Title:
DEVICE FOR DRIVING VARI-FOCAL LENS OF TWO-GROUP CONSTITUTION
Document Type and Number:
Japanese Patent JPH04361212
Kind Code:
A
Abstract:
PURPOSE:To expands the variable power range closer to a short-focus side, to shorten the closest photographic distance, to speed up the power varying speed, to improve the accuracy of a setting position at the time of power variation and focusing, and to reduce the cost. CONSTITUTION:A driving lens barrel 3 is moved in the direction of the optical axis in a fixed lens barrel 2 with driving force generated between a lead nut screw 16 rotated with the turning force of a 1st motor 10 and a fixed lead screw 19. A base frame 4 is moved in an optical axis direction in a driving lens barrel with screw driving force generated between a lead nut gear 17 rotated by receiving the turning force of a 1st motor 10 and a moving lead screw 20. A rear-group holding frame 7 moves in the optical-axis direction in the base frame 4 with a screw driving force generated between a rear-group lead screw 23 which rotates by receiving the turning force of a 2nd motor 21 and a rear-group lead nut 25.
Inventors:
SASAKI SABURO
TSURUKAWA IKUYA
KITAGO TAKASHI
TERUI HIROSHI
TSURUKAWA IKUYA
KITAGO TAKASHI
TERUI HIROSHI
Application Number:
JP16355991A
Publication Date:
December 14, 1992
Filing Date:
June 08, 1991
Export Citation:
Assignee:
RICOH KK
International Classes:
G02B7/10; G02B7/105; G03B17/04; (IPC1-7): G02B7/10
Attorney, Agent or Firm:
Shuji Sanada