JPH10111632A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device furnished with the constitution capable of correctly performing the positioning of structure taken place in the case of combining structure allowed to freely open and close. SOLUTION: In the image forming device 1 furnished with the constitution, between first and second bisected structures 2 and 3, the structure 2 is supported by the structure 3 in freely opening and closing, a fixing device 11 provided with rollers pair constituting a transporting member is arranged in the first structure 2a, and then first and second holding means 16 and 17 are disposed for severally locking two section of the fixing device, when the first structure 2 is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus, and more particularly to a positioning structure of an openable / closable structure used in the image forming apparatus.

[0002]

2. Description of the Related Art In an electrophotographic copying system, which is one of image forming systems, a latent image corresponding to a document is formed on a photoreceptor, and the latent image is subjected to visible image processing using toner and then to plain paper or the like. Is transferred to a transfer material, and the transferred toner image is fixed to obtain a copy. An apparatus using such an electrophotographic copying system includes a copying machine, a printer, and a facsimile machine. In the image forming apparatus,
In the case where the transfer material onto which the toner image has been transferred from the photoconductor is clogged in the conveyance path, or in the case where the toner used in the development process for obtaining the toner image is supplied, the structure constituting the apparatus is divided into two parts. Some structures have a structure in which one of the structures can be opened and closed, and the inside can be exposed when the structure is opened.

[0003] An image forming apparatus having a two-part structure has a structure in which the two parts are kept at a predetermined position so that one of the two structures is not inadvertently opened when the two-part structure is closed. Positioning structures have been proposed (for example, Japanese Utility Model Laid-Open No. 5-6973, Japanese Patent Application Laid-Open No. 1-133822, and Japanese Patent Application Laid-Open No. 1-133823).

Japanese Utility Model Laid-Open Publication No. 5-6973 discloses that one of the openable and closable structures supports an openable and closable fulcrum shaft in an elongated hole of the other structure so as to be freely openable and closable. When closed with respect to the other structure, the rotation shaft of the gear located at the open / close end of one structure is fitted into a groove formed in the other structure, and the rotation shaft of the gear is hooked. Is disclosed. JP-A-1-133822 and JP-A-133823 show a configuration in which the other structure is detachably supported with respect to one structure without opening and closing. The groove formed in the side plate of the structure of
While being fitted to the rotating shaft of a roller that is disposed on the other structure and constitutes one of the conveying members, a hook having the state on one structure is engaged with a protrusion formed on the other structure. Thus, a configuration in which the data is held is disclosed.

[0005]

In some cases, a fixing device for fixing a toner image is arranged on one of the divided structures. The fixing device is disposed on one of the releasable structures when the developing device is disposed below the fixing device. When the developing device is disposed below the fixing device, the developing device is opened by exposing one of the structures. This is because the toner can be supplied to the apparatus.

The fixing device disposed on one side of the structure has a roller pair in which a heating roller and a pressure roller for fixing a toner image while also conveying a transfer material are provided inside. The driving force is transmitted to the roller pair via a transmission member such as a gear.

The transmission member mounted on the roller pair has a different load at the axial end of the roller because it is attached to one axial end of the roller. In this case, there is a distinction between an end on which the meshing reaction force from the gear acts and an end on which it does not. For this reason, the axis of the roller may be inclined without being parallel to the axis of the other transport roller.
If the directions of the axes of the rollers, which are transport members disposed in the transport path of the transfer material, are not parallel to each other, the direction of nipping and transporting the transfer material transferred between the transport members changes, A phenomenon occurs in which wrinkles are generated in the width direction of the transfer material, or the transfer position of the toner image is inclined with respect to the traveling direction of the transfer material. In addition, if the axes are not parallel, the distance between the transmission members also changes, which causes the meshing of the transmission gears to become unstable, or one of the idling phenomena of the gears. A certain tooth jump phenomenon occurs.

