Handheld symbol reader with optical element to redirect central illumination axis
An apparatus and assembly for redirecting the central illumination axis of an illumination assembly towards the central field of view (FOV) axis of an imaging assembly using an optical element that provides an optical magnification of less than 1.5×, where the central illumination axis at the point of the illumination assembly is non-parallel to the central FOV axis.
1. An assembly comprising:
a housing having a scanning head and a handle, the scanning head having a proximal end and a distal end, and a central head axis extending from the proximal end to the distal end, the scanning head further having a top portion and a bottom portion, the bottom portion being opposite the top portion, the handle being attached to the scanning head at the bottom portion;
an imaging assembly positioned within the scanning head, wherein the imaging assembly has a field of view (FOV) directed towards the proximal end, the FOV having a central FOV axis parallel in relation to the central head axis, the imaging assembly configured to capture at least one of: light reflected from a target and light emitted from a target;
an illumination assembly positioned within the scanning head in front of the imaging assembly and facing the bottom portion and the proximal end at an acute angle with respect to the central head axis, wherein the illumination assembly is configured to emit light having a central illumination axis, such that the central illumination axis at the point of the illumination assembly is non-parallel to the central FOV axis and is directed towards the bottom portion and the proximal end; and
a prism positioned within the scanning head in front of the illumination assembly, and configured to redirect the central illumination axis such that the central illumination axis converges towards the central FOV axis as both axes extend away from the proximal end.
2. The apparatus of claim 1 , wherein the acute angle with respect to the central head axis is within the range of ten degrees and twenty degrees.
3. The apparatus of claim 1 , further comprising a window at the proximal end of the scanning head, wherein the FOV extends through the window, and wherein the prism is integral with the window.
4. The apparatus of claim 1 , further comprising a window at the proximal end of the scanning head, wherein the FOV extends through the window, and wherein the prism is affixed to a surface of the window facing the illumination assembly.
5. The apparatus of claim 1 , wherein the illumination assembly is mounted on a surface of a substrate, the surface of the substrate facing the proximal end in a direction at the acute angle with respect to the central head axis.
6. The apparatus of claim 5 , wherein the substrate comprises an enclosed aperture, and the imaging assembly is mounted behind the substrate, wherein the FOV extends through the enclosed aperture.
7. The apparatus of claim 5 , wherein the substrate is a printed circuit board that extends partially within the scanning head and partially within the handle.
8. The apparatus of claim 7 , wherein the surface of the substrate is a first side of the printed circuit board, and wherein the printed circuit board is arranged relative to the handle such that the first side of the printed circuit board defines a plane that is perpendicular to a central handle axis.
9. The apparatus of claim 3 , wherein the FOV extends through an upper portion of the window and wherein the prism is integral with a lower portion of the window, the upper portion of the window being closer to the top portion of the scanning head than the lower portion, the lower portion being closer to the bottom portion than the upper portion.
10. The apparatus of claim 1 , wherein the illumination assembly and the prism are configured to provide non-diffused illumination beyond a nose of the of the scanning head.