JP2981907B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention (Industrial Application Field) The present invention relates to an image forming apparatus using an electrostatic transfer process, such as an electrostatic copying machine and the same printer.

(Problems to be Solved with the Related Art) Usually, a transferable toner image formed on a surface of an image carrier formed in a rotating cylindrical shape is transferred by the image carrier and transfer means arranged close to or in contact with the image carrier. 2. Description of the Related Art An image forming apparatus configured to transfer to a transfer material such as paper supplied to a site is conventionally known.

In this type of apparatus, as a means for supporting the image carrier, for example, when a cartridge in which the image carrier and some members such as a developing device and a cleaner are used integrally is used, as shown in FIG. The cartridge 14 supported by the support 13 on the main body side and covered with the cartridge cover 12 by the spring 14 as a whole is provided with a rotating behavior in the counterclockwise direction in the drawing, and the image carrier 4 protruding outside from the cartridge cover 12 is provided. A block 3 in which both ends of the shaft 4a are fixed to the main body.
There is known one configured to engage with an upper V-shaped groove 3a.

Such a device is suitable for attaching and detaching the cartridge portion to and from the image forming apparatus main body. However, when a transfer roller is used as a transfer unit, the roller is used as an image carrier as shown by reference numeral 5 in FIG. 4, that is, in the direction opposite to the tendency of the cartridge cover 12 to rotate by the spring 14,
Since this is pressed, the position of the image carrier 4 becomes unstable, and there is a possibility that vibration is generated and the image is degraded due to the vibration.

If the means shown in FIG. 4 is used to loosely support the shaft 4a of the image carrier 4 in a hole formed at an appropriate position in the frame F disposed inside the image forming apparatus, the above-described problem can be solved. Although it can be avoided, in such a configuration, disassembly and assembly for maintenance, repair, and the like is troublesome, and it is extremely difficult to adopt the cartridge system.

SUMMARY OF THE INVENTION The present invention has been made in order to cope with the current situation as described above, and it is possible to reliably position and arrange an image carrier at a predetermined position, and to easily attach and detach the image carrier to and from the apparatus main body even in the case of replacement or the like. It is an object to provide an image forming apparatus.

(2) Configuration of the Invention (Technical Means for Solving the Problems, Action of the Invention) In order to achieve the above object, the present invention provides a cartridge having an image carrier and detachable from the apparatus main body, and a cartridge An image forming apparatus comprising: a transfer roller provided for rotating by pressing against an image carrier; and pressing means for pressing the transfer roller against the image carrier. The image forming apparatus further includes a regulating device for regulating a position of the image carrier. The position of the carrier is determined by the pressing force of the transfer means and the thrust generated when the image carrier is actuated, and the position opposite to the transfer roller and the downstream side in the moving direction of the transfer material abut on the regulating means. Image forming apparatus.

With such a configuration, the image carrier can be stably and firmly held at all times, and an image forming apparatus having good transferability can be obtained.

(Explanation of Embodiment) FIG. 1A is a side view showing the configuration of an image forming apparatus of an embodiment of the present invention and the vicinity of a transfer roller portion pressed against the image carrier, and FIG. FIG. 2 is a cross-sectional view, in which the image carrier 4, the developing unit 11 and the cleaner unit 10 are integrally formed and covered by a cover 12 to form a cartridge. Assume that 5 is in contact.

The ends of the shaft 4a of the image carrier 4 and the shaft 5a of the transfer roller 5 are supported by a substantially E-shaped support member 9 disposed at an appropriate position in a stationary portion of the image forming apparatus.

As can be seen from FIG. 1A, the shaft 4a is loosely fitted in the upper concave portion of the support member 9 and the shaft 5a is loosely fitted in the lower concave portion, and the shaft 5a is formed in the support member. The transfer roller 5 is pressed against the image carrier 4 at a predetermined pressure by a spring 91 disposed in a vertical gap regulated by the raised portion 9a.

Thus, the shaft 4a in the upper recess of the support member 9 is
By pressing against the upper side 9b, the pressure nip between the image carrier 4 and the transfer roller 5 is regulated.

When the image carrier 4 is rotated in a direction indicated by an arrow in the drawing by an appropriate driving source, the rotational force and the shaft 4 a
A thrust in the illustrated X direction acts on the shaft 4a due to the frictional force between the shaft 4a and the shaft 4a, and the shaft 4a also strikes the side 9c.

As described above, the pressing action on the image carrier acting on the transfer roller and the abutting of the two members 9b and 9c of the support member 9 restrict the position of the shaft 4a by the members serving as the control means. The cartridge inserted into the apparatus main body from the right side in the drawing can be easily inserted into the apparatus main body at first, and is automatically seated at a predetermined position by the action of the regulating means in the final step of insertion.

FIG. 2 is a side view showing another embodiment, in which parts corresponding to those of the above-described embodiment are denoted by the same reference numerals, and a description thereof will be omitted unless necessary.

In the illustrated apparatus, a cartridge portion including the image carrier 4 is disposed below, and the transfer roller 5 is configured to be pressed from above.

With this configuration, the shaft 4a of the image carrier 4
Is more reliably brought into contact with the side of the recess of the support member 9 due to the spring force from the transfer roller side and the weight of the toner stored in the developing device 11.

Although the present invention has been described with reference to the case of a cartridge system in which an image carrier, a developing device, and a cleaner are integrally formed, the present invention is not limited to such a case. The present invention can also be applied to a configuration in which the container and the container are integrated, and a cleaner is separately provided. In this case, the shaft 4a of the image carrier 4 can be provided inside the cover 12. Further, it will be readily understood that the present invention can be applied to a well-known configuration in which the image carrier is configured to be separated from all other members.

(3) Effects of the Invention As described above, according to the present invention, an image forming apparatus including a cartridge having an image carrier and a transfer roller contacting the image carrier at a predetermined position in the apparatus main body is provided. The configuration of the portion for guiding the cartridge to the home position by the axis of the image carrier is extremely reduced, and therefore, the movement of the cartridge to the home position can be easily performed, and the image carrier is securely positioned by the restricting means. Thus, it is possible to obtain an apparatus capable of performing a good image forming operation with a low-cost configuration.

[Brief description of the drawings]

FIG. 1A is a side view of the vicinity of a transfer portion of an image forming apparatus, showing an embodiment of the present invention. FIG. 1B is a cross-sectional view of a main part of the same, FIG. 2 is a side view of another embodiment, FIG. FIG. 4 is a side view and a front view showing a supporting mode of the image carrier in the known device. 4 ... image carrier, 5 transfer roller, 9 ... support member, 10 ...
... Cleaner, 11 ... Developer, 12 ... Cartridge cover.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Yagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Tsuyoshi Waraya 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshiro Tsuchiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masato Otsuka 3-30-2, Shimomaruko, Ota-ku, Tokyo In Canon Inc. (72) Inventor Takahiro Kishida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hiroo Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-1- 229270 (JP, A) JP-A-1-197766 (JP, A) JP-A-1-155365 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 15/00 550 G03G 21/16-21/18

Claims (1)

(57) [Claims] A cartridge that has an image carrier and is detachable from the apparatus main body, a transfer roller provided in the apparatus main body and rotated by pressing against the image carrier, and pressing the transfer roller against the image carrier. An image forming apparatus having a pressing unit, wherein the image forming unit has a regulating unit that regulates a position of the image carrier, and the image carrier is separated from the transfer roller by a pressing force of the transfer unit and a thrust generated when the image carrier is operated. An image forming apparatus characterized in that the position is determined by the opposite side and the downstream side in the moving direction of the transfer material abutting on the regulating means.