Image intensity control in overland night vision systems

• US 20060017656A1
• Filed: 07/26/2004
• Published: 01/26/2006
• Est. Priority Date: 07/26/2004
• Status: Abandoned Application

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Miyahara, Shunji
• Application Number:
  US10/899,287
• Publication Number:
  US 20060017656A1
• Time in Patent Office: Days
• US Class Current: 345/8
• 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 2300/30 characterised by the type of image processing
• CPC Class Codes: B60R 2300/308 by overlaying the real scene, e.g. through a head-up display on the windscreen
• CPC Class Codes: B60R 2300/8053 for bad weather conditions or night vision
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

A near-infrared night vision system includes an infrared source that emits a near-infrared beam toward an object. The infrared beam is reflected from the object as a reflected beam. A camera receives the reflected beam and generates an image signal in response to the reflected beam. An image processor receives the image signal, generates a distribution of the intensities, compares the distribution to a threshold, and generates a display signal based on the comparison. A over-laid heads up display receives the display signal, generates a reflected image in response to the display signal, and overlays the reflected image over the actual image of the object.

Claims

1. A night vision system for a vehicle comprising:

an infrared source that emits an near-infrared beam toward an object, the infrared beam being reflected from the object as a reflected;

a camera that receives the reflected beam and generates an image signal in response to the reflected beam;

an image processor that receives the image signal, generates a distribution of the intensities, compares the distribution to a threshold, and generates a display signal based on the comparison; and

an over-laid heads up display that receives the display signal, generates a reflected image in response to the display signal, and overlays the reflected image over the actual image of the object.

2. The system of claim 1 wherein the image processor reduces the intensities received by the camera when the number of cells of the camera having an intensity exceeding the threshold is larger than a pre-determined value.

3. The system of claim 1 wherein the image processor increases the intensities received by the camera when the number of cells of the camera having an intensity exceeding the threshold is smaller than a pre-determined value.

4. The system of claim 1 further comprising an aftenuator that modifies the intensities received by the camera in response to the comparison between the distribution and the threshold.

5. The system of claim 1 further comprising a power supply coupled to the infrared source, the power source modifying the power supplied to the infrared source in response to the comparison between the distribution and the threshold.

6. The system of claim 1 wherein the near-infrared beam from the source has a wavelength of between about 0.8 μ

m to 0.9 μ

m or has a bandwidth of about 3 nm at the wavelength in the near infrared.

7. The system of claim 1 wherein the system is capable of viewing objects at a distance from the camera between about 5 m and 150m.

8. The system of claim 1 wherein the distribution of the intensities is a histogram of the number of camera cells at particular intensities.

9. A method of viewing objects at night comprising:

emitting a near-infrared beam from an infrared source toward an object, the infrared beam being reflected from the object as a reflected beam with a intensities;

receiving the reflected beam with a camera and generating an image signal in response to the reflected beam;

receiving the image signal with an image processor, processing the image signal to generate a distribution of the intensities, comparing the distribution to a threshold, and generating a display signal based on the comparison; and

receiving the display signal with a over-laid heads up display, generating a reflected image in response to the display signal, and overlaying the reflected image over the actual image of the object in the heads up display.

10. The method of claim 9 further comprising reducing the intensities received by the camera when the number of cells of the camera having an intensity exceeding the threshold is larger than a pre-determined value.

11. The method of claim 9 further comprising increasing the intensities received by the camera when the number of cells of the camera having an intensity exceeding the threshold is smaller than a pre-determined value.

12. The method of claim 9 further comprising modifying the intensities with an attenuator in response to the comparison between the distribution and the threshold.

13. The method of claim 9 further comprising modifying the power supplied to the infrared source in response to the comparison between the distribution and the threshold.

14. The method of claim 9 wherein the near-infrared beam from the source has a wavelength of between about 0.8 μ

m to 0.9 μ

m or has a bandwidth of about 3 nm in the near infrared.

15. The method of claim 9 wherein the distribution of the intensities is a histogram of the number of camera cells at particular intensities.