JPH08194346A - Electrophotographic device - Google Patents

Abstract

PURPOSE: To obtain excellent image quality even when an opening/closing cover receives shock by accurately positioning a reflection mirror while the cost of the movable mechanism of the reflection mirror is reduced. CONSTITUTION: An optical device 14 emitting a laser beam L is fixed in a main body frame 12. A mirror frame 20 whose base end side is turnably supported by a turning shaft 44 is arranged at a position on a side where the optical device 14 emits the laser beam L. A reference surface 24 is arranged on a floor surface 12B opposed to the lower surface side of the mirror frame 20 and a reference surface 26 is arranged at the part of the mirror frame 20 opposed to the reference surface 24. A leaf spring 28 energizing the mirror frame 20 downward, pressing the reference surface 26 of the mirror frame 20 to the reference surface 24 side and positioning the reflection mirror 18 is attached to the opening/closing cover 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus for recording an image by scanning and exposing a scanning object with a laser beam according to image information, such as a laser printer,
It is suitable for digital copying machines and the like.

[0002]

2. Description of the Related Art As an electrophotographic apparatus according to the prior art, the one disclosed in Japanese Utility Model Publication No. 4-42847 is known, which is shown in FIG. 10 and described below.

This electrophotographic apparatus 110 shown in FIG.
Is an optical device 114 that forms an electrostatic latent image of information by main-scanning the laser light L containing information, a charging device 166 that uniformly charges the scanned object 122, and the laser light L described above is the main. A developing device 162 that forms a toner image on the scanned object 122 after being exposed by scanning and an electrostatic latent image is formed, and a pair of conveying rollers 168 that conveys the recording paper in synchronization with the toner image. The fixing device 172 and the main body frame 112 that houses each device are installed. Further, the process cartridge 160 accommodating the scanned body 122 and the developing device 162 is supported by the positioning member 164 with the central axis of the scanned body 122 as a reference.

A reflection mirror 118 for guiding the laser beam L to the object 122 to be scanned is provided with an opening / closing cover 11 provided on the top of the electrophotographic apparatus 110 for attaching / detaching the process cartridge 160 and for maintaining the inside of the electrophotographic apparatus 110.
6 is attached via a fixed spring 128. The open / close cover 116 is attached to the main body frame 112 by a support shaft 150.

When the opening / closing cover 116 is closed, the opening / closing cover 116 is securely closed by the latch mechanism 154, and the reflecting mirror positioning member 124 provided on the main body frame 112 with the upper surface obliquely attached to the reflecting mirror 118.
Are contacted and positioned.

An electrophotographic apparatus according to another prior art is disclosed in Japanese Patent Laid-Open No. 3-260661, which is shown in FIG. 12 and described below.

An opening / closing cover 116 is provided on the upper portion of the electrophotographic apparatus 110 shown in FIG. 12 for attaching / detaching the process cartridge 160 and for maintaining the inside of the electrophotographic apparatus 110. The optical device 114 is attached via a support shaft 172 and a support portion 174.

When the opening / closing cover 116 is securely closed by the latch mechanism 154, the opening / closing cover 116 and the optical device 1 are connected.
The elastic body 176 installed between 14 presses the optical device 114, and the positioning boss 178 provided on the optical device 114 abuts the positioning portion 180 of the electrophotographic device 110 to position the optical device 114. .

As another electrophotographic apparatus according to another conventional technique, one disclosed in Japanese Patent Laid-Open No. 3-61957 is known, which is shown in FIG. 13 and described below.

An opening / closing frame 120 provided on an upper portion of the electrophotographic apparatus 110 shown in FIG. 13 has an optical device 114 and a process cartridge 160 for attaching / detaching the process cartridge 160 and for maintaining the inside of the electrophotographic apparatus 110. Is attached.

When the opening / closing frame 120 is securely closed by the latch mechanism 154, the elastic body 182 installed between both the opening / closing frame 120 and the optical device 114 and the process cartridge 160 secures the optical device 114 and the process cartridge 160. Press and urge downward.

As a result, the positioning portion 184 provided on the optical device 114 contacts the positioning member 186 provided on the process cartridge 160, and the central axis 122A of the object to be scanned in the process cartridge 160 contacts the positioning member 164. Contact and be positioned.

