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:
Jan. 20, 1998
Filed:
Sep. 13, 1995
SEIKO Precision Inc., , JP;
Abstract
A lens driving device for controlling the position of a lens setting member according to a distance to an object to be photographed has a lens barrel mounted to undergo movement in the direction of an optical axis, a lens setting member mounted to undergo rotation about the lens barrel and to move the lens barrel in the direction of the optical axis, a biasing spring for applying a biasing force for biasing the lens setting member in one direction, a ratchet engaging with the lens setting member to undergo rotation therewith, a retaining member having a pair of engaging pawls disposed to alternately engage with the ratchet to prevent rotation of the ratchet due to the biasing force of the biasing spring, an electromagnetic actuator for applying a first driving voltage for maintaining the retaining member in an engaged state and a second driving voltage for rocking the retaining member to alternately engage the pawls with the ratchet to cause the biasing spring to rotate the ratchet in a stepwise manner during periods when the ratchet is not engaged by either of the engaging pawls of the retaining member, and a driving ring for driving the lens barrel to return to an initial position by rotating the lens setting member to an initial position against the biasing force of the biasing spring and for performing at least one of an exposure operation and an aperture control operation. In the lens driving device, the first driving voltage of the electromagnetic actuator is lower than the second driving voltage such that a lower voltage is applied when the driving member is rotated and the lens setting member is at rest than when the lens setting member is not at rest.