| 摘要 |
PROBLEM TO BE SOLVED: To provide an image pickup lens which is constituted so that desired optical performance can be maintained, a back focus distance can be sufficiently secured, a high telecentric property can be secured and respective aberrations can be excellently corrected and which can be easily manufactured. SOLUTION: This image pickup lens is constituted by arraying a 1st positive- power lens 1 whose concave surface is formed at an object side near an optical axis, a 2nd negative-power lens 2 and a 3rd positive-power lens 3 in turn from the object side. At least the 1st surface of the lens 2 positioned at the object side out of the respective lenses 1, 2 and 3 is formed to be aspherical. Then, a diaphragm 4 is disposed between the lenses 1 and 2 and arranged at the more object side than a central point between the lenses 1 and 2. Besides, a light quantity regulating plate 5 is disposed at the 1st surface side of the lens 1e Then, a CCD being as the imaging device is mounted at the 2nd surface side of the lens 3 so that the image pickup surface 6 of the CCD is formed.
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