JPS6217233B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner recovery device for conveying toner removed from the surface of a photosensitive drum by cleaning with a blade to a predetermined position in a developing device in an electronic copying machine for reuse. .

Conventional toner recovery devices include those in which the developing device and cleaning device are connected through a duct, and the toner is returned inside the duct by its own weight, or the developing device and cleaning device are connected through a flexible tube and a bead chain is installed inside the tube. A device was used in which the toner was conveyed to a predetermined position in the developing device and collected by running the toner. However, although such a toner recovery device is sufficient when the copying speed is slow and the amount of toner removed by the blade is small, it is not sufficient to cope with the collection of large amounts of toner that accompanies faster copying speeds. . In other words, in a device that uses a duct to return the toner by its own weight, the toner is not forcibly fed, so the toner may get clogged in the duct, and especially if you try to return a large amount of toner, the toner gets clogged in the duct. The disadvantage is that it occurs frequently. In addition, in a device configured using a flexible tube and a bead chain,
Since the bead chain occupies a large volume within the flexible tube, the toner conveyance capacity per unit length of the bead chain is low, which has the disadvantage that it is not suitable for collecting a large amount of toner.

By using a ladder chain that circulates within the collection path, the present invention eliminates the drawbacks of the conventional example as described above, has a large toner conveying capacity, and can sufficiently cope with increased copying speeds. To provide a toner recovery device with a simple structure that does not cause toner clogging in a recovery path.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a main part thereof, in which a developing device 2 and a cleaning device 3 are arranged around a photosensitive drum 1, and 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 collects the removed toner 6, and a toner reservoir 8 that stores the removed toner 6. and a cleaning lead screw 9 that conveys the photosensitive drum 1 in the axial direction. The developing device 2 includes a developing device main body 10, a toner hopper 11, and a hopper lead screw 13 that is located inside the toner hopper 11 and conveys toner to the toner hopper 11 through a toner discharge hole 12.
It is made up of. The frame 4 has a toner recovery path 15 along which a ladder chain 14 runs, and a toner reservoir 8 is provided on a side wall 16 of the recovery path 15.
A toner intake hole 17 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 supported in the recovery path 15 by a ladder wheel 18 and a guide pulley 19 made of a flanged pulley so that it can run in circulation, and the lower ladder chain 14 is in contact with the guide 20 of the recovery path 15. ing. guide 20
guides the ladder chain 14 and is cut out above the toner discharge hole 12 to form an opening 21 . Note that the toner intake hole 17 is formed within the loop of the ladder chain 14.

The lid 22 of the frame 4 is, as shown in FIG.
It is attached to the frame 4 so as to seal the recovery path 15. One end of each of the cleaning lead screw 9 and the hopper lead screw 13 is configured to penetrate into the collection path 15 and reach near the lid 22 of the frame 4.

As shown in FIG. 4, the photosensitive drum 1 has a center hole 23 and a connecting hole 24 into which a pin 37 is driven, and a drum shaft 26 having a slot 25 at the tip is inserted thereinto so as to be freely inserted and removed. The shaft 26 is rotatably supported by a bearing 27 embedded in the frame 4. To replace the photosensitive drum 1, remove the latch 28 that prevents the drum shaft 26 from coming off, pull out the drum shaft 26 by holding the knob 29, take out the photosensitive drum 1 that is received by the collar 30 of the frame 4 upward, and install a new photosensitive drum. (not shown) is placed in the frame 4 so that it can be received by the collar 30 of the frame 4, the drum shaft 26 is inserted again, and the latch 28 is engaged.

Further, a drum gear 31 is integrally attached to the end of the photosensitive drum 1, and a gear 33 at the end of the cleaning lead screw 9 is synchronously rotated via an intermediate gear 32 provided on the frame 4.

Photosensitive drum 1 and hopper lead screw 13
is rotated by a drive motor (not shown). A spur gear 34 is attached to the end of the hopper lead screw 13, and the rudder wheel 1
It is configured to mesh with a spur gear 35 at the end of the shaft of No. 8 to drive the rudder chain 14.

