The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 20, 1994
Filed:
Jul. 14, 1993
Hitachi Metals, Ltd., Tokyo, JP;
Abstract
A developing method in which a recording region is formed between a movable image carrying element made of a photo-semiconductive material with light-transmitting properties and a hollow-cylindrical, non-magnetic sleeve opposing the image carrying element and accommodating a permanent magnet with a plurality of magnetic poles thereon. An optical signal corresponding to an original is radiated onto the recording region from the back surface of the image carrying element so that toner in a magnetic developer supplied onto the sleeve, and conveyed to the recording region by relative movement of the sleeve and the permanent magnet is selectively adhered onto the surface of the image carrying element. The magnetic developer is a mixture of a toner capable of being charged into a same polarity as the image carrying element, and magnetic particles capable of being charged into either the opposite or same polarity with respect to that of the toner. The toner has a volume resistivity of not less than 10.sup.12 .OMEGA..multidot.cm, and an average particle size of 5 to 20 .mu.m. The magnetic particles have a volume resistivity of more than 2.times.10.sup.5 .OMEGA..multidot.cm but not more than 10.sup.12 .OMEGA..multidot.cm, and an average particle size of 10 to 100 .mu.m. When the magnetic particles are ones for being charged into the same polarity as the toner, they have a smaller absolute value of triboelectric charge than the toner.