JPH05232845A - Developer recycling device - Google Patents

Abstract

PURPOSE:To connect/separate a recycling pipe to/from a developing unit simply and securely and to prevent scattering of toner. CONSTITUTION:A coil-like shutter opening/closing spring 26 is attached to the recycling pipe 22 whose left end 22b is connected to a cleaner and right end is provided with a toner supply port 22a, and also a shutter 23 is fitted in its right side. A guide pin 24 is attached to the shutter 23, and is engaged with a cam 25 provided on the side cover 27 of a process cartridge. The cam 25 is composed of the cam 25a of a bottom part and the cam 25b of an inclined part. Via the guide pin 24 which reciprocates along the surface of the cam 25, the connecting/separating of the recycling pipe 22 to/from the developing unit is interlocked with the opening/closing of a toner supply port 22a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a developer recycling device provided in an image forming apparatus such as a copying machine or an image scanner.

[0002]

2. Description of the Related Art Generally, an electrophotographic image forming apparatus such as a copying machine or an image scanner comprises a platen on which a document is placed, a document irradiation lamp which reciprocates below the platen, a reflection mirror, and a fixed projection lens and a reflection mirror. A photosensitive drum that is endlessly rotated by a scanning optical system and a band electrode that are charged with a predetermined potential, and toner is applied to the electrostatic latent image formed on the surface of the photosensitive drum by the scanning optical system. A developing device for developing the toner image, a transfer electrode for transferring a toner image onto a recording paper surface which is a transfer material conveyed below the surface of the photosensitive drum, a separation electrode and a removing electrode, and the recording paper surface. The fixing device fixes the toner image transferred onto the surface of the photosensitive member, and the cleaning device removes the toner and paper dust remaining on the surface of the photosensitive member after the transfer. In a recent popular type copying machine, for example, a process cartridge in which a cartridge in which a belt electrode, a photosensitive drum, a cleaning device and the like are unitized and a developer cartridge which can be separated and connected to the cartridge are combined into one is used as an image forming apparatus. It's made so compact that it's removable.

The toner collected by the cleaning device is supplied to the developing device by the recycling device for reuse. Then, a required toner image is successively recorded on the recording paper surface which is intermittently conveyed along a predetermined conveying path.

[0004]

Generally, a recycle device is provided with a recycle pipe connected to a cleaning device and a developing device, and the toner collected by the cleaning device is conveyed by a conveying screw incorporated in the recycle pipe to the inside of the developing device. Is being supplied to.

Then, for example, when the developing device is repaired or replaced during maintenance of the image forming apparatus and the connection state between the developing device and the recycle pipe is released, toner in the pipe is inadvertently scattered and the inside of the image forming apparatus is damaged. Contaminates mechanical parts and optical system. As a countermeasure against such a problem, JP-A-52-14504
Although the technical means disclosed in Japanese Patent No. 3 is disclosed, since the shutter that opens and closes the toner supply port of the recycle pipe is rotated by friction, its operation is not always reliable and the structure is rather complicated. It is expensive.

The present invention solves the above problems and provides a developer recycling device capable of reliably contacting and separating the recycling pipe and the developing device and preventing the toner from scattering with a simplified structure. The purpose of the task.

[0007]

This object is to collect the toner remaining on the surface of the image carrier after transfer in an image forming apparatus having at least an image carrier, a developing device and a cleaning device and supply it to the developing device. In the recycling device, a connecting portion between the recycling device and the developing device has one end connected to the cleaning device and the other end having a toner supply port, and a recycle pipe that comes in contact with and separates from the connecting portion of the developing device. A shutter that is slidably fitted to open and close the toner supply port, an elastic member that slides the shutter, a guide pin that is implanted in the shutter, and a cam that engages with the guide pin, The developer recycling device is characterized in that the cam for interlocking the contact and separation of the recycling pipe with the developing device and the opening and closing of the shutter are provided on a plate body standing upright in the vicinity of the developing device. It is achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is a side view showing the structure of a contact / separation mechanism of a recycling pipe with respect to a developing device, a top view showing the connection state of the developing device and the recycling pipe of FIG. 2, and an image forming apparatus of FIG. Will be described with reference to a side sectional view showing the structure of FIG.

However, the present invention is not limited to this embodiment.

As shown in FIG. 3, an electrophotographic image forming apparatus 18 is provided.
A platen glass P for placing a document M is provided on the upper surface of the main body 1, and a scanning optical system 2 is provided below the platen glass P in the main body 1. The scanning optical system 2 includes a reciprocating document irradiation lamp 2a, a first mirror 2b, second and third mirrors 2c forming a V shape, and a fixed lens 2.
d and the fourth mirror 2e. A photosensitive drum 3 is rotatably provided in the direction of the arrow at the center of the inside of the main body 1, and a belt electrode 4 for uniformly charging the photosensitive body 3a along the rotation direction is provided around the photosensitive drum 3, and a toner replenishing device. 5, a developing device 6 in which toner is replenished and a developing sleeve 31 is built in, a transfer electrode 7, a separation electrode 8, a charge eliminating electrode 9, and a cleaning device 10 are sequentially arranged. Paper feed cassette 11, 11 '
In the main body 1, two types of recording papers of different sizes are housed and stored in the main body 1. Reference numeral 12 denotes a first paper feed roller that feeds the recording paper stored in the paper feed cassette 11 to a standby position before the second supply roller 13, and rotates via a belt to prevent double feeding of the recording paper. Rollers 12a, 12a
And a stop roller (also referred to as a separating roller) 12b. The reference numeral 13 temporarily stops the recording paper fed by the first paper feed roller 12 at the standby position, and then the photoconductor 3
A second paper feed roller that feeds paper again toward the transfer position at an appropriate timing so that the front end of the visible image on a and the front end of the recording paper coincide with each other at the transfer position. A guide plate for guiding the formed recording paper to the position of the second paper feed roller 13, which is opened and closed by operating a lever (not shown) so that the jammed paper can be taken out by inserting a hand. .. Reference numeral 15 is a conveying device that conveys the recording paper after transfer to a fixing position, and the fixing device 16 is a heating roller 16a.
And a pressure roller 16b. Reference numeral 17 denotes a paper discharge roller that discharges the recording paper after fixing to the outside of the main body.

As shown in the drawing, a first cartridge 20 containing the belt electrode 4, the photosensitive drum 3, and the cleaning device 10, a second cartridge in which the developing device 6 and the toner replenishing device 5 are unitized. Process cartridge which is divided into two parts such as 30 so that they can be separated from each other and combined.
40 is detachably attached to the image forming apparatus 18. A pipe (not shown) of a recycle device is connected between the cleaning device 10 in the first cartridge 20 and the developing device 6 in the second cartridge 30.

When the copy button is operated in the above apparatus, the original M on the platen glass P is exposed and scanned by the scanning optical system 2, and an electrostatic latent image of the original M is formed on the photoconductor 3a of the photoconductor drum 3. It This electrostatic latent image is made into a visible image by the developing device 6, and this visible image is the paper feeding cassette of the main body 1.
Transfer electrode 7 is applied to recording paper fed from either 11 or 11 '.
Transcribed by After the transfer, the recording paper is separated from the photoconductor 3a by the separation electrode 8 and is fixed by the conveyance device 15 to the fixing device 16
The sheet is conveyed to the sheet, is fixed there, and is ejected by the sheet ejection roller 17. In this way, the required toner images are successively recorded on the recording paper surface.

After the transfer, the residual toner adhering to the peripheral surface of the photosensitive drum 3 is scraped off by the blade of the cleaning device 10, once collected in the cleaning device 10, and then developed by a recycling device (not shown). It is supplied into the container 6 and used again.

The contact / separation mechanism of the recycle pipe with respect to the developing device 6 of the present invention is constructed as follows.

