JPS61230179A - Driving device for sheet separating claw - Google Patents

Abstract

PURPOSE:To obtain a separation claw driving device of simple structure which has no mechanical coupling part and is easy in timing adjustment by providing an abutting part to a separation claw or a separation claw driving shaft to which the separation claw is fitted and providing an electromagnetic driving means which abuts on the abutting part. CONSTITUTION:When a switch SW is on, the separation claw 2 is pressed against an image carrier drum 1 because a movable piece 4 is moved down by an electromagnetic driving means (solenoid) 3 to lower the abutting member 6 fitted to a driving shaft 5 with the tension of a spring 7. A transfer sheet is separated from the drum 1 by the separation claw 2 as shown by a chain line S. When the switch SW is turned off, the movable piece 4 moves up to press up the abutting member 6, so the abutting claw 2 rotates as shown by an arrow (b) and is released from being pressed against the drum 1. The switch SW is turned on and off with a signal from a control part 8, so the timing is easily adjusted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a separation claw for separating a transfer sheet from an image carrier such as a photoreceptor drum in an electrostatic recording device such as an electronic copying machine or a laser printer. 〇 [Traditional technology] In the driving device of the driving device, the electronic copier and the laser printer, etc., form a static electronics image on images such as the photosenshu drums with a light conductor layer. Then, the obtained toner image is transferred to a transfer sheet such as paper and the desired ff! I'm getting something valuable.

During the transfer, the transfer sheet is electrostatically attracted to the surface of the image carrier, and the toner image is transferred to the surface of the transfer sheet by a corona discharge of opposite sign to the toner applied from the back side of the transfer, and the transfer is completed. After the transfer is completed, the transfer sheet is separated from the image carrier surface. To promote separation, a method such as applying an AC corona discharge from the back side to eliminate static electricity is used, but in order to ensure separation, the transfer material is further separated from the surface of the image carrier. There is a separation claw that can be used to pull it off.

The separation claw is a member with a thin tip provided so that its tip comes into pressure contact with the surface of the image carrier, and its tip cuts between the transfer sheet and the surface of the image carrier to separate the two. However, if the separation pawl is in constant pressure contact with the image carrier surface, the image forming layer in that area will wear out and be scratched, resulting in failures such as strong vertical lines on the screen. Only when the separation claw comes into pressure contact with the image carrier,
In addition, a drive mechanism is provided that operates to release the pressure contact.

Conventionally, the separation claw is driven to press against and release from the image carrier surface by directly connecting the rotating shaft from the power source of the electrostatic recording device main body to the drive shaft of the separation claw, but the structure becomes complicated. Another disadvantage is that during assembly, it is difficult to match the timing of pressing and releasing with respect to the movement of the transfer sheet.

In addition, in recording devices that have been widely used in recent years, in which the body is divided into upper and lower parts along the transfer sheet passage surface and can be opened, it is difficult to provide such a mechanical structure around the image bearing drum. [Problems to be Solved by the Invention] The present invention provides a separation claw drive device that has no mechanical coupling parts (has a simple structure and is easy to adjust timing). This is what we are trying to provide.

[Means to solve the problem]

The above problem is solved by a separation claw driving device characterized by having a contact portion provided on the separation claw or a separation claw drive shaft to which the separation claw is attached, and a drive means that contacts the corresponding contact portion. We were able to.

Although a mechanical device such as a cam may be used as the drive means, an electrical drive source such as a solenoid plunger that can be used independently is preferable.

The abutment portion on the separation claw side that the drive portion of the drive means comes into contact with may be integral with the separation claw (or may be provided on the drive shaft to which the separation claw is attached).

[Effect]

The operation of the separating claw drive device according to the present invention will be explained below with reference to Examples.

tx1 is a diagram showing an example of a separating claw drive device according to the present invention, and 1 in the figure is an image carrier drum, which rotates in the direction of arrow 1. 2 is a separation claw.

Numeral 3 is an electromagnetic drive means, ie, a relay type solenoid, which lowers the movable piece 4 when the switch SW is turned on. The separation claw 2 is fixed to a drive shaft 5, and an abutment member 6 is provided at the end of the drive shaft 5. The drive shaft extends parallel to the image carrier drum to the rear side of the screen, and a separation claw of the same type as the separation claw 2 is attached to the end of the drive shaft, but it is not shown in the figure.

Further, the drive shaft 5 is biased by a spring 7 in a direction to press the separation claw 2 against the image carrier drum 1.

The figure shows a state in which the switch SW is ON, that is, a state in which the separating claw is in pressure contact with the image carrier drum 1. The transfer sheet to which the toner image has been transferred from the image carrier drum 1 is separated by a separating claw as indicated by a chain line S, and then proceeds to the next step. When the switch SW is turned OFF, the movable piece 4 is raised and the abutting member 6 is pushed up, so that the separating claw 2 rotates in the direction of the arrow A, and the pressure contact with the image carrier drum 1 is released.

The switch SW may be configured to be turned ON and OFF by a signal from the control unit 8 of the recording apparatus main body.The ON-OFF timing of the switch SW, that is, the timing of the pressure contact and release of the separation claw, is based on the conveyance of the transfer sheet. For example, the control sequence is set so that the starting point is the activation of the registration roller for transporting the transfer sheet, and the SW is turned on after a delay of the time until the leading edge of the transfer sheet pierces the point to be separated. Just leave it there.

It is preferable that the pressure contact time of the separating claw be as short as possible from the viewpoint of abrasion of the image carrier surface, and after the separation of the leading edge of the transfer sheet has started, it is better to release the pressure contact by turning the switch s w 9I: OFF. If the leading edge of the transfer sheet separates and rides on the separation claw, separation will proceed smoothly even if the pressure contact is released.

As is clear from the above description, the separation claw drive device of the present invention has an extremely simple structure and reliable operation. Also, one feature of this device is that it can be easily separated by simply touching the separation claw part and the drive source part, and the main body can be divided into upper and lower parts and opened to check the inside of the busy recording device. It is particularly suitable for applications such as

FIG. 2 shows an example of this, in which the separating claw 2 is connected to the image carrier drum 1.
The solenoid 3 is attached to the upper body 21, and the solenoid 3 is attached to the lower body 21. When the device is closed, the separation claw 2 and the solenoid 3 are in the state shown in FIG. 1, and are ready for operation.

〔Effect of the invention〕

According to the present invention, there has been obtained a separation claw driving device which has an extremely simple structure and can easily set the timing for bringing the separation claw into and out of pressure contact with the image carrier. Further, the separating claw drive device of the present invention is suitable for use in an upper and lower split type electrostatic recording device.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a separating claw driving device of the present invention, and FIG. 2 is a diagram of an electrostatic recording device of an upper and lower split type to which the separating claw driving device of the present invention is attached. 1... Image carrier drum 2... Separation claw 3... Solenoid 5... Drive shaft 6... Contact member applicant Konishi Rokusha Kogyo Co., Ltd. Figure 1

Claims (3)

[Claims] (1) In a separation claw drive device that separates a transfer sheet from an image carrier surface of an electrostatic recording device, a contact portion provided on the separation claw or a separation claw drive shaft to which the separation claw is attached, and a corresponding contact portion. A sheet separation claw drive device, characterized in that it has a drive means that comes into contact with it. (2) The sheet separating claw driving device according to claim 1, wherein the driving means is an electromagnetic driving means. (3) The sheet separating claw driving device according to claim 1, wherein the driving means and the separating claw can be separated from each other.