Surface potential detector

Abstract

Abstract PURPOSE:To eliminate possible leakage and improve the detection sensitivity in surface potential of a photosensitive body for an electrophotographic copying equipment by applying a line of electric force to a collector electrode through a dielectric plate after the dielectric plate with the collector electrode formed thereon is mounted on the opening of a case so as to position the collector electrode within the case. CONSTITUTION:When a high voltage is applied to the surface to be inspected, a line of electric force from the surface of a high potential is admitted to a collector electrode 3 through a dielectric plate 2 and a charge is stored between the collector electrode 3 acting as one variable condensor electrode and a condenser electrode 7. When a piezo- electric tuning fork 4 is driven to vary the distance between the electrodes 3 and 7 by vibrating the condenser electrode 7, an electric charging or discharging is done with the variation in the capacity and a corresponding electrical signal is applied to an FET and a detection voltage is taken out of the FET through an amplifier. With such a closed arrangement, this prevents the infiltration of a toner or the like into the case 1 eliminating possible leakage or lower sensitivity when this equiment is used for non- destructive measurement of surface potential of an electrostatic drum in a copying machine.

Inventors

• 👤 Mitsuhiro Murata
• 👤 充弘 村田
• 👤 Akira Kumada
• 👤 明 久万田

Bibliographic Details