JPH02754Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an image forming apparatus such as a copying machine or a printer using electrophotographic technology, and particularly relates to a paper separation device.

[Prior art and drawbacks]

FIG. 1 is a block diagram of a copying machine for explaining a conventional separation device.

A separation belt 2 is provided at the bottom of the photoreceptor drum 1,
The separation belt 2 has one end fixed to the main body fixing part 3, and the other end attached to the belt spring 4, and the other end of the belt spring 4 is fixed to the main body with tension applied to the belt spring 4. Therefore, the separation belt 2 is always in contact with the outer periphery of the photosensitive drum 1 with a constant pressure.

On the other hand, the claw 5 is a mechanism that uses the claw fulcrum 5a as a fulcrum and moves toward and away from the ratchet 7 as the solenoid 6 turns on and off.When the paper 8 is not conveyed, the solenoid 6 is turned off and the claw 5 is pressed against the ratchet 7. The rotation of the registration roller 10a is stopped. When conveying the paper 8, the solenoid 6 operates to release the claw 5 from the ratchet 7. As a result, the paper 8 passes between the registration rollers 10a and 10b, and is carried between the transfer device 9 and the photosensitive drum 1. Further, after the image on the photosensitive surface is transferred onto the paper 8, the separation belt 2 provided between the photosensitive drum 1 and the paper 8 separates the photosensitive drum 1 and the paper 8, and the paper 8 is conveyed in the direction of the arrow.

However, in the case of such a device, since the separation belt 2 is always in contact with the outer circumferential photosensitive surface of the photoreceptor drum 1 and rotates, the photoreceptor drum 1 is worn out only in the contact portion of the separation belt 2, causing pieces of the photoreceptor drum 1 to be damaged. The outer periphery of the photoreceptor drum 1 is easily worn and scratched, and the separation belt 2 itself is also worn and has a short lifespan. Furthermore, when the photoreceptor drum 1 is taken in and out of the copying machine to replace the photoreceptor drum 1, etc., the separation belt 2 must be separated from the outer periphery of the photoreceptor drum 1, or the separation belt 2 must be
must be removed, making it difficult to work.

[Purpose of invention]

In view of the above-mentioned conventional drawbacks, the present invention proposes a separation device that extends the life of the photoreceptor drum and separation belt, and improves the workability of removal work even when maintenance such as removing the photoreceptor drum is required. The purpose is to provide.

[Key points of the idea]

In order to achieve the above object, the present invention includes an image carrier and a registration roll that delivers a transfer paper in synchronization with the image on the image carrier, and the transfer paper that is delivered by the registration roll. and a separating device for separating the transfer paper from the image carrier by interposing a flexible member between the image carrier and the image carrier,
A rotating member, a spring clutch that transmits the rotational force of the rotating member to the registration roll, a pawl member that disconnects and connects the spring clutch through contact or non-contact with the spring clutch, and the pawl member that An electromagnetic means that is coupled to bring the pawl member into contact with or out of contact with the spring clutch, and a connecting means that connects one end of the flexible member to the pawl member are provided, and the electromagnetic means is connected to the spring clutch, and the electromagnetic means is connected to the spring clutch. It is characterized in that when the spring clutch is disengaged, the flexible member is relaxed and the flexible member is tensioned in a connected manner.

[Example of idea]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a block diagram of a separation device according to the present invention.

In the figure, a separation belt 12 is provided below the photoreceptor drum 11, one end of the separation belt 12 is fixed to the main body fixing part 13, and the other end is fixed to the spring clutch 14.
It is attached to the tip 15a of the claw 15 that turns on and off.

On the other hand, a spring clutch 14 is provided on the shaft of the registration roller 16a to turn on and off the drive of the registration roller. A drive gear 17 transmitted from another drive system (not shown) of the main body is engaged with the input side of the spring clutch 14.
4 is provided with a ratchet 18 for turning it on and off. The spring clutch 14 is a conventionally known spring clutch, and the coil spring contained in the ratchet 18 is tightened by keeping the claw 15 out of contact with the ratchet 18, thereby transmitting the driving force of the drive gear 17 to the registration roller 16a. Shi, Tsume 15
By contacting the ratchet 18, the coil spring is loosened and the transmission of the driving force of the drive gear 17 to the registration roller 16a is cut off. The pawl 15 moves toward and away from the ratchet 18 using the pawl fulcrum 15b as a fulcrum as the solenoid 19 turns on and off. The spring 20 has a claw 15 when the solenoid is turned off.
This is for pressing the plate against the ratchet 18.

The paper separating operation in the separating apparatus having the above configuration will be explained below using the time chart shown in FIG.

