Histogram readout method and circuit for determining the time of flight of a photon
US10416293B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2016 |
| Grant date | Sep 17, 2019 |
| Priority date | — |
| Expiry date | Dec 21, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04F10/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A histogramming readout circuit is described. The readout circuit comprises a time to digital converter (TDC) configured to continually report time-stamps defining an arrival time of a laser clock and a signal output from a photosensor. Memory is provided for 10 storing TDC events. A programmable processor is configured to implement a state machine. The state machine being operable to save a time-stamp when a TDC event is detected; determine the time of flight of each of the photons detected by the photosensor; use each calculated time of flight to address a memory location; build up a histogram of the TDC data values using the memory locations as time-bins; and maintain a pointer to a maximum memory location where the highest number of TDC event resides. A calculator is operable to read the value of the maximum memory location and one or more adjacent time-bins either side for processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.