JPS62186274A - Process cartridge type image forming device - Google Patents

Abstract

PURPOSE:To surely prevent an image carrier from being damaged by arranging plural image forming means on a process cartridge case body within a half circumference of the image carrier, and in case the body is loaded/unloaded to/from a device body by moving it in the axial direction of the image carrier, preventing the plural image forming means from being abutted upon the image carrier by a guide means for separating the case body in the radius direction of the image carrier. CONSTITUTION:At the time of the cartridge body case 20 is drawn to the front side by grasping a handle 37 formed on the front side of the case body 20, the lower surfaces of projections 29, 30 on the front and back parts starts to be lifted along the inclined surfaces 32a, 33a of recessed parts, so that the whole case body is lifted upward and points A, B are receded upward from a photosensitive drum 3. At the time of the lower surfaces of the projections 29, 30 are receded from the inclined surfaces 32a, 33a and mounted on a stay 31, the case body 20 is lifted upward and image forming members such as a developing sleeve 5a, a cleaning blade 37, a scooping sheet 36, an electrostatic charger 4 are surely separated upward from the drum 3, so that these image forming members can be prevented from being abutted upon the photosensitive drum 3.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention [Industrial Field of Application] The present invention relates to a developing device, which is an image forming means in which an image bearing member is attached to the main body of the device and is located near the image bearing member. The present invention relates to a process cartridge type image forming apparatus in which at least two or more devices, such as a cleaning device and a charging device, are housed in one housing and can be attached to and detached from the main body of the device.

[Conventional technology]

An image forming apparatus such as a copying machine φ printer, etc., which consists of an image forming process means such as an image bearing member (photosensitive drum, photosensitive belt, etc.), a charging device, a developing device, a cleaning device, etc., is A-9i.
With the advent of drums, etc., the lifespan of photosensitive drums has increased, and the lifespan of the main body of the device is approaching its end.

Therefore, the drum is left in the main body of the device, and multiple means of other image forming means are integrated into a cartridge, and when the toner is used up or a problem occurs such as a defective cleaning fist discharge, the cartridge can be removed from the main body. By discarding the copying device as a consumable item, running costs can be reduced, making it possible to supply copying devices advantageously to users.

[Problem that the invention seeks to solve]

However, when the cartridge is attached to and removed from the main body of the apparatus, there is a risk that the process apparatus may come into contact with the photoreceptor and cause damage to the photoreceptor.

The present invention aims to provide a device that prevents this possibility.

Summary: Structure of the Invention [Means for Solving Problems] The present invention provides a developing device, a cleaning device, and a charging device, which are image forming means, in which an image bearing member is attached to an apparatus main body and located near the image bearing member. In a process cartridge type image forming apparatus, in which at least two or more devices such as a device are housed in a single housing and are removably attached to the main body of the device, the plurality of image forming means are arranged within half a circumference of the image carrier. The process cartridge is disposed in a process cartridge housing as shown in FIG. This is a process cartridge type image forming apparatus characterized by preventing a plurality of image forming means from coming into contact with an image carrier.

[For production]

A plurality of image forming means are arranged in a process cartridge housing so as to be within half a circumference of the image carrier, and when the housing is moved to and removed from the apparatus main body in the axial direction of the image carrier, the housing is Since the guide means for moving away from the image carrier in the radial direction is provided, the image forming means attached to the casing is not separated from the image carrier by a large distance and does not come into contact with the image carrier.

〔Example〕

The present invention will be described below using an electrophotographic copying machine as an example.

FIG. 1 shows an embodiment of an electrophotographic copying machine, in which reference numeral 1 denotes a document storage table made of a transparent member, which moves back and forth in the direction of the arrow.

Reference numeral 2 denotes an imaging element array, which slit-exposes a light image of the original image on the original table 1 onto an A-3i (amorphous silicon) photosensitive drum 3 .

Note that the photosensitive drum 3 rotates in the direction of the arrow. 4 is a corona charger that uniformly charges the photosensitive drum, and 5 is a developer that applies 7 rays 2 to the uniformly charged photosensitive drum.
The electrostatic latent image formed by photo-image exposure is developed with toner.

