Patent ID: 9704007
Date: 2017-07-11
CPC Classifications: G02B,G06K

Claim:
1. A machine-readable symbol reader comprising: a first optical element having a first base, a first end, a first major face, a second major face, a first thickness, and a first length between the first base and the first end, the second major face non-parallel to the first major face and opposed across the first thickness of the first optical element from the first major face, the first thickness which varies along the first length of the first optical element, the first and the second major faces which propagate a diminishing amount of light passing through the first optical element along the first length thereof from the first base toward the first end by total internal reflection and which exit the light passing through the first optical element from the first base by refraction through at least one of the first or second major faces; a first illumination source positioned to transmit illumination toward the first base of the first optical element; a second optical element having a second base, a second end, a third major face, a fourth major face, a second thickness, and a second length between the second base and the second end, the fourth major face non-parallel to the third major face and opposed across the second thickness of the second optical element from the third major face, the second thickness which varies along the second length of the second optical element, the third and the fourth major faces which propagate a diminishing amount of light passing through the second optical element along the second length thereof from the second base toward the second end by total internal reflection and which exit the light passing through the second optical element from the second base by refraction through at least one of the third or fourth major faces; a second illumination source positioned to transmit illumination toward the second base of the second optical element; a housing that includes a window, the window positioned to pass illumination coupled out of the first major face of the first optical element, the window positioned to pass illumination coupled out of the third major face of the second optical element; and an optical sensor array.