Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
PHOTOGRAPHIC LENS
Document Type and Number:
Japanese Patent JP2004219982
Kind Code:
A
Abstract:

To provide a compact and inexpensive photographic lens adaptive to a high pixel.

The photographic lens 1 comprises, arranged sequentially from the object side, a positive-meniscus first lens 1 with its convex plane facing the object side, a negative-power-meniscus second lens 2, and a positive-power third lens 3, and the second and the third lenses 2 and 3 function as a correction lens. The first lens 1 has strong power and both planes of the second and the third lenses are made aspherical. When the synthetic focal distance of the photographic lens is F, the focal distance of the first lens is f1, a distance to the image forming surface from the incident surface on the object side of the first lens is Σd, and the Abbe number of the 2nd lens is νd2, conditional expressions (1): 0.50<f1/F<1.5, (2): 0.50<Σd/F<1.5 and (3): 50>νd2 are satisfied.


Inventors:
KUBOTA YOJI
MATSUI TOSHIO
Application Number:
JP2003295320A
Publication Date:
August 05, 2004
Filing Date:
August 19, 2003
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NAGANO KOGAKU KENKYUSHO KK
International Classes:
G02B13/00; G02B13/18; (IPC1-7): G02B13/00; G02B13/18
Attorney, Agent or Firm:
Shiro Yokozawa