公开(公告)号：US5291008A

公开(公告)日：1994-03-01

申请号：US819480

申请日：1992-01-10

申请人： William H. Havens ,  Harry R. McKinley ,  Charles M. Hammond, Jr. ,  Joseph J. Morabito ,  Jeffrey B. Powers

发明人： William H. Havens ,  Harry R. McKinley ,  Charles M. Hammond, Jr. ,  Joseph J. Morabito ,  Jeffrey B. Powers

IPC分类号： G06K7/10

CPC分类号： G06K7/1092 ,  G06K2007/10485

摘要： There is disclosed an simplified apparatus that enables optical scanners to achieve minimum field curvature and at the same time provide uniformly distributed light on an image sensor. A single element lens, preferably an aspherical lens made of a plastic material is combined with an aperture stop. The combination is capable of reducing lens aberrations and minimizing image field curvature for an object plane that contains indicia to be scanned or read. A suitably demagnified image of the indicia is focused onto an image sensor such as a CCD array. The spatial light distribution function in the image plane can be equalized by an attenuator, such as a neutral density filter or a slit, suitably configured to compensate for the reduced optical efficiency at large field angles. An aspherical lens containing a dye or a cold mirror can be used for limiting light transmission to a range of wavelengths.

摘要翻译： 公开了一种简化的装置，其使得光学扫描器能够实现最小的场曲率，同时在图像传感器上提供均匀分布的光。 单个元件透镜，优选地由塑料材料制成的非球面透镜与孔径光阑组合。 该组合能够减少包含要扫描或读取的标记的物体平面的透镜像差并使图像场曲率最小化。 标记的适当缩小的图像被聚焦到诸如CCD阵列的图像传感器上。 图像平面中的空间光分布函数可以通过诸如中性密度滤光器或狭缝的衰减器来均衡，该衰减器被适当地配置为补偿在大场角下降低的光学效率。 可以使用包含染料或冷镜的非球面透镜来限制光透射到一定范围的波长。