Abstract: An illumination method and apparatus for machine-vision systems, including a ring-light source (e.g., LEDs arranged in one or more circular rows), and a reflective-ring focusing element. The illumination source exhibits multidirectional ring-illumination properties which are useful for illumination of small components (which are being inspected or measured) without unwanted shadows. One embodiment provides a dark field illumination system. One embodiment of the present invention uses a strobed (or pulsed) power supply to drive the LEDs. Yet another embodiment of the present invention uses a xenon strobe ring-light source and a backplane slit in place of the row of LEDs. In one such xenon strobe embodiment, a color filter is also placed in series with the light path in order to obtain a monochromatic light.

Abstract: Improved method and apparatus for hand-held portable illumination. A flashlight and corresponding method are described. The flashlight includes a housing, a plurality of LEDs, and an electrical circuit that selectively applies power from the DC voltage source to the LED units, wherein the flashlight is suitable for handheld portable operation by a user. In one embodiment, the first electrical circuit further includes a control circuit for maintaining a predetermined light output level of the LED units as a charge on a battery varies. In another embodiment, the control circuit maintains an average predetermined light output level of the LED units as the charge on the battery cell varies by changing a pulse width or frequency as the charge on the battery cell varies to maintain a given average light output.

Abstract: An illumination method and apparatus for machine-vision systems, including a ring-light source (e.g., LEDs arranged in one or more circular rows), and a reflective-ring focusing element. The illumination source exhibits multidirectional ring-illumination properties which are useful for illumination of small components (which are being inspected or measured) without unwanted shadows. One embodiment provides a darkfield illumination system. One embodiment of the present invention uses a strobed (or pulsed) power supply to drive the LEDs. Yet another embodiment of the present invention uses a xenon strobe ring-light source and a backplane slit in place of the row of LEDs 25. In one such xenon strobe embodiment, a color filter is also placed in series with the light path in order to obtain a monochromatic light.