Claims
- 1. A sensor system for use with a keyless access control system, the sensor system comprising:
an electromagnetic radiation generating element for generating an incident beam of electromagnetic radiation in the form of a pulse train; an electromagnetic sensing element for sensing the incident beam, and a signal processor coupled to the sensing element for detecting an interruption to, or modification of, the incident beam, the signal processor including a timer for detecting when the duration of the interruption or modification of the incident beam is greater than a predetermined time by detecting the presence or absence of a predetermined number of pulses varying from a predetermined level, the signal processor providing an output signal to an access control mechanism when the presence or absence of a predetermined number of pulses are counted.
- 2. A system as claimed in claim 1 wherein the sensing element is disposed adjacent to the electromagnetic radiation generating element for detecting a partial or total interruption or modification of the incident beam.
- 3. A system as claimed in claim 1 wherein the sensing element is disposed remotely from the electromagnetic radiation generating element for detecting a partial or total interruption or modification of the incident beam.
- 4. A system as claimed in claim 1 including a beam reflector spaced from the radiation generating element for receiving the incident beam and for producing a reflected beam, the sensing element sensing the reflected beam.
- 5. A system as claimed in claim 1 wherein the electromagnetic radiation generating element generates an incident beam of infra-red radiation.
- 6. A system as claimed in claim 1 wherein the electromagnetic radiation generating element is a light emitting diode.
- 7. A system as claimed in claim 1 wherein the electromagnetic radiation generating element is a laser.
- 8. A system as claimed in claim 9 wherein the laser is a laser diode.
- 9. A system as claimed in claim 1 wherein the optical sensing element is a photo-detector device.
- 10. A system as claimed in claim 9 wherein the photo-detector device is a photo-diode.
- 11. A system as claimed in claim 9 wherein the photo-detector device is a photo-transistor.
- 12. A system as claimed in claim 1 wherein the signal processor is provided by CMOS circuitry and includes an output MOSFET for providing an output signal to actuate the access mechanism.
- 13. A system as claimed in claim 1 wherein a backup switch is coupled to the signal processor for actuation by a user in the event of optical sensor failure to generate the output signal to the access control mechanism.
- 14. A system as claimed in claim 13 wherein the backup switch is a mechanical or optical switch.
- 15. A system as claimed in claim 1 wherein the signal processor is coupled to a separate locking switch, the locking switch being actuatable by a user to lock the system.
- 16. A system as claimed in claim 15 wherein the locking switch is an optical or mechanical switch.
- 17. A system as claimed in claim 1 wherein the optical sensors and/or reflectors are disposed at or near to the extremities of a handle to provide an optical beam parallel to the handle.
- 18. A system as claimed in claim 1 wherein the optical beam emitter and beam receiver are disposed in a single post which is incorporated into one end of a handle for generating a beam substantially parallel to the handle or door surface.
- 19. A system as claimed in claim 18 wherein the post includes a back-up switch mechanically linked to the handle to allow a use to actuate the sensor system in the event of optical failure.
- 20. A system as claimed in claim 18 wherein the post includes a locking switch mechanically linked to the handle to allow a user to lock the access system.
- 21. A system as claimed in claim 18 wherein the optical beam emitter and receiver are disposed adjacent each other on the post at substantially the same level on the underside of the handle.
- 22. A system as claimed in claim 18 wherein the post is connected to a sensor circuit module containing the signal processor.
- 23. A system as claimed in claim 22 wherein the circuit module contains an application specific integrated circuit for implementing the signal processor.
- 24. A system as claimed in claim 1 wherein the system includes means for measuring the level of ambient light before producing an optical pulse to prevent sensor response to changes in ambient light.
- 25. A system as claimed in claim 1 wherein power is supplied to the signal processor only during the period when a power supply pulse is supplied to the sensor circuitry to minimize power consumption.
- 26. A method of providing keyless access to a locked device or structure, the method comprising the steps of:
generating an incident beam of electromagnetic radiation, the incident beam being a pulse train, sensing the incident beam of electromagnetic radiation, sensing an partial or total interruption or modification to the incident beam lasting longer than a predetermined timed by detecting the presence or absence of a predetermined number of pulses varying from a predetermined level, and generating an output control signal when the predetermined number of pulses are counted as the result of the partial or total interruption or modification, and processing the generated control signal to produce an actuation signal for opening the access mechanism.
- 27. A method as claimed in claim 26 including the steps of:
reflecting the incident radiation beam from a reflecting element, and detecting the reflected radiation beam, and generating an output signal in response to an partial or total interruption of the incident or reflected radiation beam.
- 28. A method as claimed in claim 26 including the step of detecting the presence of a beam reflected by a reflecting object and generating an output signal in response to a total or partial interruption or modification of the beam.
- 29. A method as claimed in claim 26 wherein the method includes the steps of:
generating an infra-red signal to form the incident electromagnetic radiation signal, and detecting the infra-red signal to provide a sensed signal for processing to control actuation of the access mechanism.
- 30. A method as claimed in claim 26 including the step of measuring the level of ambient light before producing an optical pulse to prevent sensor response to changes in ambient light level.
- 31. A method as claimed in claim 26 including the step of processing signals by sensor processor only during the period when a power supply pulse is supplied to the sensor circuitry to minimize power consumption.