[0013]

By the way, the opening / closing cover 11 of the electrophotographic apparatus 110 as shown in FIG. 10 described above.
When a strong impact force P is applied to 6, the reflecting mirror 118 is attached to the opening / closing cover 116, so that the reflecting mirror 118 is attached to the reflecting mirror positioning member 1.
The laser beam L deviates from the regular optical path after deviating from 24,
The image quality may deteriorate.

When the opening / closing cover 116 is opened,
There is a drawback that a worker easily touches the reflection surface 24 of the reflection mirror 13.

On the other hand, since it is necessary to position the reflection mirror 118, the opening / closing cover 116 must be attached to the main body frame 112 with high accuracy, and it becomes necessary to form the periphery of the support shaft 150 of the opening / closing cover 116 with high accuracy. Therefore, as a result, there is a drawback that the die manufacturing cost becomes high when the external shapes of the main body frame 112 and the opening / closing cover 116 are changed.

Further, the electrophotographic apparatus 110 shown in FIG.
However, since the optical device 114 is supported by the opening / closing cover 116, it is necessary to increase the rigidity of the opening / closing cover 116, which causes a problem of high manufacturing cost.

Further, in the electrophotographic apparatus 110 shown in FIG. 13, since the optical device 114 and the process cartridge 160 are mounted so as to be housed in the open / close frame 120,
While it is necessary to increase the rigidity of the open / close frame 120,
The main body frame 112 supporting them also needs to be increased in rigidity, which further causes a high manufacturing cost.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to position the reflecting mirror with high accuracy while keeping the cost of the moving mechanism of the reflecting mirror low, and to obtain a good image quality even if a shock is applied to the opening / closing cover. An object is to provide an electrophotographic apparatus that can be obtained.

[0019]

The electrophotographic apparatus according to claim 1 is an electrophotographic apparatus having an optical scanning device for guiding a laser beam forming an electrostatic latent image to a scanning object by a reflection mirror. An apparatus main body that forms an outer frame of the apparatus to accommodate the optical scanning device, an opening / closing cover that is openably and closably supported by the apparatus main body, and the reflection mirror are mounted and movably supported in the apparatus main body. Mirror frame, a first reference surface formed on the apparatus body, a second reference surface formed on the mirror frame so as to face the first reference surface, and the second reference surface when the opening / closing cover is closed. An elastic body for urging the mirror frame to press the second reference surface against the first reference surface to position the reflection mirror.

According to a second aspect of the present invention, there is provided an electrophotographic apparatus in which one of the apparatus main body and the mirror frame is provided with a pin having a spherical head, and the other of the apparatus main body and the mirror frame is formed and is closely attached to the pin. A fitting hole portion having a chamfer on the lead-in side of the pin, a first engaging portion formed on the apparatus body, and a base end side of the mirror frame, and The mirror frame can be rotated around the base end side by engaging with the first engaging portion, and when the pin is fitted into the fitting hole portion, the pin between the pin and the fitting hole portion A second engaging portion having a gap capable of correcting the positional deviation between the first engaging portion and the second engaging portion.

[0021]

The operation of the electrophotographic apparatus according to claim 1 will be described below.

The opening / closing cover is supported by the apparatus main body accommodating the optical scanning device so as to be openable / closable, and the mirror frame on which the reflection mirror is mounted is movably supported in the apparatus main body separately from the opening / closing cover. Further, a second reference surface is formed on the mirror frame so as to face the first reference surface formed on the apparatus body. When the opening / closing cover is closed, the elastic body biases the mirror frame to press the second reference surface against the first reference surface,
Position the reflective mirror.

Therefore, since the reflecting mirror is mounted on the mirror frame which is separate from the opening / closing cover, even if an impact is applied to the opening / closing cover, this impact is less likely to be transmitted to the reflecting mirror in the opening / closing frame.

Further, not only the reflection mirror but also another optical scanning device is not attached to the opening / closing cover, so that the accuracy and rigidity of the opening / closing cover can be relaxed. Therefore, the manufacturing cost of the electrophotographic apparatus can be reduced.

