IMAGE INPUT APPARATUS, PHOTODETECTION APPARATUS, AND IMAGE SYNTHESIS METHOD

• US 20090140131A1
• Filed: 06/22/2006
• Published: 06/04/2009
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: UTAGAWA, Ken
• Granted Patent: US 7,732,744 B2
• Time in Patent Office: Days
• US Class Current: 250/226
• CPC Class Codes: G02B 27/0075 with means for altering, e.g. increasing, the depth of field or depth of focus
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0062 Stacked lens arrays, i.e. refractive surfaces arranged in at least two planes, without structurally separate optical elements in-between
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 23/957 Light-field or plenoptic cameras or camera modules
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements

Abstract

An image input apparatus includes an imaging optical system, a microlens array having a plurality of microlenses two-dimensionally arrayed with a predetermined pitch in the vicinity of a focal plane of the imaging optical system, and a photoreceptor array having a plurality of photoreceptors for each of the microlenses, each of the photoreceptors receiving bundles of rays passing through one of different exit-pupil regions of the imaging optical system. A power of the microlens and a gap between the microlens array and the photoreceptor array are determined so that a cross-sectional dimension of the bundles of rays for forming an image of each of the photoreceptors related to the microlens is equal to or smaller than the pitch of the microlens, within a range from the microlens array to a predetermined distance.

Claims

1. An image input apparatus comprising:

an imaging optical system;

a microlens array having a plurality of microlenses two-dimensionally arrayed with a predetermined pitch in a vicinity of a focal plane of the imaging optical system; and

a photoreceptor array having a plurality of photoreceptors for each of the microlenses, each of the photoreceptors receiving bundles of rays passing through one of different regions at an exit-pupil of the imaging optical system,

wherein a power of the microlens and a gap between the microlens array and the photoreceptor array are determined so that a cross-sectional dimension of the bundles of rays for forming an image of each of the photoreceptors related to the microlens is equal to or smaller than the pitch of the microlens, within a range from the microlens array to a predetermined distance.

2. The image input apparatus according to claim 1,

wherein the predetermined distance corresponds to a gap between the microlens array and a plane in which a pitch of the image of the photoreceptor is equal to the pitch of the microlens when the photoreceptors are projected toward the imaging optical system through the microlens.

3. The image input apparatus according to claim 1, further comprising:

an image synthesis unit that generates a synthetic image in an image plane at a desired position within the range to the predetermined distance, based on photoreception signals obtained by the plurality of photoreceptors.

4. The image input apparatus according to claim 3,

wherein the photoreceptor array has color filters of a plurality of colors for the plurality of photoreceptors, and

wherein the image synthesis unit generates the synthetic image related to the color having the highest density among the colors of the color filters.

5. The image input apparatus according to claim 3,

wherein the image synthesis unit generates the synthetic image by determining weighting of the photoreception signals in accordance with the position within the range to the predetermined distance.

6. The image input apparatus according to claim 1, further comprising,

an image synthesis unit that generates a synthetic image corresponding to a desired F-number of the imaging optical system, based on photoreception signals obtained by the plurality of photoreceptors.

7. The image input apparatus according to claim 6,

wherein the photoreceptor array has color filters of a plurality of colors for the plurality of photoreceptors, and

wherein the image synthesis unit generates the synthetic image related to a color having the highest density among the colors of the color filters.

8. The image input apparatus according to claim 6,

wherein the image synthesis unit generates the synthetic image by determining weighting of the photoreception signals in accordance with the F-number.

16. An image acquisition method comprising the step of:

acquiring an image based on photoreception signals obtained by the plurality of photoreceptors of the image input apparatus according to claim 1.

17. The image input apparatus according to claim 4,

wherein the image synthesis unit generates the synthetic image by determining weighting of the photoreception signals in accordance with the position within the range to the predetermined distance.

18. An image synthesis method comprising the step of

generating a synthetic image in an image plane located at a desired position based on an image acquired by an image acquisition method according to claim 16, by using a synthesis method that is changed in accordance with the desired position within the predetermined range.

19. The image synthesis method according to claim 18,

wherein the synthetic image is generated by determining weighting of the photoreception signals in accordance with the position within the predetermined range.

9. An image input apparatus comprising:

an imaging optical system;

a microlens array having a plurality of microlenses two-dimensionally arrayed with a predetermined pitch in a vicinity of a focal plane of the imaging optical system;

a photoreceptor array having a plurality of photoreceptors for each of the microlenses, each of the photoreceptors receiving bundles of rays passing through one of different regions at an exit-pupil of the imaging optical system;

color filters that provide different spectral sensitivity characteristics for the plurality of photoreceptors; and

an image synthesis unit that generates a synthetic image in an image plane at a desired position within a range from the microlens to a predetermined distance, based on photoreception signals obtained by the photoreceptors, related to a color having the highest density among the colors of the color filters.

10. A photodetection apparatus comprising:

an imaging optical system;

a microlens array having a plurality of microlenses two-dimensionally arrayed with a predetermined pitch in a vicinity of a focal plane of the imaging optical system;

a photoreceptor array having a plurality of photoreceptors for each of the microlenses, each of the photoreceptors receiving bundles of rays passing through one of different regions at an exit-pupil of the imaging optical system; and

an arithmetic unit that obtains a light amount of the bundles of rays incident on a region optionally set in an optical path of the imaging optical system, based on photoreception signals of the photoreceptors corresponding to a solid angle of the incident bundles of rays.

11. A photodetection apparatus comprising:

an imaging optical system;

a microlens array having a plurality of microlenses two-dimensionally arrayed with a predetermined pitch in a vicinity of a focal plane of the imaging optical system;

a photoreceptor array having a plurality of photoreceptors for each of the microlenses, each of the photoreceptors receiving bundles of rays passing through one of different regions at an exit-pupil of the imaging optical system; and

an arithmetic unit that interpolates and obtains a light amount corresponding to a position between images that are formed by projecting the plurality of photoreceptors toward the imaging optical system through the microlens, based on photodetection signals obtained by the plurality of photoreceptors.

12-14. -14. (canceled)

15. A photodetection method comprising the steps of:

receiving bundles of rays passing through different regions at an exit-pupil of an imaging optical system by a plurality of photoreceptors through a plurality of microlenses arrayed with a predetermined pitch in a vicinity of a focal plane of the imaging optical system; and

obtaining a light amount of bundles of rays incident on a region optionally set in an optical path of the imaging optical system, based on a solid angle of the bundles of rays incident on the region and photoreception signals obtained by the photoreceptors corresponding to the solid angle.