The fixing device disposed on one of the structures is opened and closed with respect to the other structure together with one of the structures, and when closed, is covered and fixed on the other structure. It may be used to hold the position of an image forming processing device located below a fixed fixing device. For example, in the case where a charging device that performs a charging process of the photoconductor is disposed near the lower portion of the fixing device, an elastic body is interposed between the charging device and the upper surface of the charging device to press the upper surface of the charging device. Is held. In this case, since the reaction force of the elastic body acts in a direction to push up the fixing device, the length of the conveyance path between the position of the roller pair in the fixing device and another conveyance roller tends to increase. May be. As a result, the timing at which the transfer material is nipped by the pair of rollers may be disturbed, and the leading end of the transfer material fed from another transport roller may hang down before reaching the roller pair of the fixing device, causing a jam. is there. Such a phenomenon often occurs not only due to the difference in the load in the axial direction of the roller described above, but also due to a processing error or the like in a structure supporting the member.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a conventional image forming apparatus, and more particularly, an image forming apparatus having a structure capable of accurately positioning a structure which occurs when an openable / detachable structure is combined. To provide. In particular, as the above-described structure, when the structure in which the fixing device is disposed is one structure, and when the image forming apparatus main body is the other structure, one of the structures can be accurately positioned. It is another object of the present invention to provide an image forming apparatus having a configuration capable of preventing occurrence of wrinkles of a transfer material and image inclination.

[0010]

According to the first aspect of the present invention,
It is composed of a first structure and a second structure divided into two,
In an image forming apparatus having a configuration in which a first structure is supported by a second structure so as to be openable and closable, a fixing device having a pair of rollers serving as a conveying member is disposed on the first structure. When the first structure is closed, first and second holding means are provided for locking the two positions of the fixing device, respectively.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the first and second holding means are provided with a locking portion of the fixing device when the first structure is closed. It is characterized by being constituted by a member that can be elastically engaged with the member.

According to a third aspect of the present invention, the first divided into two parts is provided.
In the image forming apparatus having a structure in which the structure of (1) is supported by the second structure so as to be openable and closable, a fixing device having a roller pair serving as a conveying member is arranged on the first structure, and When the first structure is closed, first and second holding means are provided for locking the two positions of the fixing device, respectively, and the first and second holding means are provided so as to be interlocked. It is characterized by:

According to a fourth aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein
At least one of the second holding means is constituted by a sheet metal member.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a view showing a copying machine which is an embodiment of an image forming apparatus according to the present invention. In FIG. 1, the copying machine 1 is provided with two divided structures 2 and 3. As shown in FIG. 2, the structure 2 is supported by a device main body (hereinafter, referred to as the device main body 3) forming the structure 3 via a hinge H serving as an opening / closing fulcrum so as to be openable and closable. . A drum-shaped photoconductor (hereinafter, referred to as a photoconductor drum) 4 as a latent image carrier is arranged inside the apparatus main body 3, and an image is formed around the photoconductor drum 4 around the photoconductor drum 4. A charging device 5, an image writing device 6, a developing device 7, and a transfer device 8 for performing a forming process are arranged.
A paper feeding device 9 that can be inserted into and removed from the apparatus main body 3 is disposed at a lower portion of the apparatus main body 3, and a paper output table 10 that accommodates a transfer material S carrying a toner image is provided on an upper surface of the apparatus main body 3. Are located.

The photosensitive drum 4 can rotate in the direction of the arrow shown in the figure. In the course of the rotation, the charging device 5 uniformly charges, the image writing device 6 exposes, and the developing device 7 forms and transfers a toner image. The transfer of the toner image onto the transfer material S by the device 8 is performed. The toner image electrostatically transferred to the transfer material S by the transfer device 8 is
Is established by.

The fixing device 11 includes a housing 12 fixed to one of the structures 2 constituting the copying machine 1, and includes a heating roller 13 and a pressure roller 14 inside the housing 12. A roller pair is provided. In FIG. 2, the position where the radius from the hinge portion H (see FIG. 2) serving as the opening / closing fulcrum of the structure 2 is large is the opening / closing end, and the position where the radius from the hinge portion H is small is the opening / closing base end. It has been.

The roller pair has a function of heating and fixing the toner image carried on the transfer material S and transporting the transfer material S. Therefore, the heating roller 13 and the pressure roller The rollers 14 are supported so that they can rotate while contacting each other. The roller pair is arranged at a position where the transfer material S nipped and fed by the photoreceptor drum 4 and the transfer roller of the transfer device 8 can be nipped and conveyed, and the position is defined by holding means described later. .

