| 发明名称 | Two axis encoder head assembly | ||
| 摘要 | A measurement system for measuring the position of a work piece (28) includes a stage grating (234) and an encoder head (236). A first measurement beam (38A) is directed at the stage grating (234) at a first angle, the first measurement beam (38A) being at a first wavelength. A second measurement beam (38B) is directed at the stage grating (234) at a second angle that is different than the first angle, the second measurement beam (38B) being at a second wavelength that is different than the first wavelength. At least a portion of the first measurement beam (38A) and at least a portion of the second measurement beam (38B) are interfered with one another to create a measurement signal along a signal axis. | ||
| 申请公布号 | US9243896(B2) | 申请公布日期 | 2016.01.26 |
| 申请号 | US201313796316 | 申请日期 | 2013.03.12 |
| 申请人 | Nikon Corporation | 发明人 | Goodwin Eric Peter |
| 分类号 | G03B27/54;G03B27/52;G01B11/14;G03F7/20 | 主分类号 | G03B27/54 |
| 代理机构 | Roeder & Broder LLP | 代理人 | Roeder & Broder LLP ;Roeder Steven G. |
| 主权项 | 1. A measurement system for measuring relative movement between a first member and a second member, the measurement system comprising: a grating that is coupled to one of the first member and the second member; and an encoder head that is coupled to the other of the first member and the second member; wherein the encoder head directs a first measurement beam at the grating at a first angle, the first measurement beam being at a first wavelength, and directs a second measurement beam at the grating at a second angle that is different than the first angle, the second measurement beam being at a second wavelength that is different than the first wavelength; and wherein at least a portion of the first measurement beam that is diffracted at least twice by the grating and at least a portion of the second measurement beam that is diffracted at least twice by the grating are interfered with one another to create a measurement signal along a signal axis. | ||
| 地址 | JP | ||