| 摘要 |
PURPOSE:To obtain a potential measuring device for a photoreceptor surface easy in signal processing and low in cost, by providing perforations at equal intervals in the peripheral direction of the circumference of a hollow cylinder having a center of the rotation parallel to the photoreceptor and arranged with a perforated plate there between, and installing a detecting electrode in the cylinder. CONSTITUTION:Perforations 8 in given form and size are bored at equal intervals on the circumference of hollow cylinder 7, and detecting electrode 10 in a given size is installed in cylinder 7. The forms and sizes of perforations 9a of perforated plate 9, perforations 8 of cylinder 7, and electrode 10 are selected in such a manner that the change rate of area of electrode 10 observed through perforations 9a versus time is kept constant when cylinder 7 rotates at a constant speed. At that time, the surface potential of photosensitive drum 1 can be correctly measured including polarity by the output of detecting electrode 10, and the output becomes square in wave-form, permitting signal processing to be easy. |
