05291008 is referenced by 214 patents and cites 7 patents.

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.

Title
Optical assembly and apparatus employing same using an aspherical lens and an aperture stop
Application Number
7/819480
Publication Number
5291008
Application Date
January 10, 1992
Publication Date
March 1, 1994
Inventor
Jeffrey B Powers
Syracuse
NY, US
Joseph J Morabito
Auburn
NY, US
Charles M Hammond Jr
Skaneateles
NY, US
Harry R McKinley
Southamptom
MA, US
William H Havens
Skaneateles
NY, US
Agent
Harris Beach & Wilcox
Assignee
Welch Allyn
NY, US
IPC
G06K 7/10
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