies the user of the interruption of printing via the display unit or the like. When the user instructs to restart the print process, the print job information from the continuation page of the normal print completion page before the interruption is retransmitted from the client PC 101, and the print process is continuously restarted.

This makes it possible to prevent the output of abnormal images and reduce the downtime of the printing system.

[Second Embodiment]
Next, the printing system according to the second embodiment will be described. In the case of the second embodiment, the transfer status monitoring unit 510 shown in FIG. 6 sets the write start timing to the empty page buffer and the read start timing from the page buffer not performing the write operation. Based on this, the transfer abnormality of the print output data is determined. Other than this point, the same configuration and operation as those of the first embodiment described above are shown. Therefore, in the following, only the difference between the two will be explained, and the duplicate explanation will be omitted.

Next, write / read control for each of the page buffer memories 505 and 506 will be described with reference to FIG. FIG. 9 shows an example in which normal data transfer is completed on the third page and a delay occurs in the data transfer on the fourth page to detect an abnormality.

First, as shown in FIGS. 9A and 9B, by reading the print output data P1 from the first page buffer memory 505, the print output data P3 is applied to the first page buffer 505. Can be written. The print output of the print output data P2 is such that the print output data P2 is used as the print output of the second page from the second page buffer memory 506 after the paper-to-paper transfer time of the paper has elapsed after the printing of the print output data P1 is completed. It is transferred to the forming apparatus 307. As a result, the second read start detection notification indicating the start of reading the print output data P2 from the second page buffer memory 506 is supplied from the output unit 504 to the image transfer monitoring unit 509 as shown in FIG. 9 (c). Will be done.

The writing of the print output data P3 to the first page buffer memory 505 can be started earlier than the output start of the print output data P2 by the amount of paper-to-paper transfer time. Therefore, the transfer status monitoring unit 510 starts the first writing of the print output data P3 to the first page buffer memory 505 when the second read start detection notification to the second page buffer memory 506 is supplied. If the detection notification is supplied, it is determined that the transfer operation of the next page is normally started as shown in FIG. 9D.

On the other hand, as shown in FIGS. 9 (b) and 9 (c), the transfer status monitoring unit 510 starts reading the print output data P3 from the first page buffer memory 505, and then the next It is determined whether or not the writing to the second page buffer memory 506 of the print output data of the print output data P4 which is a page has started.

As shown in FIGS. 9 (b) and 9 (c), when the first read start detection notification indicating that the print output data P3 has started to be read is supplied from the first page buffer memory 505, The second write start detection, which indicates the start of writing of the print output data P4 to the second page buffer memory 506, has not occurred. Therefore, as shown in FIG. 9D, the transfer condition monitoring unit 510 determines that there is a problem in preparing the print output data P4. As a result, the transfer abnormality notification unit 511 notifies the image forming unit 307 of the interruption instruction, and the print output of the print output data P4 and the image formation after the print output data P4 are stopped.

The transfer status monitoring unit 510 determines whether to start reading the print output data at the timing of starting reading from the page buffer memories 505 and 506. However, if a transfer buffer memory is provided in the transfer path from the page buffer memories 505 and 506 to the output control unit 507 and the image forming unit 307, the timing at which the image forming unit 307 starts actual writing. The read operation may be started from the page buffer memory at an earlier timing. Therefore, the transfer status monitoring unit 510 reads out the image data for the main scan or the image data for the main scan × the number of designated lines based on the print image size information notified by the print request from the DEF 102. The determination may be made under the condition that the detection timing is delayed so as to detect.

FIG. 10 is a flowchart showing a flow of a write / read operation for each page buffer memory 505 and 506 and a transfer abnormality determination operation in the printing system of the second embodiment. In each process of the flowchart of FIG. 10, the CPU 301 controls the image processing unit 306, the image forming unit 307, and the like based on the image forming program stored in the storage unit such as the ROM 302 provided in the image forming apparatus 103. It is executed by doing.

In the flowchart of FIG. 10, when there is a print request for the next page in step S3 as described above (step S3: Yes) and the process proceeds to step S4, the transfer status monitoring unit 510 notifies the first read start detection. Based on the above, it is determined whether or not the reading of the print output data is started from the first page buffer memory 505.

When it is determined that the reading of the print output data has started from the first page buffer memory 505 (step S4: Yes), the process proceeds to step S5. In step S5, the transfer status monitoring unit 510 determines whether or not the writing of the print output data to the second page buffer memory 506 has already started based on the second write start detection notification.

Although the reading from the first page buffer memory 505 has been started (step S4: Yes), the writing of the print output data of the next page to the second page buffer memory 506 has not been started. (Step S5: No), which means that a delay error in the print output data has occurred. Therefore, the transfer status monitoring unit 510 notifies the transfer error notification unit 511 of the delay error of the print output data (step S6). As a result, the transfer abnormality notification unit 511 notifies the image forming unit 307 of the interruption instruction, and the print cancellation process is performed as described above (step S7).

