ACTIVE NIGHT VISION SYSTEM WITH FULLY SYNCHRONIZED LIGHT SOURCE AND RECEIVER

• US 20050247862A1
• Filed: 05/05/2004
• Published: 11/10/2005
• Est. Priority Date: 05/05/2004
• Status: Abandoned Application

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Faytlin, Alexander, Hein, David, Moore, Mark
• Application Number:
  US10/709,438
• Publication Number:
  US 20050247862A1
• Time in Patent Office: Days
• US Class Current: 250/214.VT
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: B60R 1/24 in front of the vehicle
• CPC Class Codes: B60R 1/30 providing vision in the non-visible spectrum, e.g. night or infrared vision
• CPC Class Codes: B60R 2300/103 using camera systems provided with artificial illumination device, e.g. IR light source
• CPC Class Codes: B60R 2300/106 using night vision cameras
• CPC Class Codes: B60R 2300/205 using a head-up display
• CPC Class Codes: B60R 2300/8053 for bad weather conditions or night vision
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

A method of operating an active night vision system includes generating a first oscillating signal (48). A trigger signal (43) is generated having a duty cycle (51) with a cycle start time (52) and a cycle end time (53). The cycle end time (53) is synchronized with a pulse end time (54) of the first oscillating signal (48). A light source (26) is operated in response to the duty cycle (51).

Claims

1. A method of operating an active night vision system comprising:

generating a first oscillating signal;

generating a trigger signal having a duty cycle with a cycle start time and a cycle end time;

synchronizing said cycle end time with a pulse end time of said first oscillating signal; and

operating a light source in response to said duty cycle.

2. A method as in claim 1 further comprising operating a receiver in response to said duty cycle.

3. A method as in claim 2 wherein said light source and said receiver are activated at said cycle start time and deactivated at said cycle end time.

4. A method as in claim 1 wherein generating a trigger signal having a duty cycle with a cycle start time and a cycle end time is performed via a controller.

5. A method as in claim 1 wherein synchronizing said cycle end time with a pulse end time of said first oscillating signal is performed via a controller.

6. A method as in claim 1 further comprising:

generating a second oscillating signal in response to said first oscillating signal; and

synchronizing said cycle start time with a pulse start time of said second oscillating signal.

7. A method as in claim 1 further comprising synchronizing said cycle start time with a pulse end time of said first oscillating signal.

8. A method as in claim 7 wherein synchronizing said cycle start time with a pulse end time comprises synchronizing a rising edge of said duty cycle with a falling edge of said first oscillating signal.

9. A method as in claim 1 wherein synchronizing said cycle end time with a pulse end time comprises synchronizing a first falling edge of said duty cycle with a second falling edge of said first oscillating signal.

10. An active night vision system comprising:

a counter circuit receiving a first oscillating signal and generating a second oscillating signal;

a duty cycle generator generating a pre-trigger signal having a first duty cycle in response to said first oscillating signal and said second oscillating signal;

a pulse end detector detecting pulse endings of said first oscillating signal and said second oscillating signal and generating a post-trigger signal having a second duty cycle; and

a light source controller operating a light source in response to said second duty cycle.

11. A system as in claim 10 further comprising a receiver operating in response to said second duty cycle.

12. A system as in claim 10 further comprising a receiver having an oscillator generating said first oscillating signal.

13. A system as in claim 12 wherein said oscillator is a horizontal oscillator.

14. A system as in claim 10 wherein said pre-trigger signal is partially synchronized with said first oscillating signal.

15. A system as in claim 10 wherein said post-trigger signal is fully synchronized with said first oscillating signal.

16. A system as in claim 10 wherein said second oscillating signal is in the form of an approximately 60 Hz oscillating signal.

17. A system as in claim 10 wherein said duty cycle generator is in the form of a resistor/capacitor (RC) circuit.

18. A system as in claim 10 wherein said pulse end detector is in the form of a flip-flop circuit.

19. An active night vision system comprising:

a first counter circuit receiving a first oscillating signal and generating a second oscillating signal;

a second counter circuit generating a trigger signal having a duty cycle with a cycle start time and a cycle end time in response to said first oscillating signal and said second oscillating signal;

said second counter circuit synchronizing said cycle end time with a second pulse end time of said first oscillating signal; and

a light source controller operating a light source in response to said duty cycle.

20. A system as in claim 19 wherein said second counter circuit synchronizes said cycle start time with a first pulse end time of said first oscillating signal.