发明名称 |
Optical system for data reading having large depth of field |
摘要 |
An optical system and method for data reading in which a light source generates an optical beam directed toward an object to be read and a variable aperture mechanism positioned in the outgoing light path establishes at least two separate focal planes. The variable aperture device may comprise a variable aperture system in which the size of the aperture is selectively varied about a range within the diffractive limit of the light beam. A preferred aperture mechanism is an electronically actuable mechanism with no moving parts which may include a liquid crystal aperture with one or more aperture regions which are selectively or consecutively activated. The optical system therefore establishes two or more separate waist locations from a single light source resulting in greater depth of field or multiple depths of field.
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申请公布号 |
US5945670(A) |
申请公布日期 |
1999.08.31 |
申请号 |
US19970858597 |
申请日期 |
1997.05.19 |
申请人 |
SPECTRA-PHYSICS SCANNING SYSTEMS, INC. |
发明人 |
RUDEEN, ROBERT W. |
分类号 |
G02B5/00;G02B26/10;G06K7/10;(IPC1-7):G06K7/10 |
主分类号 |
G02B5/00 |
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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