JP2006220993A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of preventing a photoreceptor and an intermediate transfer belt, which is an endless belt, from being scratched even when the replacement of the photoreceptor is carried out with a power source off. <P>SOLUTION: The image forming apparatus includes: the photoreceptor attachable/detachable to/from the main body of the apparatus; a unit attachable/detachable to/from the main body of the apparatus and including the endless belt that can be brought into contact with the photoreceptor; a contact separation mechanism incorporated in the unit including the endless belt, and used to bring the endless belt into contact with the photoreceptor and separate it therefrom without changing the position of the unit; and a contact separation drive used to drive the contact separation mechanism. The image forming apparatus is characterized by including a linkage mechanism that is linked to an opening/closing member serving as the covering of the main body of the apparatus, and returns the contact separation mechanism of the unit including the endless belt to its initial position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a color copying machine or a color printer.

  Conventionally, as a method of separating an intermediate transfer belt, which is an endless belt, from a photosensitive member, as shown in Patent Document 1, there has been proposed a method that is configured to be interlocked with opening / closing of an opening / closing member that also serves as an exterior of an apparatus main body. Yes.

JP 2001-272864 A (page 8, FIG. 6)

  However, recently, in order to prevent consumption of unused color photoconductors when performing monochrome printing with an inline color printer or the like, it is necessary to separate the intermediate transfer belt, which is an endless belt, from the color photoconductor during printing. It has come out.

  Accordingly, it is not sufficient to separate the intermediate transfer belt, which is an endless belt, in conjunction with an opening / closing member that also serves as an exterior, and a mechanism that automatically separates according to the printing mode is required. In the normal usage method, when the opening / closing of the opening / closing member that also serves as the exterior is detected, it is possible to operate the automatic separation mechanism to separate the intermediate transfer belt, which is an endless belt. When the power is turned off while the power is turned off, it cannot be returned to the separated state, and there is a problem that the photoconductor and the intermediate transfer body are damaged when the photoconductor is replaced.

  The present invention has been made in view of the above problems, and the purpose of the present invention is to reduce the risk of scratching the photoreceptor and the intermediate transfer belt, which is an endless belt, when the photoreceptor is replaced even when the power is turned off. An object of the present invention is to provide an image forming apparatus that can be eliminated.

  In order to achieve the above object, the present invention provides a photosensitive member that can be attached to and detached from the apparatus main body, a unit including an endless belt that can be attached to and detached from the apparatus main body and can contact the photosensitive member, and the endless belt. A contact / separation mechanism that contacts and separates the endless belt from the photosensitive member without moving the position of the unit itself, and a contact / separation drive that drives the contact / separation mechanism. The image forming apparatus includes an interlocking mechanism that returns a contact / separation mechanism of the unit including the endless belt to an initial position in conjunction with an opening / closing member that also serves as an exterior provided in the apparatus main body.

  According to the present invention, the contact / separation mechanism can be returned to the initial position by the opening operation of the opening / closing member also serving as the exterior, and therefore, when the opening / closing member also serving as the exterior is opened, the photosensitive member and the intermediate transfer belt, which is an endless belt, are separated from each other. Even when the power is turned off, it is possible to eliminate the risk of scratching the photoreceptor and the intermediate transfer belt, which is an endless belt, when the photoreceptor is replaced.

  Hereinafter, embodiments of the image forming apparatus according to the present invention will be described with reference to FIGS.

  In FIG. 1, 21 is a paper feed cassette, 22 is a pickup roller, 23 is a feed roller, 24 is a retard roller, and 25 is a registration roller pair installed in the apparatus main body.

  1 and 2, reference numeral 27 denotes an intermediate transfer belt unit, 27D is a driving roller, 27T is a tension roller, and an intermediate transfer belt 27B, which is an endless belt, is stretched and brought into contact with the secondary transfer roller 26. 39Y, 39M, 39C, and 39Bk are primary transfer rollers, and are pressed by a spring (not shown).

  The intermediate transfer belt unit 27 is detachably held in the apparatus main body by opening the opening / closing door 43 on the side of the main body. Reference numeral 40 denotes a bearing for the primary transfer roller, which has protrusions in part, and is inserted into holes 36Y, 36M, 36C, and 36Bk of a separation plate 36 that is a contact / separation mechanism. The separation plate 36 as the contact / separation mechanism is engaged with the separation levers 37F and 37R held by the separation shaft 37, and moves linearly when the separation levers 37F and 37R rotate. The separation shaft 37 is held integrally with the separation gear 37G so as to be movable in the axial direction with respect to the separation levers 37F and 37R, and is urged to the arrow F side in the drawing by the separation shaft spring 37SP. Further, a separation plate spring 36SP is hung on the separation plate 36 and is urged toward the tension roller side.

