Image forming apparatus having aperture electrode unit including insulating member with high dielectric constant
AssigneeBrother Kogyo Kabushiki Kaisha
InventorShigeru Kagayama
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Abstract
An aperture electrode unit of an image forming apparatus includes an insulating sheet, control electrodes formed on the insulating sheet and apertures formed in the aperture electrode unit. The insulating sheet is formed of material having a dielectric constant higher than a toner layer. With this construction, a voltage applied across the control electrodes and the toner carry roller is divided in accordance with a capacity rate of these elements. Thus, the voltage is effectively applicable to the toner layer, so that the toner control performance can be improved even at a low-voltage driving time. Therefore, an excellent image recording operation can be performed by a low-voltage driving operation.
Claims17
An image forming apparatus for forming an image on a support comprising:
- a toner supply means for supplying charged toner particles to the support for forming the image thereon, the charged toner particles having a first dielectric constant;
- and
- a toner flow control means for controlling a flow of charged toner particles from the toner supply means to the support, the toner flow control means disposed adjacent to and in contact with the toner supply means, wherein the toner flow control means comprises an aperture electrode unit including an insulating member with apertures therein and control electrodes surrounding each aperture that are adapted to be electrically coupled to a voltage source, and wherein the insulating member confronts the toner supply means and has at least a portion with a second dielectric constant that is higher than the first dielectric constant of the charged toner particles.
An image forming apparatus comprising:
- a toner carrier that carries and supplies charged toner particles having a dielectric constant to an image supporter for forming an image thereon;
- and
- an electric-field controller having apertures therein and disposed to face and contact the toner carrier that controls a flow of the charged toner particles through the apertures from the toner carrier to the image supporter with an electric field, wherein at least a part of the electric-field controller in which the apertures are formed is made of a high dielectric substance having a dielectric constant higher than the dielectric constant of the charged toner particles.
Dependencies are inferred from the claim text.