JPH0713006Y2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an image forming apparatus for collecting a residue removed from an image carrier drum in an internal space of the image carrier drum.

[Prior Art and Problems] In an image forming apparatus, particularly in a dry copying machine or an electrophotographic copying machine using a powder developer (hereinafter referred to as a toner), a latent image formed on a photosensitive drum as an image carrier drum is used. The image is developed by the developing device and transferred onto the transfer paper. At that time, the toner on the photosensitive drum is not completely transferred, and a part of the toner remains on the photosensitive drum. Toner as a residue remaining on the photosensitive drum is cleaned by a cleaning device using a plate-shaped rubber blade or the like. The toner collected from the photosensitive drum by the cleaning device may be returned to the developing device and used again. However, reuse of such toner adversely affects the image and is not preferable, and is generally not preferable. The collected toner is collected in an appropriate collection container and then discarded.

Conventionally, it has been practiced to provide a collection container for collecting the collected toner in the copying machine main body, and when a certain amount of toner is accumulated in the collection container, the collection container is taken out from the copying machine main body and the toner is discarded. . Further, recently, a method has been proposed and implemented in which the toner removed by the cleaning device is conveyed to the inner space of the photoconductor drum by using the conveying means and the inner space of the photoconductor drum is used as a toner storage container.
In this method, the photosensitive drums used in the past, especially organic photosensitive members, have a short service life of several thousand to 20,000 sheets and are collected by the service life of the photosensitive drum with respect to the internal volume of the photosensitive drum. Since the toner amount was small, it was not necessary to provide a toner amount full detection means and was discarded when the photosensitive drum was replaced.

However, recently, with the advent of long-life organic photoconductors and the development of small-diameter photoconductor drums with a small space volume, there is a problem that the toner becomes full before the life of the photoconductor,
Furthermore, since the toner storage container (photosensitive drum) is a rotating body, it is difficult to detect the full amount because the toner inside is constantly rotating and flowing, and the load on the toner conveying means increases when the toner is full. However, there have been problems that the toner conveying / rotating member, the drive system gear, and the like are finally damaged, and the toner is dropped and scattered from the seal portion.

[Object of the Invention] The present invention overcomes the above-mentioned drawbacks of the prior art, and when the amount of residue collected and stored in the internal space of the image carrier drum exceeds a certain amount, the collection operation is automatically stopped and the image carrier is carried. An object of the present invention is to provide an image forming apparatus that prevents damage to the drive mechanism of the body drum.

To achieve the above object, the present invention provides a rotatable image carrier drum for carrying an image, a transport means for transporting a residue removed from the image carrier drum into the image carrier drum, and In an image forming apparatus having an image carrier drum and a driving force transmission unit having an engaging portion for transmitting a driving force to the transport unit, when the amount of the residue transported inside the image carrier drum reaches a predetermined amount. And a stop means for interrupting the engagement state of the engagement portion and stopping the transmission of the driving force by the driving force transmission means.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, which will be described below.

Reference numeral 1 is a rotating image carrier drum, which is supported by shafts 6 and 9. Although not shown in the drawing, an image forming unit, a unit for transferring the image onto a transfer sheet, and a unit for cleaning the toner after the transfer are arranged around the image carrier drum 1. The toner removed by the cleaning means is collected by the collecting unit 12, and is passed through the carrying pipe 11 by the carrying coil 8 serving as a carrying means to the image carrier drum 1
Be transported inside. The carrier coil 8 is provided with a gear 13
It is driven to rotate. As the driving force transmitting means for transmitting the driving force to the image carrier drum 1 and the conveying coil 8, the flange 2 is used.
The joint 3, the drive gear 4, the spring 7, and the gear 13 are provided.
The gear 13 is driven by meshing with a gear integrally formed with the flange 2 of the image carrier drum 1. The joint 3 is pressed against the flange 2 by a compression spring 7. Further, the flange 2 is formed with a protruding portion a for receiving the rotational driving force from the joint 3. Further, the joint 3 is formed with a concave portion b that engages with the protruding portion a. The joint 3 is engaged with the drive gear 4. That is, the driving force from the main motor (not shown) is transmitted to the drive gear 4, and when the drive gear 4 rotates, the joint 3 also rotates.
Since the joint 3 is pressed against the flange 2 by the spring 7, the protrusion a and the recess b are in an engaged state, so that the image carrier drum 1 also rotates. The surface C that receives the rotational driving force of the protrusion a formed on the flange 2 also functions as a stopping unit that stops the driving force by the driving force transmitting unit,
This surface C (see FIG. 2) is oblique. Therefore,
When a large amount of toner accumulates inside the image carrier drum 1 and the rotational load increases, the joint 3 receives a force in the direction away from the flange 2, and this force becomes stronger than the compression force of the spring 7. The engagement state between the flange 2 and the joint 3 is cut off, so that the joint 3 rotates idly. That is, the rotational driving force is not transmitted to the flange 2, and the image carrier drum 1 does not rotate. Also, since the gear 13 does not rotate,
The conveying coil 8 also does not rotate and toner is not conveyed. That is, the toner is not conveyed to the inner space of the image carrier drum 1. Further, reference numeral 15 is a microswitch disposed in the path in which the joint 3 moves due to an increase in load,
From the OFF state to the ON state due to the movement of joint 3,
A mini lamp or LED arranged on the operation unit is turned on to indicate that the image carrier drum 1 is filled with toner.

Another embodiment is shown according to FIG. Reference numeral 1 denotes a rotating image carrier drum, and the toner is collected and retained inside the image carrier drum 1 by the same mechanism as in FIG. The driving force transmitting means includes a flange 2, a driving gear 4, and a driving pin 19. The drive pin 19 is provided on the flange 2 of the image carrier drum 1.
Is arranged and engaged with the drive gear 4 to transmit the driving force. The drive pin 19 is always pushed by the lever 17 from the inside to the outside of the flange 2. Inside the image carrier drum 1, there is disposed a threshold member 21 having the same cross-sectional shape and movable in the arrow direction of FIG.
It moves in the direction of arrow B according to the amount of toner. When the amount of toner exceeds a certain amount, the threshold member 21 pushes one end of the lever 17. The lever 17 rotates about a support shaft 18, and the end pushing the drive pin 19 comes off. As a result, the drive pin 19 is disengaged from the engagement state with the drive gear 4 by the action of the compression spring 20. That is, a part of the drive transmission path is automatically cut off according to the amount of the collected toner. That is, as the stopping means for stopping the driving force by the driving force transmitting means,
21, a lever 17, and a compression spring 20 are provided.

As described above, according to the present invention, it is possible to automatically stop the conveyance of the residual material when the amount of the residual material reaches a predetermined amount without providing a sensor or the like inside the photosensitive drum. is there.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a toner collecting device using the present invention, FIG. 2 is a perspective view of a joint portion, and FIG. 3 is a sectional view showing another embodiment. 1 ... Image carrier drum, 2 ... Flange 3 ... Joint, 4 ... Drive gear 8 ... Transport coil

Claims (1)

[Scope of utility model registration request] 1. A rotatable image carrier drum for carrying an image, a transport means for transporting a residue removed from the image carrier drum into the image carrier drum, the image carrier drum and the image carrier drum. In an image forming apparatus having a driving force transmitting unit that includes an engaging unit that transmits a driving force to a conveying unit, when the amount of the residue conveyed inside the image carrier drum reaches a predetermined amount, An image forming apparatus comprising: a stopping unit that shuts off an engaged state and stops transmission of a driving force by the driving force transmitting unit.