Image-taking lens system and digital apparatus using the same
AssigneeKonica Minolta Opto, Inc.
InventorMasashi Isono
Life of this patent
Estimating the term…
Abstract
An aperture stop, a first lens having a positive power, a second lens having a negative power, a third lens having a positive power, and a fourth lens whose concave face is directed toward the image surface side and having a meniscus shape are disposed in order from the object side. The second and third lenses are cemented to each other. Further, focal length “f” of the entire system and total focal length “f23” of the second and third lenses satisfy the following conditional expression. |f/f23|<0.4
Claims9
An image-taking lens system for forming an image on an imaging element, said lens system comprising from an object side:
- a first lens having a positive power;
- a cemented lens of a second lens having a negative power and a third lens having a positive power;
- and
- a fourth lens whose concave face is directed toward the image side and having a meniscus shape,
- wherein the following conditional expression is fulfilled,
- |f/f23<0.4
- where f:
- focal length of the entire system
- f23:
- total focal length of the second and third lenses.
An image-taking lens system for forming an image on an imaging element, said lens system essentially consisting of from an object side:
- an aperture stop;
- a first lens having a positive power;
- a cemented lens of a second lens having a negative power and a third lens having a positive power;
- and
- a fourth lens whose concave face is directed toward the image side and having a meniscus shape.
An image taking apparatus comprising:
- imaging elements for converting an optical image to an electrical signal;
- and
- an image-taking lens system for forming an optical image of the object on a receiving surface of said imaging elements,
- said lens system including from the object side:
- a first lens having a positive power;
- a cemented lens of a second lens having a negative power and a third lens having a positive power;
- and
- a fourth lens whose concave face is directed toward the image side and having a meniscus shape,
- wherein the following conditional expression is fulfilled,
- |f/f23|<0.4
- where f:
- focal length of the entire system
- f23:
- total focal length of the second and third lenses.
A digital apparatus comprising an imaging unit which includes imaging elements for converting an optical image to an electrical signal, and an image-taking lens system for forming an optical image of the object on a receiving surface of said imaging elements,
- said lens system including from an object side:
- a first lens having a positive power;
- a cemented lens of a second lens having a negative power and a third lens having a positive power;
- and
- a fourth lens whose concave face is directed toward the image side and having a meniscus shape,
- wherein the following conditional expression is fulfilled,
- |f/f23|<0.4
- where f:
- focal length of the entire system
- f23:
- total focal length of the second and third lenses.
Dependencies are inferred from the claim text.