On the other hand, the transfer sheet P is fed onto the surface of the drum 3 by a feeding roller 6 and a register roller 7, and the toner image on the drum is transferred by a transfer charger 8. Thereafter, the sheet is separated from the drum by the separating means 13 and the guide 9
The sheet is sent to a fixing device 10 by a roller 9a located at the end of the conveyance path passing over the sheet, the toner image on the sheet is fixed by the fixing device 10, and the sheet is discharged onto a tray 12 by a discharge roller 11. On the other hand, toner remaining on the photosensitive drum 3 without being transferred is collected by a cleaning device 14 (hereinafter referred to as a cleaner). Furthermore, 15 is an illumination system for exposing the original, and 16 is a filter such as a heat ray absorption filter.

Now, as shown in FIG. 2, this copying machine has an upper body 17 and a lower body 18 that are separably connected by a support shaft 19, and the upper body 17 rotates upward around this support shaft 19. It is configured to move. This upper body 17 includes an illumination optical system 2, 15, a photosensitive drum 3φ developing device 5, and a cleaner 14.
Image forming means such as the following are arranged. In addition, the lower body 1
8 includes a feeding roller 6Φ transfer charger 8Φ separation means 13.
A guide 9, a fixing device 10, and the like are arranged on the sheet conveyance path.

Furthermore, in this embodiment, as shown in FIG.
- An image forming device such as the charger 4 is attached and arranged in the housing 20 to constitute a process cartridge, and this is moved in the longitudinal direction of the photosensitive drum 3 to be attached or detached.

The present invention provides a process cartridge type image forming apparatus having the above-mentioned structure, for example, which has the structure described in the claims.
In the case where 4 is the photosensitive drum 3 in the housing 20, it is arranged and supported within the upper half of the circumference.

When the cartridge 20 is loaded into the main body 17 of the apparatus, each of the process means 4, 5-14 is naturally in a normal position relative to the photosensitive drum 3, as shown in FIG. When the cartridge 20 is pulled out from this state toward the front side, or vice versa when it is inserted and loaded, the cartridge 20 is moved away from the photosensitive drum l in the radial direction (in the case of the figure, upward) as shown in FIG. is separated from the photosensitive drum 3.

The configuration will be described in detail below with reference to the illustrated embodiment.

First, as shown in FIGS. 5 and 6, the photosensitive drum 3 has shafts 21 and 22 on the rear and front sides mounted on bearings 23Φ provided in the main body 17 of the apparatus.
24 and is rotated by a driving force transmitted to a gear 25.

The cartridge housing 20 has a bin 26 provided on the back side plate 20a.
As shown in FIG. 5, the U-shaped groove 28 provided in the front side plate 20b of the cartridge fits into the vertical round elongated hole 27 of the rear side plate 17 of the main body of the apparatus, and the U-shaped groove 28 provided on the front side plate 20b of the cartridge is connected to the rotation shaft 22 on the front side of the drum as shown in FIG. As shown in Fig. 5, they fit together and position in the left and right direction.

Next, the vertical positioning of the cartridge is determined by the projections 29 and 29 provided on the front and rear lower surfaces of the left and right side plates 20c and 20d of the housing 20.
30 is placed in alignment with the recesses 32 and 33 provided in the stay 31 provided in the device main body 17 by precision drawing or the like to achieve dimensional accuracy in the height direction. Further, a leaf spring 34 is provided on the main body 17 so as to face the upper surface of the cartridge case 20, so that the mounted case 20 is constantly pressed downward.

Furthermore, regarding the front-rear direction of the cartridge housing 20, when the rear side plate 20a of the housing abuts against the stopper 35 provided on the rear side plate 17 of the main body, the triangular protrusion 36 provided on the upper side of the housing hits the leaf spring 34. The slope 34a urges it toward the back and prevents it from being pulled out toward the front.Next, as shown in FIG. 30 projects slightly (for example, 2 mm) lower than the front projection 29, and the corresponding stay 31
The recess 33 of the receiver is also formed deeper than the front recess 32 by the above height difference.

