发明名称 |
Displacement detecting apparatus |
摘要 |
A displacement detecting apparatus for detecting a displacement between an object lens thereof and a measured surface in a non-contact manner. The displacement detecting apparatus comprises an object lens for focusing laser beam on the measured surface. A detecting optical system is provided to detect a focus error signal which represents a difference between a distance of the object lens from the measured surface and a focal distance of the object lens, in accordance with a reflected light from the measured surface. An actuator is provided to move the object lens in an optical axis in a manner to cause the object lens distance to coincide with the focal distance, in accordance with an output signal from the detecting optical system. A moving body includes a linear scale or a scale head and movable with the object lens. The linear scale is disposed coaxially with the optical axis and connected to the actuator. A support member is provided to movably support the moving body. Additionally, a balance weight is connected to the moving body in a manner that the center of gravity of the moving body coincides with the center of driving force of said actuator and with the center of support of the support member.
|
申请公布号 |
US5477333(A) |
申请公布日期 |
1995.12.19 |
申请号 |
US19940319105 |
申请日期 |
1994.10.06 |
申请人 |
SONY MAGNESCALE INC. |
发明人 |
SHODA, YOSHIO;TAKEDA, NARIMASA |
分类号 |
G01B11/00;G01C3/06;G01D5/26;(IPC1-7):G01B11/14 |
主分类号 |
G01B11/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|