FIG. 3 is a diagram showing the structure of the holding means, which is a main part of the first and second embodiments of the present invention.
In the figure, the holding means is provided for locking two places of the housing 12, and the first holding means provided on the side wall 3 a of the apparatus main body 3 corresponding to the open / close end side of the housing 12. 16 and second holding means 17 provided on the housing 12 corresponding to the opening / closing base end side of the housing 12.

The first holding means 16 is constituted by a swingable sheet metal member whose base end is supported by a support pin 18, and has a bending piece 16a at the swinging end. 16
A raising piece 16b bent upward is formed at the top of a. An elastic body 19 for urging the first holding means 16 in the clockwise direction in FIG. 3 is arranged at the swinging end of the first holding means 16. The first holding means 16 defines a clockwise swing amount by abutting against a stopper (not shown) provided on the side wall 3 a of the apparatus main body 3 by urging of the elastic body 19, and the rising piece is raised. The position where 16b is oriented in a substantially vertical direction is the normal position. This normal posture is
This corresponds to a state in which the housing 12 can be locked when the structure 2 is closed.

The second holding means 17 includes a support shaft 2 inserted into a support portion 12a provided on the lower surface of the housing 12.
It is constituted by a sheet metal locking claw that is rotatably supported by a zero. When the structure 2 is closed, the support shaft 20 is fitted and supported in a concave portion 3b formed in the side wall 3a of the apparatus main body 3. The recess 3b is used to define the position of the housing 12 when the structure 2 is closed.
The second holding means 17 is formed by a helical spring (not shown).
In FIG. 3, it is biased counterclockwise.

The second holding means 17 has a claw portion 17a formed at one end in the longitudinal direction around the support shaft 20, and an operation portion 17b provided at the other end in the longitudinal direction. Operation unit 17
As shown in FIG. 4, b is constituted by a lever extending upwardly of the housing 12. The operating portion 17b is inserted into a guide groove (not shown) and protrudes above the housing 12, and restricts the amount of rotation of the second holding means 17 by being impacted by the guide groove. 4 and the subsequent drawings mainly show the configuration of the roller pair, the housing 12, and the first and second holding units 16 and 17 included in the fixing device 11, and are provided inside the fixing device 11 such as a conveyance guide. Other members are omitted.

At the side bottom of the housing 12 corresponding to the first holding means 16, a bent piece 16a of the first holding means 16 is provided.
A locking piece 12b projecting toward is formed. The locking piece 12b has a size of a contact surface with the bent piece 16a (in FIG. 3,
The length of the range indicated by the symbol L corresponds to the bent piece 1
When the upper surface is locked by 6a and the structure 2 is opened, the first holding means 16 is set to have such a size that the first holding means 16 is easily released from the bent piece 16a while swinging.

The apparatus main body 3 corresponding to the second holding means 17
An engaging member 21 having a protrusion 21a that can be engaged with the claw 17a is integrally formed on the side wall 3a.

Since the present embodiment is configured as described above, its operation will be described with reference to FIG. FIG.
(A) shows a state in which the structure 2 is completely closed. In this state, the closed position of the structure 2 is defined by the apparatus main body 3 (only the side wall 3a is shown in the figure). When the structure 2 is completely closed, the locking piece 1 of the housing 12 is attached to the lower surface of the bent piece 16a of the first holding means 16.
2b is pressed by being inserted and engaged, and the claw portion 17a of the second holding means 17 is engaged with the engaging member 21 of the apparatus main body 3.
With the projection 21a. Thereby, the fixing device 11
Since the open / close end of the housing 12 is locked and locked at two locations by the first holding means 16 and the open / close base end of the housing 12 by the second holding means 17, the position of the roller pair is photosensitive. A predetermined positional relationship is set with respect to a position where the body drum 4 (see FIG. 1) and a transfer roller included in the transfer device 8 (see FIG. 1) face each other.

FIG. 5B shows the structure 2 being closed toward the apparatus main body 3. In this case, the locking piece 1 of the housing 12 is interlocked with the closing of the structure 2.
2b moves toward the raising piece 16b of the first holding means 16 as shown by the arrow in the figure.

