Imaging apparatus

Patent metadata

Field	Value
Publication number	US-9635264-B2
Application number	US-201514607558-A
Country	US
Kind code	B2
Filing date	Jan 28, 2015
Priority date	Jan 30, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

An imaging apparatus includes a front lens group having a front lens element and a reflector, in that order from an object side. The reflector includes a reflection surface which reflects light rays, from the front lens element, toward a different direction; a rear lens group positioned closer to an image plane than the front lens group, the imaging apparatus performs an image-stabilizing operation by driving the front lens element, a movable frame holding the front lens element; a support member supporting the reflector and is immovable relative to an optical axis of the front lens element, in a reference state; and a support mechanism which supports the movable frame to spherically swing about a spherical-swinging center, positioned on an extension of the optical axis of the front lens element extending behind an underside of the reflection surface of the reflector.

First claim

What is claimed is:

1. An imaging apparatus comprising:
a front lens group which constitutes part of an imaging optical system of said imaging apparatus and includes at least one front lens element and a reflector, in that order from an object side, wherein said reflector includes a reflection surface which reflects light rays, exiting from said front lens element, toward a different direction, and wherein said imaging apparatus performs an image-stabilizing operation by driving said front lens element in response to vibrations applied to said imaging optical system in order to reduce image shake on said image plane;
at least one rear lens group which constitutes another part of said imaging optical system and is positioned closer to an image plane than said front lens group;
a movable frame which holds said front lens element;
a support member which supports at least said reflector and is immovable relative to an optical axis of said front lens element in a reference state in which said imaging apparatus does not drive said front lens element when said image-stabilizing operation is not performed; and
a support mechanism which supports said movable frame in a manner to allow said movable frame to spherically swing along an imaginary spherical surface about a spherical-swinging center which is positioned on an extension of said optical axis, of said front lens element, extending behind an underside of said reflection surface of said reflector.

2. The imaging apparatus according to claim 1 , wherein a surface closest to the image side of said front lens element comprises a concave surface.

3. The imaging apparatus according to claim 1 , wherein a surface closest to the object side of said front lens element is smaller in refractive power than that of a surface closest to the image side of said front lens element.

4. The imaging apparatus according to claim 1 , wherein said imaging apparatus satisfies the following condition (1):
−0.6<( SC−R 2)/ f 1<0.4  (1)

wherein R2 designates a radius of curvature a surface closest to the image side of said front lens element,
SC designates a distance along said optical axis from said surface closest to the image side of said front lens element to said spherical-swinging center, and
f1 designates a focal length of said front lens element.

5. The imaging apparatus according to claim 4 , wherein said imaging apparatus satisfies the following condition (2):
SF<− 0.5,  (2)

wherein SF=(R2+R1)/(R2−R1), and
R1 designates a radius of curvature of a surface closest to the object side of said front lens element.

6. The imaging apparatus according to claim 1 , wherein said front lens element comprises a single lens element.

7. The imaging apparatus according to claim 1 , further comprising:
an image sensor which receives said light rays that are passed through said imaging optical system; and
a housing which is immovable relative to said optical axis of said front lens element in said reference state,
wherein said image sensor is fixedly mounted to said housing.

8. The imaging apparatus according to claim 1 , further comprising a second reflector provided at a position closer to the image side than said rear lens group, said second reflector including a reflection surface which reflects said light rays, which are passed through said rear lens group, toward a different direction.

9. The imaging apparatus according to claim 1 , wherein said reflector comprises a prism.

10. The imaging apparatus according to claim 1 , wherein said support mechanism makes a projecting portion, which is formed on one of said movable frame and said support member, abut against a contacting portion formed on the other of said movable frame and said support member, and
wherein said support mechanism makes said movable frame spherically swing about said spherical-swinging center by obliquely moving said projecting portion relative to said contacting portion.

11. The imaging apparatus according to claim 10 , wherein said contacting portion comprises a recess in which said projecting portion is engaged.

12. The imaging apparatus according to claim 10 , wherein said contacting portion comprises a flat surface with which an end of said projecting portion is in contact.

13. The imaging apparatus according to claim 1 , wherein said extension of said optical axis, of said front lens element, extends through part of said support mechanism.

14. The imaging apparatus according to claim 1 , wherein said support mechanism comprises:
a pair of recessed portions, each having a hemispherical inner surface which are respectively formed on said movable frame and said support member to face each other; and
a spherical guide member which is installed between said pair of recessed portions,
wherein said support mechanism makes said movable frame spherically swing about said spherical-swinging center by said hemispherical inner surfaces of said pair of recessed portions being in sliding contact with said spherical guide member.

15. The imaging apparatus according to claim 1 ,
wherein said support mechanism comprises an intermediate member which supports said movable frame in a manner to allow said movable frame to swing about a first axis, and is supported to be allowed to swing relative to said support member about a second axis orthogonal to said first axis, and
wherein said support mechanism makes said movable frame spherically swing about said spherical-swinging center by making said movable frame and said intermediate member swing about said first axis and said second axis, respectively.

16. The imaging apparatus according to claim 1 , wherein said support mechanism includes a spherical-swinging support portion provided on said support member, and a supported portion which is formed on said movable frame and abuts against said spherical-swinging support portion,
wherein said movable frame includes a pressed surface which is formed as a spherical surface that is centered about said spherical-swinging center, said pressed surface positioned rearwardly from said underside of said reflection surface of said reflector with respect to a direction along said optical axis of said front lens element, and
wherein said imaging apparatus includes a biaser which is supported by said support member and is provided with a pressing portion, which abuts against said pressed surface of said movable frame, said biaser applying a biasing force against said movable member to cause said supported portion to abut against said spherical-swinging support portion via said pressing portion and said pressed surface.

17. The imaging apparatus according to claim 16 , wherein said pressed surface of said movable frame comprises a convex spherical surface facing toward the object side in a direction along said optical axis of said front lens element,
wherein said biaser biases said movable frame by pressing said pressed surface in a direction that is opposite to the direction toward the object side along said optical axis of said front lens element.

18. The imaging apparatus according to claim 16 , wherein said biaser comprises a mount which is mounted onto said support member at a position that is offset, from said optical axis of said front lens element, in a direction that is opposite to the light-ray traveling direction after light rays are reflected by said reflection surface of said reflector.

19. The imaging apparatus according to claim 16 , wherein said biaser comprises a mount which is mounted onto said support member at a position that is

Assignees

• Hoya Corp

Inventors

• Nomura Hiroshi
• Suzuka Shinya
• Morinaga Takahiro
• Nakamura Toshiki
• Tada Eijiroh

Classifications

• H04N23/687 Primary

  by shifting the lens or sensor position · CPC title

• H04N23/686

  with a variable apex prism · CPC title

• H04N23/55 Primary

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• H04N5/23287 Primary

  Electricity · mapped topic

• H04N5/2254

  Electricity · mapped topic