JP2006065135A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus where the occurrence of jamming is prevented from being erroneously decided at the time of turning on a power source without losing all the jamming information stored in a non-volatile memory by sudden trouble. <P>SOLUTION: In a copying machine 1, the same jamming information is stored in a plurality of storage areas in the non-volatile memory or a plurality of storage areas in a plurality of non-volatile memories, so that the jamming information is prevented from being lost by the sudden trouble, and paper is conveyed without erroneously deciding the occurrence of jamming even when the power source is turned on in a state where the paper is inserted in a manually paper feeding port 33. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and the like, and more particularly, to a paper transport technique that solves a problem of erroneous detection of jam occurrence.

  In a conventional image forming apparatus, a paper feed unit serving as a paper feed start position includes a paper feed cassette in which a plurality of papers are stored, and a manual paper feed operation for each paper or every plurality of papers. There is a paper feed slot. The paper feed cassette and the manual paper feed port are connected to one paper conveyance path. The paper conveyance path includes a registration mechanism for temporarily stopping the paper and a registration mechanism for detecting the paper conveyed to the registration mechanism. And a sensor.

  Between the registration sensor and the registration mechanism on the paper conveyance path, there are a roller for conveying the paper detected by the registration sensor to the registration mechanism and a roller for conveying the paper temporarily stopped by the registration mechanism to the image forming unit. Has been placed.

  When the sheet is conveyed from the sheet feeding unit to the image forming unit, the registration mechanism temporarily stops the sheet and adjusts the conveyance timing in order to synchronize with the toner image position on the photosensitive drum. At this time, the registration sensor detects the sheet fed to the registration mechanism, and after the predetermined time has elapsed since the detection, the registration mechanism releases the temporary stop, thereby conveying the sheet to the image forming unit at an appropriate timing.

  In addition, since the registration sensor detects the paper conveyed to the registration mechanism, the registration sensor detects, for example, when the registration sensor continues to detect the paper after a predetermined time has elapsed after the registration mechanism releases the temporary stop of the paper. In the case of occurrence of jam, lamp lighting, buzzer sound generation, etc. are executed to notify the user of the occurrence of jam.

  In the image forming apparatus as described above, a dedicated detection sensor for detecting that a sheet is inserted into the manual sheet feed port is usually required. However, a position where the sheet inserted into the manual sheet feed port can be detected. There is a low-cost image forming apparatus in which a registration sensor is disposed in the camera and no dedicated paper detection sensor is disposed.

  In such an image forming apparatus, when the paper is inserted into the manual paper feed slot and the power is turned on, the registration sensor detects the paper and determines that a jam has occurred. For this reason, a jam that has not actually occurred is erroneously detected, the operation of the image forming apparatus stops, and there is a problem that the user is forced to perform an unnecessary jam processing.

As a method for solving this problem, for example, an EEPROM (Electrically Erasable Programmable Read Only Memory) of a nonvolatile memory is provided as a state storage means for storing the judgment state of the occurrence of jamming even after the power is turned off, and the paper is fed to the manual feed slot If the registration sensor detects a sheet when the power is turned on with the power inserted, and if the information on the occurrence of a jam at the time of power interruption is stored in the EEPROM of the nonvolatile memory, it is determined that a jam has occurred when the power is turned on. If the paper feed from the manual feed slot is stopped and the jam occurrence at the time of power shut-off is not stored, the paper feed from the manual feed slot will be started without judging that the jam has occurred when the power is turned on. An image forming apparatus provided is disclosed and proposed (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-90963

  Certainly, with the above method, it is not erroneously determined that a jam has occurred even if the power is turned on again after the power is turned off and the paper is inserted into the manual paper feed slot.

  However, in the conventional image forming apparatus, jam information stored in the state storage unit such as a nonvolatile memory may be lost due to an unexpected and unexpected trouble caused by an overcurrent or a power failure when the power is turned off. . If a jam actually occurs when the power is turned on with the paper inserted in the manual feed slot, the jam information in the non-volatile memory will be displayed due to a sudden trouble as described above. If it has disappeared, it is determined that no jam has occurred when the power is turned off, and the sheet is erroneously conveyed as it is from the manual sheet feed port, which may cause a malfunction of the apparatus. Therefore, the conventional image forming apparatus has room for further improvement in the method for storing jam information in the state storage means such as a nonvolatile memory.

  In view of the above problems, the present invention prevents all the jam information stored in the nonvolatile memory from being lost due to a sudden trouble, and turns on the power with the paper inserted into the manual paper feed slot. An object of the present invention is to provide an image forming apparatus that is not erroneously determined to be jammed.

  In order to achieve the above object, an image forming apparatus according to the present invention includes a power source that supplies power to each unit of the apparatus, an image forming unit that forms an image on a sheet, and manual sheet feeding in which the sheet is manually fed. A registration sensor that detects a sheet, a registration roller that conveys the sheet to the image forming unit, and a registration roller that is positioned at a position where the sheet is inserted into the manual feed slot. When the registration sensor detects a sheet after a predetermined time has elapsed after starting conveyance, and when the registration sensor detects a sheet when the power is turned on, a jam determination unit that determines that a jam has occurred; and When the jam occurrence is canceled while the power is on, the information on the jam occurrence is erased. When the jam occurrence is not canceled while the power is on, the jam is detected even after the power is shut off. Non-volatile memory for storing occurrence information and information on the occurrence of jam at the time of power-off in the non-volatile memory even when the registration sensor detects the paper in the manual feed slot when the power is turned on. Determination control means for preventing the jam determination unit from determining the occurrence of a jam if it is not stored, the information on the occurrence of the jam as the same jam information in a plurality of storage areas in the nonvolatile memory The determination control means may store the jam information from a plurality of storage areas in the nonvolatile memory.

  The nonvolatile memory of the image forming apparatus according to the present invention includes a plurality of nonvolatile memories, and the information on the occurrence of the jam is stored as the same jam information in a plurality of storage areas of each of the nonvolatile memories. The determination control means may detect and determine the jam information from a plurality of storage areas of each of the nonvolatile memories.

  With the image forming apparatus according to the present invention, it is possible to prevent the loss of jam information in the non-volatile memory due to a sudden trouble, and jam occurs even when the power is turned on with the paper inserted in the manual feed slot. Thus, it is possible to carry the sheet without erroneous determination.

  Hereinafter, a case where the present invention is applied to a copying machine will be described as an example. FIG. 1 is a block diagram showing a main configuration of a copying machine 1 according to the present invention. As shown in FIG. 1, a copier 1 of this embodiment includes a power supply 10 that supplies power to each part of the apparatus, and a central processing unit 11 (hereinafter referred to as a CPU [Central Processing Unit] 11) that controls the operation of the entire apparatus. An operation unit 12 including operation means (such as a numeric keypad and a touch panel), a document transport unit 13 that automatically transports a document, and a document capture unit that captures a document transported from the document transport unit 13 and generates image data. Unit 14, display unit 15 including a display means (liquid crystal display or the like), ROM [Read Only Memory] storing various control programs, RAM [Random Access Memory] used as a work area, and jamming even after power is cut off A memory unit 16 comprising a non-volatile memory or the like as information storage means, a paper feeding unit 17 comprising a paper feed cassette or a manual paper feed port as a paper feed start position, An image forming unit 18 (such as a printer head or a photosensitive drum) that forms an image on a sheet based on the image data, a fixing unit 19 that heats and fixes the image obtained by the image forming unit 18, and an image of the sheet And a registration roller unit 20 (such as a registration roller, a registration sensor, and a main motor) conveyed to the forming unit 18.

  The CPU 11 controls the operation of the entire apparatus according to a control program stored in the memory unit 16 and performs processing related to control such as storage of jam information in the memory unit 16 and determination of jam occurrence, which will be described in detail later.

  Next, the document copying operation in the copying machine 1 configured as described above will be described. In the document copying operation in the copying machine 1, first, when an instruction to start copying is given from the operation unit 12, the document is transported from the document transport unit 13 to the document fetching unit 14, and the document fetching unit 14 captures the document (image). Data generation). The generated image data is temporarily stored in the memory unit 16, read out again, and sent to the image forming unit 18. Thereafter, the image forming unit 18 performs an image forming process on a sheet based on the input image data, and then the fixing unit 19 performs an image fixing process on the sheet.

  Note that the copier 1 of this embodiment is turned on in a state in which the paper is inserted into the manual paper feed port without losing all the jam information stored in the nonvolatile memory due to a sudden trouble. However, the sheet is conveyed without being erroneously determined as jammed. Therefore, a method for determining jam information in the copying machine 1 according to the present embodiment and a method for storing the jam information in a nonvolatile memory will be described below.

  FIG. 2 is a diagram showing a sheet conveyance path between the sheet feeding unit 17 and the image forming unit 18 in the copying machine 1 according to the present invention. As shown in FIG. 2, the paper transport path 30 includes a plurality of cassettes, and a paper feed cassette 31 that feeds paper and a paper feed roller 32 that transports the paper one by one from the paper feed cassette 31. A manual paper feed port 33 that feeds paper by sheet, and a single registration sensor 34 that is disposed at a position where the paper placed in the manual paper feed port 33 can be detected and detects paper. The driving force of the main motor is transmitted via a gear, a clutch, etc., rotates, conveys the paper to the photosensitive drum 36, and a registration roller 35 consisting of a pair of rollers and a toner image on the drum surface according to the image data. A photosensitive drum 36 to be formed and a transfer roller 37 for transferring the toner image on the photosensitive drum 36 to a sheet are disposed.

  Next, conveyance of a sheet between the sheet feeding unit 17 and the image forming unit 18 will be described. As shown in FIG. 2, the manual paper feed port 33 or the paper feed cassette 31 is selected as the paper feed start position. One sheet inserted from the manual paper feed port 33 is the leading edge of the paper. Is inserted in a state where it is in contact with the registration roller 35 in a stationary state, or sheets fed from the sheet feeding cassette 31 are conveyed one by one to the registration rollers 35 by the sheet feeding roller 32. The sheet conveyed to the registration roller 35 is detected by the registration sensor 34, and the leading edge of the sheet is aligned by the stationary registration roller 35 in order to synchronize the position of the leading edge of the sheet and the position of the toner image on the photosensitive drum 36. Then, after a predetermined time has elapsed, conveyance toward the photosensitive drum 36 is started by the registration roller 35. The toner image on the photosensitive drum 36 is transferred onto the sheet conveyed to the photosensitive drum 36 by the transfer roller 37 and conveyed to the fixing unit 19 (not shown).

  Further, the jam determination is determined by the CPU 11 using a determination control program. For example, even when a predetermined time elapses after the registration sensor 34 detects the sheet as described above, the passage of the trailing edge of the sheet is not detected. If the paper is continuously detected, it is determined that a jam has occurred.

  FIG. 3 is a diagram showing a flowchart of the jam generation process in the energized state in the copying machine 1 according to the present invention. As described above, when the registration sensor 34 detects the sheet, the sheet is conveyed toward the photosensitive drum 36 by the registration roller 35 in accordance with the toner image position on the photosensitive drum 36. At this time, if the sheet conveyance is started 41 from the registration roller 35 and the registration sensor detects the sheet 42 after a predetermined time has elapsed (YES in 42), it is determined that the jam has occurred 43. As shown in FIG. 6, after the jam occurrence information is written as the same jam information in a plurality of locations in the nonvolatile memory 71 arranged in the memory unit 16, for example, from the storage area a to the storage area d as shown in FIG. Informing the user that a jam has occurred by means of a buzzer sound or a display 45.

  Further, as shown in FIG. 7, the jam information is stored in a nonvolatile memory composed of a plurality of memories 16 by the CPU 11, for example, in a storage area composed of a plurality of nonvolatile memories a and b. It may be written as the same jam information.

  FIG. 4 is a diagram showing a flowchart of jam release processing in the copying machine 1 according to the present invention. When the jammed paper is removed 52 from the jammed state 51, it is next determined 53 whether or not there is paper at the registration sensor 34 position. If the sheet is at the registration sensor 34 position, it is determined that the jammed sheet has not been removed (53: YES), and the jam state 54 continues. If there is no sheet at the registration sensor 34 position, it is determined that the jammed sheet has been removed (NO in 53), all the jam information stored in the nonvolatile memory of the memory unit 16 is erased 55, and the jam clearing process is performed. Complete.

  Also, jam paper removal work is performed with the power supply 10 turned off, and the power supply 10 is often turned on after the work is completed, and a cover or the like covering the paper conveyance path 30 of the copying machine 1 is opened. In many cases, the power supplied from the power supply 10 to each unit is cut off, and the power supply is returned from the power supply 10 to each unit by returning to the original state after the work is completed. Further, when the copying machine 1 is not used for a long time, the power supply 10 is turned off, and the power supply 10 is newly turned on during use. The jam detection process at the time of power-on that is frequently performed will be described below.

  FIG. 5 is a diagram showing a jam detection process when the power is turned on in the copying machine 1 according to the present invention. When the power is turned on 61, it is determined whether or not there is a sheet at the registration sensor 34 position. If it is determined that there is no sheet at the position of the registration sensor 34 (NO in 62), the printable state 63 is entered. When it is determined that there is a sheet at the position of the registration sensor 34 (YES in 62), it is determined 64 whether jam information at the time of power shut-off is stored in the nonvolatile memory of the memory unit 16. Here, in order to confirm the correctness of the jam information, a plurality of locations in the nonvolatile memory of the memory unit 16 are confirmed. For example, as shown in FIG. 6, if the jam information stored in the storage area d is confirmed from the storage area a in the nonvolatile memory 71 and there is jam information in two or more storage areas (YES in 64). Jam state 64 is determined. Alternatively, as shown in FIG. 7, if jam information stored in a plurality of areas in the non-volatile memory a and the non-volatile memory b in the memory unit 16 is confirmed, and there is jam information in two or more storage areas (YES in 64), it is determined that the jam state 64. For example, when the number of jam information stored in the nonvolatile memory of the memory unit 16 is 1 or less (NO in 64), it is determined that there is a sheet 66 in the manual paper feed port 33.

