JP2008120502A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of preventing a paper feeding cassette from being pulled out of the device in an improper condition. <P>SOLUTION: This image forming device 100 is provided with the paper feeding cassette 120 mounted to allow it to be pulled out of a device body 110, a pick-up roller 51 for delivering the uppermost recording paper stacked on the paper feeding cassette 120, a paper feeding roller 53 for conveying the recording paper delivered by the pick-up roller 51 into a conveyance passage 112, and a retard roller 54 brought into pressure-contact with the paper feeding roller 53 through the recording paper and rotating in the direction for returning the recording paper onto a pick-up roller 51 side to form an image on the recording paper conveyed in the conveyance passage 112. When a first sensor 55 detects the recording paper positioned between a pressure-contact position P of the paper feeding roller 53 and the retard roller 54 and an end part of the paper feeding cassette 120, the paper feeding cassette 120 is locked to prevent it from being pulled out of the device body 110. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes an image forming apparatus such as a printer, a facsimile machine, and a copying machine that forms an image such as characters and graphics on a recording sheet. The present invention relates to an image forming apparatus.

  Examples of image forming apparatuses for recording characters and graphics on recording paper include printers, facsimiles, and multifunction peripherals. In general, such an image forming apparatus includes a paper feeding cassette on which a large number of recording papers are stacked so that the paper feeding cassette can be pulled out, and the recording paper fed out from the paper feeding cassette is transported through a transport path to be charged, exposed, An image is formed by development and transfer. There are various types of paper feed mechanisms that feed the recording paper from the paper feed cassette, but the uppermost recording paper loaded in the paper feed cassette is fed out by the pickup roller, and the paper feed roller transports the recording paper toward the transport path. In some cases, a paper feed mechanism is used that prevents the retard roller from transporting two or more recording sheets to the transport path.

In such an image forming apparatus, when the recording paper fed out from the paper feeding cassette is jammed (paper jam), the jammed recording paper is opened after opening the side cover that opens the conveyance path and releasing the nip (clamping). Need to be removed. For example, in an image forming apparatus including a plurality of paper feed cassettes disclosed in Patent Document 1, a sensor for detecting a recording paper present at a nip position of a conveyance roller disposed in the vicinity of the paper feed cassette is provided, When the recording paper fed out from the cassette is jammed, the paper feed cassette in which the recording paper is jammed is determined by the detection signal from the sensor, so that the jam can be easily eliminated.
JP-A-5-193784

  However, when the recording paper is double fed and nipped between the paper feeding roller and the retard roller and a jam occurs, the leading edge of the recording paper may not reach the conveyance roller. In such a case, if the paper feed cassette is pulled out without releasing the nip, the other end of the recording paper is pulled while the recording paper is nipped, and the recording paper breaks. Then, there is a problem that it is very difficult to remove the broken piece of the recording paper in the nipped state. Furthermore, even if no jam occurs, if the leading edge of the recording paper is located beyond the edge of the paper cassette, pulling out the paper cassette in this state will accommodate the paper cassette. In contact with the wall surface of the apparatus main body housing, the tip end portion is bent, which makes it unsuitable as a recording sheet used for image formation.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of preventing a paper feed cassette from being pulled out in an inappropriate state.

  In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention includes a sheet feeding cassette on which a large number of recording sheets are stacked and mounted so as to be able to be pulled out from the apparatus main body, and A pickup roller that feeds the upper recording paper, a paper feeding roller that feeds the recording paper fed by the pickup roller toward a transport path, and press-contacts the recording paper through the recording paper and picks up the recording paper And a retard roller that rotates in a direction to return to the roller side. The image forming apparatus forms an image on a recording sheet conveyed through the conveyance path. In the image forming apparatus, the pressure contact position between the sheet feeding roller and the retard roller and the sheet feeding cassette When the sensor detects that the recording paper is positioned between the edge and the edge, the paper cassette is locked so that it cannot be pulled out of the main body. It is characterized in that.

  The image forming apparatus according to claim 2 is the image forming apparatus according to claim 1, wherein the recording sheet is fed from the pickup roller to the press contact position in a direction perpendicular to the press contact position and in the same phase as the press contact position. The sensor is arranged.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, when it is detected that a recording sheet is located at the pressure contact position and a jam occurs, the image formation apparatus near the pressure contact position is detected. The door is opened to open the conveyance path, and notification is made to clear the jam.

