Optics: measuring and testing – By dispersed light spectroscopy – Utilizing a spectrophotometer
Reexamination Certificate
1999-01-29
2001-01-09
Font, Frank G. (Department: 2877)
Optics: measuring and testing
By dispersed light spectroscopy
Utilizing a spectrophotometer
C359S833000
Reexamination Certificate
active
06172751
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high efficiency reflectometry illuminator collector system.
2. Discussion of the Background
Spectrophotometers may be used to measure the color spectrum on the surface of objects, such as paper, paint chips or fabric swatches. A spectrophotometer for reflectance spectrometry usually includes a light source, such as a light bulb and a power source, optics for transferring the light from the light source to the sample, such as fiber optics, lenses and/or mirrors, and optics for collecting the light, which may also include fiber optics, lenses and/or mirrors. The collected light is then transferred to a device for separating the light into its component wavelengths, such as a diffraction grading or a prism, and then to a detector to measure the intensity of one or more of the different wavelengths of the light. As a reference the intensity of one or more of the different wavelengths of the light. As a reference, the intensity of light generated by the light source may also be transferred by optics to a detector. The signal generated by the detector from the sample light, and the signal generated by the detector from the reference light, may be transferred through a data processing system, such as a computer, and the result displayed or stored. A large variety of configurations and methods are known, and are described in U.S. Pat. Nos. 5,701,175; 5,400,138; 5,319,437; 4,773,761; 3,885,878; and 3,806,256; all of which are incorporated by reference.
A typical geometry of optics closest to a sample in the directive (as opposed to integrating sphere) reflectometry industry includes illumination and collection sections, each with a specific angle from the normal to the sample surface, for example illumination at 45° to the normal of the plane of the sample surface, and collection normal to the surface of the sample. With the exception of highly mirrored samples, all reflectance samples scatter light from the illuminator at various solid angles into the space above the sample. Only a portion of the scattered light is therefore collected by the collection optics, due to the collection angle. It would be desirable, therefore, to use this wasted scattered light, in order to boost the strength of the signal and improve the accuracy and precision of the spectrophotometer.
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel illuminator and collector system to increase the efficiency of the spectrophotometer.
Another object of the invention is to provide a novel spectrophotometer which uses this illuminator and collector system.
Another object of the invention is to provide a novel reflectometry method having improved efficiency.
These objects may be achieved with a novel reflector, comprising: a truncated cone having a reflective inner surface and a conical axis, with an opening at a larger axial end of the truncated cone, an opening at a smaller axial end of the truncated cone, and an opening in the cone surface.
These objects may also be achieved with a spectrophotometer comprising this novel reflector. Furthermore, the objects may also be achieved by a method of measuring the reflectance spectrum of a surface, comprising: illuminating a surface with light at an angle greater than 0 from the normal of the plane of the surface, thereby generating reflected light normal to the plane and other reflected light; reflecting a portion of the other reflected light back to the surface at the angle, thereby generating additional reflected light normal to the plane.
If one form of the invention, a reflector is disclosed, comprising a truncated cone, comprising a cone body defining an outer surface, a reflective inner surface and a conical axis; a first opening at a larger axial end of the cone body; a second opening at a smaller axial end of the cone body; and a third opening through the reflective inner surface between the first and second openings.
In another form of the invention, a spectrophotometer is disclosed, comprising a truncated cone, comprising a cone body defining an outer surface, a reflective inner surface and a conical axis; a first opening at a larger axial end of the cone body; a second opening at a smaller axial end of the cone body; a third opening through the reflective inner surface between the first and second openings; a source of light positioned to emit light rays through the third opening; and a light collector positioned to receive light rays reflected through the second opening.
In another form of the invention, a method for measuring the reflectance spectrum of a surface is disclosed, comprising the steps illuminating a surface with light at an angle greater than 0° from the normal of the plane of the surface, thereby generating reflected light normal to the plane and other reflected light; reflecting a portion of the other reflected light back to the surface at the angle greater than 0° from the normal of the plane of the surface, thereby generating additional reflected light normal to the plane.
In another form of the invention, a spectrophotometer is disclosed, comprising a light source, optics for transferring light from the light source to a sample, optics for collecting light reflected from the surface of the sample, and a detector for detecting the intensity of light reflected from the sample, the improvement comprising a reflector, the reflector comprising a truncated cone, comprising a cone body defining an outer surface, a reflective inner surface and a conical axis; a first opening at a larger axial end of the cone body; a second opening at a smaller axial end of the cone body; and a third opening through the reflective inner surface between the first and second openings.
REFERENCES:
patent: 3759607 (1973-09-01), Boyle
patent: 4853542 (1989-08-01), Milosevic et al.
patent: 5309339 (1994-05-01), Webb
Celentano Mike
Zachidny Chris
Font Frank G.
Smith Zandra V.
UMM Electronics Inc.
Woodard Emhardt Naughton Moriarty & McNett
LandOfFree
High efficiency reflectometry illuminator and collector system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High efficiency reflectometry illuminator and collector system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High efficiency reflectometry illuminator and collector system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2487311