Infrared communication system utilizing receiver with multiple photo-sensors
View Patent ↗A communication system including an infrared receiver that receives optical infrared signals. The infrared receiver utilizes an array of photo-sensors for detecting optical infrared signals within a solid angle. Each photo-sensor, however, detects optical infrared signals in only a predetermined portion of the solid angle. On detecting optical infrared signals, each photo-sensor converts and forwards a corresponding electrical signal to a filter circuit that selectively determines whether the signal meets a predetermined criteria such as a frequency threshold. The filter circuit or other processing circuitry is thereby able to identify photo-sensor(s) providing an optimal infrared communication link. The infrared receiver may include an optical system comprising a lens assembly that directs the optical infrared signals towards the array of photo-sensors. In one embodiment, the lens assembly employs a diffused lens having an imperfect focus to facilitate the detection of optical infrared signals emanating from transmitters that have a relatively small solid angle.
1. A communication system for use with a transmitter that transmits optical infrared signals, the communication system comprising:
an infrared receiver employing an array of at least two photo-sensors that combine to detect the optical infrared signals within a solid angle;
each photo-sensor within the array of the at least two photo-sensors detects the optical infrared signals within a predetermined portion of the solid angle and generates an output signal; and
a photo-sensor selection control circuit configured to receive the output signal of each photo-sensor within the array of the at least two photo-sensors and to suppress the output signal of each photo-sensor within the array of the at least two photo-sensors that fails to meet at least one of predetermined pulse width and pulse frequency thresholds.
2. The communication system of claim 1 wherein the infrared receiver further comprises:
a lens assembly for focusing the optical infrared signals onto the array of the at least two photo-sensors.
3. The communication system of claim 2 wherein the lens assembly employs a lens having an imperfect focus.
4. The communication system of claim 1 further comprising:
a filter circuitry coupled to each of the at least two photo-sensors, the filter circuitry filtering the optical infrared signals falling below a predetermined threshold frequency value.
5. The communication system of claim 4 , further comprising:
an output summing circuitry that receives and sums unfiltered optical infrared signals.
6. The communication system of claim 4 further comprising:
a programmable gain circuitry coupled to each of the at least two photo-sensors that amplifies the output signal of each of the at least two photo-sensors.
7. The communication system of claim 6 wherein the programmable gain circuitry may dynamically adjust the amount of gain.
8. The communication system of claim 6 , further comprising:
an analog to digital converter circuitry coupled to the programmable gain circuitry for converting outputs of the programmable gain circuitry to digital signals.
9. The communication system of claim 1 wherein the array of the at least two photo-sensors is one dimensional.
10. The communication system of claim 1 wherein the array of the at least two photo-sensors is multi-dimensional.
11. The communication system of claim 1 operating in a half duplex serial mode with a range of at least one meter.
12. The communication system of claim 1 operable at the solid angle from zero to approximately thirty degrees.
13. A method for capturing optical infrared signals within a solid angle, the method comprising:
providing a photo-sensor array having at least two photo-sensors;
detecting, by each photo-sensor within the photo-sensor array, optical infrared signals within a predetermined portion of the solid angle;
converting the optical infrared signals into corresponding electrical signals; and
selectively outputting, using a signal selection circuitry coupled to the photo-sensor array, the corresponding electrical signals based on at least one of a pulse frequency threshold and a power threshold.
14. The method of claim 13 , further comprising:
providing a lens for directing the optical infrared signals to the photo-sensor array.
15. The method of claim 14 , wherein the lens is a diffused lens having an imperfect focus.
16. An infrared receiver that detects optical infrared signals, the infrared receiver comprising:
a photo-sensor array comprising a plurality of photo-sensors, each of the plurality of photo-sensors receiving optical infrared signals within a predetermined portion of a solid angle and converting received optical signals to electrical signals; and
a signal selection circuitry coupled to the photo-sensor array, the signal selection circuitry selectively outputting corresponding electrical signals based on at least one of a pulse frequency threshold and a power threshold.
17. The infrared receiver of claim 16 further comprising an optical system arranged to direct optical infrared signals to the photo-sensor array.
18. The infrared receiver of claim 16 wherein the array of photo-sensors detects signals operating within a signaling rate range of 9.6 kb/s through 4 mb/s.