JP2001282077A - Process unit and image forming device to and from which the process unit can be attached and detached - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process unit which can prevent a photoreceptor from being injured and being soiled with fingerprints at the time of loading a process unit while maintaining miniaturization of an image forming device and which forms a radiation heat reflecting barrier (partition) between the process unit and a fixing device with easy constitution and to provide the image forming device to and from which the process unit can be attached/detached. SOLUTION: A cover 14 covers an exposed part of a photoreceptor drum 5 at the time of unloading the process unit 3 and the cover 14 moves so that a reflecting member 15 comes between the process unit 3 and the fixing device 12 at the time of loading the process unit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic method for a printer, a copying machine, a facsimile, and the like, and more particularly, to a process unit including a photoreceptor and a process unit including the same. The present invention relates to a detachable image forming apparatus.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, charging, exposure, transfer, drum cleaning, paper feeding and
Elements indispensable for forming an image such as conveyance and fixing are appropriately arranged. In recent years, these image forming apparatuses have become smaller and smaller.
Various measures have been taken to meet market needs such as weight reduction and ease of maintenance, but in particular, inexpensive photosensitive drums having a relatively short lifespan are popular. Many such image forming apparatuses have been proposed which are easy to handle such as photosensitive drum replacement.However, it is possible to collectively attach and detach the essential elements for image formation as much as possible, and Many devices are equipped with a so-called process unit that can be replaced.

[0003]

In such an image forming apparatus which is intended to be replaced by the user himself, the photosensitive drum corresponding to the heart of the image forming apparatus may be damaged at the time of replacement. However, there is a problem that a fingerprint may be attached, and a design that takes this into account must be adopted. In order to solve this problem, a structure is provided in which a cover is provided to cover the surface of the photosensitive drum exposed to perform image formation when the process unit is not mounted, and the cover is retracted to a position where the cover does not hinder image formation when mounted. Some have adopted.

On the other hand, if an attempt is made to reduce the size of the image forming apparatus, the position of the fixing device and the position of the process unit are extremely close to each other. For example, the toner container after the drum cleaning of the process unit is performed. When the toner and the fixing device are located closest to each other, there is a problem that the heat-sensitive toner is agglomerated in the storage container. In order to solve this, there is also one that adopts a structure that partitions both of them with a material having high heat-shielding properties and heat-reflecting properties.

However, in order to solve both problems, it is necessary to secure a space for evacuating the cover and a space for the partition (if there is no partition, a long space between the process unit and the fixing device). However, there is a problem that the size of the image forming apparatus is increased.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and in a process unit including a photoreceptor which is detachable from an image forming apparatus, at least a part thereof includes a heat reflecting member and / or a photoreceptor. Alternatively, a cover made of a heat insulating member is provided, and the cover covers the exposed portion of the photoconductor when the process unit is not mounted on the image forming apparatus, and the fixing unit in the process unit and the image forming apparatus when mounted. And a process unit that moves so that the heat reflecting member and / or the heat insulating member are positioned between the heat reflecting member and the heat insulating member. Alternatively, in an image forming apparatus in which a process unit including a photoreceptor is detachable from an image forming apparatus main body, at least a part of the process unit is provided with a cover formed of a heat reflecting member and / or a heat insulating member, and the cover is formed of the process unit. An image forming apparatus that covers an exposed portion of the photoconductor when the unit is not mounted, and moves so that the heat reflection member and / or the heat insulating member is located between the process unit and the fixing device when mounted. is there.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a printer 1 which is an image forming apparatus of the present invention. Data sent from an external device such as a computer is sent to a laser scanner unit 2 which is an optical system by a controller (not shown). ,
The image forming process starts. The process unit 3
Developing device 4, photosensitive drum 5, charging device 6, cleaning device 7, waste toner collecting device 8, toner reservoir 9
And the like, and the toner reservoir 9 contains the toner container 1
0 is placed.

The process unit 3 is detachable by opening the cover 11 from the top of the printer 1 in case the performance of the process unit 3 is deteriorated. Further, the toner container 10 is also configured to be detachable from the process unit 3,
This facilitates toner replacement by the user.

A fixing device 12 is provided on the downstream side of the photosensitive drum 5 in the sheet conveying direction, and a sheet P mounted on a paper cassette 13 prepared below the printer 1 is provided.
Is transferred to the photosensitive drum 5 of the process unit 3 by a feed roller or the like, and the toner is transferred. When the toner on the sheet P passes between the heat roller 12a and the press roller 12b of the fixing device 12, the toner is transferred to the photosensitive drum 5 by about 170 degrees Celsius. It is heated back and forth and fixed on paper.

