Patent Publication Number: US-2007103718-A1

Title: Image forming apparatus

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates to an image forming apparatus such as a digital copying machine, wherein an image on a document is read and subjected to an image process, obtained image data is accumulated on a memory, and an image is formed by using a laser electrophotographic process.  
      A digital copying machine has the following structures and functions. After a document is read by optical means, the read image is converted to an electric signal and subjected to various image processing. Then, image data is accumulated on a memory or processed, and the image is reproduced from the data by using a laser electrophotographic process.  
      Since the digital copying machine has the above structures and functions, the following applications are possible, in addition to the copying functions of a conventional analog copying machine. For example, the digital copying machine may be connected to a public line to perform facsimile functions. Specifically, it may transmit images to the public line or may receive images from the public line to print out them. Moreover, the digital copying machine may be provided with image communication means for communication with a host computer, whereby print data is received and printed out by using a single laser electrophotographic process (laser engine).  
      In an image forming process in the digital copying machine, after a document is read by optical means, an optical signal of the read image is converted to an electric signal by using a photoelectric conversion element such as a CCD. The electric signal is subjected to various image processes, such as an analog/digital conversion process, linear/non-linear filtering processes, a frequency conversion process using a line memory for a one-line image component, an enlargement/reduction process, and a gray-scale process. The image is them reproduced from the obtained data by using a laser electrophotographic process.  
      Furthermore, using the features the digital copying machine, the following functions can be performed. For example, a memory copy function is performed, wherein the processed image signal is stored in a two-dimensional memory (page memory) for a one-page image and the content of the memory is repeatedly read out and printed. An electronic sorting function is performed, wherein the image signals stored in the page memory are encoded into data files to treat images as files, and the images may be reproduced from the data files in a changed order. A memory editing function is performed, wherein files are freely edited.  
      As has been described above, since the digital copying machine can temporarily store images in the memory, it can perform various image editing operations which cannot be achieved by the conventional analog copying machine. Using the functions which cannot be performed by the analog machine, the digital copying machine can efficiently use various paper handling options (an automatic sheet feeder, an automatic double-side printer, a sorter/finisher, etc.).  
      In the above-described memory copy function, a so-called “advance-input” can be performed by using the page memory, thereby to greatly enhance productivity.  
      In the memory copy function, however, scanning and printing are not performed in a completely synchronous manner. Even if the user suspends a current job and performs some operation/resetting, this is not reflected on the “advance-input” image. In some cases, operability is considerably degraded, compared to the conventional analog copying machine wherein the user can smoothly perform the operational routine of starting, suspending, operating, changing of setting, and restarting.  
      In order to solve this problem, there is a method in which prior to the operations of suspending/restarting, data in the page memory is always erased and scanning is done once again with updated setting. However, when some change is made during the suspension, there are cases where the operation should and should not be resumed, with the data in the page memory maintained without erasing. For example, in a case where only the number of documents to be placed is changed after C/S suspension, the printing has to be resumed with use of the data remaining in the page memory.  
     BRIEF SUMMARY OF THE INVENTION  
      The object of the present invention is to provide an image forming apparatus capable of enhancing operability after suspension of a memory copy function.  
      According to an aspect of the present invention, there is provided an image forming apparatus, wherein image data of a document is read, the read image data is stored in memory means, and the stored image data is used to form an image, the apparatus comprising:  
      interrupt means for interrupting a series of image forming operations beginning with reading of an image of the document and ending with completion of formation of an image;  
      discrimination means for determining, where image data is stored in the memory means, whether the image data is to be retained or erased, when the image forming operations have been interrupted by the interrupt means;  
      first control means for retaining, when the retention of the image data has been determined by the discrimination means, the image data stored in the memory means and, after the interrupted image formation operations are resumed, performing an image forming control with use of the retained image data; and  
      second control means for erasing, when the erasure of the image data has been determined by the discrimination means, the image data stored in the memory means and, after the interrupted image formation operations are resumed, reading image data of the document, storing the read image data in the memory means and performing an image forming control with use of the stored image data.  
