Title:
AUTOFOCUSING MECHANISM
Document Type and Number:
Japanese Patent JPS63238772
Kind Code:
A
Abstract:
PURPOSE:To shorten a time until a lens arrives at a complete focusing position and to increase accuracy by arranging two light path length changing member having the different changing quantity of a light path length between an image pickup element and a focusing lens and setting the changing quantity of the light path length in the vicinity of a focus position smaller than the changing quantity at the position away from the focusing position. CONSTITUTION:On a light path between a focusing lens 1 and an image pickup element 2, first and second slit plates (light path length changing member) 4 and 5 having different thicknesses t1 and t2 are arranged. When the focusing lens 1 is at a non-focusing position and an autofocusing action is started, only the first slit plate 4 executes a swinging action and the focusing lens 1 is made close to the focusing position by the rotation of a focusing motor. When the focusing point is exceeded, the first slit plate 4 stops the swinging action, instead, the second slit plate 5 starts the swinging action and the focusing lens 1 arrives at the focusing position by the rotation of the focusing motor.
Inventors:
NAKAJIMA HIROSHI
KANAYAMA HIDEYUKI
KANAYAMA HIDEYUKI
Application Number:
JP24865787A
Publication Date:
October 04, 1988
Filing Date:
October 01, 1987
Export Citation:
Assignee:
SANYO ELECTRIC CO
International Classes:
H04N5/232; (IPC1-7): H04N5/232
Attorney, Agent or Firm:
Takuji Nishino (1 person outside)