Signal processing circuit and method for use with an optical navigation system
US7250893B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 2005 |
| Grant date | Jul 31, 2007 |
| Priority date | — |
| Expiry date | Nov 12, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/50
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A signal processing circuit and processing method are provided for measuring an analog signal from a photo-detector. Generally, the method includes steps of: (i) sampling and storing a characteristic of the signal at a first predetermined time following a reset of the circuit; (ii) sampling the characteristic of the signal at a second predetermined time following a reset or initialization of the circuit; (iii) determining a difference between the stored characteristic of the signal sampled at the first predetermined time and the characteristic of the signal sampled at the second predetermined time; and (iv) converting the determined difference to a digital value and determining a slope of the signal from the digital value and the difference between the first and second predetermined times. Thus, the measurement of the slope is independent of and substantially unaffected by absolute values of the characteristics measured at the first and second predetermined times.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.