JP3994364B2 - Photosensitive drum module fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a shaft provided so that one end is supported by the main body of the image forming apparatus and the other end is a free end, and a photosensitive drum module provided so as to be freely removable from the free end side of the shaft. The present invention relates to a photosensitive drum module fixing device in an image forming apparatus.
[0002]
[Prior art]
It is well known that a photoconductor is used to realize an electrophotographic process in an image forming apparatus put into practical use as a laser printer or a copying machine. The form of the photoreceptor is roughly divided into a belt-like photoreceptor and a drum-like photoreceptor. Further, in an image forming apparatus using a drum-shaped photoconductor, a shaft is provided so that one end is supported by the main body of the image forming apparatus and the other end is a free end, and a photoconductor drum module is installed from the free end side of the shaft. 2. Description of the Related Art An image forming apparatus is known that can be freely inserted and removed and can be replaced with a photosensitive drum module.
[0003]
In such a configuration in which the photosensitive drum module is inserted and removed from the free end side of the shaft, a configuration as shown in FIG. 6 has been conventionally used as a configuration for positioning the photosensitive drum module with respect to the shaft.
[0004]
In FIG. 6, reference numeral 12 denotes a shaft. When the photosensitive drum module 11 is pulled out from the shaft 12, the knob 19 is turned in the direction of loosening the screw 19 a provided at the tip of the knob 19, so that the knob 19 and the ball bearing 10 are integrated. The process is performed with the cover 13 provided on the cover 3 removed. When the photosensitive drum module 11 is attached to the shaft 12, the operation is reversed.
[0005]
[Problems to be solved by the invention]
The photoconductor drum module is replaced by the user when the photoconductor drum reaches the end of its life. However, in the case of the configuration of the above-described prior art, the configuration is such that positioning and fixing are performed by tightening a knob (screw). However, it is a problem in realizing a user-friendly image forming apparatus that cannot be easily and quickly replaced, and a problem that needs to be improved.
[0006]
An object of the present invention is to provide a photosensitive drum module fixing device that eliminates the drawbacks of the above prior art and allows a user to easily and quickly replace a photosensitive drum module.
[0007]
[Means for Solving the Problems]
The above object includes a shaft provided so that one end is supported by the image forming apparatus main body and the other end is a free end, and a photosensitive drum module provided so as to be freely removable from the free end side of the shaft. In the photosensitive drum module fixing device in the image forming apparatus, the photosensitive drum module has a contact portion capable of contacting a side surface portion of the photosensitive drum module inserted into the shaft, and the photosensitive drum module is interposed through the contact portion. A biasing means that biases the shaft in the insertion direction, a stopper member having a through-hole that can be inserted into the shaft, and a circumferential groove provided in a portion of the through-hole on the outer periphery of the distal end of the shaft free end side. to engage, and an elastic member that urges the stopper member, the biasing against the photosensitive drum modules by the engagement / release of the through-hole with respect to the circumferential groove It is achieved by carrying out the grant / release of the biasing force of the stage.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0009]
First, the configuration of the locking device for the photosensitive drum module will be described in detail with reference to FIG. FIG. 1 is an exploded perspective view of a lock device, and 2 is a holder that forms a frame of the lock device. The holder 2 is formed in a cylindrical shape, and is provided with a through long hole 2a for fitting a protruding portion of a cap, which will be described later, and an opening 2b for exposing the stopper 6 on the outer peripheral surface thereof.
[0010]
3 is a slider, and the slider 3 is also formed in a cylindrical shape. The inner diameter of the slider 3 is set to a dimension that allows a shaft (not shown) protruding from the image forming apparatus main body to be inserted. A large-diameter portion 3 a that protrudes in the radial direction is provided at one end of the slider 3. The large-diameter portion 3a is provided so as to abut against the flange portion 2c formed on the other end side of the holder 2 when the slider 3 is fitted from one end side of the holder 2, and thereby the other end side of the holder 2 The slider 3 is prevented from coming off from the head.
[0011]
Reference numeral 4 denotes a coil spring, and 5 denotes a washer. The inner diameter of the coil spring 4 and the inner diameter of the hole of the washer 5 are set to dimensions that allow a shaft (not shown) protruding from the image forming apparatus main body to be inserted. ing. The slider 3 and the coil spring 4 constitute urging means.
[0012]
Reference numeral 6 denotes an L-shaped stopper, and a through-hole 6a having a dimension capable of inserting a shaft (not shown) protruding from the image forming apparatus main body is provided on a surface parallel to the washer 5. .
[0013]
Reference numeral 7 denotes an elastic body whose function is to apply a biasing force in a certain direction to the stopper 6. In this embodiment, a sponge is used for the elastic body 7, but it is not necessary to be limited to the sponge, and a spring such as a leaf spring or a coil spring may be used. The elastic body 7 is bonded to the back side of the surface 6b of the stopper 6 where the through hole 6a is not provided.
[0014]
Reference numeral 8 denotes a cap, which is provided on its side surface with a protruding portion 8a that fits into the above-described through long hole 2a of the holder. A flat portion 8b is provided on a part of the side surface of the cap 8. Here, the plane portion 8 b has a function of supporting the back surface of the elastic body 7 bonded to the stopper 6. The stopper 6, the elastic body 7 and the cap 8 constitute locking means.
