JP2006172199A - Image forming system, image supply side device, and printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently transfer additional information in a system in which a device on an image sending side transfers image data to a device on an image receiving side. <P>SOLUTION: In a controller 100 on an image sending side, a multiplexing part 130 outputs page image data and additional information to an image data line 148 while a page synchronization signal is on and off, respectively. In a receiving printing apparatus 200, a de-multiplexing control part 230 sorts the data received from the image data line 148 to a printing part 240 as the page image data and an analysis part 250 as the additional information while the page synchronization signal is on and off, respectively. The analysis part 250 extracts information on each item from the additional information and passes it to a main control part 210, and the main control part 210 uses the additional information to execute various controls. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming system that supplies image data of a page via an image data line from an image supply side apparatus to a printing apparatus during a period in which a page synchronization signal is on level.

  For example, an image forming apparatus such as a copying machine or a multifunction peripheral has a video interface for image data transmission, and sequentially transmits or receives image data at a predetermined timing for each line via the interface. For image data transmission / reception, a horizontal synchronization signal (LSYNC) as a line synchronization signal indicating the start and end of a line and a vertical synchronization signal (PSYNC) as a page synchronization signal indicating the start and end of a page are used as image data. At the same time, it is necessary to transmit and receive, and to synchronize between the transmission side and the reception side.

  In Patent Document 1, an image data transfer synchronization signal is supplied from an image data receiving device to an image data transfer device, and the image data transfer device generates a resynchronization signal from the synchronization signal. An image data transfer mechanism for transferring a synchronized image data signal to an image data receiving device is disclosed.

  In Patent Document 2, generation parameters such as a line synchronization signal and a page synchronization signal are supplied as header information preceding image data from the image data transmission side to the image data reception side via the image data line. A system is disclosed in which the receiving apparatus reproduces these synchronization signals based on the header information to realize synchronous image transmission between the transmitting and receiving sides. This method has an advantage that a signal line for transmitting a page synchronization signal or a line synchronization signal between the transmission side and the reception side becomes unnecessary.

Japanese Patent No. 2842210 JP 2001-345964 A

  When considering a digital page printing system, some recent high-end systems include a controller that generates image data for printing based on a printing instruction from a host computer, and image data supplied from the controller for paper. Some printers are configured separately from the printing apparatus for printing. In the case of this type of high-end system, since relatively high-level control is performed on the printing apparatus side, it is necessary not only to transfer page image data from the controller to the printing apparatus but also to transfer other control information. This type of control information includes, for example, page numbers necessary for duplex printing and page printing order control, resolution information used for setting the print resolution, and the like. In addition, for the cooperative processing flow control between the controller and the printing apparatus, handshake information for notifying which processing stage each apparatus is in is also such control information. Further, as the control of the printing apparatus becomes complicated, it is desired to be able to check whether there is an error in the printed page image data. Information necessary for this check is used as control information. It may be necessary to transfer.

  In a conventional system, this type of control information is transmitted via a signal line provided separately from a signal line for image data transfer and a signal line for synchronization signal transfer.

  As described above, in the method of transmitting the control information through the individually provided signal lines, an interface dedicated to the signal line is required on the transmission side and the reception side, and the apparatus becomes complicated. Also, special processing is required to ensure synchronization between the control information and the page image data, which is a burden on the transmission side and reception side devices.

  The method of Patent Document 2 can transmit the synchronization signal and the image data through the same data line, but does not consider transmission of other control information.

  An image forming system according to the present invention includes an image supply side device and a printing device that operate according to a common page synchronization signal, and image data lines from the image supply side device to the printing device during a period in which the page synchronization signal is on level. In the image forming system that transmits the image data of the page via the printer and prints the image supply side device, an image supply unit that supplies the image data of the page to be transmitted to the printing device, and processing control in the printing device The first additional information supply unit for supplying first additional information used for the purpose, the output of the image supply unit and the output of the first additional information supply unit are time-division multiplexed and the printing apparatus via an image data line The image data supplied from the image supply unit when the page synchronization signal is on level and supplied from the first additional information supply unit during the off level period And a multiplexing unit that outputs the additional information to the image data line, and the printing apparatus outputs the data in the period when the page synchronization signal is on level among the data input from the image data line. The data in the off-level period is extracted as first additional information, and a print processing unit that executes print processing based on the image data of the page extracted by the demultiplexing unit. A print processing unit that controls the print processing according to the first additional information.

