Low profile illumination for direct part mark readers
View Patent ↗An industrial reader is provided with an image formation system that is particularly adapted to read bar codes and two-dimensional symbols marked directly on objects. The image formation system includes illumination sources and illumination transmissive components that produce a combination of bright field and dark field illumination.
1. An integrated optical transmitter for use in a direct part mark reader, the transmitter comprising:
a structural frame that engages with a housing;
a first set of illuminators that generate bright field illumination within the housing;
a plurality of bright field illumination transmitters that transmit the bright field illumination from within the housing, such that the plurality of bright field illumination transmitters are molded within the structural frame;
a second set of illuminators that generate dark field illumination within the housing;
a dark field illumination transmitter that transmits low angle dark field illumination from within the housing such that the dark field transmitter is attached to the structural frame; and
a window that provides a transmission path for the reflected illumination into the housing in an optical path of a field of view for a sensor module.
2. The integrated optical transmitter of claim 1 wherein the plurality of bright field illumination transmitters are offset from the optical axis.
3. The integrated optical transmitter of claim 1 wherein the bright field illumination transmitters comprise a molded or fabricated lens.
4. The integrated optical transmitter of claim 3 wherein the lens is adapted to modify the angle or orientation of the bright field illumination.
5. The integrated optical transmitter of claim 1 wherein the bright field illumination transmitters include optical properties applied to at least one of a front of the optical transmitter and both the front and a rear of the optical transmitter.
6. The integrated optical transmitter of claim 1 wherein the dark field illumination transmitter includes an angled distal tip, the angled distal tip adapted to cause internal reflection that projects the low-angle dark field illumination in the area directly in front of the reader.
7. The integrated optical transmitter of claim 1 wherein the bright field illumination transmitters are juxtaposed with the dark field illumination transmitter so that when the dark field illumination transmitter is optically aligned with the dark field illuminators, the bright field illumination transmitters are optically aligned with the bright field illuminators and the dark field illuminators are optically misaligned with the bright field illuminators.
8. The integrated optical transmitter of claim 1 wherein the dark field illuminators and the bright field illuminators are separately actuatable.
9. The integrated optical transmitter of claim 1 wherein the window comprises an optical filter.
10. The integrated optical transmitter of claim 6 wherein the dark field illumination transmitter is a light pipe.