Phonograph tone arm control system
US4254959A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 28, 1979 |
| Grant date | Mar 10, 1981 |
| Priority date | — |
| Expiry date | Jun 28, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B3/38
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A multi-function phonograph tone arm control system for a low-friction air bearing supported linear-travelling tone arm system is disclosed. Positive horizontal linear positioning is accomplished by means of an electromagnetic force producing system in which opposing linear forces may be balanced at any point along the path of straight-line travel of the tone arm to position the tone at any desired location. A separate electromagnetic force producing system is utilized to control the vertical pivoting of the tone arm including the pressure of the stylus on a phonograph record. A further motion damping means is provided to stabilize the motion of the tone arm and prevent any unwanted vibration of the tone arm. A means for automatically shutting off the system at the end of a record is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.