Image forming apparatus
First Claim
1. In an image forming apparatus comprising an exposure light source, a printer head provided with a micro-shutter array which is disposed in the exposure light path from said exposure light source and comprises a plurality of micro-shutters each controlling the transmission or interruption of light therethrough, and an image bearing member so disposed to be irradiated with the light signal transmitted through the printer head;
- the improvement whereinsaid plurality of micro-shutters of said microshutter array are arranged in a matrix comprising a plurality of rows and a plurality of columns;
each of said micro-shutters comprises a first electrode connected to a terminal of a thin film transistor, a second electrode which serves as a common electrode and a liquid crystal interposed between said first and second electrodes; and
said first electrode is further provided with a conductor film in opposed relationship through an intermediate insulating film, said first electrode, intermediate insulating film and conductor film forming in combination a charge storage capacitor.
1 Assignment
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Accused Products
Abstract
An image forming apparatus comprises an exposure light source, an image bearing member and a printer head interposed therebetween. The printer head has a micro-shutter array which comprises a plurality of micro-shutters arranged in a matrix comprising a plurality of rows and a plurality of columns. Each micro-shutter comprises a first electrode connected to a terminal of a thin film transistor, a second electrode forming a common electrode and a liquid crystal interposed therebetween. On the first electrode is further provided an opposing conductor film through an insulating film, whereby a charge storage capacitor is formed. Because of the charge storage capacitor, an effective voltage applied across the liquid crystal is kept at a high level, whereby an optical signal with good contrast is given to the image bearing member even when the printer head is driven according to a high degree of time-division scheme.
14 Citations
15 Claims
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1. In an image forming apparatus comprising an exposure light source, a printer head provided with a micro-shutter array which is disposed in the exposure light path from said exposure light source and comprises a plurality of micro-shutters each controlling the transmission or interruption of light therethrough, and an image bearing member so disposed to be irradiated with the light signal transmitted through the printer head;
- the improvement wherein
said plurality of micro-shutters of said microshutter array are arranged in a matrix comprising a plurality of rows and a plurality of columns; each of said micro-shutters comprises a first electrode connected to a terminal of a thin film transistor, a second electrode which serves as a common electrode and a liquid crystal interposed between said first and second electrodes; and said first electrode is further provided with a conductor film in opposed relationship through an intermediate insulating film, said first electrode, intermediate insulating film and conductor film forming in combination a charge storage capacitor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15)
- the improvement wherein
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11. The image forming apparatus according to claim 11, wherein said liquid crystal is a nematic liquid crystal.
Specification