Dichroic aperture for electronic imaging device

• US 8,761,596 B2
• Filed: 01/26/2011
• Issued: 06/24/2014
• Est. Priority Date: 09/26/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Gere, David S.
• Primary Examiner(s): BLACKMAN, ROCHELLE ANN J
• Application Number:
  US13/013,894
• Publication Number:
  US 20110115964A1
• Time in Patent Office: 1,245 Days
• Field of Search: 396/50, 396/275, 348/42, 348/61, 348/222.1, 348/342, 359/722, 359/887
• US Class Current: 396/275
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02B 7/006 Filter holders

Abstract

A dichroic filter that for use with an electronic imaging device, such as a camera. The dichroic filter is located in the main imaging lens, and may permit all light to pass through a first portion and be measured by a photosensor, while restricting at least some portions of visible light from passing through a second portion thereof. In this manner, only the non-restricted portions of visible light passing through the second portion may be measured by the associated pixels of the photosensor. The filter may be formed from a first aperture permitting a first set of wavelengths to pass therethrough and a second aperture adjacent the first aperture, the second aperture permitting only a subset of the first set of wavelengths to pass therethrough. The second aperture may be a dichroic mirror or it may be an optical filter of some other type.

Claims

1. A filter for a camera, comprising:

a first aperture having a first light-transmissive property; and

a second aperture adjacent the first aperture, the second aperture having a second light-transmissive property;

wherein

the first and second light-transmissive properties are different; and

the first and second apertures are unitarily formed as a single lens.

2. The filter of claim 1, wherein the second aperture abuts the first aperture.

3. The filter of claim 1, wherein:

the first light-transmissive property comprises passing a first set of wavelengths of light;

the second light-transmissive property comprises passing a second set of wavelengths of light; and

the second set of wavelengths of light is different from the first set of wavelengths of light.

4. The filter of claim 3, wherein the second set of wavelengths is a subset of the first set of wavelengths.

5. The filter of claim 3, wherein the second set of wavelengths does not overlap with the first set of wavelengths.

6. The filter of claim 3, further comprising a third aperture abutting at least one of the first and second aperture, the third aperture transmitting substantially all wavelengths of visible light.

7. An electronic imaging device, comprising:

a filter;

a photosensor operatively connected to the filter; and

a processor operatively connected to the photosensor;

wherein

the filter defines at least a first and second region;

the first region permits light of a first wavelength set to be detected by a first portion of the photosensor;

the second region permits light of a second wavelength set to be detected by a second portion of the photosensor;

wherein

the at least first and second regions are unitarily formed as a single lens; and

a signal level of a first signal corresponding to the light detected by the first region is less than a signal level of a second signal corresponding to the light detected by the second region.

8. The electronic imaging device of claim 7, wherein:

the first region has a first f-number; and

the second region has a second f-number and is adjacent the first region.

9. The electronic imaging device of claim 8, wherein:

the first region passes light in a red region of the color spectrum; and

the second region passes light in a blue region of the color spectrum.

10. The electronic imaging device of claim 9, wherein an aperture of the second region is greater than an aperture of the first region.

11. The electronic imaging device of claim 7, wherein the processor is operative to create a single image from at least the first and second signals.

12. The electronic imaging device of claim 11, wherein:

the second signal corresponds to a blue image; and

the first signal corresponds is a non-blue image.

13. The electronic imaging device of claim 12, wherein the blue image has decreased noise and resolution in comparison to the non-blue image.