Further, when the opening / closing cover and the mirror frame are opened, the reflection surface of the reflection mirror is hard to touch because the reflection mirror is mounted inside the mirror frame.

The operation of the electrophotographic apparatus according to claim 2 will be described below. According to this claim, not only the same effect as that of claim 1 is achieved, but also the following action is achieved.

The second formed on the base end side of the mirror frame
Is engaged with the first engaging portion formed on the main body of the apparatus, and when the mirror frame is rotated around the base end side, the pin installed on either the main body of the apparatus or the mirror frame is , Is fitted into a fitting hole formed on the other side of the apparatus body or the mirror frame.

When the pin is fitted into the fitting hole, a gap that can correct the positional deviation between the pin and the fitting hole is provided between the first engaging portion and the second engaging portion. Since it is provided between the pins, the spherical head portion of the pin is guided by the chamfer of the fitting hole portion, and the pin and the fitting hole portion are tightly fitted.

Therefore, the precision between the first engaging portion and the second engaging portion that engages between the mirror frame and the apparatus body can be relaxed.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the electrophotographic apparatus of the present invention is shown in FIGS. 1 to 3, and this embodiment will be described with reference to these drawings.

FIG. 1 is a sectional view of an electrophotographic apparatus according to the first embodiment of the present invention. FIG. 2 is a plan view of the electrophotographic apparatus with the open / close cover removed. FIG. 3 is a view showing a state where the opening / closing cover of the electrophotographic apparatus of FIG. 1 is opened.

As shown in these figures, the apparatus body of the electrophotographic apparatus 10 of this embodiment is constituted by a box-shaped body frame 12. An optical device 14 for sending out the laser light L containing information while scanning is fixed in the main body frame 12 by being screwed by a screw 42. The optical device 14 includes a light source (not shown) that emits a laser beam L containing information, and a polygon motor (not shown) that deflects the laser beam L emitted from the light source in a predetermined direction. And an imaging lens system (not shown).

At a position on the side where the optical device 14 sends out the laser beam L, the base end side can be rotated by a rotating shaft 44 with high precision and a wall portion 20A is provided on each of four peripheral sides. An upright mirror frame 20 is arranged.

A floor surface 12B is formed in the main body frame 12 facing the lower surface side of the mirror frame 20,
On the floor surface 12B, a reference surface 24, which is a first reference surface having an upper surface formed in a planar shape with high accuracy, is arranged.
At a portion of the mirror frame 20 facing the reference surface 24, a reference surface 26, which is a second reference surface whose lower surface is formed in a planar shape with high precision, is arranged.

An opening 46 is formed on the side of the mirror frame 20 facing the optical device 14, and the reflection mirror 18 is mounted while being obliquely arranged so as to close the opening 46. The reflection mirror 18 is fixed by being pressed against the wall 20A around the opening 46 from the back side by a leaf spring 48 screwed to the mirror frame 20. Therefore, the laser light L from the optical device 14 is reflected by the reflection mirror 18 and bent downward.

On the other hand, an opening 12A is formed in the portion of the main body frame 12 above the mirror frame 20.
An opening / closing cover 16 rotatably supported around a support shaft 50 extending from the body frame 12 is arranged to open and close the opening 12A. In the state of FIG.
Is blocking.

A latch mechanism 54 that engages with the pin 52 arranged in the main body frame 12 is arranged at the tip end side of the opening / closing cover 16, and the pin 52 is closed when the opening 12A is closed by the opening / closing cover 16. The latch mechanism 54 is engaged with and the opening / closing cover 16 is stopped with the opening 12A closed. In the middle of the opening / closing cover 16, the mirror frame 20 is urged downward and the mirror frame 20
Of the reflection mirror 18 by pressing the reference surface 26 of the
A pair of leaf springs 28, which are elastic bodies for positioning, are attached.

Below the optical device 14 and the mirror frame 20, a process cartridge 60 accommodating the object to be scanned 22 and the developing device 62 is arranged.
The central axis 22A of the scanned body 22 is the central axis 22A.
It is rotatably supported by a positioning member 64 that positions the process cartridge 60 with reference to.

