Projecting optical system
AssigneeMinolta Co., Ltd.
InventorSoh Ohzawa
Life of this patent
Estimating the term…
Abstract
A projecting optical system projects an image formed on a primary image plane obliquely onto a secondary image plane. The projecting optical system has a plurality of partial optical systems decentered from each other. The projecting optical system also has a plurality of zoom optical systems. The zoom optical systems are moved to continuously vary an image magnification. During the movement, the secondary image plane is kept in a fixed position.
Claims19
A projecting optical system for projecting an image formed on a primary image plane obliquely onto a secondary image plane while reducing or enlarging the image, comprising:
- an aperture diaphragm;
- and
- two or more optical systems decentered from each other, wherein the following condition is satisfied:
- ##EQU4## where Sr represents a sum of optical powers of each lens element in said optical systems disposed on an enlarged image plane side of the aperture diaphragm,
- Se represents a sum of optical powers of each lens element in said optical systems disposed on a reduced image plane side of the aperture diaphragm, and
- .beta.r represents a magnification of a reduced image plane side part of the projecting optical system.
A projecting optical system for projecting an image formed on a primary image plane onto a secondary image plane, comprising:
- an aperture diaphragm;
- and
- optical systems including a partial optical system capable of being decentered rotationally, said partial optical system being capable of being decentered rotationally by a pivoting movement of said partial optical system so that an optical axis thereof is inclined with respect to an optical axis of a remaining portion of said optical systems;
- wherein, for a rotational decentering of the partial optical system in conjunction with a rotation of at least one of the primary and secondary image planes, an image distortion on the secondary image plane is substantially unchanged.
A projecting optical system for projecting an image formed on a primary image plane obliquely onto a secondary image plane, comprising:
- two or more partial optical systems decentered from each other;
- and
- a focusing optical system included and movably disposed in one of the partial optical systems, the focusing optical system being adapted to move to achieve focusing with the secondary image plane being kept inclined at a fixed angle to the primary image plane, said focusing optical system comprising a quantity of optical elements which is less than a quantity of optical elements in said one of the partial optical systems.
A projecting optical system for projecting an image formed on a primary image plane obliquely onto a secondary image plane, comprising:
- two or more partial optical systems decentered from each other;
- and
- two or more zoom optical systems each included and movably disposed in different ones of the partial optical systems, the zoom optical systems being adapted to move to continuously vary an image magnification with the secondary image plane being kept in a fixed position.
Dependencies are inferred from the claim text.