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.

Date of Patent:
May. 31, 1994

Filed:

Mar. 19, 1993
Applicant:
Inventors:

Masaaki Nomura, Saitama, JP;

Ko Aosaki, Saitama, JP;

Takashi Kubo, Saitama, JP;

Kenta Namioka, Saitama, JP;

Koji Takanose, Kanagawa, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
353 63 ; 353D / ; 353122 ;
Abstract

An overhead projector has a stage on which original material is placed. The stage has a Fresnel mirror. An electrostatic attracting structure is integral with the Fresnel mirror. The attracting structure includes a conductive membrane of ceramic and a resinous dielectric/protective layer. The conductive membrane consists of a pair of comb-shaped electrodes, which interfinger in coplanar fashion, and are covered by the dielectric/protective layer for insulation and protection. A power supply device applies a high voltage of direct current to the electrodes. The original material is attracted electrostatically by the electrodes, and can be kept flat on the stage. In a preferred embodiment, the power supply device incorporates a self-starting blocking oscillator, which is adapted to boost the voltage sufficiently for electrostatic attraction.


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