Title:
METHOD FOR MEASURING LENS DISPLACEMENT QUANTITY OF ORIGINAL DISK EXPOSING MACHINE
Document Type and Number:
Japanese Patent JPH0328811
Kind Code:
A
Abstract:
PURPOSE:To measure the quantity of displacement of an objective in the direction of the rotary surface of an original disk by detecting the phase difference of the displacement quantity output of an actuator. CONSTITUTION:Displacement detection sensors 7 and 8 detect variation in the displacement quantity of the actuator 4 in a direction intersecting orthogonally with the rotary surface of the original disk 1. Further, the voltage conversion waveform of the displacement at this time is viewed to judge that the displacement quantity of a lens supporting body 2 along the rotary surface of the original disk 1 is zero on condition that a waveform A detected by the sensor 7 conforms with a waveform B detected by the sensor 8. At this time, the lens supporting body 2 is held by a leaf spring slightly slanting from its vertical attitude. Consequently, the objective 3 is displaced along the rotary surface of the original disk 1, but this state generates the waveform A detected by the sensor 7 and the waveform B detected by the sensor 8 to have a phase difference DELTAPHI, which is detected. Consequently the displacement quantity of the objective 3 can be measured.
Inventors:
ITO YUJI
Application Number:
JP11994189A
Publication Date:
February 07, 1991
Filing Date:
May 12, 1989
Export Citation:
Assignee:
RICOH KK
International Classes:
G01B21/00; G02B7/09; G02B7/28; G11B7/26; (IPC1-7): G01B21/00; G02B7/09; G02B7/28; G11B7/26
Attorney, Agent or Firm:
Akira Kashiwagi
Next Patent: JPH0328812