As shown in FIG. 6, when the structure 2 approaches a completely closed state, the locking pieces 12b of the housing 12 are closed.
Abuts against the raising piece 16 b of the first holding means 16, and swings the first holding means 16 counterclockwise in the drawing against the bias of the elastic body 19 to lock the housing 12. Piece 12b is first
Into the lower surface of the bent piece 16a of the holding means 16.
As the first holding means 16 and the locking piece 12b of the housing 12 engage, the claw 17 of the second holding means 17
a engages with the protrusion 21a of the engagement member 21 provided on the side wall 3a of the apparatus main body 3. Thus, the state shown in FIG. 5A is obtained.

When the structure 2 is opened in a direction away from the apparatus main body 3, the second holding means 17
b is operated by the operator, the claw 17
a is separated from the protrusion 21 a of the engagement member 21. As a result, the restraint of the housing 12 by the second holding means 17 is released, and when the housing 12 is interlocked with the movement of the structure 2, the locking pieces 12 b of the housing 12 are bent by the bent pieces of the first holding means 16. 16a.

According to the above embodiment, a part of the housing 12 can be used as a part of the holding mechanism for positioning, so that the structure required for positioning can be simplified. In addition, since the rollers of the pair of rollers forming the transfer material transfer member are pre-installed in the housing 12, there is no need to adjust the contact force between the rollers as compared with the case where the rollers are individually positioned. Becomes easier.

In the above-described embodiment, as shown in FIG. 1, the elastic body P is disposed at the bottom of the housing 12 in order to maintain the position of the charging device 5 located near the fixing device 11 using the fixing device 11. It is also possible to use

Next, an embodiment of the present invention will be described with reference to FIG.
This will be described below. The embodiment shown in FIG. 7 is characterized in that the first holding means shown in FIG. 3 can be interlocked with the second holding means. Note that among the members shown in FIG. 7, the same components as those shown in FIG. 3 are denoted by the same reference numerals. FIG. 7 shows only a part of the operation unit 17b of the second holding unit 17 shown in FIG. In FIG. 7A, the first holding means 30
Has an L-shape when viewed from the side, and has a bent piece 30a and a raised piece 30b as in the example shown in FIG. 3, and separately from these pieces, Claw part 1
A pressing piece 30c facing the lower surface of 7a and a push-back piece 30d facing the upper surface of the claw 17a are provided. The oscillating end of the first holding means 30 is connected to the supporting pin 18 with respect to the oscillating end provided with the bent piece 30a and the raised piece 30b.
The pressing piece 30c and the pushing-back piece 30d are opposed to the second holding means 17 with their phases shifted by about 90 ° from the center.

Since the present embodiment has the above configuration,
The operation is as follows. FIG. 7 (A)
This shows a state where the structure 2 is completely closed. In this state, the locking piece 12b of the housing 12 is pressed by the bent piece 30a of the first holding means 30, and the claw portion of the second holding means 17 is formed by the projection 21a of the engaging member 21 of the apparatus main body 3. Is fitted. The claw head of the second holding means 17 presses the pressing piece 30 c of the first holding means 30. Thereby, the fixing device 11 having the housing 12
Since the open / close end side of the housing 12 is locked and locked at two locations by the first holding means 30 and the open / close base end side of the housing 12 by the second holding means 17, the position of the roller pair Is set in a predetermined positional relationship with respect to a position where the photosensitive drum 4 (see FIG. 1) and a transfer roller included in the transfer device 8 (see FIG. 1) face each other. Further, since the pressing piece 30c of the first holding means 30 is pressed downward in FIG. 7A by a pressing operation corresponding to the swing of the claw head of the second holding means 17, the first piece is pressed. The holding means 30 can press the locking piece 12b of the housing 12 in conjunction with the movement of the second holding means 17.

FIG. 7B shows the structure 2 being closed toward the apparatus main body 3. In this case, the locking piece 1 of the housing 12 interlocks with the closing of the structure 2.
2b moves toward the raising piece 16b of the first holding means 16. When the structure 2 is closed, the upper surface of the locking piece 12b of the housing 12 is in opposition to the bent piece 16a of the first holding means 16, but the second holding means 17 is
b (see FIG. 4) is completely rotated to a predetermined position by operating the pressing portion 30c of the first holding means 30 by the claw head portion of the second holding means 17 as shown in FIG. As shown in FIG.
In (B), the first holding means 30 rotates clockwise. Thereby, temporarily, the locking piece 12b of the housing 12
Even if is raised, it is pushed down by the lower surface of the bent piece 30a and is displaced to the state shown in FIG.

