Machine-vision ring-reflector illumination system and method

A machine-vision illumination system, comprising:

• an imaging device positioned to receive an image of an object;
• an image processor operatively coupled to the imaging device to process a signal representative of the image of the object;
• and
• an illumination source coupled to the image processor, the illumination source comprising:
• a ring light source emitting light from a plurality of points or from a line, the points or line being substantially in a plane that intersects the optical axis, each of the points or the line disposed at least a first distance from the optical axis and less than a second distance from the optical axis;
• and
• a first ring reflector, the ring reflector having an exit opening through which the optical axis passes, a majority of the emitted light from the ring light source being generally directed toward, and centered on lines that intersect, a reflecting surface of the ring reflector, the ring reflector by a single reflection directly reflecting the emitted light from the light source through the exit opening to the object inwards and generally towards the optical axis or an area around the optical axis.

An apparatus comprising:

• a first ring reflector for use in reflecting light from a ring light source, the ring light source emitting light from a plurality of points or from a line, the points or line being substantially in a plane that intersects an optical axis, the first ring reflector comprising:
• a substantially circular exit opening through which the optical axis passes;
• and
• a reflective surface surrounding the exit opening, the reflective surface extending from approximately a first circle centered on the optical axis and having a first radius, to approximately a second circle centered on the optical axis and having a second radius, the second radius being larger than the first radius, the first radius being larger than the difference between the second radius and the first radius, whereby the emitted light from the ring light source being generally directed centered on lines that intersect the reflecting surface of the ring reflector, the ring reflector reflecting the emitted light from the light source though the exit opening inwards and generally towards the optical axis or an area around the optical axis, wherein the first ring reflector is configured to be replaceably affixed to a machine-vision system such that the first ring reflector can be interchanged with another ring reflector in order to provide different reflective characteristics to the machine-vision system.