As shown in FIGS. 1 and 2, the contact / separation mechanism 21 between the recycle pipe 22 and the developing device 6 provided in the recycle device has a left end 22b connected to the cleaning device 10 and a right end formed in a rectangular shape. The toner supply port 22a is swingable so as to come in contact with and separate from the connecting portion 6a of the developing device 6, a shutter 23 fitted into the recycle pipe 22 to open and close the toner supply port 22a, and the shutter 23. A guide pin 24 to be implanted, a shutter opening / closing spring 26 for elastically sliding the shutter 23, and a process cartridge.
The cam 25 is provided on the side cover 27 of 40 and is engaged with the guide pin 24.

The recycle pipe 22 is a bendable pipe made of, for example, a synthetic resin material. The pipe end on the right side is closed and a part of the peripheral surface of the right end portion is formed into a rectangular shape as shown in the figure. A toner supply port 22a that opens is provided. Then, the toner collected by the cleaning device 10 is conveyed to the toner supply port 22a by the flexible conveyance screw 22C (FIG. 2) in the recycle pipe 22 and from the toner supply port 22a through the opening of the connecting portion 6a of the developing device 6. It is being supplied.

A coil-shaped shutter opening / closing spring 26 is fitted to a predetermined position on the left side of the outer peripheral toner supply port 22a of the recycle pipe 22, and the left end thereof is a recycle pipe.
The right end portion is integrally fixed to the peripheral surface of 22 and abuts on the left end surface of the shutter 23 fitted to the outer periphery of the recycling pipe 22.

The shutter 23 is a slender ring-shaped molding member made of, for example, a synthetic resin material, the inner diameter of which is slidably fitted to the outer diameter of the recycle pipe 22, and the length of which is rectangular. Is long enough to cover the longitudinal dimension of the.

A guide pin 24 is integrally formed at a predetermined position on the outer peripheral surface of the shutter 23 so as to engage with a cam 25 described later. As shown in FIG. 1, the cam 25 is formed into an L-shape in which the cam surface is continuous by the cam 25a at the bottom and the cam 25b at the inclined portion. For example, the guide pin 24 is provided to penetrate the side cover 27 of the process cartridge 40. Are engaged to slide on the surface of the cam 25. The recycling pipe 22 is provided in the left-right direction along the inside of the side cover 27 (the direction perpendicular to the paper surface) as shown in the figure. Then, when the guide pin 24 is positioned on the right end abutting surface of the cam 25a at the bottom of the cam 25, the shutter is released.
A predetermined pressing force is applied to the shutter opening / closing spring 26 to open the toner supply port 22a of the recycle pipe 22, and the toner supply port 22a is brought into contact with the connecting portion 6a of the developing device 6. Further, when the guide pin 24 is positioned on the right end abutting surface of the cam 25b of the inclined portion, the recycling pipe 22 is separated from the connecting portion 6a by the shutter 23 and the toner supply port 22a is closed. Therefore, as shown in the figure, the cam 25a at the bottom of the cam 25 and the cam 25 at the inclined portion
b The vertical distance H of each right end (abutting portion of the guide pin 24) is a stroke for separating the recycling pipe 22 from the developing device 6, and the difference D in length in the left-right direction is an operating stroke of the shutter 23. ing. As shown in FIG. 2, the guide pin 24 has a knob 28 integrally attached to the outside of the side cover 27 (downward in the drawing).
The shutter (including the shutter 23) is manually slid on the surface of the cam 25.

The recycle pipe 22 thus configured
The interlocking between the contact and separation of the developing device 6 with the opening and closing of the shutter 23 is operated as follows. That is, for example, when releasing the connection between the recycling pipe 22 and the developing device 6 at the time of maintenance or repair of the developing device 6, the user simply slides the knob 28 to the left in the direction of the arrow to locate the cam 28a on the bottom side. The guide pin 24 moves along the surface of the cam 25a, and at the same time, the shutter 23 also slides to the left on the outer peripheral surface of the recycling pipe 22 against the elasticity of the shutter opening / closing spring 26.

