| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens responding to a small imaging element of high pixel (for example, from a CCD image sensor and CMOS image sensor having a pixel pitch of 1.75μm and 5 mega pixels to a CCD image sensor and CMOS image sensor having a pixel pitch of 1.4μm and 8 mega pixels). SOLUTION: The imaging lens 7 includes, in the order from the object side to the image surface side, an aperture diaphragm 5, a first lens 1 having positive power, a second lens 2 that has negative power and consists of a meniscus lens where the lens surface on the image surface side is concave, a third lens 3 that has positive power and consists of a meniscus lens where the lens surface on the image surface side is convex, and a fourth lens 4 that has negative power and where both lens surfaces have an aspheric surface shape and the lens surface on the image surface side is concave near the optical axis. A diffraction optical element is formed on the lens surface of any one of the first lens 1 and second lens 2. COPYRIGHT: (C)2011,JPO&INPIT |
