Optical system for photographing a stereoscopic image, zoom lens and image pickup optical system

• US 6,414,791 B1
• Filed: 06/29/1999
• Issued: 07/02/2002
• Est. Priority Date: 07/01/1998
• Status: Expired due to Term

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sugawara, Saburo
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): Curtis, Craig
• Application Number:
  US09/342,382
• Time in Patent Office: 1,099 Days
• Field of Search: 348/42-59, 359/691, 359/462, 359/472, 359/473, 359/464, 359/480, 359/497, 359/386, 396/324, 396/327, 396/331, 600/111, 600/117
• US Class Current: 359/464
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G03B 35/10 having single camera with stereoscopic-base-defining system

Abstract

An optical system is provided with a pair of forward optical components each having a shutter for controlling the amount of transmission of a light from an object, an optical member for laying the optical axes of the pair of forward optical components one upon the other, and a rearward optical component disposed so that the optical axis thereof may coincide with the optical axes laid one upon the other. The optical system alternately varies the amounts of transmission of the light transmitted through the shutters of the pair of forward optical components to thereby time-serially form a parallax image.

Claims

1. An optical system comprising:

a pair of forward optical components each having a shutter for controlling the amount of transmission of a light from an object;

an optical member for laying the optical axes of said pair of forward optical components one upon the other;

a rearward optical component disposed so that the optical axis thereof may coincide with said optical axes laid one upon the other; and

a stop disposed at or near a position whereat the optical axes of said pair of forward optical components intersect with each other;

said optical system alternately varying the amounts of transmission of the light transmitted through the shutters of said pair of forward optical components to thereby time-serially form a parallax image.

2. The optical system of claim 1, wherein each of said pair of forward optical components further has:

a mirror for reflecting the light from said object; and

a lens unit for refracting the light from said object.

3. The optical system of claim 1, wherein said optical member is a triangle pole prism having two reflecting surfaces, and the optical axes of said pair of forward optical components and the optical axis of said rearward optical component intersect with one another on a ridgeline formed by said two reflecting surfaces.

4. The optical system of claim 3, wherein the angle Q formed by said two reflecting surfaces satisfies the condition that

5. The optical system of claim 1, wherein said rearward optical component has a plurality of lens units movable in the direction of the optical axis thereof for focal length change.

6. The optical system of claim 1, wherein said shutters are disposed most adjacent to the object side.

7. The optical system of claim 2, wherein said shutters are disposed between said mirror and said lens unit.

8. The optical system of claim 1, wherein said shutters are liquid crystal shutters.

9. The optical system of claim 8, wherein a quarter wavelength plate is disposed on at least one of the object side and the image plane side of each of said liquid crystal shutters.

10. An optical system comprising:

a pair of forward optical components each having a shutter for controlling the amount of transmission of a light from an object;

an optical member for laying the optical axes of said pair of forward optical components one upon the other;

a rearward optical component disposed so that the optical axis thereof may coincide with said optical axes laid one upon the other; and

a stop disposed at or near a position whereat the optical axes of said pair of forward optical components intersect with each other,

said optical system alternately varying the amounts of transmission of the light transmitted through the shutters of said pair of forward optical components to thereby time-serially form a parallax image;

wherein said forward optical components have negative refractive power as a whole, and said rearward optical component has positive refractive power as a whole.

11. An image pickup optical system for a camera which takes an image formed on an image pickup surface, said image pickup optical system comprising:

quantity-of-light controlling means for controlling the amount of transmission of light by the utilization of polarization;

an image pickup lens for forming an image by the use of the light transmitted through said quantity-of-light controlling means; and

a quarter wavelength plate disposed on at least the image plane side of said quantity-of-light controlling means.

12. An image pickup apparatus comprising:

quantity-of-light controlling means for controlling the amount of transmission of light by the utilization of polarization;

an image pickup lens for forming an image by the use of the light transmitted through said quantity-of-light controlling means;

an optical low-pass filter utilizing double refraction;

an image pickup element for periodically introducing the image thereinto; and

a quarter wavelength plate disposed on at least one of the object side and the image plane side of said quantity-of-light controlling means.