      According to another aspect of the invention, there is provided an image forming apparatus, wherein image data of a document is read, the read image data is stored in memory means, and the stored image data is used to form an image, the apparatus comprising:  
      interrupt means for interrupting a series of image forming operations beginning with reading of an image of the document and ending with completion of formation of an image;  
      display means for showing, where image data is present in the memory means, that the image data is present in the memory means, when the image forming operations have been interrupted by the interrupt means;  
      first control means for retaining, when the retention of the image data displayed on the display means has been determined, the image data present in the memory means and performing an image forming control with use of the retained image data; and  
      second control means for erasing, when the erasure of the image data displayed on the display means has been determined, the image data stored in the memory means and, after the interrupted image formation operations are resumed, reading image data of the document, storing the read image data in the memory means and performing an image forming control with use of the stored image data.  
      According to still another aspect of the invention, there is provided an image forming apparatus, wherein image data of a document is read, the read image data is stored in memory means, and the stored image data is used to form an image, the apparatus comprising:  
      interrupt means for interrupting a series of image forming operations beginning with reading of an image of the document and ending with completion of formation of an image; and  
      control means for performing, where image data is stored in the memory means, a control as to whether the image data is to be retained or erased, when the image forming operations have been interrupted by the interrupt means.  
      Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
      The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.  
       FIG. 1  is a block diagram schematically showing an entire structure of a digital copying machine serving as an image forming apparatus according to the present invention;  
       FIG. 2  is a block diagram schematically showing an entire structure of a digital copying machine serving as an image forming apparatus according to the present invention;  
       FIG. 3  shows a structure of an operation panel;  
       FIG. 4  is a flow chart illustrating a control operation of a digital copying machine to which the present invention is applied;  
       FIG. 5  illustrates an example of a memory copying operation when one page memory is used;  
       FIG. 6  illustrates an example of a memory copying operation when a plurality of page memories are used;  
       FIG. 7  is a flow chart illustrating a control operation in a case where a function clear key has been depressed;  
       FIG. 8  is a flow chart illustrating a control operation in a case where an auto-clear timer has operated;  
       FIG. 9  is a flow chart illustrating a control operation in a case where a non-operation timer has operated;  
       FIG. 10  is a flow chart illustrating a control operation in a case where a preheat key has been depressed;  
       FIG. 11  is a flow chart illustrating a control operation in a case where there is no document on an automatic document feeder and there is no sheet on a finisher; and  
       FIG. 12  is a flow chart illustrating control operations for displaying an alarm and deleting a message in a case where there is data in a page memory. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      An embodiment of the present invention will now be described with reference to the accompanying drawings.  
       FIGS. 1 and 2  schematically show the entire structure of a digital copying machine  1  functioning as an image forming apparatus according to the present invention. The digital copying machine  1  includes a scanner  2  and a printer  3  and it has an automatic document feeder (ADF)  4  on an upper part of the machine body.  
      The digital copying machine  1  generally comprises two blocks, i.e. a base unit  301  and a page memory unit  302 . The base unit  301  has an image processing section  314  connecting the scanner and the printer  3  and constitutes the digital copying machine  1 . The page memory unit  302  functions as storage means for storing image data received from the base unit  301  and transferring the stored image data to the base unit  301  once again, thereby achieving a memory copying function.  
      The base unit  301  and page memory unit  302  are connected by a base unit system interface  316  for transmission of control data and a base unit image interface  317  for transmission of image data.  
      The base unit  301  comprises the scanner  2  serving as input means, the printer  3  serving as output means, image processing means (image processing section)  314 , and control means (base unit CPU)  311  for controlling these structural elements.  
      As is shown in  FIG. 2 , a system CPU  100  in the control means (base unit CPU)  311  is connected to a ROM  102 , a RAM  104 , an image memory  106 , a timer memory  108 , a password code memory  110 , a timer  112 , an internal interface  122  and an external interface  124 .  
      The internal interface  122  is connected to an operation panel  114 , and the external interface  124  is connected to the automatic document feeder (ADF)  4  and a finisher  126 . A message display  93 , a start key  101 , ten-keys  105 , etc. are disposed on the operation panel  114 .  
