Systems and methods for providing illumination in machine vision systems

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS(S) The description below pertains to several illustrative embodiments of the invention.
These are described merely for illustrative purposes, as the scope of the invention is not to be limited in any way by the disclosure below.
The development of high brightness LEDs and the development of digital lighting technology has created many opportunities for LED lighting.
U.
S.
Pat.
Nos.
6,016,038 and 6,211,626 describe many such lighting devices.
U.
S.
Pat.
Nos.
6,016,038 and 6,211,626 are hereby incorporated by reference herein.
These patents describe methods of controlling the light output from a lighting system comprised of different colored LEDs for example.
Embodiments of these patents describe the use of pulse width modulation (PWM) and independent control of the LEDs to produce varying color within a color spectrum.
In one embodiment of the present invention, an LED lighting device with color changing capabilities may be used to illuminate objects in a vision system or machine vision system.
The device may be an independently controlled device with operator control or the device could be incorporated into the machine vision system.
The lighting device may also be networked to other devices in the manufacturing or inspection system.
As an example, an upstream process change may take place and a signal could be sent to the lighting device to change its mode of operation.
If the lighting device was incorporated into the vision system, the vision system processor may control the operation of the device.
A light detection unit could also be employed to constantly or periodically measure the light output from the lighting device.
This information could be used to recalibrate the device for overall intensity or particular wavelengths.
A lighting device according to the principles of the present invention may include two or more different colored LEDs or it could have a single colored LED.
The intensities of the respective LEDs could be varied and controlled through pulse width modulation or other LED control techniques