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:
Apr. 20, 1993
Filed:
Nov. 27, 1991
Mitsuji Marumo, Sagamihara, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A vacuum attraction type substrate holding system includes a vacuum source; a distributor for distributing a vacuum from the vacuum source into plural vacuum lines; a plurality of vacuum attraction type substrate holding portions corresponding to the vacuum lines, respectively, each of the substrate holding portions having a valve which is openable and closable for control of the supply of vacuum to the corresponding substrate holding portions, wherein the opening or closing of each valve is influential to control attraction or release of a substrate to or from a corresponding substrate holding portion; and a plurality of restriction valves each being disposed between the distributor and corresponding one of the valves, for serving as a resistance to a gas flowing from the corresponding valve.