JPH04319973A - Development unit positioning device - Google Patents

Abstract

PURPOSE:To prevent a photo-sensitive body from being damaged by automatically positioning a development unit upon closing an upper frame. CONSTITUTION:In the state where upper and lower frames 1a and 1b are closed, the pressing section 7c of a turning lever 7 is pressed downward by a pressing- down section 9. In this case, a support section 6a moves in an arrow (a) direction, and a slider 6 nears a photo-sensitive body unit 2a, thereby energizing a development unit 2b toward the photo-sensitive body unit 2a. As a result, a photo-sensitive body 3 comes in slight contact with a development roller 4. Thereafter, when the upper frame 1a is opened, a pressing force of the pressing-down section 9 is released. Then, the turning lever 7 moves in a direction opposite to a direction C, due to the reset force of a spring 8, and a force to energize the unit 2b toward the unit 2a is released. Both units 2b and 2a are thereby caused to part from each other. According to this construction, the development unit 2b can be taken out from a storage section 5, without causing any damage to the photo-sensitive body 3.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to an image forming apparatus such as a copying machine or a laser printer, in which a unitized photoreceptor unit and a developing unit are housed in a frame, and the developing unit is brought into pressure contact with the photoreceptor unit. The present invention relates to an improvement of a developing unit positioning device.

0002

2. Description of the Related Art FIG. 2 is a diagram showing a conventional method for positioning a developing unit. The frame of the main body of the image forming apparatus is divided into an upper frame 1a and a lower frame 1b, and the lower frame 1b can be opened and closed like a shell with respect to the upper frame 1a. A photoreceptor unit 2a, a developing unit 2b, etc. are housed in the lower frame 1b, and when this is housed,
The developing unit 2b must be mounted at a predetermined distance from the photoreceptor unit 2a. However, it is very difficult to accurately position the developing unit 2b within the narrow lower frame, and there is a risk of damaging the photoreceptor, so in conventional devices, the photoreceptor unit 2a and the developing unit 2b are It was previously stored in the unit case 20 and attached to the lower frame 1b together. With this method, the photoreceptor unit 2a,
Since the positional relationship of the developing unit 2b is fixed in advance before it is attached to the lower frame, there is no need to perform positioning within the narrow lower frame, making the attaching operation easier.

0003

[Problems to be Solved by the Invention] However, the photoreceptor unit 2a and the developing unit 2b must be installed in advance in the unit case 2.
0 and then set it in the lower frame 1b,
Since the work of housing the photoreceptor unit 2a and the developing unit 2b in the unit case 20 must be performed outside the main body of the image forming apparatus, there is a problem in that extra work space is required. Furthermore, when storing the photoreceptor unit 2a and the developing unit 2b in the unit case 20, the developing unit 2b must be accurately positioned and stored with respect to the photoreceptor unit 2a. The surface of the photoreceptor may be damaged due to contact.

An object of the present invention is to allow a photoreceptor unit and a developing unit to be mounted on a lower frame without damaging the surface of the photoreceptor, and also to allow mounting of a photoreceptor unit and a developing unit directly into the lower frame. To provide a developing unit positioning device that does not require extra space.

[0005]

[Means for Solving the Problems] The present invention provides a lower frame, an upper frame that can be opened and closed with respect to the lower frame, a photoreceptor unit housed in the lower frame, a developing unit, and a lower frame. a biasing means for biasing the developing unit toward the photoreceptor unit; and a biasing unit that releases the biasing force when the upper frame is opened and generates the biasing force when the upper frame is closed. The invention is characterized in that it is provided with a locking means for locking.

[0006]

[Operation] In this invention, when the upper frame is opened, the urging force that urges the developing unit toward the photoreceptor unit is released, so a gap is created between the photoreceptor unit and the developing unit, and the photoreceptor unit The developing unit can be easily taken out and installed without coming into contact with the developing unit. Then, when the photoconductor unit and the developing unit are directly attached to the lower frame and the upper unit is closed, a biasing force is generated and the developing unit is biased toward the photoconductor unit, and the gap between the photoconductor unit and the developing unit is maintained at a predetermined level. is set to

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus to which a developing unit positioning device according to an embodiment of the present invention is applied. The upper frame 1a is provided in a shell shape so as to be freely openable and closable with respect to the lower frame 1b around a fulcrum portion (not shown). Note that the upper and lower frames are closed in the direction of arrow A in the figure.
The upper and lower frames are opened in the direction of arrow B. A drum-shaped photoreceptor 3 is provided in the photoreceptor unit 2a, and a developing roller 4 is provided in the developing unit 2b. Although the figure shows the upper and lower frames 1a and 1b in a closed state,
At this time, the photoreceptor 3 and the developing roller 4 are brought into light contact. A housing portion 5 is provided within the lower frame 1b to house the photoreceptor unit 2a and the developing unit 2b. This storage section 5 is equipped with a slider 6, and the developing unit 2b is placed thereon. The slider 6 is moved in the directions of arrows a and b in the figure.
That is, it is movable in the direction approaching the photoreceptor unit 2a or in the direction away from the photoreceptor unit 2a. Cut and raised portions 5a are provided on both sides of the slider 6, integrally with the storage portion 5.

