Title:
LENS BARREL
Document Type and Number:
Japanese Patent JPH04134408
Kind Code:
A
Abstract:
PURPOSE:To decrease the number of parts and to reduce the size, weight and cost of the above lens barrel by extending the respective revolving shafts of motors and freely rotatably supporting these shafts via bearings in the lens barrel and providing 1st and 2nd lead screw parts varying in pitch on the respective revolving shafts thereby freely movably constituting moving lens frames. CONSTITUTION:The lens barrel 1 is constituted of the cylindrical front lens barrel 2 which is fixed and semi-cylindrical main lens barrels 3, 4 which are bisected longitudinally to the right and left. The front ends of the respective revolving shafts 22, 22 of the stepping motors 10, 10 fixed to the rear side of the main lens barrel 3 are freely rotatably supported on the thrust bearings. The respective revolving shafts 11, 11 of the motors 10, 10 are so disposed as to parallel with an optical axis C and the 1st, 2nd lead screw parts 11a, 11a varying in pitch are respectively formed before and behind these shafts. A variator lens 12 for zooming having a variable power function is held in the screw parts 11a, 11a and is supported on the 1st moving lens frame 13. The dealing with the different moving strokes of the moving lens frames 13, 15 is executed by maintaining the rotating speeds of the motors 10, 10 at the same speed and changing the moving speeds of the 1st, 2nd moving lens frames 13, 15.
Inventors:
TADA KANEHIRO
NISHIDA YASUO
MORO SHUJI
OSHIMA EIJI
NISHIDA YASUO
MORO SHUJI
OSHIMA EIJI
Application Number:
JP25775290A
Publication Date:
May 08, 1992
Filing Date:
September 27, 1990
Export Citation:
Assignee:
SONY CORP
International Classes:
G02B7/04; G02B7/08; (IPC1-7): G02B7/04; G02B7/08
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)