| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical lens having high transmittance and equipped with an antireflection film constituted of a comparatively small number of films thereby be nearly free from a manufacture error, and excellent in a visible region, and to provide a high-grade optical lens unit constituted of such an optical lens, having excellent color balance and high transmittance. <P>SOLUTION: The optical lens A is formed by layering the antireflection film 2 on a lens (base material) 1 having a thickness of its surface top of 1mm and a refractive index of 1.44. In the film 2, the first layer and the third layer counted from the lens 1 are set as a low refractive index layer 3 composed of low refractive index material whose refractive index is relatively low, for example, SiO<SB>2</SB>, the second layer is set as a middle refractive index layer 5 composed of middle refractive index material whose refractive index is higher than the low refractive index material and lower than high refractive index material, for example, Al<SB>2</SB>O<SB>3</SB>, and the fourth layer is set as a high refractive index layer 6 composed of the high refractive index material whose refractive index is relatively high, for example, ZrO<SB>2</SB>, and then the fifth layer is the low refractive index layer 7 composed of, for example, MgF<SB>2</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