  According to the image forming apparatus of the first aspect, when the sensor detects that the recording sheet is positioned between the pressure contact position between the sheet feeding roller and the retard roller and the end of the sheet feeding cassette, Lock the cassette so that it cannot be pulled out from the main unit. For this reason, when the leading end of the recording paper is positioned beyond the end of the paper feed cassette, the user cannot pull out the paper feed cassette from the apparatus main body. Accordingly, by pulling out the paper feed cassette as it is, a part of the recording paper is bent in contact with the wall surface of the apparatus main body that houses the paper feeding cassette, and the recording paper is not suitable as a recording paper used for image formation. Can be prevented.

  According to the image forming apparatus of the second aspect, the sensor is disposed in a direction perpendicular to the direction in which the recording sheet is fed from the pickup roller to the press contact position and in the same phase as the press contact position. Therefore, the sensor can reliably detect that the recording sheet is positioned between the press contact position and the end of the sheet feeding cassette. In addition, that a sensor is arranged means that the detection part of a sensor is arrange | positioned.

  According to the image forming apparatus of claim 3, when it is detected that a recording sheet is located at the press contact position and a jam has occurred, the door that opens the conveyance path near the press contact position is opened to remove the jam. Inform them to resolve. For this reason, when the recording paper is located at the press contact position and a jam occurs, the recording paper can be prevented from being broken by pulling out the paper feed cassette without releasing the nip, and the user can avoid the vicinity of the press contact position. The door that opens the conveyance path can be opened to prompt the user to clear the jam. Therefore, the user can easily remove the jam.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. A copy / facsimile multifunction peripheral 100 equipped with an image forming apparatus according to an embodiment of the present invention includes a control unit (MPU: Microprocessing Unit) 1 and a ROM (Read Only Memory) 2 as shown in a block diagram in FIG. A RAM (Random Access Memory) 3, an image forming unit 4, a paper feeding unit 5, a paper feeding cassette lock unit 6, a notification unit 7, and an operation unit 8. Are communicably connected.

  The control unit 1 controls the operation of each unit of the copy / facsimile multifunction peripheral 100. The ROM 2 stores various programs for controlling the operation of each unit of the copy / facsimile multifunction peripheral 100 by the control unit 1. The RAM 3 stores various data such as processing setting information and operation information used for processing operations of the copy / facsimile multifunction peripheral 100 in a readable and writable state.

  As shown in FIG. 2, a schematic perspective view showing the appearance of the copy / facsimile multifunction peripheral 100 includes a main body 110 including an image forming unit 4 and a paper feeding unit 5 for forming an image on a recording sheet, and a recording sheet. A sheet feeding cassette 120 to be sequentially supplied, a reading table 130 functioning as a flat bed scanner for reading an image of an original, and an operation panel 140 for inputting start of image reading and image formation are provided.

  As shown in FIG. 3, a schematic partial longitudinal sectional view showing the internal configuration of the main body 110 and the paper feed cassette 120 is provided in the copier / facsimile multifunction peripheral 100. As shown in FIG. It is installed. The image forming unit 4 is disposed above the sheet feeding cassette 120, and the sheet discharge tray 111 is disposed above the image forming unit 4. At one end of the paper feed cassette 120, a paper feed unit 5 that sequentially feeds recording sheets stored in the paper feed cassette 120 is disposed in the main body 110. A conveyance path 112 for conveying the recording paper to the paper discharge tray 111 extends upward from the paper supply unit 5 to the image forming unit 4, extends further upward, and then curves in the horizontal direction. Then, it is formed so as to communicate with the paper discharge tray 111. The reverse conveyance path 113 for forming an image on the back side of the recording paper on which the image is formed on the front surface in the image forming section 4 is diverted from the conveyance path 112 upstream of the image forming section 4. In this way, it is formed so as to join the transport path 112 on the downstream side of the image forming unit 4. Although not shown in FIG. 3, the reading table 130 and the operation panel 140 are disposed above the paper discharge tray 111.

  The image forming unit 4 includes a photosensitive drum 41, a charger 42 disposed around the photosensitive drum 41, an LED head 43, a developing device 44, a transfer roller 45, a cleaning blade 46, and a conveyance path on the downstream side of the photosensitive drum 41. 112 and a fixing device 47 disposed at 112.

  The photosensitive drum 41 is rotated at a predetermined speed by a motor, and is charged to a constant voltage by a charger 42. The charger 42 is a non-contact corona charging method called a so-called scorotron charger, and controls the amount of ions caused by corona discharge generated by applying a predetermined voltage to the discharge wire with a grid electrode. The charger 42 may employ another charging device such as a contact roller charging method instead of the non-contact corona charging method.

  The LED head 43 is a so-called self-light-emitting printer head that forms an image on the surface of the photosensitive drum 41 with the Selfoc lens array using light emitted from the LED arrays arranged in parallel. Based on the above, the surface of the photosensitive drum 41 is selectively exposed to form an electrostatic latent image on the surface. The surface of the photosensitive drum 41 charged by the charger 42 is attenuated by being exposed by the LED head 43, and an electrostatic latent image is formed by the potential difference from the unexposed portion. Further, as the image information, for example, an image of a document read by the reading table 130 functioning as a flatbed scanner is transmitted to the LED head 43 as an electrical signal. As an exposure device, a scanning optical system using a semiconductor laser in addition to the LED head 43 may be used.

  The developing unit 44 forms a toner image based on the electrostatic latent image on the surface of the photosensitive drum 41. The toner in the toner container is supplied to the developing roller through the supply roller due to the difference in bias voltage applied, and a toner layer is formed on the surface of the developing roller. The developing roller on which the toner layer is formed is rotated at a position close to the photosensitive drum 41, and the toner on the developing roller moves to the photosensitive drum 41 due to a potential difference from the electrostatic latent image on the photosensitive drum 41. A toner image is formed on the surface of the photosensitive drum 41 based on the electrostatic latent image. Such a developing device 44 is merely an example, and selection of magnetic toner or non-magnetic toner, selection of contact development method or non-contact development method, and the like are arbitrary.

  The transfer roller 45 is brought into pressure contact with the photosensitive drum 41 at a position facing the conveyance path 112, and a bias voltage is applied from an electric circuit (not shown). A toner image formed on the surface of the photosensitive drum 41 is applied by applying a bias voltage to the recording paper supplied from the paper feeding cassette 120 via the conveying path 112 by the nipping of the photosensitive drum 41 and the transfer roller 45. Is transferred to the recording paper.

  The cleaning blade 46 is pressed against the photoconductor drum 41 after transfer, and is applied with a constant voltage from an electric circuit (not shown) to remove toner and paper dust remaining on the surface of the photoconductor drum 41 and electrostatically. The latent image is erased. As a result, the surface of the photosensitive drum 41 is cleaned and continuous use is possible. It should be noted that instead of the cleaning blade 46, other contact type methods such as a cleaning roller or a non-contact type can be adopted, or a cleaning-less type can be adopted.

  The fixing unit 47 includes a heating roller 16a and a pressure roller 16b disposed at positions opposite to the conveyance path 112, and fixes the toner image on the recording paper conveyed through the conveyance path 112 by heating and pressing. is there. The surface of the heating roller 47a is maintained at a predetermined temperature by a heater, and the pressure roller 47b is pressed against the heating roller 47a with a predetermined pressure. The recording paper on which the toner image is transferred is nipped between the heating roller 47a and the pressure roller 47b, whereby the toner on the recording paper is melted and fixed. The image forming unit 4 configured as described above forms an image of a document read by the reading table 130 on a recording sheet.

  The recording sheet is transported from the paper feed cassette 120 along the transport path 112 to the image forming unit 4 configured as described above, and the recording sheet on which an image is formed by the image forming unit 4 is discharged to the discharge tray 111. The The transport path 112 extends from the paper feed cassette 120 to the image forming unit 4 substantially upward. In the middle of the conveyance path 112, a pair of registration rollers 114 are disposed at opposite positions of the conveyance path 112 so as to be in pressure contact with each other in order to correct skew of the recording paper.

  A conveyance roller 115 is appropriately provided in the conveyance path 112 between the image forming unit 4 and the sheet discharge tray 111, and a recording sheet on which an image is formed is conveyed by the conveyance roller 115, and the sheet discharge roller rotates normally. 116 is discharged to the discharge tray 111. A C path is formed from the paper feed cassette 120 to the paper discharge tray 111 by such a conveyance path 112. In the case of double-sided image formation, the recording paper having an image formed on one side is conveyed to the side of the paper discharge tray 111 by the paper discharge roller 116 that rotates forward, and then the paper discharge roller 116 is reversely rotated at a predetermined timing to switch back. To the reverse conveyance path 113. A conveyance roller 117 is appropriately provided in the reverse conveyance path 113, and a recording sheet on which an image is formed on one side is conveyed by the conveyance roller 117, and is sent again to the conveyance path 112 from the downstream side of the registration roller 114. Then, the image forming unit 4 forms an image on the back surface of the recording paper.