According to this toner recovery device, as the photosensitive drum 1 rotates, the cleaning blade 5
The scraped toner 6 is guided by a guide plate 7, and accumulates in a toner reservoir 8 due to its own weight and by being sequentially pushed out.
In the toner reservoir 8 , the toner 6 is conveyed toward the recovery path 15 by a cleaning lead screw 9 that rotates in synchronization with the photosensitive drum 1 , and is conveyed from the toner intake hole 17 to the ladder chain 14 in the recovery path 15 .
be dropped on top. The ladder chain 14, together with the guide 20 of the collection path 15, captures the toner 6 in a space 36 that functions as a toner receiving tray, and transports the toner 6 toward the developing device 2 as shown in FIG. 3 by the running of the ladder chain 14. do. When the ladder chain 14 reaches the opening 21 in the space 36, the bottom of the tray for the toner 6 is opened, and the toner 6 passes through the opening 21 and falls into the toner discharge hole 12. Furthermore, when the ladder wheel 18 engages with the ladder chain 14, it forcibly pushes out and drops the toner remaining on the ladder chain 14 because the toner cannot completely fall due to its own weight alone.

In the toner discharge hole 12, a hopper lead screw 13 rotating directly below the opening 21 takes toner into the toner hopper 11.

With the above configuration, in the toner recovery device of the present invention, the space in the recovery path can be secured above the ladder chain, so the space occupied by the ladder chain in the recovery path is small, and most of the space in the recovery path is occupied by the toner. In addition, the ladder chain forms a receiving tray together with the guide of the collection path and carries the toner.
It has the advantage of being able to transport a large amount of toner. In addition, the frictional load between the ladder chain and the collection path guide is small, and not only does the driving torque need to be small, but the tensile strength of the ladder chain is greater than that of the bead chain mentioned in the conventional example, and a large amount of toner can be removed. It has the advantage that it can be carried by force. Then, the protrusion of the ladder wheel engages with the ladder chain above the opening of the collection path that returns the toner to the developing device, so the toner that was not able to fall completely due to its own weight at the opening and remained in the ladder chain is forced to fall by the protrusion. It has the advantage of being

In addition, the ladder chain that transports toner to the developer passes below the recovery path, and the ladder chain that returns from the developer to the cleaning device passes above it, so there is no obstruction between them, and the ladder chain vibrates in small increments. Because the toner travels while moving, the toner that is not forced to fall by the protrusions falls onto the ladder chain leading to the developing device and is transported to the developing device again, so that the toner that returns to the cleaning device is It has the advantage of being extremely small.

In addition to the above advantages, the device has a simple structure, is easy to manufacture, and is inexpensive.

[Brief explanation of the drawing]

The drawings show the structure of an embodiment of the toner recovery device according to the present invention, and FIG. 1 is a perspective view of the main parts thereof with the lid omitted, FIG. 2 is a plan view thereof, and FIG. FIG. 4 is a perspective view of the main parts of the movable member and the guide section of the recovery path, and FIG. 4 is a perspective view for explaining the replacement of the photosensitive drum. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 2... Developing device, 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...Rudder chain, 15
...Recovery route, 17...Toner intake hole, 21...
Opening, 22...lid, 26...drum shaft.

Claims (1)

[Claims] 1. A toner intake hole is provided near one end and communicates with a toner reservoir of a cleaning device for removing residual toner adhering to the surface of the photosensitive drum, and near the other end is provided to remove residual toner adhering to the surface of the photosensitive drum. a frame having a toner recovery path provided with a toner discharge hole that communicates with a toner hopper attached to a toner hopper attached to a developing device; a first lead screw that transports the toner near one end of the toner recovery path; and a first lead screw that transports the toner near the one end of the toner recovery path to near the other end of the toner recovery path. A ladder chain is disposed to circulate in the toner recovery path for conveyance, and the toner conveyed by the ladder chain to near the other end of the toner recovery path is passed through the toner discharge hole and The ladder chain includes a second lead screw for transporting the toner into the toner hopper, and the ladder chain portion moves from the toner discharge hole side to the toner intake hole side in the toner recovery path and the toner intake hole side. Ladder chain parts that move from the hole side to the toner discharge hole side are arranged above and below, and a lower ladder chain part that moves from the toner intake hole side to the toner discharge hole side is arranged above and below. A toner recovery device, characterized in that the toner recovery device is configured to move in sliding contact with a lower surface portion within the toner recovery path.