JPS63118759A - Photosensitive drum protective device - Google Patents

Abstract

PURPOSE:To protect a photosensitive drum until the drum is mounted in an enclosure by forming a supporting body for freely rotatably holding the drum, fitting holding parts for freely attachably and detachably holding the supporting body to the enclosure and winding a protective sheet to which one end is arrived to a paper feeding part around the drum. CONSTITUTION:The supporting body 24 for holding a new photosensitive drum 25, a developing part 34 and a cleaning part 37 is set up on the holding parts 41-43 of a lower frame 2. The protective sheet 40 is automatically inserted between a paper feeding part 17 and a roll 39, and when an upper frame 3 is rotated in a closing direction, a cover opening switch is turned on, the paper feeding parts 16, 17, fixing rolls 20, 21 and a discharge roll 10 are driven and the protective sheet 40 is discharged. Immediately after turning on the cover opening switch, a jam sensor is canceled as initializing operation. Since the photosensitive body 25 is protected by the protective sheet 40 until the drum 25 is unlapped and mounted in the enclosure 1, the drum 25 can be prevented from being damaged by interference with peripheral parts or deteriorated by exposure to external light.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a photosensitive drum protection device used in an electrostatographic apparatus.

2. Description of the Related Art In a conventional electrostatic photographic apparatus, in the process of rotating a photosensitive drum once, an electrostatic latent image is first formed on the outer periphery of the photosensitive drum by an electrostatic latent image forming means, and this electrostatic latent image is developed by a developing section. Develop,
Generally, the developed image is transferred to paper by a transfer section, and then the transferred image on the paper is fixed by a fixing section, and the outer periphery of the photosensitive drum is cleaned by a cleaning section. .

Problems to be Solved by the Invention On the other hand, photosensitive drums are consumable items that are subject to replacement parts, but even if they are carefully packaged, they are likely to interfere with surrounding objects and be damaged when installed in a housing. Furthermore, if the photosensitive surface is exposed to external light for a long time, there is a risk that the photosensitive surface will deteriorate.

Means for Solving the Problems A photosensitive drum, an electrostatic latent image forming means, a developing section, a transfer section, a cleaning section, a paper path passing between the transfer section and the transfer section, and a paper path passing between the transfer section and the transfer section, In an electrostatic photographic apparatus in which a paper feeding section and a fixing section located on a passage are built into a housing, a support is provided for rotatably holding at least the photosensitive drum, and a holder for detachably holding the support. A protective sheet is provided in the housing, and a protective sheet whose one end reaches the paper feeding unit is wound around the photosensitive drum.

Therefore, if the photosensitive drum is attached to the housing together with the support while the protective sheet is still wound, the protective sheet will reach the paper feed section, and the protective sheet will be ejected along the paper path by driving the paper feed section. Ru. Therefore, the photosensitive drum is protected until it is attached to the housing.

Example An embodiment of this invention will be described based on the drawings.

Reference numeral 1 denotes a casing, and the casing 1 has a lower frame 2 and an upper frame 3 rotatably connected by a support shaft 4.

The upper frame 3 is provided with an electrostatic latent image forming means 5 and a removal section ii. The electrostatic latent image forming means 5 includes a charging section 7 that applies an electric charge to the entire outer periphery of the photosensitive drum, which will be described later.
It consists of an exposure section 8 that applies a laser beam to the charged layer.

The upper frame 3 is provided with a paper path 9 and a discharge roller 10.

Further, a cassette case 12 containing sheets of paper 11 is detachably attached to the lower frame 2.

A paper path 15 that is continuous with the paper path 9 is formed by a guide plate 13 fixed to the lower frame 2 and a guide plate 14 fixed to the upper frame 3. On this paper path 15, there are paper feeding sections 16 and 17, a transfer section 18,
A fixing section 19 is provided. The fixing section 19 includes a fixing roller 20 attached to the upper frame 3 and a fixing roller 21 attached to the lower frame 2. Further, the lower frame 2 is provided with a paper feed roller 22 that contacts the uppermost layer of paper 11 in the cassette case 12.

A support 24 with a handle 23 is then provided. This support body 24 is formed with a notch 28 for holding a bearing 27 for supporting a rotating shaft 26 protruding from both ends of the photosensitive drum 25, and protrusions 29 protruding from both sides.

Furthermore, hooks 30 are formed on both sides of the handle 23. A developing section 34 is formed by a toner container 32 having a shaft 31 supported by these hooks 30 and a magnet roller 33 rotatably held by this toner container 32.
is formed. Furthermore, a cleaning section 37 having a blade 35 and a cleaning roller 36 that comes into contact with the outer peripheral surface of the photosensitive drum 25 is held on the support body 24 . Further, a lever 3 rotatably attached to the support body 24
8 supports a roller 39. The paper feeding section 1
7 is a roller, and this roller includes roller 3 of the support body 24.
9 is what comes into contact. A protective sheet 40 made of strong synthetic resin is wound around the outer periphery of the photosensitive drum 25. This protective sheet 40 is held between the photosensitive drum 25 and the magnet roller 33, and one end thereof is attached to the roller 39.
and is fixed so as to reach the paper feeding section 17.

