Patent ID: 6947091
Filing Date: 2005-09-20
Classification: G02B,H04N

Abstract:
1. A focussing and focal length adjusting device for an optical lens system in an endoscopic video camera, comprising: a drive device for a focussing lens of the lens system, the drive device comprising a focussing sleeve encompassing the focussing lens, the focussing lens having an optical axis; two parallel strip-like piezoelectric bending actuators arranged to lie opposite one another on both sides of the focussing sleeve symmetrically to and along the optical axis, a free end of each said actuator being connected to the focussing sleeve by a respective joint member; an automatic focussing circuit for producing a focus adjusting signal which can be supplied to the piezoelectric actuators, the focussing circuit comprising a picture focussing acquisition device operative to acquire a degree of an in-focus position of the focussing lens, and a comparative device operative to compare the acquired degree of focussing with an earlier degree of focussing, the comparison producing an input signal for a voltage generator; an electromotoric zoom drive connected to a zoom objective of the optical lens system; and a zoom control circuit which with a manually inputted zoom signal produces a focal length adjusting signal for the zoom drive, wherein from a vertical synchronous impulse (V wherein the voltage generator produces a focusing voltage corresponding to a focusing lens position and synchronously applies the voltage to both bending actuators.