A charging device 66 for uniformly charging the object 22 to be scanned is arranged at a position facing the lower left side of the object 22 to be scanned in FIG. Therefore, the scan target 22 uniformly charged by the charging device 66 is exposed by the laser light L sent from the optical device 14 via the reflection mirror 18, and an electrostatic latent image is formed, and further developed. A toner image is formed by the device 62.

That is, the optical device 14 and the reflection mirror 18
However, an optical scanning device that guides the laser light L that forms the electrostatic latent image to the scan target 22 is configured.

A plurality of conveying roller pairs 68 for sandwiching and conveying recording papers (not shown) are arranged below the process cartridge 60, and the recording papers are conveyed by these conveying roller pairs 68. The route S is formed. For this reason, the developed image is transferred from the scan target 22 to the recording paper conveyed on the conveyance path S. A fixing device 72 is disposed below the transport path S, and the developing device 72 fixes the developed toner image transferred onto the recording paper.

Next, the operation of the electrophotographic apparatus 10 according to this embodiment will be described below. When attaching / detaching the process cartridge 60 or performing maintenance inside the electrophotographic apparatus 10,
As shown in FIG. 3, the opening / closing cover 16 is opened and the mirror frame 20 is rotated, and then these operations are performed. That is, not only the opening / closing cover 16 is opened, but also the mirror frame 20 is rotated to create a large space inside the electrophotographic apparatus 10. This space can be used to easily attach / detach the process cartridge 60 or to perform electrophotography. It becomes possible to perform maintenance inside the device 10.

When the opening / closing cover 16 is closed, the mirror frame 20 is rotated to bring the reference surface 26 of the mirror frame 20 into contact with the reference surface 24 on the body frame 12 side as shown in FIG. The open / close cover 16 is rotated about the support shaft 50 to close it. As a result, the opening / closing cover 16 is positioned so that the opening 12A is closed, and the opening / closing cover 1
When the front end side of 6 is securely engaged by the latch mechanism 54, the leaf spring 28 urges the mirror frame 20 to press the reference surface 26 against the reference surface 24, and the mirror frame 20 and the reflection mirror 18 move in the vertical direction. Position.

Therefore, the reflecting mirror 18 is the opening / closing cover 1
Mirror frame 2 which is a separate body from the open / close cover 16 instead of 6.
Since it is mounted on 0, even if an impact is applied to the opening / closing cover 16, this impact is less likely to be transmitted to the reflection mirror 18 in the opening / closing frame.

Further, the opening / closing cover 16 is provided with a reflecting mirror 18
In addition, since the other optical scanning device is not attached, the accuracy and rigidity of the opening / closing cover 16 can be relaxed. Therefore, the manufacturing cost of the electrophotographic apparatus 10 can be reduced.

Furthermore, as shown in FIG. 3, when the mirror frame 20 is opened, the reflecting surface 18A of the reflecting mirror 18 is surrounded by the wall portion 20A of the mirror frame 20, so that it becomes difficult for an operator to touch the reflecting surface 18A.

The mirror frame 20 is attached to the opening / closing cover 16
The mechanism for pressing with is not limited to that shown in the figure, and for example, a coil spring or a rubber material may be used instead of the leaf spring 28. Further, the latch mechanism 54 may be provided on the body frame 12 side, or an elastic body such as the leaf spring 28 may be provided on the mirror frame 20 side.

Next, a second embodiment of the electrophotographic apparatus of the present invention is shown in FIGS. 4 to 9, and this embodiment will be described based on these drawings. The same members as those described in the first embodiment are designated by the same reference numerals, and the duplicate description will be omitted.

FIG. 4 is a sectional view of the electrophotographic apparatus according to the second embodiment of the present invention. FIG. 5 is a plan view of the electrophotographic apparatus with the open / close cover removed. FIG. 6 is a view showing a state in which the opening / closing cover of the electrophotographic apparatus of FIGS. 4 and 5 is opened. 7 to 9 are enlarged views of the main part of this embodiment.