- 32. A method as claimed in claim 26 including the step of providing an optical adaptive feedback circuit for preventing the sensor providing false detections caused by variation of optical beam characteristics by factors other than the interruption or modification of the beam by a user.
- 33. A circuit for sensing the presence of an object, the circuit comprising:
an electromagnetic radiation generating element for generating an incident beam of electromagnetic-radiation in the form of a pulse train; an electromagnetic sensing element for sensing the incident beam; a signal processor coupled to the sensing element for detecting an interruption or modification to the beam by an object for detecting the presence or absence of a predetermined number of pulses varying from a predetermined level, the signal processor providing an output signal when the predetermined number of pulses are counted, and a power management unit coupled to the signal processor for supplying power to the circuit only during the period when a power supply pulse is supplied to minimize power consumption
- 34. A circuit as claimed in claim 33 wherein the object sensed is a raindrop.
- 35. A method of sensing the presence of an object, the method comprising the steps of:
generating an incident beam of electromagnetic radiation, the incident beam being in the form of a pulse train; sensing the incident beam of electromagnetic radiation; sensing a partial or total interruption or modification to the incident beam by the presence of an object by detecting the presence or absence of a predetermined number of pulses varying from a predetermined level; generating a control signal as the result of the interruption or modification of the incident beam when a predetermined number of pulses are counted, and processing the generated control signal to product an output signal corresponding to the beam interruption or modification; and processing signals by a sensor processor only during the period when a power supply pulse is supplied to the sensor circuitry to minimize power consumption.
- 36. A method as claimed in claim 35 for sensing the presence of rain.
- 37. A circuit for use in an electromagnetic radiation sensing system, the circuit comprising:
a circuit power supply regulator; an output stage with an optical source for emitting pulses of electromagnetic radiation of a predetermined duration; a sensing and amplification stage for detecting pulses emitted by the optical source; a timing circuit coupled to the power supply regulator for generating timing signals and an internal timing power supply, the timing signals and the internal timing power supply being fed to the amplification stage and to the output stage for synchronizing the emission and detecting of light pulses and minimizing the electrical power consumption, and a pulse counter for counting the pulses, the pulse counter generating an output signal in response to a predetermined number of pulses being counted which vary from a predetermined level.
- 38. A circuit as claimed in claim 37 wherein the counter generates an output signal in response to the absence of a predetermined number of pulses less than a preset level.
- 39. A circuit as claimed in claim 37 wherein the counter generates an output signal in response to the presence of a predetermined number of pulses greater than a preset level.
- 40. A circuit as claimed in claim 37 wherein the circuit is provided by an application specific integrated circuit.
- 41. A circuit as claimed in claim 40 wherein the ASIC incorporates an electromagnetic radiation detector.
- 42. A circuit as claimed in claim 37 wherein the circuit is used in a keyless access control mechanism and the output signal is used to actuate the keyless access control mechanism.
- 43. A sensor device for use with a keyless access control mechanism, the sensor device comprising:
a post for incorporation into one end of a door handle; an electromagnetic radiation emitter and receiver located in the post for generating an incident beam of electromagnetic radiation substantially parallel to the handle, and for receiving a reflected beam of electromagnetic radiation; and a signal processing circuit coupled to the emitter and receiver for detecting a partial or total interruption or modification of the incident beam, the signal processing unit generating an output signal when the interruption or modification to the beam is detected for transmitting to an access control mechanism.
- 44. A sensor device as claimed in claim 43 wherein the emitter and receiver are disposed adjacent each other on the post at the same level.
- 45. A sensor device as claimed in claim 43 for use with a vehicle keyless access system wherein the post is connected to a module carrying the signal processing circuit, the module being totally or partially locatable behind a door skin such that the post and a door handle use the same aperture in the door skin.
- 46. A sensor device as claimed in claim 43 wherein the post includes a back-up switch, the back-up switch being mechanically coupled to the handle and electrically coupled to the signal processing unit for actuation by a user to cause the signal processor to generate the output signal in the event of failure of the optical system.
- 47. A sensor device as claimed in claim 43 wherein the post includes a locking switch, the locking switch being mechanically coupled to the handle and to the signal processing unit, the locking switch being actuatable by a user to send a locking signal to the keyless access control mechanism.
- 48. A sensor device as claimed in claim 43 wherein the optical processing circuit is implemented in an application specific integrated circuit.
- 49. A sensor device as claimed in claim 43 wherein the signal processing unit includes a counter for counting pulses received from the detector, the signal processing unit providing an output signal when the counter counts the presence of a predetermined number of detected pulses greater than a preset level.
- 50. A sensor device as claimed in claim 43 wherein a beam reflector is disposed at the other end of the handle for reflected incident electromagnetic radiation from the emitter to be detected.
- 51. A sensor device as claimed in claim 50 wherein the signal processing unit includes a counter for counting pulses received from the detector, the signal processing unit providing an output signal when the counter counts the absence of a predetermined number of pulses less than a present level.
Priority Claims (1)
Number |
Date |
Country |
Kind |
0016089.5 |
Jul 2001 |
GB |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International application PCT/GB01/02919 filed Jun. 29, 2001, the entire content of which is expressly incorporated herein by reference thereto.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/GB01/02919 |
Jun 2001 |
US |
Child |
10330309 |
Dec 2002 |
US |