Camera hardware design for dynamic rearview mirror

Patent metadata

Field	Value
Publication number	US-9304301-B2
Application number	US-201314040969-A
Country	US
Kind code	B2
Filing date	Sep 30, 2013
Priority date	Dec 26, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

An apparatus for capturing an image includes a plurality of lens elements coaxially encompassed within a lens housing. One of the lens elements includes an aspheric lens element having a surface profile configured to enhance a desired region of a captured image. At least one glare-reducing element coaxial with the plurality of lens elements receives light subsequent to the light sequentially passing through each of the lens elements. An imaging chip receives the light subsequent to the light passing through the at least one glare-reducing element. The imaging chip includes a plurality of green, blue and red pixels.

First claim

The invention claimed is:

1. Apparatus for capturing an image, comprising:
a plurality of lens elements coaxially encompassed within a lens housing, one of the lens elements including an aspheric lens element having a biconvex surface profile configured to enhance a center region of a captured image, said biconvex surface profile including a first convex aspheric surface and a second convex aspheric surface;
at least one glare-reducing element coaxial with the plurality of lens elements and receiving light subsequent to the light sequentially passing through each of the lens elements;
a color sensitive imaging chip receiving the light subsequent to the light passing through the at least one glare-reducing element, the color sensitive imaging chip including a plurality of color pixels and an imaging chip, each of the plurality of color pixels adjustable between one of a short-exposure time and a long-exposure time; and
an infrared cut-off filter lens element coaxially disposed between the aspheric lens element and the at least one glare-reducing element, the infrared cut-off filter configured to block infrared light within a predetermined range of wavelengths such that color fidelity is maintained in the color sensitive imaging chip.

2. The apparatus of claim 1 , wherein the surface profile of said aspheric lens element enlarges the center region of the captured image without using imaging processing to stretch the captured image.

3. The apparatus of claim 1 , wherein the surface profile of said aspheric lens element is configured in accordance with following relationship:

z
⁡

(
r
)

=

r
2

R
(

1
+

1
-

(

1
+
k

)

⁢

r
2

R
2

+

α
1

⁢

r
2

+

α
1

⁢

r
4

+

α
3

⁢

r
6

+
…

,

wherein
Z is an optical axis having a direction,
Z(r) is a displacement of the surface from the vertex in the z-direction, at distance r from the axis,
r is a radius from the vertex,
R is a radius of curvature,
κ is a conic constant, and
α i represents coefficients describing a deviation of the surface from an axially symmetric quadric surface specified by R and κ.

4. The apparatus of claim 1 , wherein the at least one glare-reducing element comprises at least one of a polarized element and a photochromic element.

5. The apparatus of claim 4 , wherein the polarized element is configured to reduce glare resulting from partially-polarized light in a horizontal plane by reflection.

6. The apparatus of claim 5 , wherein the polarized element is configured to transmit only vertically-polarized light to reduce the partially-polarized light in the horizontal plane by reflection.

7. The apparatus of claim 4 , wherein the photochromic element is configured to transition from a clear state to a darkened state when exposed to a light intensity exceeding an intensity threshold and transition back to the clear state when the photochromic element is no longer exposed to the light intensity exceeding the intensity threshold.

8. The apparatus of claim 7 , wherein the light intensity is directly proportional to power of a source transmitting the light and indirectly proportional to a distance between the source and the photochromic element.

9. The apparatus of claim 7 , wherein only corresponding portions of the photochromic element that are exposed to light intensity exceeding the intensity threshold transition to the darkened state while all other portions not exposed to light intensities exceeding the intensity threshold remain in the clear state.

10. The apparatus of claim 9 , wherein the darkened state includes a varying magnitude of dimming applied to the corresponding portions of the photochromic element directly proportional to light intensity exposed upon the corresponding portions.

11. The apparatus of claim 1 , further comprising:
an electrochromism layer configured to transition to a darkened state in response to photo sensors disposed on the electrochromism layer detecting saturation.

12. The apparatus of claim 1 , wherein said at least one glare-reducing element covers the imaging chip with no other elements disposed between said at least one glare-reducing element and the imaging chip.

13. The apparatus of claim 1 , further comprising:
a cover glass coaxially disposed at a location comprising one of:
between the at least one glare-reducing element and the imaging chip; and
on top of the at least one glare-reducing element.

14. Apparatus for capturing glare-reduced images, comprising:
an aspheric lens element having a biconvex surface profile selected to enhance a center region within captured images, said biconvex surface profile including a first convex aspheric surface and a second convex aspheric surface;
coaxial with the aspheric lens element, at least one glare-reducing element comprising:
a polarized lens element configured to transmit only vertically-polarized light to reduce partially-polarized light in a horizontal plane by reflection off a ground surface, said partially-polarized light in the horizontal plane passing through the aspheric lens element before being received at the polarized lens element; and
a photochromic element configured to transition from a clear state to a darkened state when exposed to light subsequent to the light passing through the as

Assignees

• Gm Global Tech Operations Inc

Inventors

• Zhang Wende
• Wang Jinsong
• Lybecker Kent S
• Piasecki Jeffrey S
• Frakes Ryan M
• Hester Travis S

Classifications

• G02B19/009

  for use with infrared radiation · CPC title

• G02B19/0076

  for use with a detector (G02B19/009, G02B19/0095 take precedence) · CPC title

• G02B13/14 Primary

  for use with infrared or ultraviolet radiation ({G02B13/008, } G02B13/16 take precedence) · CPC title

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• H04N9/00

  Details of colour television systems · CPC title