Furthermore, as shown in FIGS. 1 and 2, the lower frame 2 includes a holding portion 41 that supports the bearing 27 of the photosensitive drum 25.
A holding portion 42 that supports the protrusion 29 of the support body 24 and a holding portion 43 that supports the shaft 31 of the toner container 32 are formed. These holding parts 41, 42, and 43 are cutouts with open tops. Further, the upper frame 3 includes a rotatable lifting lever 44 that lifts up the handle 23 of the support body 24, and a rotatable pressing lever that elastically presses the bearing 27 against the holding part 41 by the spring 45. 46, a spring 47 for pressing the toner container 32, and an operating rod 48 for rotating the lifting lever 44.

In such a configuration, in the process of rotating the photosensitive drum 25 once, the charging section 7 first forms a charged layer on the outer periphery of the photosensitive drum 25, and by scanning the charged layer with a laser beam from the exposure section 8, the electrostatic charge is removed. A latent image is formed, this electrostatic latent image is developed as a toner image by the developing section 34, and the paper 1 is fed by the paper feeding roller 22 and the paper feeding section 16, 17.
The transfer unit 18 transfers the toner image on the photosensitive drum 25 to the photosensitive drum 25, and then the paper 11 is fixed by the fixing rollers 20 and 21, and the paper 11 is ejected by the ejection roller 1o.

On the other hand, in preparation for the next printing, the remaining toner on the photosensitive drum 25 is cleaned by the cleaning section 37, and the electrostatic latent image is removed by the static eliminating section 6.

A photosensitive drum 25 held on a support 24 and a developing section 34
Although the cleaning part 37 is treated as a consumable item that is a replacement part, when replacing it, press the operating rod 48 from the state shown in FIG. 2, rotate the lifting lever 44 clockwise to remove it from the handle 23, In this state, as shown in FIG. 1, open the upper frame 3, grasp the handle 23, and pick up the support body 24 remaining on the lower frame 2. Then, the support body 24 holding the new photosensitive drum 25, the developing section 34, and the cleaning section 37 is attached to the holding sections 41 and 4 of the lower frame 2.
Place it on 2.43. At this time, the protective sheet 40 is naturally held between the paper feeding section 17 and the roller 39 6. Then, when the upper frame 3 is rotated in the closing direction, a cover open switch (not shown) is turned on, and the paper feeding section 1
6, 17, fixing rollers 20, 21, and discharge roller 10 are driven, and the protective sheet 40 is discharged. At this time, since the protective sheet 4o is located in the middle of the paper path 15, the jam sensor detects it as a normal printing jam and the drive system is stopped, so immediately after the cover open switch is turned on. cancels the jam sensor as an initialization operation. The photosensitive drum 25 is protected by the protective sheet 4o until it is unpacked, installed in the housing 1, and used, and is protected from scratches due to interference with surrounding objects or deterioration due to exposure to external light. There's nothing to do.

Further, the handle 23 of the support 24 on which the new photosensitive drum 25 etc. are attached is suspended from the suspension lever 44, and in this state, the protective sheet 40 is pulled out by hand.Then, the upper frame 3 is lowered and the support 24 is suspended. Holding parts 41, 42.4
It can also be installed on 3.

Effects of the Invention Since the present invention is constructed as described above, when the photosensitive drum is attached to the housing along with the support with the protective sheet wound around, the protective sheet reaches the paper feeding section, so the paper feeding section cannot be driven. The protective sheet can be ejected along the paper path, and the protective sheet protects the photosensitive drum until it is attached to the housing, preventing damage from interference with surrounding objects and exposure to external light. This has the effect of protecting the photosensitive drum from deterioration.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially sectional side view showing a state in which the support is replaced, and FIG.
The figure is a side view with part of the cross section showing how the support is attached.
FIG. 3 is an enlarged longitudinal sectional side view showing a support structure for a photosensitive drum, etc., and FIG. 4 is a perspective view thereof. DESCRIPTION OF SYMBOLS 1... Housing, 5... Electrostatic latent image forming means, 9, 15.
...Paper path, 16.17...Paper feed section, 18...
- Transfer section, 19--Fixing section, 24...Support, 25
... Photosensitive drum, 34... Developing section, 37... Cleaning section, 40... Protective sheet, 41 to 43...
Holding part - Atsushi is Kon

Claims (1)

[Claims] A photosensitive drum, an electrostatic latent image forming means, a developing section, a transfer section, a cleaning section, a paper path passing between the transfer section and the transfer section, a paper feeding section located on the paper path, and In an electrostatic photographic apparatus having a fixing section built into a housing, a support body for rotatably holding at least the photosensitive drum is provided, a holding part for detachably holding the support body is provided in the housing, A protection device for a photosensitive drum, characterized in that a protective sheet, one end of which reaches the paper feeding section, is wound around the photosensitive drum.