Improved low parallax lens design

Abstract

This invention provides a camera lens design that captures incident light from a polygonal field of view and forms a polygonal image with improved parallax and front color performance. [Solution] The lens shape of the low parallax imaging device includes multiple imaging lens elements arranged to capture and image a polygonal field of view. The lens shape includes a group of compression lens elements and a group of wide-angle lens elements.

Claims

1. An imaging lens for use in a low-parallax multi-camera imaging system, wherein the imaging lens is A compressor lens element group comprising a truncated polygonal lens element having a meniscus lens shape and equipped with a crown optical material, wherein the compressor lens element group is configured to refract at least a portion of incident light having a spectral bandwidth as image light within a polygonal field of view, and the image light includes a principal ray of the field of view which is a ray received along the truncated edge of the compressor lens element, A wide-angle lens group configured to receive the image light from the compressor lens group, direct the image light towards the image plane, and form a polygonal image corresponding to the polygonal field of view, Equipped with, The projection of the edge-of-field principal rays, including the non-paraxial principal rays within the spectral bandwidth contained in the incident light, converges at or near a low parallax. The meniscus shape of the truncated polygonal lens element minimizes pupillary aberration (PSA) with respect to the projection of the non-paraxial principal rays crossing the low parallax amount in the imaging lens.

2. The imaging lens according to claim 1, wherein the compressor lens element group is configured to limit parallax or front color in order to reduce color-dependent vignetting at the edges of the truncated polygonal lens element.

3. The imaging lens according to claim 2, wherein the control of the front color or parallax along the edge of the polygonal image contributes to reducing the width of the seam between the imaging lens and adjacent imaging lenses in a multi-lens device.

4. The imaging lens according to claim 2, wherein the compressor lens element group is configured to introduce positive lateral color, and the wide-angle lens element group is configured to provide negative lateral color that cancels out the positive lateral color.

5. The imaging lens according to claim 1, wherein the truncated polygonal compressor lens element also functions as at least an out-of-focus field aperture.

6. The image lens according to claim 1, wherein the truncated polygonal compressor lens element has a cut or beveled polygonal lens edge corresponding to the polygonal field of view of the image lens.

7. The imaging lens according to claim 1, wherein the compressor lens element group comprises a second compressor lens element, and the truncated polygonal lens element and the second compressor lens element are color-corrected to be colorless in order to further control or limit the front color.

8. The imaging lens according to claim 1, wherein the projection of the paraxial principal ray provides an entrance pupil located at a position on the front or rear axis at a low parallax.

9. The imaging lens according to claim 8, wherein the entrance pupil is located behind the image plane.

10. The imaging lens according to claim 8, wherein the distance between the entrance pupil and the low parallax point reduces the parallax error with respect to the non-paraxial principal ray received near one of the plurality of edges.

11. The imaging lens according to claim 1, wherein control of both front color and parallax along the edge of the polygonal image reduces the required width of the extended field of view provided by the imaging lens.

12. The imaging lens according to claim 11, wherein the expanded field of view is preferably less than 5% of the nominal field of view width, and more preferably less than 1%.

13. The imaging lens according to claim 1, wherein the average PSA of the imaging field, measured as the RMS lateral principal ray error within the amount of the low parallax point, is 0.30 mm or less.

14. The imaging lens according to claim 1, wherein the compressor lens element group is configured to contribute to positive distortion, and the wide-angle lens element group is configured to contribute to negative distortion.

15. The imaging lens according to claim 1, further comprising an image sensor nominally positioned on or near the image plane.

Images