  The image forming system control method according to the present invention includes an image supply side device and a printing device that operate according to a common page synchronization signal, and the image supply side device to the printing device during a period in which the page synchronization signal is on level. And an image forming system that transmits and prints page image data via an image data line, and the printing apparatus controls the printing process during a period when the page synchronization signal is at an off level. Additional information to be used is transmitted from the image supply side apparatus to the image printing apparatus via the image data line.

  The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described below with reference to the drawings.

  FIG. 1 is a functional block diagram showing an example of an image transmission system according to the present invention. Here, a system for printing on a sheet in accordance with a print instruction from a host computer is taken as an example.

  This system includes a controller 100 and a printing apparatus 200.

  The controller 100 acquires print data from the host computer, generates image data (for example, raster image data) that can be handled by the printing apparatus 200 from this data, and supplies this to the printing apparatus 200. If the print data is data in a page description language, the controller 100 interprets it and creates image data for each page. In the case of fixed form printing such as a form, the controller 100 has fixed form data (this data is registered in advance by the system operator), and each data value in the print data input from the host computer. Is applied to the standard format to create and output image data for each page.

  The above functions of the controller 100 are known, and the main control unit 110 is shown in the drawing as means for performing such functions.

  The main control unit 110 is typically configured by a computer including a processor, a memory, and the like and a control program executed by the computer. In some cases, a part of functions required therein, for example, image processing, etc. The function may be provided as a dedicated arithmetic circuit. In addition to generating image data for each page as described above, the main control unit 110 generates various additional information used when the printing apparatus 200 executes processing.

  Such additional information includes, for example, print attribute information such as page number, paper size, and print resolution information, and a ready signal indicating that the page image data is ready, for a cooperative operation with the printing apparatus. Handshake information, etc. These are supplied from the controller to the printing apparatus in the conventional printing system. Based on an instruction from the host computer, the main control unit 110 generates such additional information at a timing when the information is required as in the conventional method by a conventionally known method. Further, the main control unit 110 generates error detection data for inspecting whether the generated page image data is correctly printed as one of the additional information. This error detection data is obtained by a method such as a checksum or CRC (Cyclic Redundancy Check Code). For example, a checksum of pixel values of each row of image data of one page is obtained, and error check data is obtained by adding the checksum for each row over all rows of one page. That is, in a recent image forming apparatus, a halftone image (multi-tone) is converted into a binary pseudo halftone image by digital halftone processing, and this is supplied to the printing unit 240 for printing. This error detection data may be obtained for this binary image.

  The controller 100 generates synchronization signals such as a video clock, a line synchronization signal, and a page synchronization signal in order to print the generated page image data in cooperation with the printing apparatus 200. Each of these synchronization signals is generated by the synchronization signal generator 120 and supplied to the printing apparatus 200 via the video clock line 142, the line synchronization signal line 144, and the page synchronization signal line 146. The video clock is a clock that is a basic unit of image data transfer, and one period thereof is, for example, a period for transmitting data (for example, 1 byte) for one pixel (or one color of one pixel) in the image data. The line synchronization signal is a signal indicating a data period of one line (row) of page image data, and the printing apparatus 200 is a data signal supplied from the image data line 148 during a period in which this signal is on. Is acquired as one line of image data. The page synchronization signal is a signal indicating a data period of one page, and the printing apparatus 200 acquires a data signal supplied from the image data line 148 as image data for one page during a period in which the signal is on. To do. FIG. 2 schematically shows the relationship between the line synchronization signal and the page synchronization signal. Such a synchronization signal is the same as that conventionally used, and may be generated and transmitted by a conventionally known method.

  In the present embodiment, the image data of the page generated by the main control unit 110 and the additional information are input to the multiplexing unit 130, and the multiplexing unit 130 time-division multiplexes both the data to generate an image data line. To 148. This multiplexing is performed based on the page synchronization signal generated by the synchronization signal generation unit 120. That is, as shown in the time chart of FIG. 2, the multiplexing unit 130 converts the image data of one page supplied from the main control unit 110 into a video clock or the like during a period in which the page synchronization signal is on level (active). Output sequentially to the image data line 148 according to the line synchronization signal, and output additional information supplied from the main control unit 110 to the image data line 148 during a period in which the page synchronization signal is at the off level (inactive).

