Active night vision thermal control system using wavelength-temperature characteristic of light source

• US 7,276,696 B2
• Filed: 11/29/2005
• Issued: 10/02/2007
• Est. Priority Date: 07/15/2003
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Remillard, Jeffrey, Nietering, Kenneth
• Primary Examiner(s): Porta; David
• Assistant Examiner(s): TANINGCO, MARCUS H
• Application Number:
  US11/164,550
• Publication Number:
  US 20070200064A1
• Time in Patent Office: 672 Days
• Field of Search: 250/330, 250/338.1, 250/339.03, 250/339.04, 250/495.1
• US Class Current: 250/330
• CPC Class Codes: B60R 2300/106 using night vision cameras
• CPC Class Codes: B60R 2300/205 using a head-up display
• CPC Class Codes: F21V 29/00 Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems lighting fixtures combined with outlets for air-treatment systems F24F13/078
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 23/12 with means for image conversion or intensification
• CPC Class Codes: H01S 5/06804 by monitoring an external parameter, e.g. temperature

Abstract

A thermal control system (11) for a light source (46) of a vision system (10) includes a heater (63) that is thermally coupled to the light source (46). A thermal sensor (60) is thermally coupled to the light source (46) and generates a temperature signal. A controller (50) is coupled to the heater (63) and to the thermal sensor (60). The controller (50) operates the heater (63) when the temperature signal is below a maximum temperature limit. The minimum temperature limit corresponds to the wavelength-temperature characteristic of the light source.

Claims

1. A thermal control system for a light source of a vision system comprising:

a heater thermally coupled to the light source; and

a thermal sensor thermally coupled to the light source and generating a temperature signal;

a controller coupled to said heater and to said thermal sensor, said controller operating said heater when said temperature signal is below a temperature limit, said temperature limit corresponding to a wavelength-temperature curve of the light source.

2. A system as in claim 1 further comprising:

a cooling assembly having a cooling device and being thermally coupled to the light source; and

a controller coupled to said cooling assembly and operating said cooling device when said temperature signal is above a minimum temperature limit, said minimum temperature limit corresponding to a wavelength-temperature curve of the light source.

3. A system as in claim 2 wherein said controller activates said cooling device before said temperature signal drifts above said minimum temperate limit.

4. A system as in claim 2 wherein said cooling assembly comprises:

a cooling fan in thermal communication with said light source;

said controller operating said cooling fan when said temperature signal is above said minimum temperature limit.

5. A system as in claim 4 wherein said cooling assembly comprises:

a heat sink thermally coupled to said light source; and

an air sleeve thermally coupled to said heat sink and said cooling fan;

said controller operating said cooling fan to circulate air across said heat sink.

6. A system as in claim 5 further comprising a thermal coupler layer thermally coupled between said light source and said heat sink.

7. A system as in claim 2 wherein said controller controls cooling output and activation duration of said cooling device.

8. A system as in claim 1 wherein said heater is activated before said temperature signal drifts below a heater deactivation zone.

9. A system as in claim 1 wherein said controller controls thermal output and duration of said output of said heater.

10. A method of thermally controlling operating range of a light source of a vision system comprising:

generating a temperature signal in response to temperature of the light source;

determining a maximum temperature limit in response to a wavelength-temperature characteristic of the light source; and

heating the light source when said temperature signal is below the maximum temperature limit.

11. A method as in claim 10 further comprising cooling the light source when said temperature signal is above a minimum temperature limit.