Shutter plate movement
AssigneeElectromask, Inc.
InventorEdward Grant Hill
Life of this patent
Estimating the term…
Abstract
A variable aperture shutter is provided with a pair of shutter blades reciprocably mounted on a drive formed by an endless belt stretched between, and driven by, a pair of capstans. One blade is attached to each side of the endless belt loop and both extend across the width of the loop. Reversible rotation of the capstans controls the separation of the blades. A light beam, aligned orthogonally with the shutter, is intercepted when the shutter blades are in the closed position, with their adjoining edges abutting. Light is permitted to pass through a gap between confronting blade edges upon controlled rotation of the capstan drive. Apertures of varied sizes and shapes may be generated by superimposing two or more shutters and selectively controlling their capstan drives.
Claims11
A variable aperture shutter for intercepting and shaping a beam of light emitted from a source, comprising:
- a base;
- an endless belt;
- capstan means rotatably mounted to said base, supporting said endless belt in a loop having two opposed linear regions lying in spaced parallel alignment, and imparting circulatory motion to said belt;
- reversible drive means driving said capstan means;
- a first shutter blade positioned within said loop intermediate said linear regions thereof and pivotably secured to said belt in one of said linear regions;
- a second shutter blade positioned within said loop intermediate said linear regions thereof to confront said first shutter blade and pivotably secured to said belt in the other of said linear regions;
- positioning means operatively connected to said first and second shutter blades to rotate said blades and thereby selectively adjust the angle between the confronting edges thereof and the linear regions of said loop;
- and
- control means controlling said drive means to vary the positions of said shutter blades and thereby vary the aperture defined by confronting edges of said blades.
A variable aperture shutter for intercepting and shaping a beam of light emitted from a source, comprising, in combination, a pair of shutter mechanisms mounted in a frame in superimposed alignment with the optical axis of said light beam, each shutter mechanism comprising:
- a base;
- an endless belt;
- capstan means, rotatably mouned to said base, supporting said endless belt in a loop having two opposed linear regions lying in spaced parallel alignment, and imparting circulartory motion to said belt;
- reversible drive means driving said capstan means;
- a first shutter blade positioned within said loop intermediate said linear regions thereof and secured to said belt in one of said linear regions;
- a second shutter blade positioned within said loop intermediate said linear regions thereof to confront said first shutter blade and secured to said belt in the other of said linear regions;
- control means controlling said drive means to vary the positions of said shutter blades and thereby vary the aperture defined by confronting edges of said blades;
- and
- alignment means for controllably rotating the base of at least one of said shutter mechanisms about said optical axis in a plane normal to the optical axis of said light beam.
Dependencies are inferred from the claim text.