JPH0873097A - Electrophotographic device - Google Patents

Abstract

PURPOSE: To improve the opening/closing operation for a paper discharge tray, etc., for the paper discharge part of an electrophotograghic device and a transfer guide for the jam processing for a paper sheet. CONSTITUTION: A helical tooth gear 5 is installed in the rotatable and movable manners in the axial direction on the shaft 4 of a device body 1, and regulating surfaces 6 and 7 are installed on both the sides in the axial direction. A helical gear tooth shaped part 8 is formed on a paper discharge tray 2. When the paper discharge tray 2 is opened from an accommodation state, the helical tooth shaped part 8 and the helical tooth gear 5 turn in the opposite direction, and the helical tooth gear 5 shifts, being applied with the revolution torque and the thrust force, and the first side surface frictionally turns, making contact with a regulating surface 6. Each surface roughness of the first side surface and the regulating surface 6 is set to a prescribed value or more, and the turning moment of the paper discharge tray 2 is softened by the frictional force. When the paper discharge tray 2 is closed, the second side surface and the regulating surface 7 are brought into contact, and accommodation is enabled by a relatively small force, reducing the frictional force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, and more particularly to an electrophotographic apparatus having an improved opening / closing of a discharge tray of a discharge section and a conveyance guide for jamming a sheet.

[0002]

2. Description of the Related Art In an electrophotographic apparatus such as a copying machine, a rotatable paper discharge tray 2 is provided in a main body 1 of the apparatus as shown in FIG. When the tray 2 is opened and set to a state where the sheets 3 can be stacked, the operator releases the locking means between the sheet discharge tray 2 and the apparatus main body 1, and the sheet 3 can be stacked mainly by the weight of the sheet discharge tray 2. A mechanism for rotating to various positions is often used (for example, JP-A-63-123759). In the conventional mechanism of this type, the paper discharge tray 2 can stack the paper 3 by its own weight by simply rotating the rotary portion or only having a biasing means for switching between the use position and the non-use position and holding it. When it is rotated to such a position, the paper ejection tray 2 comes into contact with the regulating member on the side of the apparatus main body 1 and stops. However, at this time, the paper ejection tray 2 and the regulating member collide with each other. As a result, the discharge tray 2 may vibrate to generate an undesired impact sound, and the discharge tray 2 and the regulating member may be deteriorated in strength or damaged.

Further, an electrophotographic apparatus as shown in FIG. 7 may be provided with a rotary conveyance guide for jamming a sheet or the like (for example, Japanese Unexamined Patent Publication No. 62-102266). There is a possibility that the same trouble as in the case of the above-mentioned paper ejection tray may occur.

The present invention has been made in view of the above problems of the prior art, and is provided with a mechanism capable of applying or releasing a braking force associated with a turning operation, to alleviate the turning force due to its own weight, and It is an object of the present invention to provide an electrophotographic apparatus capable of preventing the above problems and capable of rotating with a relatively small force that resists its own weight when the discharge tray or the conveyance guide is stored in the apparatus main body.

[0005]

In order to achieve the above-mentioned object, the electrophotographic apparatus according to the present invention is provided with a discharge tray of a discharge section and a conveyance guide for jamming the sheet in the apparatus main body. In an electrophotographic apparatus that rotates and opens and closes around a fulcrum shaft, a fulcrum shaft provided in the main body of the apparatus is provided with a helical gear that can move in the axial direction within a certain range, and a rotary shaft of the paper ejection tray or a conveyance guide is provided. A helical tooth-shaped portion that meshes with the helical gear is formed, and the friction coefficient between the first side surface of the helical gear and the first regulating surface of the apparatus body that is axially close to the first lateral surface of the helical gear, The two side surfaces and the second regulating surface axially adjacent to the two side surfaces have different friction coefficients.

In the electrophotographic apparatus according to the present invention, the surface roughness of the first side surface of the helical gear and the first regulating surface axially adjacent to the gear side are both 6.3a (center line average roughness). The above configuration can be adopted.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. Although only the case of the discharge tray will be described below, the present invention is not limited to this example, and can be applied to a conveyance guide for jam clearance and the like and other similar mechanisms.

1 to 6 show one embodiment of the electrophotographic apparatus according to the present invention. In the following, the portions common to the conventional ones will be described with the same reference numerals. In this embodiment, a helical gear 5 is provided on a shaft 4 fixed to the apparatus main body 1 so as to be movable in both the rotation direction and the axial direction, and restriction surfaces 6 and 7 are provided on both sides in the axial direction. . On the other hand, the discharge tray 2 is provided with a helical tooth-shaped portion 8 that meshes with the helical gear 5 about the rotation axis.

