JPS6489042A - Focus error detector - Google Patents
Focus error detectorInfo
- 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
Links
Landscapes
- Optical Recording Or Reproduction (AREA)
- Automatic Focus Adjustment (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.
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)
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 |
-
1987
- 1987-09-30 JP JP24615587A patent/JPS6489042A/en active Pending
Cited By (1)
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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