Patent ID: 6969003
Filing Date: 2005-11-29
Classification: G02B,G06T,H04N

Abstract:
1. An optical reader for reading an optically encoded indicia, the optical reader having a maximum amount of misfocus error and an operational depth of field, the optical reader comprising: an illumination source configured to emit a light beam; an illumination optical assembly coupled in the illumination source, the illumination optical assembly including at least one phase mask, the at least one phase mask being configured to modify a phase of the light beam in a predetermined manner such that a phase modified light beam illuminates the optically encoded indicia; and an image processing assembly configured to receive the phase modified light beam reflected from the optically encoded indicia, the image processing assembly being configured to employ a recovery function to thereby generate a corrected image signal having a reduced focusing error and increased depth of field relative to the maximum amount of misfocus error and the operational depth of field.