Imaging device and lens array used therein

• US 20090122175A1
• Filed: 03/20/2006
• Published: 05/14/2009
• Est. Priority Date: 03/24/2005
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Yamagata, Michihiro
• Granted Patent: US 7,880,794 B2
• Time in Patent Office: Days
• US Class Current: 348/335
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 3/0031 Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
• CPC Class Codes: G02B 3/0043 Inhomogeneous or irregular arrays, e.g. varying shape, size, height
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• 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 3/0075 characterized by non-optical structures, e.g. having integrated holding or alignment means
• CPC Class Codes: H01L 27/14627 Microlenses

Abstract

An object of the present invention is to provide: a thin imaging device in which a high image resolution is obtained and in which the resolution does not uniformly vary even when the shooting distance is changed; and a lens array used therein. The present invention relates to an imaging device comprising: a lens array 130 constructed by arranging in parallel a plurality of lens elements having optical power in at least one surface; and an image sensor 110 in which an optical image formed by an optical system having each of the lens elements is received by each of mutually different imaging regions each having a plurality of photoelectric conversion sections so that the optical image is converted into an electric image signal, wherein each lens element and the imaging region corresponding to the lens element constitute an imaging unit, while the imaging units have diverse imaging region areas. The present invention relates also to a lens array used therein.

Claims

1. An imaging device comprising:

a lens array constructed by arranging in parallel a plurality of lens elements having optical power in at least one surface; and

an image sensor in which an optical image formed by an optical system having each of the lens elements is received by each of mutually different imaging regions each having a plurality of photoelectric conversion sections so that the optical image is converted into an electric image signal, wherein

each lens element and the imaging region corresponding to the lens element constitute an imaging unit, while the imaging units have diverse imaging region areas.

2. The imaging device as claimed in claim 1, wherein the areas of the imaging regions of imaging units located in the most peripheral part of the image sensor are smaller than the areas of the imaging regions of imaging units located in the center part of the image sensor.

3. The imaging device as claimed in claim 2, wherein imaging units located in the most peripheral part of the image sensor have a lens element provided with a symmetry axis decentered in parallel to an axis passing through the center of the corresponding imaging region.

4. The imaging device as claimed in claim 2, wherein imaging units located in the most peripheral part of the image sensor have a lens element provided with a symmetry axis in agreement with an axis passing through the center of the corresponding imaging region.

5. The imaging device as claimed in claim 1, wherein the imaging units have a lens element having a shape obtained by cutting off a part of an axial symmetric lens element in a plane parallel to the symmetry axis.

6. The imaging device as claimed in claim 1, wherein the imaging units have an axial symmetric lens element provided with an axial symmetric lens face having a shape of a circle approximately inscribing the rectangular imaging region.

7. The imaging device as claimed in claim 1, further comprising a partition means for partitioning a space between the lens array and the image sensor for each of the imaging units.

8. The imaging device as claimed in claim 7, wherein the partition means is a partition member that is arranged separately from the lens element and that has a grid-shaped partition section formed such as to surround each imaging region in correspondence to the rectangular imaging region.

9. The imaging device as claimed in claim 7, wherein the partition means is a grid-shaped groove section that is formed in a manner integrated with the lens element and that is formed such as to surround each imaging region in correspondence to the rectangular imaging region.

10. A lens array used in the imaging device as claimed in claim 1.