In the figure, high indicates that each device is on, and low indicates that each device is off. However, for the separation belt 12, a high value indicates that it is in contact with the photoreceptor drum 11, and a low value indicates that it is in a non-contact state with the photoreceptor drum 11.

When a print key (not shown) is turned on, the main motor rotates and the photosensitive drum 11 starts rotating. At the same time, by turning on the paper feed clutch, the paper feed roller rotates and the optical system also starts moving forward. At this time, since the solenoid 19 is in an off state, the separation belt 12 is not in contact with the photosensitive drum 11, and the registration rollers 16a and 16b are stopped.

That is, FIG. 4 is a configuration diagram of the separating device showing this state. When the solenoid 19 is in the off state, the pawl 15 engages with the ratchet 18, the spring clutch 14 is in the off state, and the registration rollers 16a and 16b are in the off state. It's stopped. At this time, the separation belt 12 is not in contact with the photoreceptor drum 11 and there is some slack.

Next, the solenoid 19 is turned on by turning on the timing switch activated by forward scanning of the optical system, and the separation belt 12 comes into contact with the photoreceptor drum 11.
Registration rollers 16a and 16b start rotating. That is, FIG. 5 is a configuration diagram of the separation device showing this state, in which the engagement between the pawl 15 and the ratchet 18 is released, the spring clutch 14 is turned on, and the registration rollers 16a, 16b start rotating, and at the same time the separation occurs. The belt 12 contacts the outer periphery of the photoreceptor drum 11. Therefore, the paper that has passed between the registration rollers 16a and 16b is carried between the photoreceptor drum 11 and the transfer device 21, and after the image on the photoreceptor drum 11 is transferred, the paper is transferred to the separation belt 12.
It is separated from the photoreceptor drum 11 while being guided by.

Next, the optical system finishes forward scanning and moves on to backward scanning. When the trailing edge of the paper passes between the registration rollers 16a and 16b, the solenoid 19 is turned off to stop the registration rollers 16a and 16b. At the same time, the separation belt 12 separates from the photosensitive drum 11.

Next, the optical system finishes backward scanning and moves on to forward scanning for the second sheet. The same operation as described above is performed for the second and subsequent sheets.

In the present invention, as described above, the separation belt 12 contacts the photoreceptor drum 11 only when it is necessary to separate sheets, and is separated from the photoreceptor drum 11 when the separation function is not required. This device uses registration rollers 16 to synchronize the image on the photosensitive drum 11 with the paper.
By attaching one end of the separation belt 12 to the claw 15 that is linked to the operation of the solenoid 19 that turns on and off the a and 16b, this is a rational device in which the photosensitive drum 11 and the separation belt 12 come into contact only when the solenoid is on. be.

Further, when replacing or cleaning the photoreceptor drum 11, the photoreceptor drum 11 is moved in the direction A or B as shown in FIG. 2 and taken out from the copying machine main body.
Since it is separated from the photoreceptor drum 11, it is possible to take out the photoreceptor drum 11 as it is.

[Effect of idea]

According to the present invention with the above configuration, the life of the separation belt is extended without damaging the photoreceptor drum, and
Furthermore, since there is no need to worry about loosening or removing the separation belt when replacing the drum, there is no need for a drive source, control circuit, etc. for loosening the separation belt.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional separation device, Fig. 2 is a configuration diagram of a separation device according to the present invention, Fig. 3 is a tire chart diagram, and Fig. 4 is a configuration diagram of the separation device according to the present invention in which the solenoid is in an OFF state. FIG. 5 is a configuration diagram showing the solenoid in the OFF state in the separation device according to the present invention. 11... Photosensitive drum, 12... Separation belt,
13... fixed part, 14... spring clutch,
15... claw, 16a, 16b... registration roller, 17... drive gear, 18... ratchet, 1
9... Solenoid, 20... Spring, 21...
...Transfer device.

Claims (1)

[Scope of utility model registration request] It has an image carrier, and a registration roll that sends out a transfer paper in synchronization with the image on the image carrier, and a flexible material is provided between the transfer paper sent out by the registration roll and the image carrier. In a separating device that separates the transfer paper from the image carrier using a member, a rotating member, a spring clutch that transmits the rotational force of the rotating member to the registration roll, and contact/non-abutment between the spring clutch and the rotating member are provided. a pawl member that disconnects and connects the spring clutch by contacting the spring clutch; an electromagnetic means that is connected to the pawl member and brings the pawl member into or out of contact with the spring clutch;
coupling means for coupling one end of the flexible member to the pawl member, the flexible member being relaxed when the spring clutch is disengaged in conjunction with the operation of the electromagnetic means; A separation device characterized by tensioning a sexual member.