In a fixing device of a printer having a heat source of such a high temperature, conventionally, the periphery of the fixing device 12 is designed to be covered with a reflective material or a heat insulating material in consideration of the effects of conduction heat and radiation heat. However, in the present invention, when the process unit 3 is not mounted, the cover 14 that covers the exposed portion of the photoconductor drum 5 is provided, and a heat reflection member and / or a heat insulating member is formed on a part of the cover 14, and the cover 14 is mounted when the process unit 3 is mounted. Is moved, and the heat reflecting member and / or the heat insulating member are located between the process unit 3 and the fixing device 12 so as to serve as a partition wall. In the present embodiment, a case is shown in which an aluminum foil reflecting member 15 is attached to a part of the cover 14 as a heat reflecting member and / or a heat insulating member, but a member having a high heat shielding or heat insulating effect is used. Any material may be used as long as it is coated and the cover member itself may be formed of such a member.

FIG. 2 is a view showing the process unit 3 when mounted, and FIG. 3 is a view showing the process unit 3 when mounted and when not mounted.
As is clear from the figure, the cover 14 is provided with an actuator lever 16 substantially integrally, and when attached, the actuator lever 16 contacts a projection (not shown) provided at a predetermined position of the printer 1. While rotating counterclockwise in the drawing via the shaft 17, the surface of the photosensitive drum 5 is exposed, and at the same time, the cover 14 moves to form the reflection member 15 between the process unit 3 and the fixing device 12. Form a radiant heat reflective barrier. At the time of removal, the actuator lever 16 separates from the projection, and the cover 14 rotates clockwise by the action of the spring 18 to cover the exposed portion of the photosensitive drum 5. Note that, in FIG. 3, the state A of FIG. 3 of the cover 14 is when the cover 14 is mounted, and the state B of FIG. 3 is when the cover 14 is not mounted.

According to the present invention, when the process unit 3 is mounted on the printer 1, the cover 14 covers the exposed portion (the portion C in FIG. 3) of the photosensitive drum 5 when the process unit 3 is not mounted. It is possible to prevent the user from accidentally scratching or touching the fingerprint, and when the process unit 3 is mounted, a radiant heat reflection barrier can be formed by the reflection member 15.

Further, the air heated by the heat roller 12a by forming the distal end portion 19 of the cover 14 into a substantially funnel shape as shown in this embodiment exhibits a chimney effect, that is, air other than the vicinity of the heat roller 12a, that is, Natural convection is generated while entraining relatively cool air in the vicinity of the waste toner collecting device 8, and the natural convection is released to the outside of the printer. The process unit 3 that is weak to heat, particularly the waste toner collecting device 8, is a heat roller 12a. From radiant heat and radiant heat from the vehicle. In the present embodiment, the waste toner collecting device 8 is arranged closest to the fixing device 12 in the process unit 3 on the layout. However, the present invention can obtain the same effect in other configurations.

[0014]

As described above, according to the image forming apparatus of the present invention, at least a part of the process unit is provided with a cover made of a heat reflecting member and / or a heat insulating member, and this cover is used for the process unit. The size of the image forming apparatus can be reduced by covering the exposed portion of the photoconductor when not mounted and moving the heat reflecting member and / or the heat insulating member between the process unit and the fixing device during mounting. While maintaining the process unit, it is possible to prevent the photoconductor from being accidentally scratched when the process unit is mounted, or to prevent fingerprints from being brought into direct contact with the process unit. It is possible to provide a process unit for forming a reflection barrier (partition) and an image forming apparatus capable of detachably attaching the process unit. So as to.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an image forming apparatus of the present invention.

FIG. 2 is a view showing a state in which a process unit of the present invention is mounted.

FIG. 3 is a diagram illustrating two states of a process unit according to the present invention when the process unit is mounted and when the process unit is not mounted.

[Explanation of symbols]

 1: Printer 2: Laser scanner unit 3: Process unit 4: Developing device 5: Photoreceptor drum 6: Primary charging device 7: Cleaning device 8: Waste toner collecting device 9: Toner reservoir 10: Toner container 11: Cover 12: Fixing device 12a: Heat roller 12a 12b: Press roller 13: Paper cassette 14: Cover 15: Reflecting member 16: Actuator lever 17: Shaft 18: Spring 19: Tip

Claims (2)

[Claims] A process unit including a photoreceptor detachable from an image forming apparatus, the cover including at least a part formed of a heat reflecting member and / or a heat insulating member;
The cover covers the exposed portion of the photoconductor when the process unit is not mounted on the image forming apparatus, and the heat reflecting member and / or the fixing unit in the image forming apparatus is mounted between the process unit and the fixing device when the process unit is mounted. Alternatively, the process unit moves so that the heat insulating member is located. 2. An image forming apparatus in which a process unit including a photoreceptor is detachable from a main body of the image forming apparatus.
Alternatively, a cover made of a heat insulating member is provided, and the cover covers the exposed portion of the photoconductor when the process unit is not mounted, and the heat reflecting member and / or the heat insulating member are provided between the process unit and the fixing device when the process unit is mounted. An image forming apparatus, wherein a member moves so as to be positioned.