JPS61149979A - Separating device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To perform stable separation even when the environment changes by separating transfer paper from on a photosensitive body by using a sticky separating roller. CONSTITUTION:A toner image on the photosensitive drum 1 is transferred to the transfer paper 3 by a transfer charger 2 and the separating roller is driven synchronously where the front end of the transfer paper advances to a separation position, so that the top of the surface 4a of a cylinder abuts on the front end of the transfer paper 3. Then, the front end of the transfer paper 3 is clamped between the photosensitive drum 1 and sticky cylinder surface of the separating roller 4 and drawn with its adhesive strength, and the transfer paper 3 is separated from the photosensitive drum 2 continuously according to the rotation of the separating roller 4; and the transfer paper 3 separates from the separating roller 4 by its own elasticity when the separating roller 4 rotates to some extent and the separating roller 4 stops rotating with its sticky flat surface 4b opposite the photosensitive drum 1. Then, the transfer paper 3 is separated according to the rotation of the photosensitive drum 1 without being restrained by the separating roller 4 and then conveyed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for separating transfer paper from a photosensitive drum (image bearing member) after toner transfer in an electrophotographic copying machine.

Generally, the most commonly used separation device for electrophotographic copying machines is one based on the corona static elimination separation method. However, the separation equipment using this method is delicately affected by changes in environmental characteristics over time, so-called
A defective transferred image called transfer missing may occur. Furthermore, in terms of cost, the corona static elimination separation device requires a high-voltage power supply and a static elimination charger system, so it occupies a considerable amount of cost relative to its functionality.

1 sail The present invention does not use a separate charger.

The present invention aims to provide a new device that can easily and reliably separate the transfer paper from the photoreceptor drum after toner transfer.

The separation device for an electrophotographic copying machine according to the present invention is such that an adhesive separation member is bonded to the back surface of the transfer paper after the toner image on the photoreceptor drum has been transferred, and is moved in a direction away from the surface of the photoreceptor. This device separates transfer paper, and will be explained below according to an embodiment shown in the drawings.

FIG. 1 is a schematic sectional view showing a state immediately before the transfer paper is separated from the photoreceptor in a separation device according to the present invention, and FIG. 2 is a schematic sectional view showing the state where the leading edge of the transfer paper is about to separate.
FIG. 3 is a schematic sectional view showing the state after the leading edge of the transfer paper is separated from the photoreceptor, and FIG. 4 is a perspective view showing the schematic configuration of the apparatus.

After the photoreceptor drum (image carrier) l transfers the developing toner on the photoreceptor drum onto the transfer paper 3 by the transfer charger 2,
In order to separate the transfer paper 3 from the photoreceptor drum after the transfer charger 2, in place of the normally used separation belt or separation charger, in the present invention, a semicircular separation roller is provided at the separation position. 4 are provided.

This half-moon-shaped separation roller 4 has the shape of a cylindrical body cut in half vertically, the cylindrical surface 4a is made of an adhesive material, and the half-cut flat surface 4b is a non-adhesive surface,
It is rotatable around the cylindrical central axis 4C, and the cylindrical surface 4a
is disposed at a position in contact with the back surface of the transfer paper 3 that is attached to the photoreceptor drum 1 and transferred. That is, the cylindrical surface 4a of the half-moon-shaped separation roller 4 holds the photoreceptor tram l with the transfer paper 3 in between.
In the case of contact with the photoreceptor drum l, the cylindrical surface 4a contacts the photoreceptor drum l via the transfer paper 3 with zero gap.
Setting conditions, driving torque,
It is also effective when considering the side effects of impact. A good hardness is about 20 to 50 degrees.

There are various possible adhesive substances for the cylindrical surface 4a, for example: (1) Si roller manufactured by Shin-Etsu Chemical used in the Nagaoka record cleaner roller.

(2) A configuration in which a foamed elastic material is impregnated with an adhesive on the surface of a half-moon-shaped cylinder.

(3) Rubber adhesive (Picolite S-
70), etc. may be used.

Next, the procedure for separating the transfer paper 3 from the photoreceptor drum l will be explained step by step.