As shown in these figures, a support hole 38 is provided on the base end side of the mirror frame 20 of this embodiment, and the main body frame 1 loosely fitted into the support hole 38.
The mirror frame 20 is supported by a support shaft 36 provided on the second frame 2, and the mirror frame 20 is rotatable. As shown in FIG. 7, a clearance X, which is a gap that allows the mirror frame 20 to move by a predetermined value, is provided between the support hole 38 of the mirror frame 20 and the support shaft 36 of the main body frame 12. . Therefore, the support shaft 36 constitutes the first engagement portion, and the support hole 38 constitutes the second engagement portion.

On the lower surface side of the mirror frame 20,
Three reference planes 26 are provided, and in the center of the two reference planes 26 arranged on the tip side of the mirror frame 20 in these, pins 32 each having a spherical head at the tip are implanted. ing.

Corresponding to these three reference planes 26, the three reference planes 2 are provided on the floor surface 12B of the main body frame 12.
4 is arranged, and one of the two reference surfaces 24 facing the reference surface 26 in which the pin 32 is implanted,
A round hole 80 having a chamfered portion 84 is formed in the upper portion, and a long hole 82 similarly having a chamfered portion 84 in the upper portion is formed on the other side. That is, the round hole 80 and the elongated hole 82 form a fitting hole portion having a chamfer on the introduction side of the pin 32.

The pin 32, the round hole 80, the elongated hole 82 and the reference surfaces 24 and 26 are formed with high precision.

Next, the operation of the electrophotographic apparatus 10 according to this embodiment will be described below. When attaching / detaching the process cartridge 60 or performing maintenance inside the electrophotographic apparatus 10,
As shown in FIG. 6, the opening / closing cover 16 is similar to the first embodiment.
After opening the and rotating the mirror frame 20,
Try to do these tasks.

Further, when the opening / closing cover 16 is closed, the opening / closing cover 16 is rotated around the support shaft 50 to be closed as in the first embodiment. The positioning of the mirror frame 20 at this time will be described below with reference to FIG. This will be described with reference to FIGS. 8 and 9.

Here, FIG. 7 is a view during the rotation of the mirror frame, FIG. 8 is a view of a process of inserting a pin into the hole during the rotation of the mirror frame, and FIG. 9 is a view showing that the mirror frame and the opening / closing cover are closed. FIG.

When the mirror frame 20 is rotated so as to be closed from the state shown in FIG. 7, the pin 32 is displaced by the maximum clearance X as shown in FIG.
The chamfered portion 84 is abutted without being inserted into 2.

Further, when the mirror frame 20 is rotated,
The spherical head of the pin 32 slides down the chamfered portion 84, and the pin 32 is fitted into the round hole 80 and the elongated hole 82. afterwards,
As shown in FIGS. 4 and 9, when the opening / closing cover 16 is securely engaged by the latch mechanism 52, the leaf spring 28 urges the mirror frame 20 to press the reference surface 26 against the reference surface 24. The mirror frame 20 and the reflection mirror 18 are positioned.

That is, when the pin 32 is fitted into the round hole 80 and the elongated hole 82 as the mirror frame 20 rotates, a clearance X which can correct the positional deviation between the pin 32 and the round hole 80 and the elongated hole 82. Is provided between the support shaft 36 and the support hole 38, so that the spherical head of the pin 32 has a round hole 8
0 and the chamfered portion 84 of the long hole 82, and the pin 32 is guided.
Moves toward the center of the round hole 80 and the long hole 82, and the pin 32 and the round hole 80 and the long hole 82 are tightly fitted.

As described above, the pin 32 having a spherical head and the round hole 80 and the long hole 82 each having the chamfered portion 84
The mirror frame 20 is positioned in the vertical and horizontal directions in FIG.

Therefore, the precision between the support shaft 36 and the support hole 38 that engages between the mirror frame 20 and the main body frame 12 can be relaxed.

The positioning mechanism for the mirror frame 20 and the main body frame 12 is not limited to the one shown in the drawing.
For example, the support shaft 36 may be provided on the mirror frame 20 side, the support hole 38 may be provided on the main body frame 12 side, or the round hole 80 and the elongated hole 82 may be provided on the mirror frame 20 side, and the pin 32 may be provided on the main body frame 12 side.

