Imaging Device

• US 20180166489A1
• Filed: 12/08/2017
• Published: 06/14/2018
• Est. Priority Date: 12/13/2016
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sao, Mayu, Nakamura, Yusuke, Tajima, Kazuyuki, Shimano, Takeshi
• Granted Patent: US 10,461,108 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 13/04 Reversed telephoto objectives
• CPC Class Codes: G02B 27/4205 having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
• CPC Class Codes: G02B 27/4272 having plural diffractive elements positioned sequentially along the optical path
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: H01L 27/146 Imager structures
• CPC Class Codes: H01L 27/14623 Optical shielding
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof
• CPC Class Codes: H04N 25/67 applied to fixed-pattern noise, e.g. non-uniformity of response

Abstract

An imaging device includes: a modulator with a first pantoscopic grating pattern, which is configured to modulate light intensity by passage through the first pantoscopic grating pattern; an image sensor configured to convert light passing through the modulator, to image data, and output the image data; and an image processing unit configured to conduct image processing of restoring an image with the use of the image date output from the image sensor, and the imaging device is characterized in that: the first pantoscopic grating pattern is configured to include multiple basic patterns; and each of the basic patterns has the shape of a concentric circle.

Claims

1. An imaging device comprising:

a modulator with a first pantoscopic grating pattern, the modulator configured to modulate light intensity by passage through the first pantoscopic grating pattern;

an image sensor configured to convert light passing through the modulator, to image data, and output the image data; and

an image processing unit configured to conduct image processing of restoring an image with the use of the image data output from the image sensor,

wherein the first pantoscopic grating pattern is configured to comprise multiple basic patterns, and

each of the basic patterns has the shape of a concentric circle.

2. The imaging device according to claim 1, wherein at least two or more basic patterns consisting the multiple basic patterns are identical.

3. The imaging device according to claim 1, wherein a light shielding plate is provided between the first pantoscopic grating pattern and the image sensor, and

the light shielding plate is disposed on the basis of an arrangement of the basic patterns.

6. The imaging device according to claim 1, wherein the concentric circles of the adjacent basic patterns differ by π

/2 in initial phase from each other.

7. The imaging device according to claim 1, wherein the modulator comprises a first polarization plate and a second polarization plate,

the first polarization plate is disposed closer to a surface configured to serve as an input face of the modulator,

the second polarization plate is disposed closer to a rear surface configured to serve as an output face of the modulator,

the first polarization plate and the second polarization plate have polarizing axes determined on the basis of an arrangement of the basic patterns, and

the concentric circles of the adjacent basic patterns differ by π

/2 in initial phase from each other.

8. The imaging device according to claim 1, wherein a distance from the modulator to an object of imaging is determined on the basis of a center-to-center distance between the concentric circles and a scattering angle of light from the object of imaging.

9. The imaging device according to claim 1, wherein the image sensor has a size determined on the basis of a center-to-center distance between the concentric circles and a scattering angle of light from an object of imaging.

10. The imaging device according to claim 1, wherein for each of the concentric circles in the basic patterns, with respect to a reference coordinate as a center of the concentric circle, the concentric circle has a pitch narrowed in inverse proportion to a distance from the reference coordinate.

11. The imaging device according to claim 1, wherein the image processing unit generates a moire fringe image by modulating the image data with the use of data representing a second pantoscopic grating pattern comprising a concentric circle.

12. The imaging device according to claim 1, wherein the image processing unit generates a moire fringe image by modulating the image data with the use of data representing a second pantoscopic grating pattern comprising a concentric circle, and calculates a frequency spectrum by applying Fourier transform to the moire fringe image.

4. The imaging device according to claim'"'"', wherein the modulator comprises a first polarization plate and a second polarization plate,

the first polarization plate is disposed closer to a surface configured to serve as an input face of the modulator,

the second polarization plate is disposed closer to a rear surface configured to serve as an output face of the modulator, and

the first polarization plate and the second polarization plate have polarizing axes determined on the basis of an arrangement of the basic patterns.

5. The imaging device according to claim 4, wherein the first polarization plate and the second polarization plate are disposed such that polarizing axes of adjacent polarization plates are orthogonal to each other.