Camera shutter having bobbin driven blades
AssigneePolaroid Corporation
InventorChristian C. Petersen
Life of this patent
Estimating the term…
Abstract
A light controlling system for photographic apparatus in which a pair of cooperating blades are defined by linear flights of a folded belt formed of an opaque film and having a central portion trained about a fixed axis guide roller with the free ends of the belt flights connected to reciprocable, coil carrying bobbins supported in a fixed armature frame. The bobbins are alternately driven in opposite directions to effect operative movement of the blades. An additional pair of bobbins may be supported on the frame for operating auxiliary driven components such as an adjustable aperture stop where the aforementioned belt provides simply shutter blades.
Claims15
A light controlling blade and drive system for photographic apparatus, said system comprising:
- a pair of apertured opaque blades defined by linear flights of a belt having a central bight portion trained about a fixed axis;
- linear motor drive means including a fixed frame spaced from said axis, a pair of electromagnetic force driven movable members supported by said frame for reciprocation alternately in opposite directions;
- and
- tensile means connecting said movable members to said blades for drawing said blades in opposite directions responsive to movement of said movable members.
An exposure control, blade system for photographic apparatus for controlling light passed along a given optical axis to a focal plane in said apparatus, said system comprising:
- a permanent magnet arrangement mounted in adjoining relation to said given axis and defining a blade support surface generally normal to said axis;
- a blade arrangement comprising a pair of apertured thin blade sections of light blocking material mounted on said support surface in overlying relation to each other at said optical axis, said sections being comprised in part of soft magnetically permeable material so as to be drawn against said support surface;
- and
- drive means for producing relative motion between said sections over said magnet arrangement so as to displace the apertures of said sections between a light transmitting condition wherein said apertures are in at least partial coincidence at said axis and a light blocking condition wherein said apertures are out of alignment at said axis whereby said blade sections are maintained in light sealing contact with each other by said magnet arrangement.
Dependencies are inferred from the claim text.