On the other hand, when reading from the first page buffer memory 505 has started (step S4: Yes) and writing of the print output data of the next page to the second page buffer memory 506 has already started (step S4: Yes). Step S5: Yes), the process proceeds to step S11.

In step S11, whether or not the transfer status monitoring unit 510 has completed writing the print output data of the next page to the second page buffer memory 506 based on the second write completion detection notification supplied from the output unit 504. To determine. The output unit 504 waits for the completion of writing the print output data of the next page to the second page buffer memory 506 (step S11: Yes), and switches and controls the page buffer memory to be written to the first page buffer memory 505. ..

On the other hand, reading from the first page buffer memory 505 has not started (step S4: No), and writing of the print output data of the next page to the first page buffer memory 505 has not been started (step S4: No). Step S8: No), which means that a delay error in the print output data has occurred. Therefore, the transfer status monitoring unit 510 notifies the transfer error notification unit 511 of the delay error of the print output data (step S6). As a result, the transfer abnormality notification unit 511 notifies the image forming unit 307 of the interruption instruction, and the print cancellation process is performed as described above (step S7).

On the other hand, when the reading from the first page buffer memory 505 has not started (step S4: No) and the writing of the print output data of the next page to the first page buffer memory 505 has already started. (Step S8: Yes), the process proceeds to step S11.

In step S11, whether or not the transfer status monitoring unit 510 has completed writing the print output data of the next page to the first page buffer memory 505 based on the first write completion detection notification supplied from the output unit 504. To determine. The output unit 504 waits for the completion of writing the print output data of the next page to the first page buffer memory 505 (step S11: Yes), and switches and controls the page buffer memory to be written to the second page buffer memory 506. ..

As a result, the same effect as that of the first embodiment described above can be obtained.

Finally, each of the above embodiments is presented as an example and is not intended to limit the scope of the invention. Each of the novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Such embodiments and variations of each embodiment are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

101 Client PC
102 Information processing equipment (DEF)
103 Image forming device 306 Image processing unit 307 Image forming unit 400 Paper feed tray 406-1 Paper ejection port 406-2 Paper ejection port 501 Printing processing order determination unit 503 Print output data generation unit 504 Output unit 505 First page Buffer memory 506 Second page Buffer memory 507 Output control unit 509 Image transfer monitoring unit 510 Transfer status monitoring unit 511 Transfer error notification unit 520 Retransmission processing determination unit

Japanese Unexamined Patent Publication No. 2008-404172

Claims (6)

An image forming apparatus that sequentially writes and reads print information to a plurality of storage units, supplies the print information read from each of the storage units to an image forming unit, and prints the print information on paper.
A delay detection unit that detects a write delay of the print information for each storage unit, and a delay detection unit.
When the writing delay is detected by the delay detection unit, the image forming unit is controlled so as to eject the paper that has already been fed and to stop the paper feeding from the paper feeding unit. A control unit that interrupts the printing process,
An image forming apparatus characterized by having. After detecting the writing delay of the print information for each storage unit, the delay detection unit determines whether or not the writing delay of the print information for each storage unit is eliminated.
The control unit is characterized in that the image forming unit is controlled so as to restart printing when it is determined by the delay detection unit that the writing delay of the print information for each storage unit has been eliminated. The image forming apparatus according to claim 1. The image forming apparatus according to claim 2, wherein the control unit controls the image forming unit so that printing is restarted from the page next to the page on which printing is completed. The control unit controls the image forming unit so that the paper for which printing has not been completed is ejected from a paper ejection port different from the paper ejection port for which printing has been completed.
The image forming apparatus according to any one of claims 1 to 3, wherein the image forming apparatus is characterized. It is an image forming method of an image forming apparatus that sequentially writes and reads print information to a plurality of storage units, supplies the print information read from each of the storage units to an image forming unit, and prints the print information on paper. hand,
A delay detection step in which the delay detection unit detects a write delay of the print information for each storage unit, and
When the write delay is detected by the delay detection unit, the control unit ejects the paper that has already been fed, and at the same time, causes the image forming unit to stop feeding the paper from the paper feed unit. A control step that interrupts the printing process by controlling
An image formation control method characterized by having. An image forming program of an image forming apparatus that sequentially writes and reads print information to a plurality of storage units, supplies the print information read from each of the storage units to an image forming unit, and prints the print information on paper. hand,
Computer,
A delay detection unit that detects a write delay of the print information for each storage unit, and a delay detection unit.
When the writing delay is detected by the delay detection unit, the image forming unit is controlled so as to eject the paper that has already been fed and to stop the paper feeding from the paper feeding unit. To function as a control unit that interrupts the printing process,
An image formation program characterized by.

Images