Semiconductor laser device protection circuit, optical pickup apparatus, and information recording/reproducing apparatus
US7952981B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 23, 2008 |
| Grant date | May 31, 2011 |
| Priority date | — |
| Expiry date | Dec 8, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/06825
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor laser device has a cathode grounded and an anode connected to a collector of a transistor. The transistor has an emitter grounded and a base connected to a first external terminal via a first resistor. A digital transistor has a collector connected to the base of the transistor, an emitter grounded, and a base connected to a second external terminal via a resistor. When a voltage equal to or higher than the predetermined first voltage is applied to the base of the transistor, the transistor is put into a conducting state, and the semiconductor laser device is grounded via the transistor and thereby protected from static electricity and leak current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.