Then, the guide pin 24 is connected to the cam 25b of the inclined portion.
When the shutter 23 is positioned at, the shutter 23 automatically starts moving diagonally upward to the right due to the elastic force of the shutter opening / closing spring 26. The toner supply port 22a of the recycle pipe 22 also begins to separate from the continuous portion 6a of the developing device 6 via the shutter 23, and the toner supply port 22a is released by the shutter 23.
Start closing 22a. Then, the elastic force of the shutter opening / closing spring 26 causes the guide pin 24, which moves diagonally rightward and upward along the surface of the cam 25b of the inclined portion, to come into contact with the abutting surface of the right end portion of the cam 25b and stop to move diagonally upward right. The shutter 23 separates the recycle pipe 22 from the predetermined position above the developing device 6 and closes the toner supply port 22a.

When maintenance or repair is completed and the recycling pipe 22 and the developing device 6 are returned to the connected state, the guide pin 24 is operated by the reverse operation to the guide pin 24 so that the shutter opening / closing spring is opened. The cam 25b at the inclined portion is moved against the elastic force of 26 and moves to the cam 25a at the bottom portion, and then the elastic force of the shutter opening / closing spring 26 makes contact with the abutting surface of the right end portion of the cam 25a at the bottom portion.

Then, the toner supply port 22a of the recycle pipe 22 is opened by the shutter 23 and is brought into contact with the connecting portion 6a of the developing device 6. In this way, the shutter 23 reciprocating along the cam 25 makes contact and separation between the recycling pipe 22 and the developing device, and at the same time, the toner supply port 22a of the recycling pipe 22 is opened and closed in conjunction with this contact and separation operation. Therefore, the operation is reliably performed, and the toner scattering into the image forming apparatus 18 is prevented.

The cam 25 is not limited to the side cover 27 of the process cartridge 40 described above, but may be provided on an appropriate side plate or frame in the image forming apparatus 18. Further, for example, the photosensitive drum 3 which is not made into a cartridge
Even when the developing device 6 and the developing device 6 are separately mounted in the image forming apparatus 18, the gist of the present invention is naturally applied.

[0025]

EFFECTS OF THE INVENTION With a simplified contact / separation mechanism that interlocks the contact / separation of the recycle pipe and the opening / closing of the toner supply port with respect to the developing device of the present invention, for example, in the case of releasing the connected state at the time of repair or maintenance of the developing device, one-touch operation. Since the toner supply port is closed at the same time that the recycle pipe is reliably separated from the developing device, not only the operation is extremely easy, but also toner scattering in the image forming apparatus is prevented. Further, when the recycling pipe is connected to the developing device, the toner supply port is surely opened.

[Brief description of drawings]

FIG. 1 is a side view showing a structure of a contact / separation mechanism of a recycling pipe with respect to a developing device according to an embodiment of the present invention.

FIG. 2 is a top view showing a connected state of a developing device and a recycle pipe according to one embodiment of the present invention.

FIG. 3 is a side sectional view showing the configuration of the image forming apparatus.

[Explanation of symbols]

 3 Photoconductor drum 6 Developing device 6a Connection part 10 Cleaning device 18 Image forming device 22 Recycle pipe 22a Toner supply port 23 Shutter 24 Guide pin 25 Cam 25a Bottom cam 25b Inclined cam 26 Shutter opening / closing spring 27 Side cover

Claims (1)

[Claims] 1. A recycling device for recovering the toner remaining on the surface of the image carrier after transfer in an image forming apparatus having at least an image carrier, a developing device and a cleaning device and supplying the toner to the developing device. One end of the connecting portion between the apparatus and the developing device is connected to the cleaning device, and the other end portion has a recycle pipe that has a toner supply port and comes in contact with and separates from the connecting portion of the developing device, and is slidably fitted to the pipe. A shutter for opening and closing the toner supply port, an elastic member for sliding the shutter, a guide pin implanted in the shutter, and a cam with which the guide pin engages. A developer recycling device characterized in that the cam for interlocking contact and separation with opening and closing of a shutter is provided on a plate standing upright near a developing device.