Image forming apparatus

Abstract

The invention provides an image forming apparatus comprising a fixing device capable of shortening start time and saving energy. The apparatus comprises an exposure device 3 that forms a latent image in an image carrier; a developing device 4 that develops the latent image formed on the image carrier through a toner; a transfer printing device 5 that prints the developed toner image on the image carrier in a recoding material S in a transfer printing manner; and a paper feeding and conveying device 8a.6 that synchronously conveys the papery recording material S piled in a paper feeding part 8and the toner image developed by the developing device to the transfer printing device. The fixing device fixes the toner image printed in the recording material in a transfer printing manner by the transfer printing device and comprises a first fixing device 11 that is arranged in the path 9 of conveying the recording material after the toner image is printed in a transfer printing manner so as to soften the toner printed in the recording material in a transfer printing manner; and a second fixing device 12 that is arranged at the downstream of the first fixing device near to the conveying direction of the recording material and used for smoothing and fixing the surface of the toner softened by the first fixing device.

Description

technical field [0001] The present invention relates to image forming apparatuses such as copiers, printers, plotters, facsimile machines, and multifunction machines thereof, and particularly to image forming apparatuses characterized by a fixing method. Background technique [0002] Conventionally, in image forming apparatuses such as copiers and printers, in order to fix the toner image transferred onto the recording material to the recording material, a configuration including a fixing device is generally employed. Then, in order to suppress the occurrence of fixing defects, many fixing methods have been disclosed. At present, the heat roller method is generally adopted, that is, the heating roller heated by the heating source is used as the fixing roller, and the fixing roller is arranged opposite to the fixing roller to form a nip. The pressure roller, the unfixed image is fixed to the recording material by the fixing roller and the pressure roller. [0003] As a fixin...

AI Technical Summary

Problems solved by technology

[0042] (1) The alignment accuracy of the toner image and laser irradiation is low

[0043] In the transfer step, when the toner image is transferred from the photoreceptor to the recording material, the position of the recording material tends to shift due to the bending of the recording material until it is conveyed to the conveying belt.

This is the cause of deviation between the position of the toner image and the laser irradiation position

In the conventional technology described in the above-mentioned Patent Document 20, in order to cover this deviation, the image memory for changing the laser irradiation width is provided with a width change mode. At the same time, it will shorten the life of the laser light emitting device

[0044] (2) Image deterioration due to toner scattering

[0045] Since the recording material is transported to the conveyor belt after the toner is transferred, the toner may scatter when the recording material comes into contact with the conveyor belt, resulting in image degradation.

[0046] (3) Insufficient fixing

In order to make up for the lack of heat, in the prior art described in Patent Document 20, it is described that the selected toner has a low melting point and has high fixing properties even without applying pressure, but the type of toner is limited. itself will become a constraint on the entire equipment including the imaging system, resulting in the problem of low versatility

On the other hand, in the conventional technology described in Patent Document 22, a plurality of laser light sources are used to make up for the lack of power, which leads to the disadvantages of complicated equipment and high cost.

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