JP2009116266A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of detecting inexpensively incomplete locking in a locking mechanism, even when one set switch is provided in a side part cover member. <P>SOLUTION: In the image forming device, the side part cover member assembled with a transfer roller and a one-side member of a conveying route for conveying a paper sheet is attached turnably between an opened state and a closed state around a turning shaft supported by a device body, and the paired locking mechanisms are provided along a longitudinal axial direction of the device body, to lock the side part cover member to the device body in order to bring the transfer roller into a prescribed positional relation with a toner carrier, under the closed state. The image forming device includes the set switch for detecting the opened and closed states of the side part cover member, and a locking state detecting part for detecting a locked state of the locking mechanism, based on a voltage value or a current value of a transfer bias applied to the transfer roller, when the closed state is detected by the set switch. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

  In the image forming apparatus described above, a plurality of cover members that can be freely opened and closed are provided in the apparatus main body for paper jams and maintenance.

  For example, in the image forming apparatus described in Patent Document 1, a transfer roller that transfers a toner image formed on a toner carrier onto a sheet and a sheet on which the toner image is transferred are conveyed to a fixing unit on the side of the apparatus. A side cover member in which one side member of the transport path is incorporated is provided.

  Such a side cover member is pivotably attached between an open state and a closed state around a rotation shaft supported by the apparatus main body. When the side cover member is in the closed state, the transfer roller and the toner carrier are transferred. A pair of locking mechanisms for locking the side cover member to the apparatus main body so that the belt or the photosensitive drum is in a predetermined positional relationship are provided in the front-rear direction along the longitudinal axis direction of the apparatus main body.

JP 2004-240329 A

  When the side cover member described in Patent Document 1 is set in the apparatus main body, the side cover member is rotated upward around the rotation shaft and locked by a pair of front and rear locking mechanisms. The transfer roller and the toner carrier are positioned so as to be disposed at appropriate positions.

  However, even if the side cover member is pivoted upward around the pivot axis, the pair of front and rear locking mechanisms do not always reach the locked state at the same time. There is a problem that a proper transfer process is not performed and a defective image is generated.

  In order to configure the pair of front and rear locking mechanisms to be in the locked state at the same time, it is necessary to increase the rigidity of the side cover member and increase the dimensional accuracy of the locking mechanism. Or an increase in machine weight, which is not preferable.

  Therefore, it is conceivable to provide a set switch for detecting the operating state of each lock mechanism in order to detect the lock state of the pair of front and rear lock mechanisms, but there is a problem in that the cost of the parts similarly increases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can detect a single hook of a lock mechanism at a low cost even if there is only one set switch of a side cover member.

  In order to achieve the above object, a first characteristic configuration of an image forming apparatus according to the present invention is that a toner image formed on a toner carrier is transferred to a sheet as described in claim 1 of the claims. The side cover member incorporating the transfer roller and the one side member of the transport path for transporting the sheet on which the toner image has been transferred to the fixing unit is opened and closed around the rotation shaft supported by the apparatus main body. A locking mechanism that locks the side cover member to the apparatus main body so that the transfer roller and the toner carrier are in a predetermined positional relationship when the transfer roller and the toner carrier are in a closed position. A pair of image forming apparatuses provided at the front and rear along the front-rear axial direction of the apparatus main body, comprising a set switch for detecting an open / closed state of the side cover member, and the closed state is detected by the set switch. When you are, it lies in that it includes a lock status detector for detecting a locked state of the lock mechanism based on a voltage value or current value of the transfer bias applied to the transfer roller.

  If the pair of front and rear locking mechanisms are normally locked, the toner carrier and the transfer roller are positioned, and a predetermined transfer current flows due to the transfer bias applied to the transfer roller from the transfer bias power source. However, the impedance due to the gap between the toner carrier and the transfer roller increases, and an appropriate transfer current does not flow. For example, if the transfer bias power source is a constant current power source, the output voltage increases as the impedance increases.

