| 摘要 |
PCT No. PCT/EP97/05211 Sec. 371 Date Jun. 21, 1999 Sec. 102(e) Date Jun. 21, 1999 PCT Filed Sep. 23, 1997 PCT Pub. No. WO98/16802 PCT Pub. Date Apr. 23, 1998An optical position measuring system that has a scale graduation with a graduation period, TP, and connected with a first object that has a graduation and a scanning unit connected to a second object that moves relative to the first object, so that there is a displacement between the scale graduation and the scanning unit. The scanning unit includes a scanning plate with a first and second scanning fields that are arranged offset from each other in a measuring direction (x) by a distance, D. A first deflection element associated with the first scanning field and a second deflection element associated with the second scanning field, wherein the first and second deflection elements spatially separate the phase-shifted partial signals from the first and second scanning fields. First and second detector elements are placed downstream of the scanning plate and associated with the first scanning field. Third and fourth detector elements are placed downstream of the scanning plate and associated with the second scanning field. The first and second scanning fields are arranged on the scanning plate so that the offset distance D=TP/2*(N++E,fra 1/4+EE ), wherein N=0, 1, 2, . . .
|
