JP4978960B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus in which a developing unit is fixed by being brought into contact with an intermediate unit whose position is fixed.

As a conventional color image forming apparatus, there is a tandem type color image forming apparatus that uses an intermediate transfer member, and temporarily transfers four colors of toner onto the intermediate transfer member, and then transfers the full color image onto a transfer sheet at once. , Widely known. Further, the arrangement of each component (various units) in the tandem type color image forming apparatus using the intermediate transfer member is as follows: toner container, intermediate transfer unit, image forming unit (consisting of a developing unit and a drum unit) from the top of the apparatus. In many cases, the optical units are configured in this order.
On the other hand, each unit needs to be configured so that it can be easily attached and detached for the assembly and maintenance of the color image forming apparatus. However, in the color image forming apparatus, the positional accuracy of the developing unit with respect to the intermediate transfer unit is particularly important, and there is a problem of achieving both the positional accuracy and the detachability workability. For example, as an example of achieving both fixing of the correct position of the developing unit and workability of detachment, a guide rail for guiding the mounting of the developing unit in the same direction as the bus bar of the drum unit is provided in the main body of the apparatus, and it is perpendicular to the bus bar of the drum unit. And a guide arm that can swing in any direction. As a result, the developing unit is inserted into the apparatus along the guide rail, and then moved to a predetermined position along the guide arm, whereby the developing unit can be accurately fixed. Further, by performing the reverse operation, it is possible to easily perform detachment (see Patent Document 1).
Japanese Patent Laid-Open No. 10-3215

  However, the configuration as described in Patent Document 1 requires a dedicated member such as a guide rail or a guide arm for fixing the position, and there is a problem that the manufacturing cost increases. Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to accurately position the developing unit with respect to the intermediate transfer unit while suppressing the manufacturing cost, thereby greatly improving the maintainability. It is another object of the present invention to provide a color image forming apparatus improved.

In order to achieve the above object, the present invention provides an image forming apparatus in which a toner container, an intermediate transfer unit, and a developing unit are arranged in this order from the upper part to the lower part, and the developing unit is located at a fixed upper position. The image forming apparatus is configured to be fixed by being pressed by an elastic body toward the intermediate transfer unit and contacting the intermediate transfer unit.
With this configuration, a dedicated member such as a guide rail or a guide arm is not required for fixing the position of the developing unit, so that the manufacturing cost can be reduced and the fixing position of the developing unit to the intermediate transfer unit can be accurately fixed. That is, positioning is possible. Also, in the case of a color image forming apparatus, by removing the intermediate transfer unit, unlocking of the four of the developing unit is line e at a time, it becomes possible to greatly improve the maintainability.
As a specific example, the intermediate transfer unit includes an intermediate transfer side toner receiving unit that receives toner from the toner container, and an intermediate transfer side toner supply unit that supplies the toner to the developing side toner receiving unit of the developing unit. A toner conveyance path for conveying the toner from the intermediate transfer side toner receiving portion to the intermediate transfer side toner supply portion, and the development side toner receiving portion is in contact with the intermediate transfer side toner supply portion Thus, the developing unit is fixed. With this configuration, a toner supply path from the toner container to the developing unit can be formed in a compact manner.
Further, it is conceivable that an elastic body is interposed between the intermediate transfer side toner supply unit and the development side toner receiving unit. By interposing the elastic body in this way, toner leakage from between the intermediate transfer side toner supply unit and the development side toner receiving unit can be prevented.
A developing-side gear provided on a main body frame of the image forming apparatus that supports the intermediate transfer unit and meshed with a driving gear that drives the developing unit ; one longitudinal end portion of the developing unit, cover the formed in the body frame fitting portion to be fitted into a substantially U-shaped groove which is opened upwardly is provided is provided, wherein the developing unit is , the downward pressing force created by the rotation of the front Symbol fitting portion and said drive gear and said developing gear, the one end the main frame by being in contact with the bottom of the substantially U-shaped groove fixed The developing-side toner receiving portion provided at the other end in the longitudinal direction of the developing unit is brought into contact with the intermediate transfer-side toner supply portion, so that the other end becomes the intermediate transfer unit. Is constant, it is conceivable to configure to be fixed Te its ends smell. In this way, by fixing both ends of the developing unit in the longitudinal direction, the developing unit can be more accurately fixed.