  Therefore, when the side cover member is pressed from the open state to the toner carrier side and the closed state is detected by the set switch, the voltage value or current value of the transfer bias applied to the transfer roller by the lock state detection unit is Whether or not the lock state is proper can be detected based on whether or not the value is appropriate.

  In addition to the first feature configuration, the second feature configuration operates in the vicinity of one of the lock mechanisms, when the one lock mechanism is locked, as described in claim 2. The set switch is arranged, and an electrode contact for applying a transfer bias to the transfer roller from the apparatus main body is provided in the vicinity of the other lock mechanism.

  Of the pair of lock mechanisms, the lock state on the side where the set switch is arranged can be confirmed by the set switch, and in the vicinity of the other lock mechanism where no set switch is arranged, the lock mechanism is in a normal lock state. If an electrode contact that contacts is provided in some cases, if the lock mechanism is not in a normal locked state, the electrode contact does not contact, so that the current of the transfer bias is not detected or the voltage value is excessive. Therefore, the locked state can be detected properly.

  According to the third feature configuration, in addition to the first or second feature configuration, the third feature configuration is provided with an openable / closable exterior cover that covers the side cover member, and the set switch is provided with the exterior switch. It is also used as a cover set switch.

  According to the configuration described above, by using the set switch that detects the open / closed state of the side cover member and the open state of the exterior cover, if the side cover member is not normally closed, the exterior cover is also normally closed. Therefore, the number of parts can be reduced without providing a new set switch for detecting the open / closed state of the exterior cover.

  As described above, according to the present invention, it is possible to provide an image forming apparatus that can detect a single hook of a lock mechanism at a low cost even with a single set switch of a side cover member.

  In the following, an embodiment of an image forming apparatus capable of inexpensively detecting a single hook of a locking mechanism even if there is only one set switch of a side cover member according to the present invention will be described.

  As shown in FIGS. 1A and 1B, the image forming apparatus 100 includes an upper housing 101 and a main body housing 102.

  The upper housing 101 includes a document placement unit 200 for setting recording paper as a document, a main body operation unit 300 on which a plurality of menu setting keys for setting various menus of the image forming apparatus, and an image for reading a document. A reading unit 400 and a document discharge unit 201 that discharges a document read by the image reading unit 400 are provided.

  The main body housing 102 forms a toner image on the paper based on the manual paper feed unit 103, the paper feed cassettes 104 and 105 in which a plurality of papers are housed, and the image data read by the image reading unit 400. Output image forming unit 500, fixing unit 600 that heats and fixes the toner image output on the sheet to be fixed on the sheet, sheet conveyance path 700, and sheet discharge that discharges the sheet on which the toner image is fixed Part 106 is provided.

  The image forming unit 500 includes a toner carrier 530 in the image forming apparatus 100 and a side cover member 510 that is pivotally mounted about the rotation shaft 1 supported by the main body housing 101. Yes.

  In addition, the main body housing 101 includes an exterior cover 511 that is pivotally mounted about the rotation shaft 1 so as to be openable and closable so as to cover the side cover member 510.

  As shown in FIGS. 2, 3, and 4, the side cover member 510 includes a transfer roller 540 that transfers a toner image formed on the toner carrier 530 constituting the image forming unit 500 onto a sheet, and a toner image. One side member 710 for conveying the transferred paper to the fixing unit 600 and an opening / closing member 520 for opening and closing the side cover member 510 are provided around the rotation shaft 1 supported by the main body housing 101. By pivotally attaching to the image forming apparatus 100, the image forming apparatus 100 can be opened and closed between an open state 510a and a closed state 510b.

  The image forming unit 500 locks the side cover member 510 to the main body housing 101 so that the transfer roller 540 and the toner carrier 530 are in a predetermined positional relationship when the side cover member 510 is in the closed state 510b. The image forming apparatus 100 includes a pair of front and rear locking mechanisms 521 along the longitudinal axis direction of the image forming apparatus 100. The pair of locking mechanisms 521 is associated with a pair of hook portions 524 provided on an opening / closing member 520 described later, and the hook portions 524. It is comprised with the hook latching | locking part 525 of the main body side to stop.