A state in which the discharge tray 2 is stored (see FIG. 2,
3) is set at a position where sheets and the like can be stacked (FIGS. 4 and 5), that is, when the discharge tray 2 is rotated clockwise in FIG. 3 around the fulcrum shaft 9, The helical toothed portion 8 rotates in the direction of time, and the helical gear 5 rotates in the counterclockwise direction. At this time, the helical gear 5 is twisted in the left direction,
Since the helical tooth portion 8 has a right-handed twisting direction, the helical gear 5 receives a thrust force in the leftward direction in FIG. 2 together with the rotational torque, and the state shown in FIGS. Move to. Then, the helical gear 5 rotates while rubbing the first side surface 5a of the helical gear 5 against the regulation surface 6 and friction.

On the contrary, when the paper discharge tray 2 is stored from the paper stacking position (FIGS. 4 and 5) (FIGS. 2 and 3), the paper discharge tray 2 is placed.
5 is rotated counterclockwise in FIG. 5, the helical gear 8 is rotated counterclockwise, and the helical gear 5 is rotated counterclockwise. At this time, the helical gear 5 moves to the right as shown in FIG. Then, the helical gear 5 has the second side surface 5 thereof.
The b is brought into contact with the regulation surface 7 and is rotated while being frictioned.

Here, the coefficient of friction between the first side surface 5a and the restriction surface 6 is relatively high (for example, the surface roughness of both the first side surface 5a and the restriction surface 6 is 6.3a (center line average roughness) or more). Yes, the friction coefficient between the second side surface 5b and the restriction surface 7 is set lower than this. Then, when the paper ejection tray 2 is opened, the frictional force generated between the first side surface 5a and the restriction surface 6 acts as a braking force for relaxing the turning force of the paper ejection tray 2 due to its own weight (range A in FIG. 6). It is possible to prevent vibration, impact noise, strength deterioration and breakage due to a collision when the paper discharge tray 2 contacts a regulating member (not shown) on the apparatus body 1 side. Further, when the paper discharge tray 2 is closed, it operates smoothly because of its low friction (range B in FIG. 6).

[0012]

As described above, the electrophotographic apparatus according to the present invention has a braking force that resists its own weight when the discharge tray or the like is opened by utilizing the thrust force generated when the helical gear rotates. Since the paper ejection tray and the like do not collide with the regulating member of the apparatus body, it is possible to prevent the generation of impact noise and the deterioration and damage of the paper ejection tray and the regulating member. When the above is closed, this braking force does not work, and there is an effect that the sheet can be stored with a relatively small force that resists the weight of the discharge tray and the like.

In the electrophotographic apparatus according to claim 2,
Since the surface roughness of the first side surface of the helical gear and the regulating surface is set to a certain value or more, in addition to the common effects described above, an appropriate braking force can be effectively obtained when opening the discharge tray or the like. There is an effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an electrophotographic apparatus according to the present invention.

FIG. 2 is a plan view of the apparatus of FIG. 1 with a discharge tray closed.

FIG. 3 is a side sectional view of the apparatus of FIG. 1 with a discharge tray closed.

FIG. 4 is a plan view showing a state in which a sheet discharge tray is opened by the apparatus shown in FIG.

5 is a side sectional view of the apparatus shown in FIG. 1 in a state in which a discharge tray is opened.

FIG. 6 is a diagram showing a relationship between opening / closing of a sheet discharge tray and braking force in the apparatus of FIG.

FIG. 7 is a sectional view of a general electrophotographic apparatus.

[Explanation of symbols]

 1 Device Main Body 2 Paper Ejection Tray 4 Shaft 5 Lotus Gear 5a First Side of Lotus Gear 5b Second Side of Lotus Gear 6, 7 Restriction Surface 8 Lotus Tooth Shape 9 Support Point Shaft

Claims (2)

[Claims] 1. An electrophotographic apparatus in which a conveyance tray for ejecting a sheet in a sheet ejection section or a jam treatment of a sheet is opened and closed around a fulcrum shaft provided in the apparatus body, and is provided in the apparatus body. The fulcrum shaft is provided with a helical gear that is movable in the axial direction within a certain range, and a helical tooth portion that meshes with the helical gear is formed on the rotation shaft of the paper ejection tray or the transport guide,
A coefficient of friction between the first side surface of the helical gear and a first regulating surface of the apparatus body that is axially close to the helical gear, and a second side surface of the helical gear and a second regulation that is axially close to the second lateral surface. An electrophotographic device characterized in that the friction coefficient of the surface is different. 2. The surface roughness of each of the first side surface of the helical gear and the first regulating surface axially adjacent to the first side surface is 6.3.
The electrophotographic apparatus according to claim 1, wherein the electrophotographic apparatus has a (center line average roughness) or more.