  1 and 3, reference numerals 28 to 31 denote photosensitive drums that are image carriers, which are image carriers, and can be attached and detached in the direction of the central axis of the photosensitive drums 28 to 31 by opening an opening / closing member 41 that also serves as an exterior. It is held by the device body. Reference numeral 32 denotes a laser scanner serving as an exposure unit, which exposes the photosensitive drums 28 to 31 serving as image carriers.

  Reference numeral 33 denotes a fixing device, 34 denotes a pair of paper discharge rollers, and 35 denotes a paper discharge tray, which are installed at the top of the apparatus main body.

  In FIG. 2, 38 is a separation drive gear which is a contact / separation drive, and is configured to be rotated to three positions of separation, monochrome contact and contact by a motor (not shown). A separation gear 37G receives driving from the separation drive gear 38 and rotates the separation levers 37F and 37R.

  2, 4, and 5, reference numeral 42 denotes an interlocking rod that is an interlocking mechanism. The interlocking rod 42 is swingably held by the apparatus main body, and is engaged with a pin 44 provided on an opening / closing member 41 that also serves as an exterior. ing. The other end of the interlocking rod 42 that is the interlocking mechanism is in a position that does not contact the tip of the separation shaft 37 when the opening / closing member 41 that also serves as the exterior is closed, and is separated when the opening / closing member 41 that also serves as the exterior is opened. It moves to a position where the tip of the shaft 37 is pushed.

  Next, the operation will be described in order.

  In the initial state, as shown in FIGS. 6 and 7, the separation drive gear 38 that is a contact separation drive is in a separation position that is not in contact with the separation gear 37G. Therefore, the separation plate 36 as a contact / separation mechanism is urged toward the tension roller by the separation plate spring 36SP, and the bearings 40 of the primary transfer roller are all pushed down by the holes 36Y, 36M, 36C, 36Bk of the separation plate 36. In a separated state.

  From here, the separation drive gear 38 which is a contact separation drive is rotated by a motor (not shown). When the separation drive gear 38 rotates from the separation position to the monochrome contact position, the separation gear 37G rotates, the separation levers 37F and 37R rotate, and the separation plate 36 that is a contact / separation mechanism moves to the intermediate position.

  In this state, only the hole 36Bk of the separation plate 36 has a shape that releases the depression of the bearing 40 of the primary transfer roller, and is in a monochrome contact state.

  When performing color printing, a motor (not shown) further rotates a separation drive gear 38 that is a contact / separation drive, and the separation drive gear 38 is rotated to a contact position. As a result, the separation gear 37G rotates, the separation levers 37F and 37R rotate, and the separation plate 36 that is a contact / separation mechanism is completely moved.

  In this state, all of the holes 36Y, 36M, 36C, and 36Bk of the separation plate 36 have a shape that releases the depression of the bearing 40 of the primary transfer roller, and a contact state as shown in FIG.

  In this contact state, the paper fed from the paper feed cassette 21 by the pickup roller 22 is separated into one sheet by the feed roller 23 and the retard roller 24 and conveyed to the registration roller pair 25. Here, the paper stops.

  The image exposed to the photosensitive drums 28 to 31 as an image carrier by the laser scanner 22 is developed by a developing device (not shown), and is primarily transferred to an intermediate transfer belt 27B as an endless belt. The image primarily transferred onto the intermediate transfer belt 27B, which is an endless belt, proceeds to the secondary transfer roller 26, and the paper stopped by the registration roller pair 25 is restarted in accordance with the image. The restarted paper has its image transferred to the paper by the secondary transfer roller 26, the image is fixed by the fixing device 23, and is discharged onto the paper discharge tray 25 by the paper discharge roller pair 24.

  When the printing operation ends, the motor (not shown) is reversely rotated to reversely rotate the separation drive gear 38 that is a contact / separation drive, and the separation drive gear 38 is rotated to the separation position. As a result, the separation gear 37G rotates, the separation levers 37F and 37R rotate, and the separation plate 36, which is a contact / separation mechanism, is completely returned to the initial position shown in FIG.

  In this state, all of the holes 36Y, 36M, 36C, and 36Bk of the separation plate 36 are pushed down the bearing 40 of the primary transfer roller and return to the separation state.

  In normal operation, when printing is finished, the motor is separated by a motor (not shown). When replacing the photosensitive drum in this state, the photosensitive drum and the intermediate transfer belt, which is an endless belt, are rubbed and scratched. There will be no problem with.

  Further, when the apparatus main body is turned off in the contact state, it cannot be returned to the separated state by a motor (not shown).

