TOF range finding with background radiation suppression
US8648998B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2009 |
| Grant date | Feb 11, 2014 |
| Priority date | — |
| Expiry date | Jul 6, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/587
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for measuring time of flight of radiation includes emitting modulated radiation (51) in response to a first modulation signal, projecting the modulated radiation (51) onto a scene (55), and receiving radiation, the received radiation including at least modulated radiation reflected by the scene (55). The received radiation (26, 27) is converted into a radiation induced electrical signal. The radiation induced electrical signal is mixed with a second modulation signal, thus generating a mixed signal, which is integrated, thus generating an integrated signal. When the integrated signal exceeds a threshold value (Vref), charge is injected into the integrated signal. The method includes applying changes to the first and/or second modulation signal at one or more moments in time, and measuring the integrated signal at one or more moments in time, thus obtaining at least one TOF pair difference signal (62). The measuring includes using a single detector node (38) and associated memory element (25), to obtain a TOF pair difference signal (62). The method furthermore includes using one or more TOF pair difference signals to determine time of flight of radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.