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:
Oct. 16, 1990
Filed:
Feb. 21, 1989
Takao Kariya, Hino, JP;
Hidehiko Fujioka, Atsugi, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A device for detachably holding a mask at least a portion of which is made of a magnetic material. The device includes a holding member, on which the mask is to be held, the holding member having a portion made of a magnetic material; a first system for producing holding magnetic lines of force so as to generate a magnetic force between the magnetic portion of the holding member and the magnetic portion of the mask, to thereby hold the mask on the holding member; and a second system for producing releasing magnetic lines of force which are operative against the magnetic lines of force produced by the first system so as to reduce the same to a degree sufficient to disengage the mask from the holding member. Also, disclosed is a mask holding device for detachably holding a mask, typically for use in the manufacture of microcircuits, which device is arranged to hold the mask by use of a magnetically attracting force, the magnetically attracting force being made variably controllable so as to correct the flatness of the mask.