JPH07113803B2 - Photoconductor drum support mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photosensitive drum supporting mechanism of an electrostatic recording device.

2. Description of the Related Art With the widespread use of electrostatic recording devices such as electrophotographic copying machines, facsimiles, and electrostatic printers, recently, of course, toner replenishment is of course required.
Recording devices are now available in the world that allow users to replace the photoconductor and the cleaning unit by hand. Particularly for printers, it is strongly demanded that general users can easily perform such operations. Therefore, conventionally, a method has been adopted in which an image forming unit including a photoconductor, a developing unit, a cleaning unit, and a charger is integrated, and the image forming unit is exchanged after a preset period of time. But in this case, 1
The cost of parts for each replacement is high, the burden on the user is large, and the life of the photoconductor, the toner replenishment interval, and the life of the cleaning unit differ from each other, so even if the photoconductor is still fully usable, the life of other photoconductors can be extended. Since it is discarded together, it is wasteful and the cost per print is high.

Therefore, a machine in which a replacement cycle is set for each unit forming the image forming unit and each unit is separately replaced is also commercialized. However, this method poses a problem in workability when the user exchanges. Especially when exchanging the photoconductor, the photoconductor surface is not very robust, and it touches the surface when it is set on the machine or scratches the photoconductor surface by rubbing against other members. Then, there is a possibility of degrading the performance.

Due to these problems, in the case of a belt-shaped photoreceptor,
This is exchanged as a cartridge stored in a casing, and in the case of a drum-shaped photosensitive member, it is general that a user does not perform replacement by hand and relies on a serviceman. In that case, a method is adopted in which the photosensitive drum is set by sliding it from the side of the machine.

In view of the above situation, the present invention makes it possible for a general user to easily replace a photoconductor drum of an electrostatic recording device without damaging or touching the surface of the photoconductor. It is an object of the present invention to provide a supporting mechanism for a photosensitive member.

In order to achieve the above object, the present invention provides an outer cylinder having a trunnion rotatably fitted to a bracket attached to an image forming unit face plate that can be drawn out from the machine body, and a slidable inner cylinder. A socket which is freely fitted and is biased in a direction projecting from the outer cylinder by a spring interposed between the inner cylinder and the bottom plate of the outer cylinder, and a bottomed inner cylinder provided with a means for preventing the outer cylinder from slipping off; A journal portion formed by press-fitting a cap, which is fitted to the inner peripheral surface of the inner cylinder of the socket, so as to be slidable in the axial direction and rotatable about the shaft, at one shaft end of the photosensitive member; A circular hole that is provided at the center of the other end and has an engaging portion that is fitted to the drive shaft of the machine body and that transmits the driving force is provided.

Embodiments of the present invention will be described below in detail with reference to the drawings.

1 to 3 are views showing an embodiment of the present invention. FIG. 1 shows a state in which an image forming unit in which a photosensitive drum 1, a developing device 2 and a cleaning unit 3 are mounted in a case is pulled out from a machine body 10 such as a printer. The unit case is held by the guide rails 6 and 7. A handle 5 is attached to the front plate 4 of the case, which allows the unit to be easily pulled out and set. Positioning holes 4a are formed in the upper portions of both ends of the front plate 4, and in a state where the unit is stored in the main body, the positioning holes 4a are fitted and positioned with the pins 8 and 9 planted in the front side plate of the main body 10.

The support mechanism of the photosensitive drum in the image forming unit will be described below.

The shaft end on the front side of the photosensitive drum 1 is inserted into a socket provided on the front plate of the unit case to support the shaft, and the rear end is a flange.
24 is received by the notch on the rear plate of the unit case, and the unit is stored in the main body, so that a circular hole with a conical section with a large number of grooves along the generatrix provided at the center of the flange at the back A shaft 11 having a shaped tip is engaged and supported.

The socket 20, as shown in FIG. 2 and FIG.
A trunnion 34 that rotatably fits into a recess 23a of a bracket 23 attached to the outer cylinder 21 and a cylinder 33 that is axially slidable on the inner peripheral surface of the outer cylinder 21. The compression spring 31 interposed between the bottom plate and the bottom plate provided inside the middle part of the inner cylinder 33 and the bottom plate of the inner cylinder 33, which was fixed to the bottom plate of the inner cylinder 33 and passed through the bottom plate of the outer cylinder, was attached with a retainer ring to prevent removal. It is composed of a shaft 32.

On the other hand, a cap 22 which is slidable in the axial direction and rotatable around the shaft is press-fitted onto the inner surface of the inner cylinder 33 of the socket 20 at the shaft end on the front side of the photosensitive drum 1 to form a journal. Is forming.

Therefore, when the photoconductor drum 1 is installed, the socket 20
The conical hole of the rear flange 24 is pressed against the conical portion of the tip of the drive shaft 11 on the main body side by the action of the compression spring 31, and the grooves are meshed with each other to transmit the driving force. Is the inner cylinder 33 of the socket 20 at the front end and the drive shaft of the main body at the rear end.
Supported by 11.

When replacing the photoconductor drum, pull out the unit case from the main body and the rear end will be separated from the front end of the drive shaft on the main body side.
The inner cylinder 33 is pushed out by the action of the spring 31 until the retainer ring comes into contact with the outer surface of the outer cylinder bottom plate as shown in FIG. 3, and accordingly the journal portion of the photosensitive drum 1 is projected from the mounted state. Next, as shown in FIG. 4, the photosensitive drum 1
While pushing the flange 24 of the socket toward the front side, pull up the trunnion 34 of the socket 20 as an axis, and hold both end surfaces of the photoconductor drum 1 with both hands to lift the socket 20 easily.
The journal can be pulled out to remove the photoconductor.

Then install a new photoconductor drum in the reverse order of the above,
It can be supported by the socket 20 and the drive shaft 11 on the main body side. In addition, it is desirable to wind a protective sheet such as paper so that the new photoreceptor does not interfere with holding the peripheral surface by hand.

Effects As described above, according to the present invention, the workability of replacing the photosensitive drum of the electrostatic recording device such as a printer is improved, and the user can easily replace the photosensitive drum without damaging it.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which an image forming unit is pulled out from a recording apparatus main body to which the present invention is applied, FIG. 2 is a perspective view showing both end portions of the photosensitive drum, and FIG. 3 is its socket portion and journal. FIG. 4 is a cross-sectional view of a portion, and FIG. 4 is a perspective view showing a process of attaching and detaching the photosensitive drum. 1 ... Photosensitive drum, 2 ... Developing device, 3 ... Cleaning unit, 4 ... Unit case front plate, 10 ... Recording device body, 11 ... Drive shaft, 20 ... Socket, 21 ... Outer cylinder , 22 …… cap, 23 …… bracket, 24 …… flange, 31 …… spring, 32 …… shaft, 33 …… inner cylinder, 34 …… trunnion

Claims (1)

[Claims] 1. An outer cylinder having a trunnion rotatably fitted to a bracket attached to an image forming unit face plate which can be drawn out from a machine body, and an outer cylinder slidably fitted to an inner peripheral surface of the outer cylinder. And a bottom plate, and a socket formed of a bottomed inner cylinder biased in a direction projecting from the outer cylinder by a spring interposed between the bottom plate and the outer cylinder, and an inner circumference of the inner cylinder of the socket. Provided at the center of the journal part formed by press-fitting and attaching a cap that is fitted to the surface so as to be slidable in the axial direction and rotatable about the axis to one shaft end of the photoconductor and the other end part of the photoconductor And a circular hole having an engaging portion to which a driving force is transmitted and which is fitted to a drive shaft of a machine body.