  Further, when it is determined that there is a sheet at the position of the registration sensor 34 at the time of power-on 61 (YES in 62), and jam information at the time of power-off is recorded in the nonvolatile memory of the memory unit 16 (64 YES), jammed paper may have been removed during power shutdown. In such a case, the release of the jammed paper while the power is cut off is not recognized by the CPU 11, and therefore, it is determined to be a jammed state 65 when the power is turned on. In such a case, a jam-released button or the like may be provided on the operation unit 12 so that the CPU 11 can recognize that the jammed paper has been released by pressing the jam-released button.

  Therefore, in the case of the copying machine 1 according to the embodiment of the present invention, as described above, the same jam information is stored in a plurality of storage areas in a non-volatile memory or in a plurality of non-volatile memories. Since it is stored in the storage area, it is possible to prevent the loss of jam information due to a sudden trouble. Therefore, even if the paper is inserted into the manual paper feed port 33 and the power is turned on, an erroneous determination of the occurrence of the jam It becomes possible to convey the sheet without any problem.

  The present invention can be widely applied to image forming apparatuses such as printers and facsimiles in addition to copying machines, and in particular, a pair of sheets for conveying a sheet to a photosensitive drum between a manual feed port and a photosensitive drum. For an image forming apparatus having a registration roller and a single registration sensor for detecting paper, the jam information stored in the nonvolatile memory is prevented from being lost due to a sudden trouble, and a misdetection of the occurrence of a jam at the time of power-on is detected. This is a useful technique for paper conveyance that solves the problem.

FIG. 2 is a block diagram showing a main configuration of a copier according to the present invention. FIG. 4 is a diagram illustrating a sheet conveyance path between a sheet feeding unit and an image forming unit in the copier according to the present invention. These are diagrams showing a flowchart of a jam generation process in an energized state in the copying machine according to the present invention. These are diagrams showing a flowchart of jam release processing in the copying machine according to the present invention. These are diagrams showing a jam detection process at power-on in the copying machine according to the present invention. FIG. 3 is a diagram showing a storage area in a non-volatile memory in the copying machine according to the present invention. These are figures which show the some non-volatile memory in the copying machine which concerns on this invention.

Explanation of symbols

1 Copier 10 Power Supply 11 Central Processing Unit (CPU)
DESCRIPTION OF SYMBOLS 12 Operation part 13 Document conveyance part 14 Document taking-in part 15 Display part 16 Memory part 17 Paper feed part 18 Image formation part 19 Fixing part 20 Registration roller part 30 Paper conveyance path 31 Paper feed cassette 32 Paper feed roller 33 Manual feed Mouth 34 Registration sensor 35 Registration roller 36 Photosensitive drum 37 Transfer roller 71 Non-volatile memory

Claims (2)

A power source that supplies power to each part of the apparatus, an image forming unit that forms an image on paper, a manual paper feed port through which paper is manually fed, and a paper inserted into the manual paper feed port can be detected A registration sensor that detects a sheet, a registration roller that conveys the sheet to the image forming unit, and the registration sensor that has passed a predetermined time after the registration roller starts conveying the sheet. And when the paper is detected by the registration sensor when the power is turned on, a jam determination unit that determines the occurrence of a jam, and the jam when the occurrence of the jam is canceled while the power is on. If the occurrence information is erased and the jam occurrence is not released while the power is on, a nonvolatile memory that stores the jam occurrence information even after the power is turned off, and when the power is turned on Even if the registration sensor detects the paper at the manual paper feed slot, if the information on the occurrence of the jam at the time of the power shutdown is not stored in the nonvolatile memory, the jam judgment unit judges the occurrence of the jam. An image forming apparatus comprising: a determination control unit that does not allow
The jam occurrence information is stored as the same jam information in a plurality of storage areas in the nonvolatile memory, and the determination control means detects and determines the jam information from the plurality of storage areas in the nonvolatile memory. An image forming apparatus.   The non-volatile memory includes a plurality of non-volatile memories, and information on the occurrence of the jam is stored as the same jam information in a plurality of storage areas of each of the non-volatile memories, and the determination control unit includes the non-volatile memory. The image forming apparatus according to claim 1, wherein the jam information is detected and determined from a plurality of storage areas of each memory.

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