How to control electrophotography

Abstract

Abstract PURPOSE:To correct and control automatically the density of a formed picture in accordance with the state of an original picture by controlling variably the quantity of illuminating and exposure light of the original or development conditions on a basis of a fundamental characteristic curve determined in accordance with the classification of the original. CONSTITUTION:Frequencies Ndc, potential differences Vac, and DC potential differences Vdc of AC biases for diazo, photographic, and document originals are arranged into a table 1 by characteristic curves selected by switches 291-293. For example, in case that the diazo original is copied, the signal which turns on the contact 291 to control the frequency Ndc and the voltage Vac to 1kHz and 1,600V respectively is sent from an operation control circuit 28 to a power source 20, and the signal which controls the lighting voltage of a lamp 11 to 63V is sent from the operation control circuit 28 to a power source 22. A photosensitive body 1 is rotated to start the electrostatic latent image forming operation, and an optical system is scanned to measure an electrostatic latent image potential Vs of the original on the photosensitive body 1 by a potentiometer 25. The operation control circuit 28 calculates the voltage Vdc on a basis of a change rate, which is selected by turning-on of the contact 291, and the electrostatic latent image potential Vs and sends the control signal to the power source 20.

Inventors

• 👤 Takeshi Watanabe
• 👤 毅 渡辺
• 👤 Takao Honda
• 👤 本田　孝男

Bibliographic Details