JPS5845026B2 - electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic apparatus having a structure for returning toner removed from the surface of a photosensitive drum by a cleaning blade or the like to a developing device in order to reuse the toner.

Conventionally, various structures have been proposed for devices for reusing toner, but most of them have a developing device and a cleaning device that are originally installed separately in the device. are connected by a duct, and the toner is returned to the developing device through the duct. Therefore, when replacing the photosensitive drum or removing the developing device and cleaning device from the main unit, it is necessary to remove the duct from the developing device or cleaning device. Therefore, there was a problem in that toner spilled from the opening of the duct, staining the inside and outside of the device with toner.

The present invention solves the problems of the conventional example and makes the structure more compact by forming the toner collection path using a part of the frame that integrally supports the photosensitive drum, the developing device, and the cleaning device. profit and maintenance,
An object of the present invention is to provide an electrophotographic device that is easy to inspect.

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a partially cutaway perspective view of the photosensitive drum 1.
A developing device 2 and a cleaning device 3 are arranged near the periphery of the photosensitive drum 1, the developing device 2, and the cleaning device 3 are integrally attached to a frame 4.

The cleaning device 3 includes a cleaning blade 5 that contacts the photosensitive drum 1, a guide plate 7 that guides the flow of the removed toner 6, a toner reservoir 8 that stores the removed toner 6, and a toner reservoir 8 that is located within the toner reservoir 8. The cleaning lead screw 9 includes a cleaning lead screw 9 that conveys the toner 6 to one end of the photosensitive drum 1 in the axial direction (to the right in FIG. 1).

The developing device 2 includes a developing device main body 10 and a toner hopper 1.
1, and a hopper lead screw 13 which is located in the toner hopper 11 and conveys toner to the toner hopper 11 through a toner discharge hole 12, which will be described later.

The frame 4 has a recess 15 for forming a toner recovery path that allows a ladder chain 14, which is an endless toner transport member constituting the first toner transport mechanism, to circulate. is the toner reservoir 8
A toner intake hole 1T communicating with the toner hopper 11 and a toner discharge hole 12 communicating with the toner hopper 11 are provided.

The ladder chain 14 is located within the recess 15,
A ladder wheel 18 and a guide pulley 19 made of a flanged pulley are provided so that the toner can circulate between a first position near the toner intake hole 17 and a second position near the toner discharge hole 12. It is supported so that it can be hung and circulated.

Here, as is clear from the drawing, in the ladder chain 14, a ladder chain part that moves from the second position to the first position and a ladder chain part that moves from the first position to the second position are located above and below. The lower ladder chain portion, which is arranged as shown in FIG.

The guide 20 is formed to guide the conveyance of toner by the movement of the lower ladder chain portion, and its upper portion extends to the opening 21 above the toner discharge hole 12.

Further, the toner intake hole 17 is formed in the side wall 17 near the first position in the recess 15 and facing the inside of the loop of the ladder chain 14.

As shown in FIG. 2, the lid member 22 of the frame 4 is detachably attached to the frame 4 so as to seal the recess 15.

One end of each of the cleaning lead screw 9 constituting the second toner conveyance mechanism and the hopper lead screw 13 constituting the third toner conveyance mechanism (see FIGS. 1 and 2).
The right end in the figure) is located within the recess 15 and is configured to reach close to the lid member 22 of the frame 4.

This is because the cleaning lead screw 9 transports the toner 6 in the toner reservoir 8 along the toner intake hole 17 to the first position in the recess 15 or its vicinity, and also transports the toner 6 into the hopper. Lead screw 1
3, this is for discharging the toner at or near the second position in the recess 15 (at the opening 21) so as to lead it to the developing device 2 through the toner discharge hole 12.

As shown in FIG. 4, the photosensitive drum 1 has a center hole 23.
A drum shaft 26 having a slit 25 at its tip is inserted into and inserted into the connecting hole 24 in such a manner that it can be freely inserted and removed.

This drum shaft 26 is inserted into the frame 4 and the lid member 22 so that it can be inserted into and removed from the frame 4 and the lid member 22. When inserted, it can be freely rotated by a bearing 27 embedded in the frame 4. It is gaining support.

To replace the photosensitive drum 1, remove the latch 28 that prevents the drum shaft 26 from being pulled out, then pull out the drum shaft 26 by holding the knob 29, and then remove the photosensitive drum 1, which is stopped by the collar 30 of the frame 4. Take it out upwards, put a new photosensitive drum (not shown) into the frame 4 so that it can be received by the flange 30 of the frame 4, insert the drum shaft 26 again, and attach the latch 28. can be done.

Further, a drum gear 31 is integrally attached to the other end of the photosensitive drum 1, and an intermediate gear 3 is provided on the frame 4.
2, a gear 33 attached to the end of the cleaning lead screw 9 is rotated synchronously.

The photosensitive drum 1 and the hopper lead screw 13 are rotated by a drive motor (not shown).

A spur gear 34 is attached to one end of the hopper lead screw 13.
is attached to the rudder wheel 18, and is configured to mesh with a spur gear 35 attached to the shaft end of the rudder wheel 18 to drive the rudder chain 14.

According to this device, as the photosensitive drum 1 rotates, toner 6 is scraped off by the cleaning blade 5.
The toner is guided by the guide plate 7, and due to its own weight, the toner is sequentially pushed out to form a toner reservoir 8.
It accumulates.

Inside the toner reservoir 8, the toner 6 is moved into the recess 15 by a cleaning lead screw 9 that rotates in synchronization with the photosensitive drum 1.
The toner particles are conveyed toward the toner intake hole 17 and dropped into the first position in the recess 15 or in the vicinity thereof (some of them are dropped onto the ladder chain 14).