      The page memory unit  302  will now be described with reference to  FIG. 1 . The page memory unit  302  comprises the following elements: system control means  304  which controls access to a page memory  323  and includes a communication memory  305 ; storage means (PM: page memory)  323  for temporarily storing image data; an address control section  306  for generating addresses in the page memory  323 ; an image bus  320  for data transfer among devices in the page memory unit  302 ; a control bus  321  for transferring control signals between each device in the page memory section  302  and the system control means  304 ; data control means  307  for controlling data transfer via the image bus  320  between the page memory  323  and other devices; image data I/F means  308  serving as an interface for image data transferred to the base unit  301  via the base unit image interface  317 ; resolution conversion/two-value rotary means  325  for converting a resolution of image data to resolutions of other devices at the time of transmitting the image data to devices with different resolutions, converting a resolution of image data received from other devices with different resolutions to a resolution of the printer  3  of the base unit  301 , or executing a 90° rotary process of two-value image data; compression/extension means  324  for compressing input image data for devices which transmit or store compressed image data, as in cases of facsimile transmission and optical disk storage, and extending compressed image data for visible printing; and a multi-value rotary memory  309 , connected to the image data I/F means  308 , for rotating image data over 90° or −90° to be output from the printer  3 .  
       FIG. 3  shows an example of the structure of the operation panel  114 . Specifically, the operation panel  114  includes a message display  93 , which comprises a graphics liquid crystal and a touch panel, a start key  101 , a clear/stop key  103 , an all-clear key  104 , ten-keys  105 , an interrupt key  106 , a preheat key  107 , etc.  
      The control operation of the digital copying machine  1  with the above structure, to which the present invention is applied, will now be described with reference to a flow chart of  FIG. 4 .  
      A copying operation is started and a storage area is set in the page memory  323 .  
      When the copying operation has been suspended by the clear/stop key  103 , etc. (ST 1 ), the system CPU  100  checks whether there is data in the page memory  323  (ST 2 ). If there is no data, the control goes to step ST 6 .  
      If there is data in the page memory  323 , the system CPU- 100  causes the message display  93  to display a selection screen for the user to select the holding or releasing of the data in the page memory  323  (ST 3 ).  
      Upon an operation by the user, the system CPU  100  discriminates the retention/release of image data. If the system CPU  100  determines the retention of image data, the control goes to step ST 7  at the time the setting has been changed and the copying operation resumed (ST 4 ). If the system CPU  100  determines the release of image data, the system CPU  100  releases (erases) data in the page memory  323  (ST 5 ) and shifts control to step ST 7  at the time the setting has been changed and the copying operation resumed (ST 6 ).  
      Since the copying operation is resumed, the system CPU  100  performs re-scanning by means of the scanner  2  and stores data in the page memory  323  (ST 7 ). If there is data held in step ST 3 , the data in the page memory  323  including such data is printed out by the printer  3  (ST 8 ).  
       FIG. 5  shows an example of a memory copying operation when one page buffer is used in a case where four copies of one document are to be made. The system CPU  100  scans the document by the scanner  2  and accumulates the scan data in the page memory (PM)  323 . The system CPU  100  reads out data from the page memory  323  to print the first, second, third and fourth copies of the document by means of the printer  3 .  
       FIG. 6  shows an example of the memory copying operation when a plurality of page buffers are used in a case where four copies of each of three documents are to be made. Two areas (double buffer) PB 1  and PB 2  are provided in a storage area of the page memory  323 , and image data corresponding in amount to one document is stored in each of the areas PB 1  and PB 2 .  
      The system CPU  100  scans the first document on the ADF  4  by means of the scanner  2  (S 1 ) and accumulates the scan data in the area PB 1  in the page memory  323 . Then, the system CPU  100  scans the second document on the ADF  4  by means of the scanner  2  (S 2 ) and accumulates the scan data in the area PB 2  in the page memory  323 . By reading out the data on the first document from the area PB 1  in the page memory  323 , four copies of the first document are printed by means of the printer  3 .  
