Turntable for mounting recording medium in disk form
US4841516A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1987 |
| Grant date | Jun 20, 1989 |
| Priority date | — |
| Expiry date | Sep 15, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B19/2009
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A turntable comprising a disk-shaped substrate and a portion for receiving a disk-shaped recording medium is disclosed. The disk-shaped substrate is shaped from a thermoplastic composite resin having a dynamic shear modulus, G', of at least 1.5.times.10.sup.10 dyne/cm.sup.2, a G.sub.1 '(-40.degree. C.)/G.sub.2 '(100.degree. C.) ratio of up to 1.5, and a density of up to 2.0 g/cm.sup.3, and the receiving portion is formed on the top of the substrate from a thermoplastic elastomer having a hardness of 5 to 40. The turntable has high dimensional precision and will experience reduced warpage. The turntable is capable of being revolved in a stable manner to ensure an increased precision in reading information. In addition, the turntable has a rapid access time and is capable of attaining a steady speed of revolution in a shorter period of time after the power has been switched on.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.