  However, when the opening / closing member 41, which also serves as an exterior, is opened for replacement of the photosensitive member, the interlocking rod 42 as the interlocking mechanism moves to a position where the tip of the separation shaft 37 is pushed in, as shown in FIGS. As a result, the separation shaft 37 moves in the direction of the arrow R in the figure together with the separation gear 37G. By this movement, the engagement between the separation gear 37G and the separation drive gear 38 is released. The disengagement gear 37G that has been disengaged returns to the initial position because the separation plate 36 that is interlocked by the separation levers 37F and 37R is urged by the separation spring 36SP. When the spacing plate 36 returns to the initial position, all of the holes 36Y, 36M, 36C, 36Bk of the spacing plate 36 are pushed down the bearing 40 of the primary transfer roller, and the spacing state is returned. As a result, there is no problem that the photosensitive drum and the intermediate transfer belt, which is an endless belt, are rubbed and scratched.

  In this state, the separation gear 37G remains displaced to the side surface of the separation drive gear 38. However, the relationship between the separation drive gear 38 and the separation gear 37g can be restored by the following operation.

  That is, first, when the opening / closing member 41 that also serves as the exterior is closed and the power is turned on, the motor (not shown) is rotated to return the separation drive gear 38 that is the contact / separation drive to the separation position that is the initial position. The separation drive gear 38 and the separation gear 37G are not in contact with each other. Then, the separation shaft 37 and the separation gear 37g are moved in the direction of arrow F in the figure by the force of the separation shaft spring 37SP, so that they return to the original state.

  As described above, the contact / separation mechanism that can automatically perform contact / separation is provided, and even when the power is turned off, the opening / closing member 41 that also serves as the exterior is opened, so that the separation mechanism is in the initial state. Therefore, in any case, the photosensitive member and the intermediate transfer belt, which is an endless belt, are not damaged when the photosensitive member is replaced.

  In this embodiment, an intermediate transfer belt, which is an endless belt, is described as an example of the endless belt, but it is needless to say that an endless belt such as an electrostatic conveyance belt can produce the same effect as the present invention.

1 is a cross-sectional view of an image forming apparatus according to the present invention. FIG. 6 is a perspective view showing a contact state of the intermediate transfer unit according to the present invention. FIG. 2 is a perspective view showing a state in which an opening / closing member that also serves as an exterior of the image forming apparatus according to the present invention is opened. It is sectional drawing which shows the state where the opening / closing member which served as the exterior of the contact-separation mechanism and interlocking mechanism part which concerns on embodiment of this invention closed. It is sectional drawing which shows the state which the opening / closing member which served as the exterior of the contact-separation mechanism and interlocking mechanism part which concerns on embodiment of this invention open | released. FIG. 6 is a perspective view showing a separated state of the intermediate transfer unit according to the embodiment of the invention. It is an enlarged view of the gear part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Paper feed cassette 22 Pickup roller 23 Feed roller 24 Retard roller 25 Registration roller pair 26 Secondary transfer roller 27 Intermediate transfer belt unit 27B Intermediate transfer belt which is an endless belt 27D Drive roller 27T Tension roller 28-31 Photosensitive which is an image carrier Drum 32 Laser scanner 33 Fixing device 34 Discharge roller pair 35 Discharge tray 36 Separation plate 37 which is a contact / separation mechanism 37 Separation shaft 37F, 37R Separation lever 37G Separation gear 38 Separation drive gear 39 Primary transfer roller 40 Bearing of primary transfer roller 41 Opening / closing member also serving as exterior 42 Linking rod as interlocking mechanism 43 Opening / closing door 44 Pin

Claims (4)

A unit that includes a photosensitive member that can be attached to and detached from the apparatus main body, a unit that is detachable from the apparatus main body and that can contact the photosensitive member, and a unit that includes the endless belt. An image forming apparatus comprising: a contact / separation mechanism that contacts and separates the endless belt from the photosensitive member without moving a position; and a contact / separation drive that drives the contact / separation mechanism.
An image forming apparatus comprising: an interlocking mechanism for returning a contact / separation mechanism of a unit including the endless belt to an initial position in conjunction with an opening / closing member provided as an exterior provided in the apparatus main body.   2. The image forming apparatus according to claim 1, wherein an initial position of the contact / separation mechanism is such that an endless belt is in a separation position with respect to the photosensitive member.   The image forming apparatus according to claim 1, wherein the contact / separation mechanism is returned to an initial position by turning off the contact / separation drive and the drive transmission of the contact / separation mechanism by the interlocking mechanism.   4. A plurality of the photoconductors, wherein the contact / separation mechanism is operated, and a part of the photoconductors and the endless belt can be separated during a printing operation. The image forming apparatus described.

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