Automatic power control system for optical disc drive and method thereof
US7474235B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2007 |
| Grant date | Jan 6, 2009 |
| Priority date | — |
| Expiry date | Jun 5, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/129
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An automatic power control system, a down sampling circuit and a down sampling method. The automatic power control system is incorporated in an optical disc drive comprising a laser diode for receiving a control signal to generate a laser beam; and a photodetector for detecting the laser beam to generate an analog input signal. The automatic power control system comprises an analog-to-digital converter, a down sampling circuit, a comparator, and a digital-to-analog converter. The analog-to-digital converter converts the analog input signal to digital data. The down sampling circuit, coupled to the analog-to-digital converter, comprises a down sampler, a counter, and a controller. The down sampler receives a predetermined amount of digital data to generate representation data. The counter, coupled to the down sampler, calculates the amount of digital data, and resets the down sampler when the amount equals or exceeds the predetermined count. The controller, coupled to the counter, disables the counter when the digital data is invalid. The comparator, coupled to the down sampling circuit, compares the representation data with predetermined target data to generate error data. The digi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.