发明名称 |
Optical device and optical pickup device using the same |
摘要 |
An optical element having a substrate and a composite grating pattern formed thereon. The pattern is constituted with two different kinds of grating patterns superimposed on the substrate. When one of the two kinds of grating patterns is formed in a Fresnel lens pattern, a light focusing or collimating function (i.e. a lens function) is implemented. When the other pattern is formed in an equally separated linear grating pattern, the optical element develops the lens function and a function to diffract lights through the linear grating. When one of the two kinds of grating patterns is formed in a Fresnel lens pattern and the other pattern is implemented in an unequally separated linear grating pattern, a lens function to focus lights onto a point and a cylindrical lens function to focus lights in a linear contour are obtained. Consequently, when parallel lights are incident to the optical element, there occurs astigmatism.
|
申请公布号 |
US5122903(A) |
申请公布日期 |
1992.06.16 |
申请号 |
US19900492489 |
申请日期 |
1990.03.12 |
申请人 |
OMRON CORPORATION |
发明人 |
AOYAMA, SHIGERU;OHGAKI, TATSUO;YAMASHITA, TUKASA |
分类号 |
G02B3/08;G02B5/18;G11B7/135;G11B11/10;G11B11/105 |
主分类号 |
G02B3/08 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|