Object detecting system for imaging-based barcode readers

摘要

An apparatus includes a light emitting diode operative to emit mostly invisible light within an invisible bandwidth, and a scattering surface configured to scatter a first portion of the invisible light from the light emitting diode out of the window. The scattering surface is also partially transparent to allow a second portion of the invisible light from the light emitting diode to pass through the scattering surface and strike the reflector that is configured to reflect at least some of the second portion of the invisible light towards the window. The apparatus further includes a photodetector configured to detect returned invisible light from the target object.

主权项

1. An apparatus comprising:
a housing having a window; an illumination source within the housing for providing illumination light directed toward a target object; an imaging sensor having an array of photosensitive elements for capturing an image from the target object; a light emitting diode within the housing operative to emit mostly invisible light within an invisible bandwidth; a reflector within the housing; a scattering surface located within the housing and configured to scatter a first portion of the invisible light from the light emitting diode out of the window, wherein the scattering surface is also partially transparent to allow a second portion of the invisible light from the light emitting diode to pass through the scattering surface and strike the reflector that is configured to reflect at least some of the second portion of the invisible light towards the window; a photodetector configured to detect returned invisible light from the target object to generate an electrical signal; and a controller configured to activate the illumination source for providing the illumination light directed toward the target object for image capturing when the electrical signal generated by the photodetector indicates that the returned invisible light from the target object is detected.