[0008] The storage section 5 is provided with a rotating lever 7. As shown in FIG. The rotating lever 7 is configured in an L-shape, and its bent portion is rotatably supported by a fulcrum 7a above the cut-and-raised portion 6a closer to the photoreceptor unit. The vertical piece 7b of the rotating lever 7 faces downward, and the support part 6 in the center
A slider 6 is supported at a. Further, a spring locking portion 7b is provided at the tip of the rotating lever. In addition, a pressing portion 7 is provided at the tip of the horizontal piece of the rotating lever.
c is provided. A compression spring 8 is hung between the cut and raised portion 6a and the locking portion 7b of the rotating lever. On the other hand, a push-down part 9 is provided on the upper frame 1a. The pressing portion 9 faces the pressing portion 7c, and presses down the pressing portion 7c when the upper frame 1a is closed.

The procedure for replacing the photoreceptor unit 2a and developing unit 2b in the image forming apparatus configured as described above will be explained. When the upper and lower frames 1a and 1b are closed, the pressing portion 7c of the rotating lever is pressed downward by the pressing portion 9 (in the direction of arrow C). Then, the support portion 6a moves in the direction of arrow a, and the slider 6 moves toward the photoreceptor unit 2a.
, the developing unit 2b is urged toward the photoreceptor unit 2a. Then, the photoreceptor 3 and the developing roller 4 come into light contact. Note that this movement is performed against the compression force of the compression spring 8.

Next, when the upper frame 1a is opened, the pressing force exerted by the pressing part 9 is released. Then, the rotating lever 7 is rotated in the counter-C direction by the return force of the spring 8, the urging force that urges the developing unit 2b toward the photoreceptor unit 2a is released, and the developing unit 2b is separated from the photoreceptor unit 2a. In this way, the photoreceptor unit 2a and the developing unit 2b
By separating them, the developing unit 2b can be taken out from the storage section 5 without damaging the photoreceptor 3. When storing a new developing unit in the storage section 5, it is only necessary to set it on the slider 6 while being separated from the photoreceptor unit 2a, and the photoreceptor 3 is not damaged at this time. After that, when the upper frame 1a is closed, the pressing part 9 pushes down the pressing part 7c, and the developing unit 2
b is urged toward the photoreceptor unit 2a. In other words, in this embodiment, there is no need to adjust the distance between the photoreceptor 3 and the developing roller 4 (positioning the developing unit), and by simply closing the upper frame 1a, the developing unit 2b approaches the photoreceptor unit 2a side, and the automatic Since the positioning is performed automatically, there is no need to perform a positioning operation.

[0011]

[Effects of the Invention] According to the present invention, since the positioning of the developing unit is automatically performed by closing the upper frame, there is no need to perform a positioning operation when installing the photoreceptor unit and the developing unit, making the installation operation easy. There are advantages to becoming In addition, when the photoreceptor unit and developing unit are installed, they can be stored in the lower frame while being separated from each other, eliminating the need for the trouble and extra space of assembling both units in advance. It is also possible to prevent the photoreceptor from being damaged.

[Brief explanation of drawings]

[Fig. 1] This is an embodiment of the present invention, and is a diagram showing a state in which a developing unit is installed.

FIG. 2 is a diagram illustrating the prior art, and is a diagram illustrating the state in which the developing unit is installed.

[Explanation of symbols]

1a Upper frame 1b Lower frame 2a Photoconductor unit 2b Developing unit 3 Photoreceptor 4 Developing roller 5 Storage section 5a Cut and raise part 6 Slider 6a Support part 7 Rotating lever 7c Pressing part 8 Compression spring 9 Press down part

Claims (1)

[Claims] 1. A lower frame, an upper frame that can be freely opened and closed with respect to the lower frame, a photoconductor unit and a developing unit housed in the lower frame, and a photoconductor unit and a developing unit in the lower frame. A biasing means for biasing toward the body unit side, and a locking means for releasing the biasing force when the upper frame is opened and generating the biasing force when the upper frame is closed. A developing unit positioning device characterized by: