Varifocal lens

Patent metadata

Field	Value
Publication number	US-2016103253-A1
Application number	US-201314889819-A
Country	US
Kind code	A1
Filing date	May 9, 2013
Priority date	May 9, 2013
Publication date	Apr 14, 2016
Grant date	—

Abstract

A varifocal lens capable of exhibiting high lens performance even with low lens power, and also capable of realizing a comparatively large aperture includes a first elastic membrane arranged between a first medium and a second medium. The first elastic membrane is capable of elastic deformation by pressure from the first medium or the second medium. A drive section causes change in curvature of the first elastic membrane by causing variation in pressure or volume of the first medium or the second medium. The first tensile force applying section applies isotropic tensile force to the first elastic membrane.

First claim

1 . A varifocal lens, comprising a housing section, a first elastic membrane, a first medium, a second medium, a drive section, and a first tensile force applying section, wherein:
the housing section is capable of passing light along an optical axis direction of a lens, and the housing section comprises a first space and a second space arranged along the optical axis direction, the first elastic membrane is arranged between the first space and the second space, and is configured to partition between the first space and the second space by extending in a direction that intersects the optical axis direction, the first medium is filled into the first space, the second medium is filled into the second space, refractive indices of the first medium and the second medium are respectively different, the first elastic membrane is arranged between the first medium and the second medium, and the first elastic membrane is capable of being elastically deformed by a pressure difference between the first medium and the second medium, the drive section is configured to change a curvature of the first elastic membrane by causing a variation in pressure or volume of the first medium or the second medium, and the first tensile force applying section applies isotropic tensile force to the first elastic membrane.

2 . The varifocal lens according to claim 1 , wherein the first medium and the second medium are both liquid.

3 . The varifocal lens according to claim 1 , wherein the first tensile force applying section comprises:
a holding section for holding the periphery of the first elastic membrane, and a pressing section for generating isotropic tensile stress in the first elastic membrane by pressing the vicinity of the periphery of the first elastic membrane, in a state of being held by the holding section, substantially uniformly in the optical axis direction.

4 . The varifocal lens according to claim 1 , wherein a chromatic dispersion characteristic of the first medium and a chromatic dispersion characteristic of the second medium are made respectively different characteristics.

5 . The varifocal lens according to claim 1 , further comprising a second elastic membrane, a third medium, and a second tensile force applying section, wherein:
the housing section further comprises a third space, the third space is arranged at a position along the optical axis direction with respect to the first space and the second space, the second elastic membrane is arranged between the second space and the third space, and is configured to partition between the second space and the third space by extending in a direction that intersects the optical axis direction, the third medium is filled into the third space, the refractive index of the third medium is different than the refractive index of the first medium or the second medium, the second elastic membrane is arranged between the second medium and the third medium, and the second elastic membrane is capable of being elastically deformed by a pressure difference between the second medium and the third medium, and wherein: the drive section causes change in curvature of the second elastic membrane by causing variation in pressure or volume of the second medium or the third medium, and the second tensile force applying section applies isotropic tensile force to the second elastic membrane.

6 . The varifocal lens according to claim 5 , wherein the tensile force applied to the first elastic membrane and the tensile force applied to the second elastic membrane are different in magnitude.

7 . The varifocal lens according to claim 5 , wherein a chromatic dispersion characteristic of the first elastic membrane and a chromatic dispersion characteristic the second elastic membrane are made different characteristics.

8 . An imaging device comprising the varifocal lens according to claim 1 .

9 . A projection device comprising the varifocal lens according to claim 1 .

Assignees

• Univ Tokyo

Inventors

• Oku Hiromasa
• Wang Lihui
• Ishikawa Masatoshi

Classifications

• G02B3/14 Primary

  of variable focal length · CPC title

• G02B27/0025

  for optical correction, e.g. distorsion, aberration · CPC title