      After the four copies of the first document have been printed, the system CPU  100  reads out the data on the second document from the area PB 2  in the page memory  323  and starts to print four copies of the second document by means of the printer  3 . At the same time, the third document on the ADF  4  is scanned by the scanner  2  (S 3 ) and the scan data is accumulated in the area PB 1  in the page memory  323 . In this manner, after the area PB 1  in the page memory  323  is cleared, the data on the third document is read in.  
      After the four copies of the second document data have been printed, the data on the third document stored in the area PB 1  of the page memory  323  is read out and four copies thereof are printed.  
      A control operation in a case where a function clear key of the digital copying machine  1  has been depressed will now be described with reference to a flow chart of  FIG. 7 .  
      A copying operation is started and a storage area is set in the page memory  323 .  
      When the clear/stop key  103  has been depressed (ST 11 ), the system CPU  100  checks whether there is data in the page memory  323  (ST 12 ). If there is no data, the control goes to step ST 18 .  
      If there is data in the page memory  323 , the system CPU  100  releases the data in the page memory  323  (ST 15 , ST 16 ) and clears the set function (ST 17 ) when the function key (FC) displayed on the message display  93  has been depressed (ST 13 , ST 14 ).  
      If the copying operation is resumed (ST 18 ), the system CPU  100  performs re-scanning by means of the scanner  2  and stores data in the page memory  323  (ST 19 ) and resumes the printing of the data in the page memory  323  (ST 20 ).  
      A control operation in a case where an auto-clear timer in the digital copying machine  1  has operated will now be described with reference to a flow chart of  FIG. 8 .  
      An auto-clear time is set in the timer memory  108  (ST 21 ).  
      The system CPU  100  starts the copying operation and sets a storage area in the page memory  323  (ST 22 ). If the copying operation is suspended by the clear/stop key  103 , etc. (ST 23 ), the timer  112  is notified without operation (ST 232 ). For example, at a time of a current value +5 (ST 24 ), the timer  112  checks whether an auto-clear time set in the timer memory  108  has passed (ST 25 ).  
      If the timer  112  determines that the auto-clear time has passed, the system CPU  100  checks whether there is data in the page memory  323  (ST 26 ). If there is no data, the control goes to step ST 29 .  
      If there is data in the page memory  323 , the system CPU  100  releases the data in the page memory  323  (ST 27 , ST 28 ) and clears the set function (ST 29 ).  
      When the copying operation has been resumed (ST 30 ), the system CPU  100  causes the scanner  2  to perform re-scanning and stores data in the page memory  323  (ST 31 ) and resumes the printing of data in the page memory  323  by means of the printer  3  (ST 32 ).  
      Referring to a flow chart of  FIG. 9 , a description will now be given of a control operation in a case where the non-operation timer in the digital copying machine has operated.  
      A non-operation time is set in the timer memory  108  (ST 41 ).  
      The system CPU  100  starts the copying operation and sets a storage area in the page memory  323  (ST 42 ). When the copying operation has been suspended by the depression of the clear/stop key  103 , etc. (ST 43 ), the system CPU  100  notifies the timer  112  at every five seconds in the non-operation state (ST 44 ) and the timer  112  checks in step ST 46  whether the non-operation time set in the timer memory  108  has passed at a time of a current value +5 (ST 45 ).  
      If the timer  112  determines that the non-operation time has passed, the system CPU  100  checks whether there is data in the page memory  323  (ST 47 ). If there is no data, the control goes to step ST 50 .  
      If there is data in the page memory  323 , the system CPU  100  releases the data in the page memory  323  (ST 48 , ST 49 ) and sets the operation state at “READY” state in which a background job is acceptable (ST 50 ).  
      When the copying operation has been resumed (ST 51 ), the system CPU  100  causes the scanner  2  to perform re-scanning and stores data in the page memory  323  (ST 52 ) and resumes the printing of data in the page memory  323  by means of the printer  3  (ST 53 ).  
      A control operation in a case where the preheat key  107  of the digital copying machine  1  has been depressed will now be described with reference to a flow chart of  FIG. 10 .  
      The copying operation is started and a storage area is set in the page memory  323 .  
