Fast Access Method Of Optical Disk Memory

Masaharu Ogawa; Osamu Ito; Keiji Nakatsu; Shigeo Hayashi; Isao Watanabe; kunimaro Tanaka

doi:10.1117/12.967407

1 January 1987 Fast Access Method Of Optical Disk Memory

Masaharu Ogawa, Osamu Ito, Keiji Nakatsu, Shigeo Hayashi, Isao Watanabe, kunimaro Tanaka

Proceedings Volume 0817, Optomechanical Systems Engineering; (1987) https://doi.org/10.1117/12.967407
Event: 31st Annual Technical Symposium on Optical and Optoelectronic Applied Sciences and Engineering, 1987, San Diego, CA, United States

Abstract

A fast access control method of optical disk memory was developed. When this method is used, an optical spot can directly reach any destination track by driving a linear motor which carries the optical head in radial direction of a pregrooved disk, even though its track pitch is as narrow as only 1.6 μm. To realize this method, in the first, distorted track crossing signal by recorded pits, which was detected by a split-type photo detector in an optical head, was compensated by an appropriate signal processing method. Therefore, the total number of crossing tracks can be counted correctly and the traveling velocity of the head can be controlled accurately by utilizing the compensated crossing sensor signal. In the next, a state observer based on the advanced control theory was applied to make the velocity controlling performance improve high enough. As a result, the track crossing velocity of the optical spot has been able to be controlled accurately while seeking. Since it hardly needs to make reseeks and any track jump motion, the average access time of optical disk memory has been shortened no more than 70 msec including average rotational latency.

Citation Download Citation

Masaharu Ogawa, Osamu Ito, Keiji Nakatsu, Shigeo Hayashi, Isao Watanabe, and kunimaro Tanaka "Fast Access Method Of Optical Disk Memory", Proc. SPIE 0817, Optomechanical Systems Engineering, (1 January 1987); https://doi.org/10.1117/12.967407

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available