To compensate chromatic aberration without increasing the constituting number of a lens by arranging a 1st lens having negative refractive power and a 2nd lens having positive refractive power in order from an object side and forming a grating element surface on at least one surface of the 2nd lens.
The 1st lens 1, the 2nd lens 2, and a glass plate 4 and an image surface 5 optically equivalent to a crystal filter and the face plate of the image pickup device are arranged in this order from the object side. This optical system with a grating element is constituted by using the 1st lens 1 whose emitting surface is concave and which has the negative refractive power and the 2nd lens 2 whose incident surface is convex and which has the positive refractive power. In such a case, the grating element surface 40 having the positive refractive power is provided on the emitting surface of the 2nd lens 2. The 2nd lens 2 having the grating element surface 40 constituted in kinoform shape is formed by glass molding. Thus, a lens excellent in transferability is obtained.
ONO SHUSUKE
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