      When the clear/stop key  103  has been depressed (ST 61 ), the system CPU  100  checks whether there is data in the page memory  323  (ST 62 ). If there is no data, the control goes to step ST 68 .  
      If there is data in the page memory  323 , the system CPU  100  releases (ST 65 , ST 66 ) the data in the page memory  323  at the time the preheat key  107  has been depressed (ST 63 , ST 64 ), and sets the machine in the preheat state and clears the setting (ST 67 ).  
      When the copying operation has been resumed (ST 68 ), the system CPU  100  causes the scanner  2  to perform re-scanning and stores data in the page memory  323  (ST 69 ) and resumes the printing of data in the page memory  323  by means of the printer  3  (ST 70 ).  
      A control operation in a case where there is no document on the ADF  4  of the digital copying machine  1  and there is no paper sheet on the finisher  126  will now be described with reference to a flow chart of  FIG. 11 .  
      The copying operation is started and a storage area is set in the page memory  323 .  
      Where the clear/stop key  103  is depressed and the document on the ADF  4  is removed and also the sheet on the finisher  126  is removed, the system CPU  100  checks (ST 74 ) whether there is data in the page memory  323  at the time the sheet on the finisher  126  has been removed (ST 73 ). If there is no data, the control goes to step ST 80 .  
      If there is data in the page memory  323 , the system CPU  100  checks whether there is a document on the ADF  4  (ST 75 ). If there is a document, the control goes to step ST 80 .  
      If there is no document on the ADF  4 , the system CPU  100  checks whether there is a sheet on the finisher  126  (ST 76 ). If there is a sheet, the control goes to step ST 80 .  
      If there is no sheet on the finisher  126 , the system CPU  100  determines that the copying operation has been finished (suspended) (ST 77 ) and releases the data in the page memory  323  (ST 78 , ST 79 ).  
      When the copying operation has been resumed (ST 80 ), the system CPU  100  causes the scanner  2  to perform re-scanning and stores data in the page memory  323  (ST 81 ) and resumes the printing of data in the page memory  323  by means of the printer  3  (ST 82 ).  
      Referring now to a flow chart of  FIG. 12 , a description will now be given of a control operation for alarm display and message deletion in a case where there is data in the page memory  323  of the digital copying machine  1 .  
      The copying operation is started and a storage area is set in the page memory  323 .  
      Where the clear/stop key  103  is depressed (ST 91 ), the system CPU  100  checks whether there is data in the page memory  323  (ST 92 ). If there is no data, the control goes to step ST 99 .  
      If there is data in the page memory  323 , the system CPU  100  displays “DATA IS PRESENT IN PAGE MEMORY” on the message display  93  as well as a selection screen for prompting the user to decide whether the data in the page memory  323  should be retained or released (ST 93 , ST 94 ).  
      where the user selected and depressed “HOLD” on the message display  93 , the system CPU  100  deletes the message “DATA IS PRESENT IN PAGE MEMORY” on the message display  93  (step ST 96 ) at the time the setting has been changed and the copying operation has been resumed (ST 95 ). The control then goes to step ST 101 .  
      On the other hand, where the user selected and depressed “RELEASE” on the message display  93 , the system CPU  100  releases the data in the page memory  323  (ST 97 ) and deletes the message “DATA IS PRESENT IN PAGE MEMORY” on the message display  93  (step ST 98 ). When the copying operation has been resumed, the system CPU  100  causes the scanner  2  to perform re-scanning and stores data in the page memory  323 . The control then goes to step ST 101  (ST 100 ).  
      In step ST 101 , the system CPU  100  causes the printer  3  to resume the printing of data in the page memory  323 .  
      As has been described above, according to the embodiments of the present invention, when the user has suspended a job and performed some operation/re-setting, the change of the setting intended by the user can be smoothly effected at the time of resuming the job even if image data is retained on the page memory.  
      In addition, when the user has suspended a job and performed some operation/re-setting, even if image data is retained on the page memory, the memory copying function with high productivity can be performed while the user smoothly perform operations.  
      Furthermore, since the user is positively notified that there is data in the page memory, security can be provided on information on the user&#39;s image formation medium.  
      Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.