  Note that not all of the additional information exemplified above is transferred for each off-level period of the page synchronization signal. For example, the resolution information may be sent when, for example, one print job is started, and a signal indicating completion of generation of page image data for handshaking may be sent at the time of completion. As described above, since the various types of additional information exemplified above have been conventionally generated by the controller 100 and transmitted using the dedicated data communication line, the various types of additional information are required by the same processing as in the past. The generated additional information may be output to the image data line 148 during a period close to the timing in the off-level period of the page synchronization signal. The error detection data for the page image data can generally be obtained only after the page image data is generated. Therefore, the error detection data may be transferred during the next off-level period after the page image data is transferred. . When sending additional information during the off-level period, a bit string of a predetermined pattern indicating that it is additional information is sent to the head of the additional information, and then data of individual additional information items such as page number, resolution, error detection data, etc. are sent. . A header or the like for identifying each item is added to each item of the additional information so that the printing apparatus 200 can identify each item.

  The controller 100 has been described above. Next, the printing apparatus 200 will be described.

  The printing apparatus 200 prints image data of each page supplied from the controller 100 on a sheet according to a video clock, a line synchronization signal, and a page synchronization signal.

  The main control unit 210 of the printing apparatus 200 is an apparatus that controls the entire printing apparatus 200, and typically includes a computer including a processor and a memory and a control program executed by the computer. Some of the functions required therein, for example, functions such as image processing may be provided as a dedicated arithmetic circuit. The main control unit 210 receives a video clock, a line synchronization signal, and a page synchronization signal supplied from the controller 100, and controls each unit in the printing apparatus 200 according to these.

  The buffer 220 is a first-in first-out memory that temporarily stores data input via the image data line 148 for timing adjustment with the demultiplexing process performed by the demultiplexing control unit 230. The demultiplexing control unit 230 distributes the output destination of the output data of the buffer 220 between the printing unit 240 and the analysis unit 250 according to the page synchronization signal input from the page synchronization signal line 146. That is, switching is performed so that the output of the buffer 220 is given to the printing unit 240 while the page synchronization signal is on level, and the output of the buffer 220 is given to the analysis unit 250 while it is off level. By such switching, the printing unit 240 can acquire image data of a necessary page at a conventional timing, and can execute printing. On the other hand, the analysis unit 250 receives additional information sent via the image data line 148 during the off-level period, identifies and extracts data of each item from this additional information, and sends it to the main control unit 210. The main control unit 210 performs processing according to each item of the received additional information. In the case of print attribute information, handshake information, and the like, the same processing as that in the case where these pieces of information have been received via a conventional dedicated data communication line may be performed. How to use the error detection data will be described below with reference to FIG.

  In the example shown in FIG. 3, a case is shown in which a sheet 300 provided with a non-contact IC tag 310 such as an RFID (Radio Frequency IDentification) tag in the form of punching or sticking is used. The printing apparatus 200 includes a tag writer 250 and a tag reader 260 on the paper transport path 248. The tag writer 250 is provided upstream of the printing mechanism including the photosensitive member 246, the developing unit, the transfer unit, and the fixing unit (not shown), for example, in the vicinity of the exit of the paper feed tray, and the error detection data acquired as additional information. Is written in the non-contact IC tag 310 of the paper 300 in accordance with the control of the main control unit 210. Since it is necessary to write error detection data corresponding to the image data of the page printed on the paper 300 to the non-contact IC tag 310 of the paper 300, the transmission timing of the error detection data from the controller 100 and the tag writer 250 The position is set within a range that satisfies the necessary conditions. For example, if the page image data arrives from the controller 100 and the paper for the page is fed from the paper feed tray, a tag writer 250 may be provided near the exit of the paper feed tray.

  Now, the sheet 300 thus fed and corresponding error detection data written to the non-contact IC tag 310 is subjected to printing of corresponding page image data by a printing mechanism including the photosensitive member 246. Here, the print control unit 242 in the printing unit 240 generates a binary laser drive signal of an on / off pattern based on the page image data supplied from the buffer 220, and a laser diode (LD) is generated by this drive signal. ) 244 is driven to sensitize the photosensitive member 246 with the pattern of the page image. As a result, the developed image on the photoreceptor 246 is developed with toner, transferred to the paper 300, and fixed.

