Vision system
The present invention relates to improved optical structures, related manufacturing processes and assemblies incorporating the improved optical structures. In at least one embodiment accurate light source color information is provided throughout substantially the entire associated field of view.
1. An image acquisition system, comprising:
a lens structure configured to project an image on an image surface of an image sensor, said lens structure comprising a compound lens, said compound lens comprising at least a first and a second lens element each comprising at least one substantially non-planar lens surface, said first and second lens elements comprising different lens materials, said first and second lens elements are in direct contact with one another, such that there is no interposing material, such as a glue layer, an air gap, or any other imposing material therebetween, wherein said first and second lens elements are configured to function in combination to at least partially correct chromatic aberration.
2. The image acquisition system as in claim 1 said first lens element comprising acrylic.
3. The image acquisition system as in claim 1 said first lens element comprising polycarbonate.
4. The image acquisition system as in claim 1 further comprising an aperture mask between said first lens element and said image sensor.
5. The image acquisition system as in claim 1 further comprising a diffuser configured to uniformly set the width of diffusing to approximately equal a center-to-center spacing of adjacent pixels of said image sensor measured in the direction of said diffusing.
6. The image acquisition system as in claim 1 , wherein said first lens element is further away from said image sensor than said second lens element, said first lens element comprising a material with a higher Abbé number than said second lens element.
7. The image acquisition system as in claim 6 said first lens element comprising a scene side convex surface and an image sensor side convex surface.
8. The image acquisition system as in claim 6 , wherein a thickness of said first lens element is greater than a scene side surface radius thereof.
9. The image acquisition system as in claim 1 , wherein said first lens element is further away from said image sensor than said second lens element, said first lens element comprising a material with a lower Abbé number than said second lens element.
10. The image acquisition system as in claim 9 said first lens element comprising a scene side convex surface and an image sensor side concave surface.
11. The image acquisition system as in claim 9 , wherein a thickness of said first lens element is less than a scene side surface radius.
12. The image acquisition system as in claim 1 that is substantially free of air gaps between said lens elements and said image surface.
13. The image acquisition system as in claim 1 further comprising a red spectral filter between said first compound lens and said image sensor.
14. The image acquisition system as in claim 13 further comprising a red compliment spectral filter between said second compound lens and said image sensor.
15. The image acquisition system of claim 1 , wherein a change in an index of refraction of said second lens element is greater than a change in an index of refraction of said first lens element over a given temperature range.
16. The image acquisition system of claim 1 , wherein an index of refraction of said first lens element changes more quickly as a function of temperature than an index of refraction of said second lens element.
17. An image acquisition system, comprising:
a lens structure configured to project an image on an image surface of an image sensor, said lens structure comprising:
a compound lens comprising:
a first lens element; and
a second lens element, wherein each of said first and second lens elements comprise at least one substantially non-planar lens surface and different lens materials, said first and second lens elements are configured to function in combination to at least partially correct chromatic aberration, wherein a change in an index of refraction of said second lens element is greater than a change in an index of refraction of said first lens element over a given temperature range, and an index of refraction of said first lens element changes more quickly as a function of temperature than an index of refraction of said second lens element thereby reducing a change in focal length of said compound lens over said temperature range.
18. An image acquisition system, comprising:
a lens structure configured to project an image or an image surface of an image sensor, said lens structure comprising:
a compound lens comprising:
a first lens element;
a second lens element, wherein each of said first and second lens elements comprise at least one substantially non-planar surface and different lens materials, said first and second lens elements are configured to function in combination to at least partially correct chromatic aberration; and
an aperture mask between said first lens elements and said image sensor.
19. The image acquisition system of claim 18 , wherein said first lens element is further away from said image sensor than said second lens element, said first lens element comprising a material with a higher Abbé number than said second lens element.
20. The image acquisition system of claim 18 , wherein said first lens element is further away from said image sensor than said second lens element, said first lens element comprising a material with a lower Abbé number than said second lens element.