  The opening / closing member 520 includes a rotation shaft 522 that connects a pair of hook portions 524, and an opening / closing lever 523 is connected to one of the hook portions 524, and the opening / closing lever 523 is operated to thereby center the rotation shaft 522. The hook portion 524 rotates and is configured to be in a released state 524a or a locked state 524b with respect to the hook locking portion 525.

  Further, the transfer roller separation member 527 is pivotally attached to the rotation shaft 522 of the opening / closing member 520, and the transfer roller support member 526 is connected to the transfer roller separation member 527, so that the opening / closing lever 523 is operated and the hook portion 524 is operated. The transfer roller 540 is configured to be separated from the toner carrier 530 when is in the release state 524a.

  That is, when the side cover member 510 is in the closed state 510b, the lock mechanism 521 is unlocked by operating the open / close lever 523 and setting the hook portion 524 of the lock mechanism 521 to the released state 524a. The cover member 510 can be opened, and at this time, since the transfer roller separating member 526 is pivotally attached to the rotation shaft 522, the transfer roller separation member 526 rotates according to the rotation operation of the opening / closing lever 523, and the transfer roller The transfer roller support member 525 is moved by the rotation of the separation member 526, and the transfer roller 540 moves from the contact state 540b to the separation state 540a with respect to the toner carrier 530.

  The transfer roller support member 526 has a spring-like urging member that urges the transfer roller 540 toward the toner carrier 530, so that when the side cover member 510 is in the closed state 510 b, the transfer roller 540 is moved to the toner. A predetermined positional relationship can be secured by pressing the carrier 530 with an appropriate pressure.

  Further, the image forming unit 500 includes a transfer roller guide groove 541 so as to fit both ends of the rotation shaft 542 of the transfer roller 540. When the side cover member 510 is operated from the open state 510a to the closed state 510b, the transfer roller 540 can be accurately guided to the position of the contact state 540b with respect to the toner carrier 530.

  The transfer roller 540 supports the transfer roller 540 in a state where play is provided while the guide direction of the transfer roller guide groove 541 and the rotation direction of the side cover member 510 intersect, thereby transferring the transfer roller. The separation state 540a and the contact state 540b with respect to the toner carrier 530 of the 540 can be moved, and the position of the transfer roller 540 with respect to the toner carrier 530 can be fixed in the contact state 540b. ing.

  In the vicinity of one of the pair of lock mechanisms 521, a set switch 560 is provided at a predetermined position such that the side cover member 510 abuts in the closed state 510b. Thus, if the side cover member 510 is in contact with the set switch 560, the set switch 560 detects that the side cover member 510 is in the closed state 510b, and the side cover member contacts the set switch 560. If not, the open state 510a is detected.

  As shown in FIG. 10, an electrode contact that applies a transfer bias to the transfer roller 530 from the main body of the image forming apparatus 100 is provided in the vicinity of the other lock mechanism 521 that does not include the set switch 560.

  As shown in FIGS. 8 and 9, the image forming apparatus 100 includes a control unit 800 having a microcomputer for controlling each of the main body of the apparatus 100 and a transfer bias for applying a transfer bias to the transfer roller. A high-voltage power supply 900 is provided, and the control unit 800 includes at least one of a pair of lock mechanisms 521 provided in the side cover member 510 by a set switch 560 that detects the closed state of the exterior cover 511 and the side cover member 510. When the closed state 521b is detected, a lock state detection unit 810 that detects the lock state of the lock mechanism 521 based on the voltage value or current value of the transfer bias applied by the transfer roller 540 is provided.

  When the lock state detection unit 810 determines that the lock state is not appropriate, the lock state detection unit 810 displays a message indicating that the side cover member is not properly set on the operation unit of the apparatus to alert the operator, and the lock state is detected. Is determined to be appropriate, the control unit is configured to start up the apparatus in a printable state.

  Hereinafter, detection of the opening / closing operation of the side cover member 510 will be described in detail.