  According to the present invention, an image forming apparatus in which a toner container, an intermediate transfer unit, and a developing unit are arranged in this order from the upper part to the lower part, and the developing unit is located at the upper intermediate transfer unit whose position is fixed. The guide rail is fixed to the position of the developing unit by being configured as an image forming apparatus that is fixed by being pressed by an elastic body toward and toward the intermediate transfer unit. Since no special member such as a guide arm or the like is required, the manufacturing cost can be reduced and the developing unit can be accurately positioned with respect to the intermediate transfer unit. Further, in the case of a color image forming apparatus, by removing the intermediate transfer unit, it is possible to release the fixing of the four developing units at a time and to greatly improve the maintainability.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
1 is a cross-sectional view of a tandem color image forming apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view showing a part of FIG. 1, and FIG. 3 is an intermediate transfer unit mounted on a main body frame. FIG. 4 is a diagram showing a state where the intermediate transfer unit is mounted on the drive-side main body frame, FIG. 5 is a diagram showing a state where the developing unit is pressed by an elastic body, and FIG. 6 is a diagram showing the intermediate transfer unit. 7 is a perspective view of the unit, FIG. 7 is an enlarged view of a contact portion between the developing unit and the intermediate transfer unit, FIG. 8 is a perspective view showing one end portion in the longitudinal direction of the developing unit, and FIG. 9 is a drive in which the developing unit is fitted. FIG. 10 is a schematic diagram of the side main body frame, and FIG. 10 is a diagram illustrating a state where the fitting portion of the developing unit is fitted to the driving side main body frame.
As shown in FIG. 1, the image forming apparatus X includes a toner container 1, an intermediate transfer unit 2, a developing unit 3 (see FIG. 2), an image forming unit 4 including a drum unit, an optical unit 5, and the like from the top to the bottom. ing. As shown in FIG. 2, the toner container 1, the intermediate transfer unit 2, and the developing unit 3 are arranged in this order.
As shown in FIG. 3, the intermediate transfer unit 2 is fixed in position and rotatably mounted in a substantially U-shaped groove 8 formed in the main body frame 7a of the image forming apparatus and opened laterally. The intermediate transfer unit 2 is accurately fixed to the main body frame 7a by inserting the bush 20 and fixing the bush 20 at the position where the bush 20 is prevented. The intermediate transfer unit 2 is similarly fixed to a drive-side main body frame 7b (see FIG. 4) of the image forming apparatus which is disposed so as to sandwich the intermediate transfer unit 2 between the intermediate transfer unit 2a. ing. Further, the intermediate transfer unit 2 is fixed to the main body frame 7a and the driving side main body frame 7b by screws 21 at two other corners (see FIG. 4). That is, the intermediate transfer unit 2 is accurately fixed to the main body frame 7a and the driving side main body frame 7b at the four corners. Further, by removing the screw 21 and rotating the bush 20 to release it from the retaining position, it can be easily detached.
On the other hand, as shown in FIG. 5, the developing unit 3 is moved upward (above-mentioned) by two springs 9 (an example of an elastic body) that serve as electrical contacts to a well-known sleeve roller and mag roller (not shown) provided in the developing unit. The developing unit 3 is abutted and fixed to the intermediate transfer unit 2 by the abutting portion 6 as shown in FIG.
With such a configuration, a dedicated member such as a guide rail or a guide arm is not required for fixing the position of the developing unit 3, so that the manufacturing cost can be reduced and the developing unit 3 can be accurately fixed. It is. Further, by removing the intermediate transfer unit 2, the four developing units 3 can be fixed and released at a time, and the maintainability can be greatly improved.

Next, a specific contact example between the intermediate transfer unit 2 and the developing unit 3 will be described.
As shown in FIG. 6, the intermediate transfer unit 2 includes an intermediate transfer unit 22 on which an intermediate transfer belt (not shown) travels, and a toner transport unit 23 adjacent thereto. The toner transfer unit 23 includes an intermediate transfer side toner receiving unit 24 that receives toner from the toner container 1 and an intermediate transfer side that supplies the toner to the developing side toner receiving unit 34 (see FIG. 7) of the developing unit 3. A toner supply unit 25, the development-side toner receiving unit 34, and the intermediate transfer-side toner supply unit 25 are vertically connected, and the toner is supplied from the intermediate transfer-side toner receiving unit 24 to the intermediate transfer-side toner supply unit 25. A toner conveyance path 23a (see FIG. 7) for conveyance.
As shown in FIG. 7, the developing unit 3 includes a developing-side toner receiving unit 34 that receives the toner from the intermediate transfer-side toner supply unit 25, and the intermediate transfer-side toner supply unit 25 and the developing-side toner receiving unit The part 34 is in contact (corresponding to the contact part 6 in FIG. 2). As described above, the developing unit 3 is pressed toward the intermediate transfer unit 2 by the two springs 9, and the developing-side toner receiving portion 34 is brought into contact with the intermediate-transfer-side toner supply portion 25. The position is fixed.
With this configuration, a toner supply path from the toner container 1 to the developing unit 3 can be formed in a compact manner.
Further, a sponge 30 (an example of an elastic body) is interposed between the intermediate transfer side toner supply unit 25 and the development side toner receiving unit 34, and the intermediate transfer side toner supply unit 25 and the development side toner reception unit. Toner leakage from the portion 34 is prevented.

