JPS6489042A - Focus error detector - Google Patents

Focus error detector

Info

Publication number
JPS6489042A
JPS6489042A JP24615587A JP24615587A JPS6489042A JP S6489042 A JPS6489042 A JP S6489042A JP 24615587 A JP24615587 A JP 24615587A JP 24615587 A JP24615587 A JP 24615587A JP S6489042 A JPS6489042 A JP S6489042A
Authority
JP
Japan
Prior art keywords
light
convex lens
focus error
converged
detecting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP24615587A
Other languages
Japanese (ja)
Inventor
Akino Inoue
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Priority to JP24615587A priority Critical patent/JPS6489042A/en
Publication of JPS6489042A publication Critical patent/JPS6489042A/en
Pending legal-status Critical Current

Links

Landscapes

  • Automatic Focus Adjustment (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To miniaturize an optical system and simultaneously, to obtain high detecting sensitivity by arranging a convex lens before a light detector and arranging the light detector in the vicinity of a beam waist position prepared by means of the convex lens. CONSTITUTION:A laser beam from a laser diode 2 as a light source for detecting a focus error is converged by a lens 3 for collimating. Thereafter, the converged light is made incident through an objective 5 provided in the course of the converging light on a disk surface 1, reflecting light from the disk surface 1 is converged by a convex lens 6, the light is conducted to a light detector 7 arranged in the vicinity of the beam waist position by the convex lens 6, and a focus error is detected. Thus, since the high detecting sensitivity can be obtained, simultaneously, the light path length for detecting a focus error can be shortened, further, available optical parts such as a semiconductor laser and a convex lens can be used, and even a complex beam reducing system can be made unnecessary, the optical system can be miniaturized.
JP24615587A 1987-09-30 1987-09-30 Focus error detector Pending JPS6489042A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24615587A JPS6489042A (en) 1987-09-30 1987-09-30 Focus error detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24615587A JPS6489042A (en) 1987-09-30 1987-09-30 Focus error detector

Publications (1)

Publication Number Publication Date
JPS6489042A true JPS6489042A (en) 1989-04-03

Family

ID=17144313

Family Applications (1)

Application Number Title Priority Date Filing Date
JP24615587A Pending JPS6489042A (en) 1987-09-30 1987-09-30 Focus error detector

Country Status (1)

Country Link
JP (1) JPS6489042A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007296074A (en) * 2006-04-28 2007-11-15 Okamura Corp Leg end implement of chair or the like

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007296074A (en) * 2006-04-28 2007-11-15 Okamura Corp Leg end implement of chair or the like

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