  In this embodiment, the laser drive signal supplied to the LD 244 at this time is also supplied to the main control unit 210. The main controller 210 applies the same algorithm that the controller 100 uses to generate error detection data of the page image data to the on / off pattern of the laser drive signal for one page. Error detection data corresponding to the image used for printing the page is obtained. Then, the main control unit 210 reads the error detection data from the non-contact IC tag 310 of the paper 300 by the tag reader 260 provided downstream of the photoconductor 246 and compares it with the error detection data obtained from the laser drive signal. . If the two match, the main control unit 210 assumes that the correct page image data has been printed on the paper 300, and discharges the printed paper 300 to the normal paper tray 282. The destination switching unit 270 is switched. On the other hand, if they do not match, the paper discharge switching unit 270 switches the paper to the abnormal paper tray 284.

  As described above, according to the configuration of FIG. 3, the error detection data provided from the controller 100 to the printing apparatus 200 as additional information is used up to the stage of the laser drive signal, but the correct page to be printed on the paper 300 is detected. It can be determined whether or not printing processing has been performed. Therefore, it is possible to detect an error such as the order of pages to be printed on the printing apparatus 200 side being changed, or the image of the page being changed by image processing or signal processing on the printing apparatus 200 side.

  In the example of FIG. 3, the error detection data supplied from the controller 100 is written to the non-contact IC tag 310 of the paper 300, so that the correspondence between the paper 300 and the error detection data of the image to be printed thereon is correlated. Management becomes easy.

  In the above, the discharge destination of the printed paper is switched according to the print error detection result using the error detection information, but this is just an example. In addition, for example, it is possible to perform control such as stopping the printing operation of the printing apparatus 200 when a printing error is detected.

  Here, the electrophotographic printing unit has been described as an example, but such a printing error check mechanism can also be applied to other types of printing units such as an inkjet method.

  In the above example, error detection information is written to the non-contact IC tag 310. In addition to this, page number information, which is additional information, is written from the writer 250, and laser driving is performed when printing on the corresponding paper. The page number is detected from the image indicated by the signal or the image obtained by reading the printed paper 300, and this is combined with the page number read by the reader 260 to determine whether the page order is correctly printed. You can also.

  Further, information on the paper size as additional information is written in the non-contact IC tag 310 by a tag writer provided near the exit of the paper feed tray, and the actual paper size detected by the paper size sensor on the paper transport path 248; It is also preferable to determine whether the paper size read from the non-contact IC tag 310 matches. By doing this, it is possible to detect, for example, when a wrong size paper is mixed on the paper feed tray.

  If the tag reader 260 is replaced with a writable reader / writer and error detection results and the like are written in the non-contact IC tag 310, the result can be read out from the tag 310 of the printed paper. Even if the destination switching unit 270 malfunctions, an incorrect print result can be found later.

  As described above, in the present embodiment, the transmission capacity of the image data line 148 is effectively used while the page synchronization signal that has not been used in the past is in the off period, and the image data and the synchronization signal of the page are excluded. Various kinds of additional information can be transferred, and there is an advantage that a separate communication line for transferring additional information becomes unnecessary. Further, when a request for exchanging information that has not been exchanged between the conventional controller 100 and the printing apparatus 200 is generated, the conventional system needs to provide an interface for the controller 100 and the printing apparatus 200. The configuration of this embodiment can cope with such a case without changing the hardware configuration.

  The case where additional information is provided from the controller 100 to the printing apparatus 200 has been described above. However, if the image data line 148 can be bidirectionally communicated by a half-duplex method or the like, the page synchronization signal is turned off. During a certain period, the printing apparatus 200 can send additional information, which has been sent through a dedicated data communication line, to the controller 100. Examples of such additional information include handshake information for flow control of print processing such as completion of warm-up and a request for transmission of image data for the next page.

  The system configuration that supplies various synchronization signals from the controller 100 to the printing apparatus 200 has been described above. However, as disclosed in Patent Document 1, the printing apparatus generates a synchronization signal such as a video clock and provides it to the controller. The system of this embodiment can also be applied to a system configuration in which the controller generates and controls the resynchronization signal based on the video clock.

  In the above description, the controller 100 generates image data and additional information and provides the printing apparatus 200 with the image data and additional information. However, such a controller 100 is provided with a printer interface unit as disclosed in Patent Documents 1 and 2. The system of the above embodiment can also be applied to the system configuration replaced with. That is, in this case, the printer interface unit receives the image data and additional information of the page from the host device, temporarily stores them in the buffer memory, multiplexes them in synchronization with the printing device 200, and passes through the image data line 148. Is provided to the printing apparatus 200. Accordingly, when viewed inside the printer interface unit, the buffer memory is a supply source of page image data and additional information.

