Double-face electronic processor-camera mechanism and method for controlling its toner image concentration

Abstract

A duplex electro-photographic developing machine including a printing medium tray loading a printing medium, a tray open / closed detecting unit detecting whether the printing medium tray has been opened and closed, a transferring roller transferring a toner image onto the printing medium, a resistance measuring unit measuring a resistance value of the printing medium passing the transferring roller, and a concentration controlling unit controlling a concentration of the toner image according to the measured resistance value measured by the resistance measuring unit in response to the printing medium tray having changed from an open state to a close state.

Description

technical field [0001] The invention relates to a paper impedance detection device of an electro-photographic developing machine, in particular to a paper impedance detection device of a duplex electro-photographic developing machine, which is used for detecting the impedance of a sheet of paper, and Accordingly, the density of a toner image is controlled to a desired level, and a method thereof. Background technique [0002] Generally, an electrophotographic developing mechanism is an integrated office equipment (OA) device that includes the functions of a copying machine, a printing machine, a facsimile machine, and the like. A photosensitive medium, such as a photosensitive belt or drum, is often used in an electrophotographic developing mechanism. The surface of this photosensitive medium is charged by the charging voltage control device. Subsequently, the potential level is selectively changed by the scanning of the light beam, thereby forming an electrostatic latent ...

AI Technical Summary

Problems solved by technology

[0008] However, in a conventional electrophotographic developing mechanism, especially in a duplex electrophotographic developing mechanism, since the impedance value of the transferred toner image is added to the impedance value of the printing medium, the impedance value of the front side of the printing medium may be Different from the impedance value on the back side of the printed medium

Thus, it becomes impossible to properly control the density of the toner image with respect to changes in the humidity of the printing medium according to changes in the environment

In addition, in the case where the front side printing and the back side printing of the printing medium are repeated, since the measured impedance value is constantly changed, the change of the concentration to be controlled is also repeated, and the constant repetition of the control value may cause the electrophotographic developing mechanism to go wrong

Since the control operation of the density of the toner image is accomplished only by the measurement of the printing medium passing between the transfer roller 19 and the fixing roller 21, if the same printing medium is provided at the same temperature and humidity, electronic The photo-developing mechanism is more likely to have the above problems

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