发明名称 |
Illumination apparatus with polarizing elements for beam shaping |
摘要 |
Illumination apparatus includes a light source which directs a polarized source beam in a downstream direction along an optical axis and desirably focuses the beam. A polarization-altering element downstream from the source such as a birefringent plate alters the polarization in a portion or portions of the source beam, so that the altered beam includes portions having different polarization directions. The altered beam passes downstream through a polarization-selective filter. The output beam from the polarization-selective filter can include either portion depending on the orientation of the filter. The arrangement can be used to provide a spot of a given size and shape at the focal location in a scanner such as a bar code scanner. The size and depth of field of the spot can be varied dynamically during operation.
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申请公布号 |
US6975456(B2) |
申请公布日期 |
2005.12.13 |
申请号 |
US20030746313 |
申请日期 |
2003.12.24 |
申请人 |
METROLOGIC INSTRUMENTS, INC. |
发明人 |
GIORDANO PATRICK A.;AMUNDSEN THOMAS;GOOD TIMOTHY A. |
分类号 |
G02B27/28;G06K7/10;(IPC1-7):G02B5/30 |
主分类号 |
G02B27/28 |
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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