When the structure 2 is opened in a direction away from the apparatus main body 3, the second holding means 17 operates the operating portion 17b by an operator to cause the claw portion 17a to project from the projection of the engaging member 21. Separate from 21a. This allows
The claw head of the second holding means 17 is the first holding means 30
7A, the first holding means 30 is rotated counterclockwise in FIG. 7A. When the first holding means 30 rotates counterclockwise, the bent piece 30a
Is detached from the locking piece 12b of the housing 12, so that the housing 12 can be opened.

According to the above-described embodiment, the housing by the first holding means 30 can be formed only by setting the relationship in which a part of the first holding means 30 and a part of the second holding means 17 are engaged with each other. Even if the pressing action of the locking pieces 12b on the locking pieces 12b is insufficient, the locking pieces 12b
Since the pressing operation of the fixing device 11 can be made sufficient, the fixing device 11 can be reliably positioned.

[0036]

According to the first and second aspects of the present invention,
When the first structure is closed, the first and second holding means for locking the fixing device at two positions are provided, so that the fixing device is closed when the first structure is completely closed. It can be positioned at a predetermined position. Thereby, the change in the direction of the axis of the roller pair included in the fixing device can be suppressed, and the length of the conveyance path between the fixing device and another conveyance member reaching the fixing device is defined.
The generation of wrinkles on the transfer material and the inclination of the transferred toner image can be prevented, and the drive transmission can be performed normally.

According to the third aspect of the present invention, the first and second holding means can be interlocked, so that only the operation of one of the holding means ensures that the one side of the structure is moved forward and closed in the closing movement direction. The rear side in the moving direction can be locked. Thereby, the first and second structures can be positioned by a simple operation, thereby preventing wrinkles of the transfer material and bending of the image and simplifying an operation for surely transmitting the driving force. It becomes possible to do.

According to the fourth aspect of the present invention, since the holding means is constituted by a sheet metal member, the processing of the holding means can be performed easily, thereby reducing costs and securing mechanical strength. Heat resistance against heat generation can be secured, and positioning accuracy between the first structure and the second structure can be secured.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a diagram illustrating an open state of the image forming apparatus illustrated in FIG. 1;

FIG. 3 is a perspective view illustrating a configuration of a main part of the image forming apparatus illustrated in FIG. 1;

FIG. 4 is a diagram illustrating an operation unit of a second holding unit used for the main configuration shown in FIG. 3;

FIG. 5 is an arrow view in a direction indicated by a symbol K in FIG.
(A) shows a state where one of the structures is closed, and (B)
Indicates that one of the structures is being closed.

FIG. 6 is a diagram showing a state in which one of the structures used in the main part configuration shown in FIG. 3 is being closed.

7A and 7B are views for explaining an embodiment of the invention according to claim 3, wherein FIG. 7A shows a state in which one of the structures is closed, and FIG. 7B shows a state in which one of the structures is being closed. Is shown.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copier as one of the image forming apparatuses 2 One of the structures 3 The apparatus main body which forms the other of the structures 4 Photoconductor drum 8 Transfer device 11 Fixing device 12 Housing 12b Locking piece 13 Heating roller 14 Pressure roller 16, 30 first holding means 17 second holding means

Claims (4)

[Claims] An image forming apparatus comprising a first structure and a second structure divided into two parts, wherein the first structure is supported by the second structure to be openable and closable. In the first structure, a fixing device having a pair of rollers serving as a conveying member is disposed on the first structure, and when the first structure is closed, the first and second fixing members respectively lock the two positions of the fixing device. An image forming apparatus comprising: a second holding unit. 2. The image forming apparatus according to claim 1, wherein said first and second holding means elastically engage with a locking portion of said fixing device when said first structure is closed. An image forming apparatus comprising a member capable of being used. 3. An image forming apparatus having a structure in which a first structure body divided into two is supported by a second structure body so as to be openable and closable, wherein the first structure body has a roller serving as a transport member. A fixing device having a pair is arranged, and when the first structure is closed, 2 of the fixing device is disposed.
An image forming apparatus comprising: first and second holding means for locking respective locations; and wherein the first and second holding means are provided so as to be interlocked. 4. An image forming apparatus according to claim 1, wherein at least one of said first and second holding means is constituted by a sheet metal member. Forming equipment.