  A side cover 118 that can open the reverse conveyance path 115 is provided on one side of the main body 110 as shown in FIGS. The side cover 118 is pivotally supported by the main body 110 by a support shaft 118P at the lower end thereof, and can be opened and closed with respect to the main body 110. As shown in FIG. 4, when the recording sheet conveyed through the reverse conveyance path 113 is nipped and jammed between the conveyance rollers 117 arranged in the reverse conveyance path 113, the side cover 118 is opened, and the gap between the conveyance rollers 117. The jammed recording paper can be easily removed by releasing the nip and opening the reverse conveyance path 113. The main body 110 is also provided with an intermediate cover 119 that can open the transport path 112. The intermediate cover 119 is pivotally supported by the main body 110 by a support shaft 119P at the lower end thereof, and can be opened and closed with respect to the main body 110 only when the side cover 118 is open. When the recording paper conveyed through the conveyance path 112 is nipped between the conveyance rollers 115 arranged in the conveyance path 112 or between the paper feed roller 53 and the retard roller 54, the side cover 115 and the intermediate cover 115 are removed. The jammed recording paper can be easily removed by opening and releasing the nip between them to open the conveyance path 112.

  As shown in FIG. 5 in particular, the paper feed cassette 120 is a box-shaped container capable of storing recording papers of various sizes, and is provided at the bottom of the apparatus main body 110 so that it can be pulled out. The main body 110 can be pulled out toward the front in FIG. 5 so that it can be loaded. The housing of the apparatus main body 110 is provided with a substantially rectangular recess space for accommodating the paper feed cassette 120 so that its outer shape is indicated by a two-dot chain line in FIG. Inside the paper feed cassette 120, a guide 121 for holding a recording paper of a predetermined size at the paper feed position is disposed. The guide 121 is provided so as to be able to swing within a predetermined range, and its bottom plate is biased upward by a spring (not shown) or the like to hold a plurality of recording sheets in a stacked state, One end side of the uppermost paper is always positioned at the paper feed position.

  The paper feed unit 5 includes a pickup roller 51, a friction pad 52, a paper feed roller 53, and a retard roller 54, and is disposed in the main body 110.

  The pickup roller 51 and the friction pad 52 are provided at the sheet feeding position of the sheet feeding cassette 120, and the uppermost sheet of the recording sheet positioned at the sheet feeding position by the guide 121 comes into pressure contact with the pickup roller 51. The pickup roller 51 is rotatably supported on the distal end side of a pickup arm that is pivotally locked to the roller shaft of the paper feed roller 53 and rotated by a clutch (not shown). The pickup arm rises in the standby state when the paper feeding cassette 120 is pulled out and the like so that the pickup roller 51 is separated from the recording paper. When the recording paper is fed out, the pickup arm 51 is rotated downward so that the pickup roller 51 Move down to contact the top of the recording paper. The pickup roller 51 rotates counterclockwise while being pressed against the uppermost sheet, thereby feeding the recording sheet to a nip position (pressing position) P between the sheet feeding roller 53 and the retard roller 54. The paper feed roller 53 and the retard roller 54 are disposed in the main body 110.

  The paper feeding roller 53 is rotated counterclockwise by a driving unit (not shown) and conveys the uppermost sheet of recording paper fed from the pickup roller 51 toward the conveyance path 112. The retard roller 54 is counterclockwise by a driving means (not shown) via a torque limiter (not shown) so that the retard roller 54 is pressed against the paper supply roller 53 via the recording paper and rotates in a direction to return the recording paper to the pickup roller 51 side. While being rotated in the circumferential direction, it is pressed against the paper feed roller 53 by an elastic mechanism (not shown). When the recording sheet is fed to the nip position P, the retard roller 54 slides beyond the limit torque, and is driven to rotate by the sheet feeding roller 53 to feed the recording sheet to the conveyance path 112. On the other hand, when two or more recording sheets are fed to the nip position P, the limiter torque overcomes the frictional force between the recording sheets, the retard roller 54 is rotated in the reverse direction, and the lower recording sheet is pushed back to prevent a large number of sheets from being fed. To do. As a result, the recording sheets are fed into the conveyance path 112 one by one.

  However, when the pickup roller 51 is lowered onto the recording paper at the start of feeding, the recording paper is displaced, and the lower recording paper protrudes forward in the feeding direction from the upper recording paper. In this state, when the recording sheet is fed to the nip position P, the leading end of the protruding lower recording sheet enters the nip position P in advance, so that the recording sheet is not returned by the retard roller 54. Then, it is sent to the conveyance path 112 side together with the upper recording sheet. In such a case, the recording paper remains nipped at the nip position P, and a jam (paper jam) occurs.

  A first sensor 55 is provided for detecting whether a recording sheet is positioned between the nip position P between the sheet feeding roller 53 and the retard roller 54 and the end of the sheet feeding cassette 120. The first sensor 55 is preferably arranged in a direction perpendicular to the direction in which the recording paper is fed from the pickup roller 51 to the nip position P and in the same phase as the nip position P. A second sensor 55 is provided for detecting whether or not the recording sheet is positioned between the nip position P and the vicinity of the starting point Q of the conveyance path 112. Each of the first sensor 55 and the second sensor 56 outputs a detection signal corresponding to whether or not the recording sheet is positioned, and includes various detection means such as an optical sensor, a photo sensor, and a micro switch. It may be provided with a feeler.

  The sheet cassette lock unit 6 (see FIG. 1) is provided on the far side (the right far side in FIG. 2) in the pulling direction of the sheet cassette 120. As shown in FIG. It is possible to lock the drawing from the main body 110. The sheet cassette lock unit 6 includes a shaft 61 fixed to the main body 110, a link member 62 that can rotate around the shaft 61, and a solenoid 63 that is connected to the base end of the link member 62. . At the tip of the link member 62, a locking portion 62 a that locks with a notch 122 formed in the back wall of the paper feed cassette 120 is provided. The solenoid 63 is operated by a control signal from the control unit 1. When the paper cassette lock unit 6 locks the drawer of the paper cassette 120, as shown by the solid line in FIG. 6, the locking portion 62 a engages with the notch 122 of the paper cassette 120 by turning on the solenoid 63. . As a result, the paper feed cassette 120 cannot be freely moved in the pull-out direction (the leftward direction in FIG. 6). On the other hand, when the drawer of the sheet cassette 120 is not locked, as shown by a two-dot chain line in FIG. 6, the link member 62 rotates clockwise by turning off the solenoid 63, and the locking portion 62 a and the sheet cassette 120 are rotated. The engagement with the notch 122 is released. As a result, the paper feed cassette 120 can freely move in the pull-out direction.

  As shown in FIG. 1, the operation panel 140 (see FIG. 2) is an LCD (Liquid Crystal Display) that displays various notification screens, the operation state of the copy / facsimile multifunction peripheral 100, etc. with characters and graphics. ), A notification unit 7 including a speaker (not shown) that performs a notification operation by sounding voice data or a buzzer sound, a start key for instructing start of reading, copying, transmission, etc. of a document, the number of copies And an operation unit 8 including various operation keys such as a numeric keypad for inputting a transmission destination number and the like, and a cursor key and a button key for inputting various settings.

  Hereinafter, processing operations performed in the copy / facsimile multifunction peripheral 100 when an image is formed on a recording sheet will be described with reference to a flowchart shown in FIG. The processing operation of the copy / facsimile multifunction peripheral 100 described based on the following flowchart is performed according to a command issued by the control unit 1 based on a program stored in the ROM 2.

  First, it is determined whether or not the recording paper is positioned between the nip position P between the paper feed roller 53 and the retard roller 54 and the end of the paper feed cassette 120 (S1). Specifically, it is determined whether or not a detection signal for detecting that the recording sheet is located at the position is output from the first sensor 55. Here, when it is determined that the recording sheet is positioned between the nip position P and the end of the paper feed cassette 120 (S1: YES), the paper feed cassette lock unit 6 locks the paper feed cassette 120 so as not to be pulled out. (S2).

  Then, it is determined whether or not the recording paper is nipped at the nip position P between the paper feed roller 53 and the retard roller 54 to cause a jam (S3). Specifically, a detection signal for detecting that the recording sheet is positioned between the nip position P and the start point Q of the conveyance path 112 is continuously output from the second sensor 55 for a predetermined time or more. Determine whether or not. When it is determined that the recording paper has been nipped at the nip position P (S3: YES), the notification unit 7 opens the side cover 118 and the intermediate cover 119 and removes the jammed recording paper. Notification is made (S4). Specifically, a message such as “Paper is jammed at the outlet of the paper feed cassette. Open the side cover and intermediate cover and remove the paper.” Is displayed on the LCD of the operation panel 140.

  On the other hand, when it is determined that the recording sheet is not positioned between the nip position P and the end of the sheet cassette 120 (S1: NO), the sheet cassette 120 can be pulled out freely by the sheet cassette lock unit 6. In such a manner, the lock is released (S5).

  As described above, according to the copier / facsimile multifunction peripheral 100, the recording paper is positioned between the nip position P between the paper feed roller 53 and the retard roller 54 and the end of the paper feed cassette 120. When one sensor 55 is detecting (S1: YES), the sheet cassette 120 is locked by the sheet cassette lock unit 6 so as not to be pulled out from the apparatus main body 110 (S2). Therefore, when the leading end portion of the recording paper is located beyond the end portion of the paper feed cassette 120, the user cannot pull out the paper feed cassette 120 from the apparatus main body 110. Therefore, by pulling out the paper feed cassette 120 as it is, a part of the recording paper is bent in contact with the wall surface of the housing of the apparatus main body 110 that houses the paper feeding cassette 120, and the recording paper is used for image formation. It can be prevented from becoming unsuitable.

  Further, when it is detected that the recording paper is located at the nip position P between the paper feed roller 53 and the retard roller 54 and a jam occurs (S3: YES), the side that opens the conveyance path 112 near the nip position P is opened. A notification is made to open the cover 118 and the intermediate cover 119 to eliminate the jam (S4). Therefore, when the recording paper is located at the nip position P and a jam occurs, the recording paper can be prevented from being broken by pulling out the paper feed cassette 120 without releasing the nip, and the side cover 118 and The intermediate cover 119 can be opened to prompt the user to clear the jam. Therefore, the user can easily remove the jam.

  The configuration of the copy / facsimile multifunction peripheral 100 shown in the present embodiment is only one aspect of the photosensitive drum and the image forming apparatus according to the present invention, and various modifications can be made without departing from the gist of the present invention. Implementation is possible. For example, the second sensor 56 may be disposed upstream of the starting point Q of the conveyance path 112.

  Further, in the present embodiment, the mode in which the image forming apparatus is implemented as the copy / facsimile multifunction peripheral 100 has been described. However, the image reading apparatus is not limited to this, and a printer, a facsimile machine, a copier, and any of these multifunction peripherals. Etc. are applicable.

1 is a block diagram illustrating a configuration example of a copy / facsimile multifunction peripheral 100 according to an embodiment of the present invention. 1 is a schematic perspective view showing an external appearance of a copy / facsimile multifunction peripheral 100. FIG. 2 is a schematic partial longitudinal sectional view showing a main body 110 and a paper feed cassette 120 of the copy / facsimile multifunction peripheral 100. FIG. It is a schematic partial longitudinal cross-sectional view which shows the state which opened the side cover 118 and the intermediate cover 119. FIG. 3 is a schematic partial longitudinal sectional view of the vicinity of a sheet feeding unit 5. FIG. 6 is an explanatory view showing a paper feed cassette lock unit 6. 3 is a flowchart showing processing operations performed in the copy / facsimile multifunction peripheral 100.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 4 Image formation part 5 Paper feed part 6 Paper feed cassette lock part 7 Notification part 51 Pickup roller 52 Friction pad 53 Paper feed roller 54 Retard roller 55 1st sensor 56 2nd sensor 100 Copy / facsimile compound machine (image formation) apparatus)
110 Device main body 118 Side cover (door)
119 Intermediate cover (door)
120 Paper cassette 140 Operation panel

Claims (3)

A paper feeding cassette on which a large number of recording papers are stacked and mounted so as to be able to be pulled out from the apparatus main body, a pickup roller for feeding out the uppermost recording paper loaded in the paper feeding cassette, and a recording paper fed out by the pickup roller A sheet feed roller that conveys the recording sheet toward the conveyance path, and a retard roller that is pressed against the sheet feed roller via the recording sheet and rotates in a direction to return the recording sheet to the pickup roller side, and conveys the conveyance path In an image forming apparatus for forming an image on a recording paper to be recorded,
When the sensor detects that the recording paper is positioned between the pressure contact position between the paper feed roller and the retard roller and the end of the paper feed cassette, the paper feed cassette cannot be pulled out from the apparatus main body. An image forming apparatus which is locked to   The image forming apparatus according to claim 1, wherein the sensor is disposed in a direction perpendicular to a direction in which a recording sheet is fed from the pickup roller to the press contact position and in the same phase as the press contact position.   When it is detected that a recording sheet is located at the press-contact position and a jam has occurred, a notification is made to clear the jam by opening a door that opens the conveyance path near the press-contact position. Item 3. The image forming apparatus according to Item 1 or 2.

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