[0063]

As described above, according to the first aspect of the present invention, the impact applied to the opening / closing cover is less likely to be transmitted to the reflecting mirror in the mirror frame, and the high quality electrophotographic apparatus can be provided. Moreover, when the opening / closing cover and the mirror frame are opened, it becomes difficult to touch the reflection surface of the reflection mirror. Further, since the accuracy of the open / close cover can be relaxed, the die manufacturing cost can be reduced when the shape of the exterior is changed according to the customer's request.

On the other hand, according to the second aspect of the present invention, the precision between the support shaft and the support hole that engages the mirror frame and the main body of the apparatus can be relaxed, so that a low cost electrophotographic apparatus is provided. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electrophotographic apparatus according to a first embodiment of the present invention, showing a state when an opening / closing cover is closed.

FIG. 2 is a plan view of the electrophotographic apparatus of FIG. 1 with an opening / closing cover removed.

FIG. 3 is a cross-sectional view of the electrophotographic apparatus according to the first embodiment of the present invention, showing the state when the opening / closing cover is opened.

FIG. 4 is a cross-sectional view of the electrophotographic apparatus according to the second embodiment of the present invention, showing the state when the open / close cover is closed.

5 is a plan view of the electrophotographic apparatus of FIG. 4 with an opening / closing cover removed.

FIG. 6 is a cross-sectional view of an electrophotographic apparatus according to a second embodiment of the present invention, showing an open / close cover.

FIG. 7 is an enlarged cross-sectional view of an essential part of the electrophotographic apparatus according to the second embodiment of the present invention, which is a view for explaining the middle of rotation of the mirror frame.

FIG. 8 is an enlarged sectional view of an essential part of the electrophotographic apparatus according to the second embodiment of the present invention, illustrating a process in which a pin is inserted into a hole while the mirror frame is rotating.

FIG. 9 is an enlarged cross-sectional view of an essential part of the electrophotographic apparatus according to the second embodiment of the present invention, when the mirror frame and the opening / closing cover are completely closed.

FIG. 10 is a sectional view of a conventional electrophotographic apparatus.

11 is a diagram illustrating a defect when a shock is applied to the opening / closing cover of the electrophotographic apparatus of FIG.

FIG. 12 is a sectional view of another conventional electrophotographic apparatus.

FIG. 13 is a sectional view of still another conventional electrophotographic apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electrophotographic apparatus 12 Main body frame (apparatus main body) 14 Optical device 16 Opening / closing cover 18 Reflecting mirror 20 Mirror frame 22 Scanned object 24 Reference plane (first reference plane) 26 Reference plane (second reference plane) 28 Leaf spring (Elastic body) 32 pins 36 Support shaft (first engaging portion) 38 Support hole (second engaging portion) 80 Round hole (fitting hole portion) 82 Long hole (fitting hole portion) 84 Chamfered portion L Laser light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 15/08 506 A H04N 1/113

Claims (2)

[Claims] 1. An electrophotographic apparatus having an optical scanning device which guides a laser beam forming an electrostatic latent image to a scanning object by a reflection mirror, wherein an outer frame of the electrophotographic device is formed to form the optical scanning device. A device body to be housed, an opening / closing cover that is openably and closably supported by the device body, a mirror frame that mounts the reflection mirror and is movably supported in the device body, and a first frame formed on the device body. No. 1 reference surface, a second reference surface formed on the mirror frame so as to face the first reference surface, and the second reference surface by urging the mirror frame when the opening / closing cover is closed. An elastic body that presses against the first reference surface to position the reflection mirror, and an electrophotographic apparatus. 2. A pin provided on one of the apparatus body or the mirror frame and having a spherical head, and a pin formed on the other of the apparatus body or the mirror frame and closely fitted to the pin. A fitting hole portion having a chamfer on the lead-in side of the pin, a first engaging portion formed on the apparatus body, a first end portion formed on the base end side of the mirror frame, and
The mirror frame can be rotated around the base end side by engaging with the engaging portion of the pin, and when the pin is fitted into the fitting hole portion, the positional deviation between the pin and the fitting hole portion is caused. 2. The electrophotographic apparatus according to claim 1, further comprising: a second engaging portion having a gap capable of correcting the difference between the second engaging portion and the first engaging portion.