Machine-vision ring-reflector illumination system and method
First Claim
1. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis and wherein each LED has a focal centerline emission axis along which emission is centered, and each LED'"'"'s emission axis is parallel to the optical axis.
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Accused Products
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. While xenon flashtube light sources tend to exhibit a five per cent (5%) flash-to-flash variation in intensity which makes accurate measurements of certain characteristics difficult, they are useful in certain cases where intense white, or especially ultraviolet, light is desired. Strobed LEDs provide very little flash-to-flash variation in intensity. The compact ring-light generator has little, if any, shadowing. The present invention also provides an inexpensive apparatus and method for changing the light-source-to-optical-axis angle.
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Citations
43 Claims
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1. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis and wherein each LED has a focal centerline emission axis along which emission is centered, and each LED'"'"'s emission axis is parallel to the optical axis. - View Dependent Claims (24, 25)
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2. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and wherein the light emitted from the LEDs is primarily within an angle of about 5 degrees from a focal centerline of each individual LED.
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3. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and further comprising a focusing element that includes a cylindrical ring lens having at least one convex face.
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4. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring reflector has a surface that enhances its reflectivity at one or more selected wavelengths of the ring light source. - View Dependent Claims (26)
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5. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring reflector and ring light source are configured to produce a darkfield illumination. - View Dependent Claims (27)
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6. A method for illuminating an object located along, an optical axis, comprising the steps of:
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(a) 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 (b) reflecting the emitted light from the light source inwards and generally towards the object at the optical axis or in an area around the optical axis, wherein the step of emitting light include emitting light from one or more light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and wherein each LED has a focal centerline emission axis along which emission is centered, and each LED'"'"'s emission axis is parallel to the optical axis. - View Dependent Claims (40)
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7. A method for illuminating an object located along an optical axis, comprising the steps of:
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(a) 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 (b) reflecting the emitted light from the light source inwards and generally towards the object at the optical axis or in an area around the optical axis, wherein the step of emitting light include emitting light from one or more light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and wherein each LED has an focal centerline emission axis along which emission is centered, and each LED'"'"'s emission axis is perpendicular to the optical axis, and further comprising the step of focusing the emitted light to a circular line.
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8. A machine-vision illumination system comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and wherein each LED has a focal centerline emission axis along which emission is centered, and each LED'"'"'s emission axis is parallel to the optical axis.
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9. A machine-vision illumination system, comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and wherein the light emitted from the LEDs is primarily within an angle of about 5 degrees from a focal centerline of each individual LED.
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10. A machine-vision illumination system, comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring light source comprises a plurality of light-emitting diodes (LEDs) arranged substantially along a circle disposed perpendicular to and centered on the optical axis, and further comprising a focusing element that includes a cylindrical ring lens having at least one convex face.
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11. A machine-vision illumination system comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring reflector has a surface that enhances its reflectivity at one or more selected wavelengths of the ring light source.
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12. A machine-vision illumination system, comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring reflector and ring light source are configured to produce a darkfield illumination.
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13. A 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 ring reflector comprising:
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a substantially circular exit opening though 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 reflective surface comprises a plurality of adjoining conical sections. - View Dependent Claims (14, 38, 39)
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15. A 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 ring reflector comprising:
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a substantially circular exit opening though 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 reflective surface comprises a plurality of reflective facets. - View Dependent Claims (16)
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17. A 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 ring reflector comprising:
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a substantially circular exit opening though 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 reflective surface comprises a first conical section, and wherein the ring reflector further comprises a second conical section, the first and second conical sections each having a unique conical angle.
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18. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring reflector includes a reflective surface comprising a plurality of conical sections each having a unique conical angle. - View Dependent Claims (28)
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19. An illumination source for illuminating an object in a machine-vision system, the system having an optical axis, comprising:
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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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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, and further comprising; a ring-reflector holder that holds one of a plurality of interchangeable ring reflectors in optical communication with the ring-light source, said plurality of interchangeable ring reflectors including the first ring reflector. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37)
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20. A method for illuminating an object located along an optical axis, comprising the steps of:
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(a) 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 (b) reflecting the emitted light from the light source inwards and generally towards the object at the optical axis or in an area around the optical axis, wherein the step of reflecting the emitted light includes reflecting the light from a plurality of reflective conical sections each having a unique conical angle.
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21. A method for illuminating an object located along an optical axis, comprising the steps of:
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(a) 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; (b) reflecting the emitted light from the light source inwards and generally towards the object at the optical axis or in an area around the optical axis; and (c) changing a first ring reflective surface having a first reflective configuration to a second ring reflective surface having a different reflective configuration than that of the first ring reflective surface. - View Dependent Claims (41, 42, 43)
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22. A machine-vision illumination system, comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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 ring reflector includes a reflective surface comprising a plurality of conical sections each having a unique conical angle.
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23. A machine-vision illumination system, comprising:
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an imaging device; an image processor coupled to the imaging device; 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 though which the optical axis passes, the emitted light from the ring light source being generally directed centered on lines that intersect a 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, and further comprising; a ring-reflector holder that holds one of a plurality of interchangeable ring reflectors in optical communication with the ring-light source, said plurality of interchangeable ring reflectors including the first ring reflector.
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Specification