Then, the ladder chain 14 is connected to the guide 20 of the recess 15.
At the same time, this toner 6 is caught in a space 36 (see FIG. 3) which functions as a toner receiving tray, and is conveyed toward the developing device 2 as shown in FIG. 3 by running of the lower ladder chain section.

When the lower ladder chain portion reaches above the opening 21, the toner 6 passes through the opening 21 and enters the toner discharge hole 1 in the space 36.
Fall to 2.

Moreover, when the ladder wheel 18 engages with the ladder chain 14, it has the function of forcibly pushing out and dropping the toner remaining on the ladder chain 14 because the toner cannot be completely fallen by its own weight.

In the toner discharge hole 12, a hopper lead screw 13 rotating directly below the opening 21 transfers the toner to the toner hopper 1.
Incorporate into 1.

The frame 4 has support portions 38 on both sides and is slidably and detachably held on a U-shaped guide frame of an electrophotographic apparatus main body (not shown), and is attached to a cleaning device and a developing device. When taking out the container from the main body of the electrophotographic apparatus, the entire frame can be taken out by sliding the guide frame integrally.

As is clear from the above description, in the electrophotographic apparatus of the present invention, the toner recovery path is formed in a part of the frame that can integrally support the developing device, the photosensitive drum, and the cleaning device. When removing the container and cleaning device from the main body of the electrophotographic apparatus, by removing the frame as a whole, there is no need to separate the frame in which the toner recovery path is configured, the developing device, and the cleaning device. Since the sealing is maintained at each joint, there is no possibility of toner spilling inside or outside the electrophotographic apparatus and causing contamination.

Furthermore, even if only the photosensitive drum is attached or removed from the frame after the drum shaft is removed from the frame, the frame, developer, and cleaning device are not separated, and their joints remain sealed. Another advantage is that toner does not spill out even when replacing the toner.

Furthermore, the present invention has a structure in which an endless toner conveying member circulates within a recess for forming a toner recovery path provided on the side of the frame, and the recess is hermetically closed with a removable lid member. Therefore, manufacturing, assembly, maintenance, and inspection are easy, and the electrophotographic apparatus itself can be made more compact.

In particular, a ladder chain is used as the endless toner conveying member as in the above embodiment, and a ladder chain section that moves the ladder chain from the second position to the first position within the recess;
The ladder chain parts that move from the first position to the second position are arranged so as to be located above and below, and the lower ladder chain part that moves from the first position to the second position is arranged on the lower surface of the recess. When the toner is configured to move in sliding contact, the second toner transport mechanism (corresponding to the cleaning lead screw 9 in the above embodiment) brings the toner to the first position in the recess or its vicinity. Since the toner can be reliably transported to the second position in the recess or its vicinity, that is, to the location where it can be transported by the third toner transport mechanism (corresponding to the hopper lead screw 13 in the embodiment described above), the toner The present invention is very effective in realizing a highly reliable, compact and lightweight electrophotographic copying device with a reusable function at a low cost.

[Brief explanation of the drawing]

The drawings show the structure of an embodiment of the main part of the electrophotographic apparatus according to the present invention, and FIG. 1 is a partially cutaway perspective view of the main part with the lid member omitted, and FIG. 2 is a plan view thereof. 3 and 3 are perspective views of essential parts inside the toner recovery path, and FIG. 4 is a perspective view for explaining the photosensitive drum replacement operation. 1...Photosensitive drum, 2...Developer, 3
... Cleaning device, 4 ... Frame, 5 ... Cleaning blade, 8 ...
...Toner reservoir, 9... Cleaning lead screw, 11... Toner hopper, 12...
... Toner discharge hole, 13 ... Hopper lead screw, 14 ... Ladder chain, 15 ...
...Concavity for forming toner recovery path, 17...
・Toner intake hole, 18...Ladder wheel, 1
9... Guide pulley, 20... Guide, 2
2...Lid member, 26...Drum shaft.

Claims (1)

[Scope of Claims] 1. A photosensitive drum, a developing device that develops the surface portion of the photosensitive drum with toner, a cleaning device that removes toner adhering to the surface portion of the photosensitive drum, and the photosensitive drum and the developing device. and a frame for integrally supporting the cleaning device in a detachable manner with respect to the main body of the electrophotographic apparatus; a recess, a lid member removably attached to the side of the frame so as to seal the recess, and a cover member arranged to be able to circulate between a first position and a second position within the recess. a first toner transporting mechanism that includes an endless toner transporting member that rapidly transports toner located at or near the first position to the second position or near the second position; a second toner transport mechanism that rapidly transports the toner removed by the cleaning device to a first position within the recess or its vicinity; An electrophotographic apparatus characterized by comprising a third toner conveying mechanism that rapidly conveys toner brought near the developing device to the developing device. 2. A ladder chain is used as the endless toner conveying member, and the ladder chain has a ladder chain portion that moves from the second position to the first position in the recess for forming the toner recovery path, and a ladder chain portion that moves from the first position to the first position. Ladder chain parts that move to the second position are arranged so as to be positioned above and below, and a lower ladder chain part that moves from the first position to the second position slides into contact with the lower surface part in the recess. An electrophotographic apparatus according to claim 1, wherein the electrophotographic apparatus is configured to: 3. The photosensitive drum is rotatably supported by a drum shaft that is removably inserted into the frame and the lid member, and the drum is removable from the frame by separating the drum shaft from the frame. An electrophotographic apparatus according to claim 1 or 2, characterized in that: