Title:
PHOTOGRAPHIC LENS, ELECTRONIC STILL CAMERA, AND VIDEO CAMERA
Document Type and Number:
Japanese Patent JP3491578
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a photographic lens system where the resolution of an entire image is high in a wide range of the object distance and the overall optical length is short.
SOLUTION: This photographic lens system is provided with a first lens group having a negative power, a second lens group having a positive power, a third lens group having a positive power, a fourth lens group having a positive power, and a stop arranged between the second and third lens groups in order from the object side. The first lens group is provided with a negative meniscus lens as a first lens, of which the face having a high curvature is directed to the image side and a negative lens as a second lens, and the second lens group is provided with a double convex lens as a third lens, and the third lens group is provided with a positive lens as a fourth lens, a double concave lens as a fifth lens, and a positive lens as a sixth lens of which the face having a high curvature is directed to the image side, and the fourth lens group is provided with a positive lens as a seventh lens, and at least the face on the image side of the sixth lens is aspherical. By this constitution, the photographic lens system is provided where the resolution of an entire image is high in a wide range of the object distance and the overall optical length is short.
Inventors:
Miyatake Yoshito
Shusuke Ono
Shusuke Ono
Application Number:
JP31197599A
Publication Date:
January 26, 2004
Filing Date:
November 02, 1999
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G02B13/04; G02B13/18; H04N5/225; H04N5/335; (IPC1-7): G02B13/04; G02B13/18; H04N5/225; H04N5/335
Domestic Patent References:
| JP1123961A | ||||
| JP49101020A | ||||
| JP5862610A | ||||
| JP7218826A | ||||
| JP5489630A |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)