发明名称 |
Double pass interferometric encoder system |
摘要 |
An encoder head includes one or more components arranged to: i) direct a first incident beam to the diffractive encoder scale at a first incident angle with respect to the encoder scale; ii) receive a first return beam from the encoder scale at a first return angle, the first return angle being different from the first incident angle; iii) redirect the first return beam to the encoder scale as a second incident beam at a second incident angle; and iv) receive a second return beam back from the encoder scale at a second return angle, the second return angle being different from the second incident angle, in which a difference between the first incident angle and second incident angle is less than a difference between the first incident angle and the first return angle and less than a difference between the second incident angle and the second return angle. |
申请公布号 |
US9025161(B2) |
申请公布日期 |
2015.05.05 |
申请号 |
US201213671920 |
申请日期 |
2012.11.08 |
申请人 |
Zygo Corporation |
发明人 |
de Groot Peter;Liesener Jan |
分类号 |
G01B11/02;G03F7/20;G01D5/26;G01D5/38 |
主分类号 |
G01B11/02 |
代理机构 |
Fish & Richardson P.C. |
代理人 |
Fish & Richardson P.C. |
主权项 |
1. An encoder system comprising:
an encoder head for use with a diffractive encoder scale, wherein the encoder head comprises one or more optical components arranged to: i) direct a first incident beam to the diffractive encoder scale at a first incident angle with respect to a normal to the encoder scale; ii) receive a first return beam from the diffractive encoder scale at a first return angle with respect to the normal to the encoder scale, the first return angle being different from the first incident angle; iii) redirect the first return beam to the diffractive encoder scale as a second incident beam at a second incident angle with respect to the normal to the encoder scale; and iv) receive a second return beam back from the diffractive encoder scale at a second return angle with respect to the normal to the encoder scale, the second return angle being different from the second incident angle, wherein a difference between the first incident angle and second incident angle is less than a difference between the first incident angle and the first return angle and less than a difference between the second incident angle and the second return angle. |
地址 |
Middlefield CT US |