OPTICAL DEVICE AND IMAGING DEVICE

• US 20120249895A1
• Filed: 02/03/2012
• Published: 10/04/2012
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kaifu, Keita
• Granted Patent: US 8,659,722 B2
• Time in Patent Office: Days
• US Class Current: 349/1
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence
• CPC Class Codes: H04N 23/75 by influencing optical camera components

Abstract

There are provided an optical device including a dimming cell capable of performing low illumination imaging without varying an optical path length, and an imaging device using the optical device. The optical device includes a cell having a containing layer between a first transparent substrate disposed on a light incident side and a second transparent substrate which is disposed on a light emitting side and faces the first transparent substrate, a variable transmittance section provided in a first region of the containing layer and allowing light transmittance to be varied within a predetermined range, and a fixed transmittance section provided in a second region different from the first region as seen from the light incident side and having a light transmittance higher than that of the variable transmittance section.

Claims

1. An optical device comprising:

a cell having a containing layer between a first transparent substrate disposed on a light incident side and a second transparent substrate which is disposed on a light emitting side and faces the first transparent substrate;

a variable transmittance section provided in a first region of the containing layer and allowing light transmittance to be varied within a predetermined range; and

a fixed transmittance section provided in a second region different from the first region as seen from the light incident side and having a light transmittance higher than that of the variable transmittance section.

2. The optical device according to claim 1, wherein the variable transmittance section is configured of a liquid crystal section, and the fixed transmittance section is configured of a transparent section.

3. The optical device according to claim 2, wherein a face, close to the transparent section, of the liquid crystal section is parallel to an optical axis.

4. The optical device according to claim 2, wherein the face, close to the transparent section, of the liquid crystal section is inclined with respect to the optical axis.

5. The optical device according to claim 1, wherein the first region and the second region are partitioned by a partition section.

6. The optical device according to claim 5, wherein the partition section is configured of an orientation film.

7. The optical device according to claim 2 further comprising a cell movement control section shifting the cell in a direction in which the liquid crystal section and the transparent section are arranged, and placing, on the optical axis, the liquid crystal section, the transparent section, or a region near the boundary between the liquid crystal section and the transparent section.

8. The optical device according to claim 2, wherein the liquid crystal section and the transparent section have substantially the same refractive index.

9. The optical device according to claim 8, wherein the refractive index of the transparent section is a value between a maximum value and a minimum value of the refractive index of the liquid crystal section, the refractive index of the liquid crystal section being varied according to a variation in the light transmittance of the liquid crystal section.

10. The optical device according to claim 2, wherein a plurality of the liquid crystal sections and a plurality of the transparent sections are arranged along the optical axis.

11. The optical device according to claim 2, wherein the liquid crystal section is configured of a guest-host (GH) type liquid crystal containing a dichroic dye.

12. An imaging device including an imaging element and an optical device, the optical device comprising:

a cell having a containing layer between a first transparent substrate disposed on a light incident side and a second transparent substrate which is disposed on a light emitting side and faces the first transparent substrate;

a variable transmittance section provided in a first region of the containing layer and allowing light transmittance to be varied within a predetermined range; and

a fixed transmittance section provided in a second region different from the first region as seen from the light incident side and having a light transmittance higher than that of the variable transmittance section.