发明名称 |
Optical encoder with dual diffraction gratings |
摘要 |
An optical encoder includes: a light source; a first grating plate having a first diffraction grating for diffracting a light beam emitted from the light source; a second grating plate having a second diffraction grating for further diffracting the light beam diffracted by the first diffraction grating; a reflector for reflecting the light beam from the second grating plate so as to allow the light beam to reenter the second grating plate; and a light-receiving portion for receiving the light beam reflected by the reflector and successively diffracted by the second and first grating plates, wherein a diffraction angle of plus and minus first-order diffracted light beams of the first diffraction grating is substantially equal to that of the plus and minus first-order diffracted light beams of the second diffraction grating, and the light-receiving portion generates an electric signal in accordance with the amount of the plus and minus first-order diffracted light beams of the first diffraction grating.
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申请公布号 |
US5661295(A) |
申请公布日期 |
1997.08.26 |
申请号 |
US19950504708 |
申请日期 |
1995.07.20 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
FUKUI, ATSUSHI;NISHII, KANJI;TAKAMOTO, KENJI;ITO, MASAMI |
分类号 |
G01B11/00;G01D5/38;G02B5/18;G02B27/42;G03F9/00;(IPC1-7):G01B9/02;H01J3/12 |
主分类号 |
G01B11/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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