[0015]
When the stopper 6 to which the slider 3, the coil spring 4, the washer 5 and the elastic body 7 are bonded is assembled in the holder 2 and confined with the cap 8, the locking device 1 having the appearance shown in FIG. 2 is completed. . In the state of FIG. 2, the stopper 6 can be pushed in the direction of arrow a like a switch button, and when the finger is released from the stopper 6, it is pushed back in the direction of arrow b by the restoring force of the elastic body 7.
[0016]
Next, the relationship among the shaft, the photosensitive drum module, and the locking device will be described with reference to FIG.
[0017]
In FIG. 3, reference numeral 12 denotes a shaft. One end of the shaft 12 is supported by the image forming apparatus main body (not shown), and the other end is provided as a free end. A tip 12 on the free end side of the shaft 12 is provided with a taper 12a, and a circumferential groove 12b is provided on the outer periphery of the shaft near the root of the taper region. Further, the diameter increases from the circumferential groove 12b to the shaft fixed end side, and a stepped portion 12c is provided.
[0018]
On the other hand, the photosensitive drum module 9 mounted on the shaft 12 is provided with a photosensitive drum 11 and a ball bearing 10 that are driven using the shaft 12 as a rotation axis. Further, when the photosensitive drum module 9 is inserted into the shaft 12, an abutting surface 11 a for contacting the stepped portion 12 c of the shaft and positioning the photosensitive drum 11 is provided on the photosensitive drum module 9. Yes.
[0019]
If the photosensitive drum module 9 is inserted into the shaft 12, the locking device 1 is fitted to the tip of the shaft 12, and the mounting of the photosensitive drum module 9 is completed.
[0020]
A state until the locking device 1 is set will be described with reference to FIG.
[0021]
FIG. 4A shows a state immediately after the locking device 1 is attached to the shaft 12. A force in the direction of arrow b is always applied to the stopper 6 by the action of the elastic body 7. In this state, when the locking device 1 against the reaction force of the coil spring 4 is pushed in the direction of the arrow c, the stopper 6 that is moved in the direction of the arrow b follows the taper 12a at the tip end of the shaft 12 (the direction of the arrow a). ).
[0022]
When the lock device 1 is further pushed in, the position of the circumferential groove 12b of the shaft 12 and the stopper 6 coincide with each other as shown in FIG. 2B, and the stopper 6 is moved to the arrow b by the restoring force of the elastic body 7 as shown in FIG. It moves in the direction and engages with the circumferential groove 12b to complete the locking. In this state, the tip (abutting portion) of the slider 3 abuts in a state where a predetermined urging force is applied to the ball bearing 10 forming a part of the photoreceptor drum module, and the photoreceptor drum module is aligned. The When releasing the locked state, pressing the stopper 6 releases the engaged state of the stopper 6 with respect to the circumferential groove 12b, and the locking device 1 can be removed.
[0023]
FIG. 5 shows a modification of the present invention. In this modification, the holder 2 is substituted by a front cover 13 that constitutes a part of the photosensitive drum module 9. In FIG. 5, 13 is a front cover, 14 is a front cover cap, and the front cover cap 14 is provided with a push button 15.
[0024]
When the stopper 6 is engaged with the shaft 12, the push button 15 is pushed. Reference numeral 16 denotes an elastic body, which is a member that applies a restoring force for returning the push button 15 to a predetermined position. Reference numeral 17 denotes a spring holder, which holds and guides the spring 4 and serves as a seat for the ball bearing 10. Reference numeral 18 denotes an elastic body having a function equivalent to that of the elastic body 7 of the previous embodiment, and a member for moving the stopper 6.
[0025]
【The invention's effect】
As described above, according to the present invention, there is provided a photosensitive drum module fixing device that can easily and quickly attach and detach a photosensitive drum module without the troublesome tightening operation using screws as in the prior art. can do.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a locking device according to the present invention.
FIG. 2 is an external perspective view of a locking device.
FIG. 3 is a cross-sectional side view showing a relationship between a photosensitive drum module and a locking device.
FIG. 4 is an explanatory diagram showing a state from when a lock device is set to a shaft until it reaches a locked state.
FIG. 5 is a sectional side view showing a modification of the present invention.
FIG. 6 is a sectional side view showing a conventional technique.
[Explanation of symbols]
2 ... Holder, 3 ... Slider, 4 ... Coil spring, 5 ... Washer, 6 ... Stopper, 7 ... Elastic body, 8 ... Cap.

Claims (1)

An image forming apparatus comprising: a shaft having one end supported by the image forming apparatus main body and the other end being a free end; and a photosensitive drum module detachably provided from the free end side of the shaft. In the photosensitive drum module fixing device,
An urging means having an abutting portion capable of abutting against a side surface portion of the photosensitive drum module inserted into the shaft, and urging the photosensitive drum module in the inserting direction via the abutting portion;
A stopper member having a through hole that can be inserted into the shaft;
An elastic body that urges the stopper member so that a part of the through hole engages with a circumferential groove provided on the outer periphery of the distal end portion on the shaft free end side;
Photosensitive drum module connecting device, characterized in that to grant / release of the biasing force of the biasing means with respect to the photosensitive drum modules by the engagement / release of the through-hole with respect to the circumferential groove.

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