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Title:
WIDE-ANGLE LENS
Document Type and Number:
Japanese Patent JP2001281539
Kind Code:
A
Abstract:

To provide a wide-angle lens suitable for a recent high pixel imaging device.

This wide-angle lens A is constituted by arranging a 1st lens having positive refractive power and also set so that both surfaces are made aspherical, a 2nd lens 2 having negative refractive power, a 3rd lens 3 bonded with the 2nd lens 2 and having positive refractive power, a 4th lens 4 having positive refractive power and also set so that its one surface is made aspherical and a glass lens 5 such as a low-pass filter in order from an object side, and satisfies conditions of (1) and (2). (1) 0.7×r4<r6<1.3×r4, (2) ν1<35, ν2<ν3, ν4>50. Provided that r4 means the radius of curvatuer of the surface of the 2nd lens 2 on the object side, r6 means the radius of curvature of the surface of the 3rd lens 3 on an image surface side, and ν1 to ν4 are the Abbe numbers of the lenses 1 to 4.


Inventors:
ABE YASUHIKO
Application Number:
JP2000101147A
Publication Date:
October 10, 2001
Filing Date:
March 31, 2000
Export Citation:
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Assignee:
NIDEC COPAL CORP
International Classes:
G02B13/04; G02B13/18; (IPC1-7): G02B13/04; G02B13/18



 
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