Capsule endoscope

• US 20060238614A1
• Filed: 04/21/2006
• Published: 10/26/2006
• Est. Priority Date: 04/26/2005
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Medical Systems Corporation (Olympus Corporation)
• Inventors: Konno, Mitsujiro
• Granted Patent: US 8,535,218 B2
• Time in Patent Office: Days
• US Class Current: 348/69
• CPC Class Codes: A61B 1/00096 Optical elements
• CPC Class Codes: A61B 1/00179 for off-axis viewing
• CPC Class Codes: A61B 1/00188 with focusing or zooming features
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 1/051 Details of CCD assembly
• CPC Class Codes: A61B 1/0661 Endoscope light sources

Abstract

A capsule endoscope is disclosed that includes first and second objective optical systems for forming images of objects viewed in the capsule insertion direction and in the opposite direction on separate areas of one plane where an image pickup surface of an image pickup device is located. The capsule endoscope also includes illuminators for illuminating the objects, and a deflector or deflectors, such as reflecting prisms, for folding light from the objective optical systems to the image pickup surface so that the image pickup surface is parallel to the capsule insertion direction. The objective optical systems are retrofocus optical systems. The illuminators may have emission surfaces centered on the centers of spheres defined by dome-shaped transparent covers aligned along a central axis of the capsule endoscope. The objective optical systems, the deflector or deflectors, and the image pickup device are arranged completely off the central axis of the capsule endoscope.

Claims

1. A capsule endoscope having a capsule insertion direction, the capsule endoscope comprising:

a first objective optical system that forms on an image surface an image of an object that is viewed by the capsule endoscope in the capsule insertion direction; and

a second objective optical system that forms on an image surface an image of an object that is viewed by the capsule endoscope in the direction opposite to the capsule insertion direction;

wherein

the two image surfaces are in the same plane or are very nearly in the same plane.

2. The capsule endoscope according to claim 1, and further comprising an image pickup device, wherein said image pickup device captures the two images on an image pickup surface that is situated at, or very nearly at, said two image surfaces.

3. The capsule endoscope according to claim 2, wherein:

each of the first and second objective optical systems includes a deflector; and

each of the deflectors folds one of each of the optical axes defined by light entering each of the first and second objective optical systems so that light exiting each of the first and second objective optical systems and forming one of the two images is incident on an image pickup area of said image pickup surface that is different from the image pickup area of the image pickup surface where light forming the other of the two images is incident.

4. The capsule endoscope according to claim 3, wherein each of the deflectors is a respective prism that includes a reflecting surface that folds the optical axis of light that enters a respective one of the first and second objective optical systems.

5. The capsule endoscope according to claim 2, and further comprising a deflector, wherein the deflector deflects the optical axes of each of said first objective optical system and said second objective optical system so that the light forming one of the two images is incident on an image pickup area of said image pickup surface that is different from the image pickup area of the image pickup surface where light forming the other of the two images is incident.

6. The capsule endoscope according to claim 5, wherein the deflector is a prism that includes two reflecting surfaces.

7. The capsule endoscope according to claim 2, wherein a plane defined by the image pickup surface is parallel to the capsule insertion direction.

8. The capsule endoscope according to claim 7, wherein:

said image pickup surface is in the shape of a rectangle; and

said rectangle has a longer side that is parallel to the capsule insertion direction.

9. The capsule endoscope according to claim 7, wherein:

the capsule endoscope includes a central axis; and

said image pickup surface faces said central axis.

10. The capsule endoscope according to claim 2, further comprising:

a first illuminator for illuminating an object in the capsule insertion direction;

a second illuminator for illuminating an object in the direction opposite to the capsule insertion direction;

a first dome-shaped transparent cover for passing illumination from said first illuminator to said object and for passing light from said object to said first objective optical system;

a second dome-shaped transparent cover for passing illumination from said second illuminator to said object and for passing light from said object to said second objective optical system;

wherein

each of said transparent covers has a spherical shape at least within the illumination field of each of the first and second illuminators; and

each of the first and second illuminators includes an emission surface situated at the center of a sphere defined by the spherical shape of each of said transparent covers.

11. The capsule endoscope according to claim 2, wherein:

a first illuminator for illuminating an object in the capsule insertion direction and a a second illuminator for illuminating an object in the direction opposite to the capsule insertion direction are provided; and

the first and second objective optical systems are placed with their entrance pupils aligned in the same plane as the illumination surfaces of the first illuminator and of the second illuminator, respectively.

12. The capsule endoscope according to claim 3, wherein each of said first objective optical system and said second objective optical system is a retrofocus optical system.

13. A capsule endoscope having a capsule insertion direction, wherein an image of an object in the capsule insertion direction and an image of an object in the direction opposite to the capsule insertion direction are acquired in different image pickup areas of one image pickup device.

14. The capsule endoscope according to claim 13, and further comprising an image pickup unit for acquiring the two images from opposite directions, the image pickup unit including:

two objective optical systems, each of which includes an object-side lens element;

an image pickup device that includes an image pickup surface; and

a deflector between the object-side lens element of each objective optical system and the image pickup surface for deflecting the optical axes of light forming images on the image pickup surface;

wherein

the capsule endoscope has a central axis; and

the image pickup device is arranged completely off the central axis of the capsule endoscope.