Next, since the developing unit 3 has a length extending over the entire width of the transfer paper, it must be supported at both ends thereof. Since the above description relates to the fixing structure of the developing unit 3 on the developing side toner receiving portion 34 side, one end portion in the longitudinal direction of the developing unit 3 that is opposite to the developing side toner receiving portion 34. Will be described.
As shown in FIG. 8, a cover 32 provided with a substantially U-shaped fitting portion 31 is provided at one end portion of the developing unit 3 in the longitudinal direction. As shown in FIG. 9, the drive-side main body frame 7b is provided with a substantially U-shaped groove 10 opened upward, and the substantially U-shaped groove 10 is formed in the substantially U-shaped groove 10 as shown in FIG. The fitting part 31 is fitted.
FIG. 11 is a view in which the cover 32 is removed at one end portion in the longitudinal direction of the developing unit 3 (the end portion on the opposite side to the developing side toner receiving portion 34). As shown in FIG. 11, the drive gear 11 that is attached to the attachment hole 12 (see FIG. 9) of the drive side main body frame 7b and drives the development unit 3, and the development side gear 33 provided in the development unit 3; And the developing gear 33 rotates in a direction opposite to the rotating direction of the driving gear 11. Accordingly, the driving gear 11 and the developing gear 33 are engaged by rotating the driving gear 11 clockwise and rotating the developing gear 33 counterclockwise according to the resistance between the gears. A pressing force downward in the tangential direction of the alignment (linear arrow in FIG. 11) is generated in the developing unit 3. With this pressing force, the fitting portion 31 at one end portion in the longitudinal direction of the developing unit 3 is pressed and brought into contact with the bottom portion of the substantially U-shaped groove 10 provided in the driving side main body frame 7b.
On the other hand, the other end portion in the longitudinal direction of the developing unit 3 is a contact portion 6 (see FIG. 2) with the intermediate transfer unit 2 fixed to the main body frame 7a and the driving side main body frame 7b as described above. It is pressed against.
Therefore, the developing unit 3 is fixed to the main body frame 7a and the driving side main body frame 7b at both ends thereof, and it is possible to fix the position accurately.

1 is a cross-sectional view of a tandem color image forming apparatus according to an embodiment of the present invention. The perspective view showing a part of FIG. FIG. 4 is a diagram illustrating a state where an intermediate transfer unit is mounted on a main body frame. FIG. 4 is a diagram illustrating a state where an intermediate transfer unit is mounted on a driving-side main body frame. FIG. 6 is a diagram illustrating a state in which the developing unit is pressed by an elastic body. The perspective view of an intermediate transfer unit. FIG. 3 is an enlarged view of a contact portion between a developing unit and an intermediate transfer unit. The perspective view which shows the one end part of the longitudinal direction of a developing unit. FIG. 3 is a schematic diagram of a driving side main body frame to which a developing unit is fitted. The figure showing the state by which the fitting part of the image development unit was fitted by the drive side main body frame. The figure which removed the cover in the one end part of the said longitudinal direction of the image development unit.

Explanation of symbols

X ... image forming apparatus 1 ... toner container 2 ... intermediate transfer unit 3 ... developing unit 7a ... main body frame 7b ... drive side main body frame 9 ... spring 10 ... substantially U-shaped groove 11 ... drive gear 30 ... sponge 31 ... fitting Part 33 ... Development side gear

Claims (3)

An image forming apparatus in which a toner container, an intermediate transfer unit, and a developing unit are arranged in this order from the top to the bottom,
The developing unit is pressed by an elastic body toward the upper intermediate transfer unit whose position is fixed, and is fixed by being brought into contact with the intermediate transfer unit,
The intermediate transfer unit includes an intermediate transfer side toner receiving unit that receives toner from the toner container, an intermediate transfer side toner supply unit that supplies the toner to a development side toner receiving unit of the development unit, and the intermediate transfer side toner receiving unit. A toner transport path for transporting the toner from the section to the intermediate transfer side toner supply section,
An image forming apparatus in which the developing unit is fixed by contacting the developing-side toner receiving portion with the intermediate transfer-side toner supply portion. The image forming apparatus according to claim 1 , wherein an elastic body is interposed between the intermediate transfer side toner supply unit and the development side toner receiving unit. At one end in the longitudinal direction of the developing unit, a developing side gear is provided which is provided on a main body frame of the image forming apparatus that supports the intermediate transfer unit and meshes with a driving gear that drives the developing unit ,
A cover provided with a fitting portion that is fitted to a substantially U-shaped groove that is formed on the main body frame and opened upward is provided at one end in the longitudinal direction of the developing unit ,
The developing unit, the downward pressing force created by the rotation of the front Symbol fitting portion and the driving gear and the developing gear, wherein one end portion by being in contact with the bottom of the substantially U-shaped groove The development-side toner receiving portion fixed to the main body frame and provided at the other end portion in the longitudinal direction of the developing unit comes into contact with the intermediate transfer-side toner supply portion, so that the other end portion becomes the intermediate transfer unit. fixed, an image forming apparatus according to claim 1 or claim 2 is fixed Te its ends smell.

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