  As described above, by opening / closing the opening / closing lever 523, the lock mechanism 521 locks (open state 521b) and releases (closed state 521a) in the closed state 510b between the side cover member 510 and the apparatus 100 main body. The hook 524 can be locked (locked state 524b) and released (released state 524a), and the transfer roller 540 can be moved between the separation position 540a and the contact position 540b with respect to the toner carrier 530 by the transfer roller support member 526. It becomes.

  Conversely, when the side cover member 540 is in the closed state 540b, the tip of the hook portion 524 comes into contact with the hook locking portion 525 by pressing the side cover member 540 toward the toner carrier 530. The hook locking portion 525 presses 528 against the guide surface formed at the tip of the hook portion 524 to rotate the hook portion 524 to change from the locked state 524b to the released state 524a, and is pivotally attached to the rotating shaft 522. The transfer roller separation member 527 rotates, and the transfer roller 540 connected to the transfer roller support member 526 moves from the contact state 540b to the separation state 540a.

  Further, when the side cover member 540 is pressed, the hook portion 524 and the hook locking portion 525 are locked to be in a locked state 521b, and the transfer roller shaft connected to the transfer roller support member 526 is rotated by the rotation of the hook portion 524. The 542 moves along the transfer roller guide groove 541 from the separated state 540a to the contact state 540b, and moves the transfer roller 540 to a predetermined position while preventing interference between the transfer roller 540 and the transfer roller guide groove 541. Can do.

  With the above configuration, when the side cover member 510 is changed from the open state 510a to the closed state 510b, if at least the lock mechanism 521 provided with the set switch 560 is not normally in the closed state 521b, the set switch Since the closed state 560b cannot be detected by 560, it can be detected that the side cover 510 is not in the closed state 510b.

  Conversely, even if the closed state 560b is detected by the set switch 560, if the other lock mechanism 521 is not normally in the closed state 521b, the electrode contact of the transfer bias high-voltage current is not in contact, If the contact is not enough, and the impedance is higher than the normal range, the voltage detector provided in the transfer high voltage power supply detects that the voltage value of the transfer bias has risen to near the no-load voltage. Alternatively, it can be detected that the transfer roller 540 is not in the normal contact state 542b with respect to the toner carrier 530 by detecting that the current detection unit outputs only a predetermined current value. It can be detected that at least one of the lock mechanisms 521 is not in the closed state 521b.

  Although the tandem type image forming apparatus has been described in the above-described embodiment, the present invention can also be applied to a monochrome type image forming apparatus.

  In the above-described embodiment, a set switch is disposed in the vicinity of one of the lock mechanisms so as to operate when the one lock mechanism is in the locked state, and a transfer bias is applied to the transfer roller in the vicinity of the other lock mechanism. A lock is provided to detect that the other lock mechanism is not properly locked when an electrode contact applied from the main body of the apparatus is provided, the electrode contact is not conducted, and an appropriate value of the transfer bias current or voltage is not detected. Although the state detection unit has been described, the present invention is not limited to such a configuration, and includes a set switch that detects the open / closed state of the side cover member, and the transfer is performed when the closed state is detected by the set switch. Any lock state detector that detects the lock state of the lock mechanism based on the voltage value or current value of the transfer bias applied to the roller. .

  For example, when one of the pair of lock mechanisms is locked and the other is not locked, the gap between the image carrier that is not properly locked and the transfer roller is wider than the gap that is properly locked. Thus, since the impedance between the image carrier and the transfer roller increases as a whole, it is detected that the voltage value or current value of the transfer bias applied to the transfer roller is different from the appropriate value.

  In addition, when an openable / closable exterior cover is provided to cover the side cover member, and the set switch is also used as a set switch for the exterior cover, the exterior cover is normally closed unless the side cover member is in a normal closed state. The number of parts can be reduced without providing a set switch in order to detect the open / closed state of the exterior cover.

  The above-described image forming apparatus is not necessarily limited to an image forming apparatus such as a copying machine, a printer, or a facsimile, and the cover member 2 that rotates around a rotation shaft supported by the apparatus main body is rotated with respect to the apparatus main body. As long as the opening / closing operation is enabled and the transfer roller 540 is supported so as to be able to come into contact with and separate from the toner carrier 530 according to the opening / closing operation, the present invention can be applied to other printing apparatuses.

  Further, although the material of each member constituting the above-described image forming apparatus is not specified, a hard plastic or a metal product such as an aluminum die cast can be employed. Depending on the use of each member, an optimal material is appropriately selected in consideration of strength, economy, and the like. The bearing of the transfer roller is made of a conductive material, so that a high-voltage current for transfer bias can flow.

  It is also possible to combine each embodiment mentioned above suitably in the range with which the effect by this invention is show | played.

  The above-described embodiments are merely examples of the present invention, and it is needless to say that the specific configuration can be appropriately changed within a range where the effects of the present invention are exhibited.

(A) is a schematic view of the image forming apparatus, (b) is a schematic view of the image forming apparatus in which the side cover member is open. Schematic of the main part of the image forming unit Explanatory drawing of the transfer roller separation member and transfer roller support member provided in the side cover member Illustration of side cover member Explanatory drawing of the image forming part in which the side cover member is in the open state Explanatory drawing of the image forming unit where the transfer roller is moved by the open / close lever Explanatory drawing of the image forming part in which the side cover member is in the closed state Explanatory drawing of the lock state detection part which detects the lock state of a lock mechanism based on the voltage value or electric current value of a transfer bias Explanatory drawing to detect locked state by electrode contact Schematic diagram of electrode contacts that apply a transfer bias to the transfer roller near the lock mechanism from the main unit

Explanation of symbols

1: rotating shaft 100: image forming apparatus 101: upper housing 102: main body housing 103: manual sheet feeding unit 104: sheet feeding cassette 105: sheet feeding cassette 106: sheet discharging unit 200: document placing unit 201: document discharging unit 300: Main body operation unit 400: Image reading unit 500: Image forming unit 510: Side cover member 510a: Open state 510b: Closed state 511: Exterior cover 520: Opening / closing member 521: Pair of lock mechanisms 521a: Open state 521b: Closed State 522: Rotating shaft 523: Opening / closing lever 524: Hook portion 524a: Release state 524b: Locking state 525: Hook locking portion 526: Transfer roller support member 527: Transfer roller separating member 528: Guide surface 529: Electrode contact 530 : Toner carrier 540: transfer roller 540 a: separated state 540 b: contact state 541: transfer roller plan Groove 542: transfer roller shaft 600: fixing portion 700: conveying path 710: one side member 800: Control unit 810: lock state detecting unit 900: high-voltage power supply for transfer bias

Claims (3)

A side cover member incorporating a transfer roller for transferring a toner image formed on a toner carrier onto a sheet and a one-side member of a conveyance path for conveying the sheet on which the toner image has been transferred to a fixing unit is supported by the apparatus main body. The side cover is attached around the rotating shaft so as to be rotatable between an open state and a closed state so that the transfer roller and the toner carrier are in a predetermined positional relationship when in the closed state. A lock mechanism for locking a member to the apparatus main body is an image forming apparatus provided in a pair at the front and rear along the longitudinal axis direction of the apparatus main body,
A set switch for detecting an open / closed state of the side cover member, and when the closed state is detected by the set switch, based on a voltage value or a current value of a transfer bias applied to the transfer roller, An image forming apparatus including a lock state detection unit that detects a lock state of a lock mechanism.   The set switch is disposed in the vicinity of one of the lock mechanisms so as to operate when the one lock mechanism is in a locked state, and the transfer bias is applied to the transfer roller from the apparatus main body in the vicinity of the other lock mechanism. The image forming apparatus according to claim 1, further comprising an electrode contact to be applied.   The image forming apparatus according to claim 1, wherein an openable / closable exterior cover that covers the side cover member is provided, and the set switch is also used as a set switch of the exterior cover.

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