The toner image on the photoreceptor drum l is transferred to the transfer paper 3 by the transfer charger 2, and then, when the leading edge of the transfer paper advances to the separation position, the separation roller 4 is rotationally driven in synchronization with this, and the cylindrical surface The leading edge of the transfer paper 4a comes into contact with the leading edge of the transfer paper 3 (see FIG. 1). Therefore, the leading edge of the transfer paper 3 is sandwiched between the photoreceptor drum 1 and the adhesive cylindrical surface of the separation roller 4.
It is attracted by its adhesive force and follows the rotation of the separation roller 4.

The leading edge of the transfer paper 3 is separated from the photosensitive drum 1.

Subsequently, the transfer paper continues to be separated as the separation roller rotates (see Figure 2), and when the separation roller 4 has rotated to a certain extent, the stiffness of the transfer paper causes the transfer paper itself to separate from the separation roller 4. Become. Thereafter, the separation roller 4 stops rotating in the state shown in FIG. 3, that is, with the non-adhesive flat surface 4b facing the photosensitive drum I. Therefore, the transfer paper is not bound by the separation roller 4 and is separated as it is conveyed from the photosensitive drum 1 by its own rigidity.

After the leading edge of the transfer paper 3 is separated from the photoreceptor drum l,
After following the movement of the sticky surface of the half-moon separation roller 4 for a while, it separates due to the rigidity of the transfer paper.

After separating from the semicircular separation roller, the transfer paper 3 falls and is conveyed by its own weight, so that the semicircular separation roller 4 is moved so that the non-adhesive flat surface 4b is connected to the photoreceptor drum 1 and the transfer paper as shown in FIG. When stopped facing the paper 3, the separated transfer paper 3 is conveyed on the non-adhesive surface.

What should be noted here is that it is important that the separation roller 4 has an appropriate adhesion force that prevents the transfer paper from being rolled up as the separation roller rotates due to the adhesion force of the separation roller.

FIG. 4 is a three-dimensional diagram showing the configuration of the separating device according to the present invention, in which rotation is transmitted to the separating roller 4 from a drive system via a clutch 5;
The length is set to the minimum transfer paper size width Q. The reason for this is that if the length is longer than that, the toner on the photoreceptor that adheres to areas other than the size of the transfer paper will adhere to the adhesive cylindrical surface 4a of the separation roller that comes into contact with it during separation, and the separation function will be lost. This is because it will disappear.

Note that the separating device according to the present invention does not use a half-moon separation roller, but after abutting and joining the adhesive member to the leading edge of the transfer paper,
It may be configured to move in a direction away from the photoreceptor surface at the same speed and then stop peeling.

As mentioned above, in the present invention, the adhesive separation roller is used to separate the transfer paper from the photoreceptor, so the simple structure makes it stable over time and against environmental changes. It is possible to provide a relatively inexpensive separation device that can perform separation without side effects such as transfer omission while satisfying the above separation performance and image quality.

[Brief explanation of drawings]

The drawings show a separation device according to the invention, FIG.
A schematic sectional view showing the state immediately before the transfer paper separates from the photoreceptor, Figure 2 is a schematic sectional view showing the state where the leading edge of the transfer paper is separating, and Figure 3 shows the state after the leading edge of the transfer paper has separated from the photoreceptor. FIG. 4 is a schematic cross-sectional view showing the state of the device, and FIG. 4 is a perspective view showing the schematic configuration of the device. 1... Photosensitive drum, 2... Transfer charger. 3... Transfer paper, 4... Half-moon separation roller,
4a... Adhesive cylindrical surface, 4b... Non-adhesive flat surface, 4c... Rotating shaft, 5... Clutch, a...
・Minimum size width of transfer paper.

Claims (2)

[Claims] (1) After the toner image on the image carrier is transferred to the transfer paper, a member made of an adhesive material is brought into contact with and adhered to the back surface of the transfer paper, and as the transfer paper advances, the adhesive separation member is A separation device for an electrophotographic copying machine, characterized in that a transfer paper is separated from an image carrier by movement. (2) The adhesive separation member is composed of a half-moon-shaped roller, and when the leading edge of the transfer paper enters the separation position, the adhesive cylinder of the separation member is activated at a timing detected in advance by the transfer paper leading edge position detection means. The surface is in contact with the transfer paper, and while it is adhered, it is rotated at the same speed as the conveyance speed of the transfer paper, and after separation, the half-moon roller is stopped with the non-adhesive flat part facing the image carrier. , claim 1
Separation device for an electrophotographic copying machine as described in .