JPS641024B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to an electrostatic recording device, and more particularly to an electrostatic recording device that improves transfer from a transfer belt to a copying material.

(Prior art) In a device that once transfers a toner image formed on an electrostatic recording medium to an intermediate transfer belt, and then transfers and fixes this transferred image to copy paper, the intermediate transfer belt includes a transfer part pressing roller, a heat roller, etc. The toner is wrapped around a fixing roller, a tension roller, and an auxiliary roller, and in the fixing section, the toner is melted and fixed onto the copy material by heat.

In order to enhance the transfer effect to the copying material and improve the speed of transfer and fixing, it is required to increase the heating efficiency of the transferred image on the intermediate transfer belt and to enhance the transfer and fixing effect to the copying material.

In order to sufficiently heat the toner that forms the transferred image, and to extend the contact time with the heating member, a belt is passed around rollers provided at both ends of the heating member, and the belt is passed over the heating member in close contact with the copying material. A sliding type can be seen (Special Publication No. 46-41679).
However, it is difficult to slide the belt over such a spread heating member with the copying material in close contact with it, especially when the copying speed is increased, to obtain a stable and good transferred and fixed image. Become.

(Problems to be Solved by the Invention) Heating, transfer, and fixing are preferably performed using a pressure roller, but the contact between the roller and the belt depends on the angle of the belt when it enters and leaves the roller. For example, if this angle is made smaller so that they are almost parallel, the contact time will be longer, but there are many restrictions on the arrangement of members inside the electrostatic recording device, and such an arrangement cannot be realized.

This invention attempts to solve the above problem by using an auxiliary roller.

Structure of the Invention (Means for Solving Problems) The electrostatic copying apparatus of the present invention transfers a toner image formed on an electrostatic recording medium to an intermediate transfer belt in a transfer section, and further copies this transferred toner image. In an electrostatic recording device that performs fixation and transfer onto a material at a fixing section, the intermediate transfer belt is stretched over at least a transfer section pressing roller that presses the photoreceptor and a fixing section pressing roller that is a heat roller located in the fixing section. , an auxiliary roller whose surface is coated with a soft resin and which has a heat source inside is brought into contact with the outside of the belt in front of the fixing unit pressing roller so as to increase the contact area between the intermediate transfer belt and the fixing unit pressing roller; It is characterized by being arranged so that

Examples Hereinafter, the present invention will be specifically explained using examples.

In the figure, 1 is an electrostatic recording medium such as a photosensitive drum, 2 is an intermediate transfer belt having an adhesive transfer layer, 3 is a transfer part press roller, 4 and 5 are fixing part press rollers, and 4 is an internal part. It is a heating roller with a heat source. 6 is a tension roller, 7 is an auxiliary roller which is a feature of the present invention, and 8 is copy paper as a copy material. The transfer belt 2 is wound around a transfer part pressure roller 3, a heat roller 4, a tension roller 6, and an auxiliary roller 7. The auxiliary roller 7 is located between the transfer part pressure roller 3 and the fixing part pressure roller 4, The intermediate transfer belt 2 is arranged so as to contact the opposite surface of the transfer belt 2 to the surface that contacts the heat roller, and to curve the transfer belt to increase the contact area between the intermediate transfer belt and the heat roller.

The toner image formed by developing the electrostatic latent image on the electrostatic recording medium 1 with toner is transferred to the transfer section pressing roller 3.
The transfer layer of the intermediate transfer belt 2 is pressed onto the toner image, and the toner image is once transferred to the transfer layer of the intermediate transfer belt 2 due to the adhesive effect and the pressure effect. Next, the transferred image formed on the transfer layer of the intermediate transfer belt 2 is heated by a fixing unit pressing roller 4, which is a heat roller, and is transferred and fixed onto the copy paper 8.

In this invention, the auxiliary roller 7 is arranged in front of the fixing unit pressing roller 4 to increase the contact area between the transfer belt 2 and the heat roller 4. In this case, the auxiliary roller 7 needs to have a surface that does not have releasability or electrostatic attraction to the transferred image formed on the intermediate transfer belt 2. For example, the surface is made of fluorine-based resin. It is preferable to form a film. Further, the auxiliary roller 7 can be provided with a heat source therein to heat the intermediate transfer belt 2, thereby improving the fixing properties to the copy paper.

(Effects of the Invention) As described above, this invention increases the contact area between the intermediate transfer belt and the heat roller through the specific arrangement of the auxiliary roller, reduces slippage between the intermediate transfer belt and the heat roller, and enhances the heating effect. Moreover, since the image is also heated by the auxiliary roller, it is possible to ensure the transfer and fixing onto the copying material and improve the speed.

Moreover, since the basic structure of the conventional electrostatic copying apparatus remains unchanged and only an auxiliary roller is added, it can be easily implemented in various electrostatic copying apparatuses.

[Brief explanation of the drawing]

The drawings are conceptual diagrams showing the configuration of an embodiment of the present invention. 1: Electrostatic recording body, 2: Intermediate transfer belt, 3: Transfer section press roller, 4: Heat roller and fixing section press roller, 5: Fixing section press roller, 6: Tension roller, 7: Auxiliary roller, 8: Copying materials.

Claims (1)

[Scope of Claims] 1. An electrostatic recording device in which a toner image formed on an electrostatic recording medium is transferred to an intermediate transfer belt at a transfer section, and the transferred toner image is further fixed and transferred to a copying material at a fixing section, The intermediate transfer belt is stretched over at least a transfer unit pressure roller that presses the photoreceptor and a fixing unit pressure roller that is a heat roller located in the fixing unit, the surface of which is coated with a fluorine-based resin, and has a heat source inside. An electrostatic recording device characterized in that an auxiliary roller is arranged so as to contact the outside of the belt in front of the fixing unit pressing roller so as to increase the contact area between the intermediate transfer belt and the fixing unit pressing roller. .