It is a block diagram which shows the structural example of the system which concerns on this invention. It is a figure which shows the relationship between a synchronizing signal and the signal on an image data line. FIG. 4 is a diagram illustrating an example of a configuration for a print check using error detection data in a printing apparatus.

Explanation of symbols

  100 controller, 110 main control unit, 120 synchronization signal generation unit, 130 multiplexing unit, 142 video clock line, 144 line synchronization signal line, 146 page synchronization signal line, 148 image data line, 200 printing device, 210 main control unit, 220 buffer, 230 demultiplexing control unit, 240 printing unit, 250 analysis unit.

Claims (10)

An image supply side device and a printing device that operate according to a common page synchronization signal are provided, and image data of a page is transmitted from the image supply side device to the printing device via an image data line during a period when the page synchronization signal is on level. In an image forming system for printing,
The image supply side device
An image supply unit for supplying image data of a page to be transmitted to the printing apparatus;
A first additional information supply unit that supplies first additional information used for process control in the printing apparatus;
A multiplexing unit that time-division-multiplexes the output of the image supply unit and the output of the first additional information supply unit and outputs the result to the printing apparatus via an image data line, and the image is output during a period when the page synchronization signal is on level. A multiplexing unit that outputs the image data supplied from the supply unit, and the additional information supplied from the first additional information supply unit to the image data line during the off-level period;
With
The printing device
Of the data input from the image data line, data in a period when the page synchronization signal is on level is extracted as page image data, and data in the off level period is extracted as first additional information;
A print processing unit that executes print processing based on the image data of the page extracted by the demultiplexing unit, and controls the print processing according to the extracted first additional information;
Comprising
Image forming system.   The image forming system according to claim 1, wherein the first additional information is handshake information for a cooperative operation between the image supply apparatus and the printing apparatus.   The image forming system according to claim 1, wherein the first additional information is attribute information indicating an attribute of image data of a page to be transmitted. The first additional information is error detection data for the image data of the page,
The print processing unit
A print section that prints the image of the page on paper;
An error determination unit that determines whether there is an error in the image data of the page supplied to the printing unit, based on the error detection data;
Comprising
The image forming system according to claim 1, wherein the image forming system is an image forming system. The print processing unit
A print section that prints the image of the page on paper;
A writing unit for writing the first additional information to the non-contact IC tag included in the paper;
The image forming system according to claim 1, further comprising: The printing apparatus includes:
A second additional information supply unit that supplies second additional information used for processing control in the image supply side device;
An output control unit for outputting the second additional information supplied from the second additional information supply unit to the image supply side device via the image data line during a period in which the page synchronization signal is off level;
With
The image supply side device includes:
A processing control unit for controlling the processing operation of the image supply side device according to the second additional information input from the image data line;
Comprising
The image forming system according to claim 1, wherein:   The image forming system according to claim 6, wherein the second additional information is handshake information for a cooperative operation between the image supply apparatus and the printing apparatus. In the image supply side device that operates according to the page synchronization signal common to the printing apparatus and transmits the image data of the page to the printing apparatus via the image data line and prints it during the period when the page synchronization signal is on level.
An image supply unit for supplying image data of a page to be transmitted to the printing apparatus;
A first additional information supply unit for supplying first additional information used for processing control in the printing apparatus;
A multiplexing unit that time-division-multiplexes the output of the image supply unit and the output of the first additional information supply unit and outputs the result to the printing apparatus via an image data line, and the image is output during a period when the page synchronization signal is on level A multiplexing unit that outputs the image data supplied from the supply unit, and the additional information supplied from the first additional information supply unit to the image data line during the off-level period;
An image supply side device comprising: A printing apparatus that operates in accordance with a page synchronization signal common to the image supply side apparatus, and that receives printing of page image data from the image supply side apparatus via an image data line and executes printing during a period in which the page synchronization signal is on level In
Of the data input from the image data line, data in a period when the page synchronization signal is on level is extracted as page image data, and data in the off level period is extracted as first additional information;
A print processing unit that executes print processing based on the image data of the page extracted by the demultiplexing unit, and controls the print processing according to the extracted first additional information;
A printing apparatus comprising: An image supply side device and a printing device that operate according to a common page synchronization signal are provided, and image data of a page is transmitted from the image supply side device to the printing device via an image data line during a period when the page synchronization signal is on level. A method of controlling an image forming system to be printed
Additional information used by the printing apparatus for controlling printing processing is transmitted from the image supply apparatus to the image printing apparatus via the image data line during a period in which the page synchronization signal is at an off level. And how to.

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