Furthermore, the projections 29 and 30 are formed with slopes at the front and rear, and the receiver has slopes at the front and rear of the four parts 32-33, and especially when the housing 20 is loaded in the normal position as shown in FIG. 29a, 32a, and 30a, 33a are formed in a substantially abutting relationship.

With the above configuration, in the state shown in FIG. 3 and FIG. The photosensitive drum 3 is in a relationship that allows it to function normally. In this case, the point of the developing sleeve 5a closest to the photosensitive drum 3 (FIG. 4 A) and the contact point of the scooping sheet 36 of the cleaner 14 with the photosensitive drum (FIG. 4 B) are defined by a horizontal line passing through the center of the photosensitive drum 3. It is located higher up.

When the cartridge housing 20 is pulled out toward the front by the handle 37 provided on the front side, the lower surfaces of the aforementioned front and rear projections 29 and 30 begin to rise along the concave slopes 32a and 33a, so that the entire housing moves upward. When the bottom surfaces of the protrusions 29 and 30 escape from the slopes 32a-33a and ride on the stay 31, the fifth point in FIG. 3 becomes the state shown in FIG. The body 20 rises high as shown in FIG. 4, and the image forming members such as the developing sleeve 5a, cleaning blade 37, scooping sheet 36, and charger 4 are reliably scraped upward from the photosensitive drum 3. 3
1 as a guide, these members do not come into contact with the photosensitive drum.

Note that the rear protrusion 30 is pulled out to the front when the front recess 29 is pulled out.
However, as mentioned above, since the height and depth are different, the casing 20 does not approach the photosensitive drum 3 as shown in FIG. 3, but is reliably separated from the photosensitive drum 3.

In the above embodiment, the housing 20 is vertically spaced apart from the photosensitive drum, but the direction is determined by the arrangement of one image forming process device.

For example, when a belt-shaped photoreceptor is used as an image carrier and a process device is disposed on the surface of a turning roller, the casing is moved diagonally upward with respect to the turning roller.

Further, when the housing 20 is attached or detached, the blade 37 of the cleaner 4 is overlapped with the scooping sheet 36 to prevent leakage of toner, but this is omitted from the drawing.

C1 As described in detail of the invention, an image forming process device that is close to a photosensitive drum in a cartridge housing is disposed within half a circumference of the photosensitive drum, and when the housing is attached or removed, the housing and the main body of the device are connected to each other. Since the casing is separated in the semicircular direction by the interlocking guide means between the two, the process device can be reliably separated from the image carrier with a simple structure and handling, and the effect of reliably preventing damage to the image carrier. There is.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an example of an electrophotographic copying machine to which the present invention is applied, and FIG. 2 is a vertical cross-sectional view of the upper main body thereof in an open state.
Figure 3 is an enlarged longitudinal sectional front view of the process cartridge section, Figure 4 is a front view of the process cartridge when it is installed and removed, Figure 5 is a side view of Figure 3, and the bearing section of the photosensitive drum is shown in Figure 3C.
6 is a side view having the same relationship as FIG. 5 in the case of FIG. 4; 3... Image carrier, 4... Charging device, 5... Developing device, 14... Cleaning device, 17, 18... Apparatus body, 20... Cartridge housing, 29, 30...・
・Casing side guide means, 31/32φ33...Body side guide means.

Claims (1)

[Claims] (1) An image carrier is attached to the main body of the apparatus, and at least two or more devices such as a developing device, a cleaning device, and a charging device, which are image forming means located near the image carrier, are housed in one housing. In a process cartridge type image forming apparatus which is removably attached to the apparatus main body, the plurality of image forming means are arranged in a process cartridge housing so as to be within half a circumference of the image carrier, and the housing is When moving the image carrier in the axial direction to attach and detach it to the main body of the device,
A process cartridge type image forming apparatus characterized in that a guide means for moving the casing away from the image carrier in a radial direction is provided to prevent a plurality of image forming means from coming into contact with the image carrier.