Abstract:
A system to provide radiant energy of selectable spectral characteristic (e.g. a selectable color combination of light) uses an optical integrating cavity to combine energy of different wavelengths from different sources. Sources of radiant energy of different wavelengths, typically different-color LEDs, supply radiant energy into the interior of the cavity. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined radiant energy. Control of the intensity of emission of the sources sets the amount of each wavelength of energy in the combined output and thus determines a spectral characteristic of the radiant energy output through the aperture. A variety of different elements may optically process the combined light output, such a deflector, a variable iris, a lens, a variable focusing lens system, a collimator, a holographic diffuser and combinations thereof. Such systems are useful in various luminous applications as well as various illumination applications.
Abstract:
A hand-held portable modular spectrometer unit. The unit includes a detachable head containing a light source and optical components for detecting spectral information from light reflected from or transmitted through a target and a processor for converting the detected spectral information into digital information. The unit also includes a plug-in rechargeable power supply and a control module for controlling the components in the measurement head. The controller includes a computer processor for analyzing the digital information produced by the measurement head and a display monitor for displaying spectral information produced by the control unit. In preferred embodiments the plug-in rechargeable power supply is a 12-volt off-the-shelf power-tool rechargeable battery unit. In preferred embodiments several measuring heads are available. These include a gas cell measuring head, a surface reflectance measuring head that includes and integrating sphere, a specular reflectance measuring head, a grazing angle measuring head, an attenuated total reflectance measuring head, a diffuse reflection measuring head, a non-volatile residues measuring head, a liquid transmission cell measuring head and a fluorescence measuring head. Each of these measurement heads includes a spectrometer. Several types of spectrometers are available including those based on filters, prisms, gratings and interferometers. The unit can operate in a wide range of wavelengths including the infrared, visible and ultraviolet spectral ranges.
Abstract:
A modular dual-beam source, sample compartment and beam-combining system are provided when used with a monochromator and detector to form a spectrophotometer consisting of: (a) a source module where two ellipsoidal mirrors each produce an image of the light source, and (b) a reflecting sample-compartment module, wherein each side has two plane-mirrors, of the four plane mirrors, three are reference and one is the sample, or (c) a transmission sample-compartment module, wherein each side has two plane-mirrors, and a sample is placed between one pair of plane-mirrors, and (d) a beam-combining module wherein the source images are imaged by a second pair of ellipsoidal mirrors on a reflective chopper that combines the images at a single location that is imaged, external to the module, by another mirror, each module being kinematically located with respect to each other so the system remains optically aligned as modules are interchanged.
Abstract:
A system for predicting blood constituent values in a patient includes a remote wireless non-invasive spectral device, the remote wireless non-invasive spectral device generating a spectral scan of a body part of the patient. Also included are a remote invasive device and a central processing device. The remote invasive device generates a constituent value for the patient, while the central processing device predicts a blood constituent value for the patient based upon the spectral scan and the constituent value.
Abstract:
The method and apparatus of the present invention provides a system wherein light-emitting diodes (LEDs) can be tuned within a given range by selecting their operating drive current in order to obtain a precise wavelength. The present invention further provides a manner in which to calibrate and utilize an LED probe, such that the shift in wavelength for a known change in drive current is a known quantity. In general, the principle of wavelength shift for current drive changes for LEDs is utilized in order to allow better calibration and added flexibility in the use of LED sensors, particularly in applications when the precise wavelength is needed in order to obtain accurate measurements. The present invention also provides a system in which it is not necessary to know precise wavelengths of LEDs where precise wavelengths were needed in the past. Finally, the present invention provides a method and apparatus for determining the operating wavelength of a light emitting element such as a light emitting diode.
Abstract:
The method and apparatus of the present invention provides a system wherein light-emitting diodes (LEDs) can be tuned within a given range by selecting their operating drive current in order to obtain a precise wavelength. The present invention further provides a manner in which to calibrate and utilize an LED probe, such that the shift in wavelength for a known change in drive current is a known quantity. In general, the principle of wavelength shift for current drive changes for LEDs is utilized in order to allow better calibration and added flexibility in the use of LED sensors, particularly in applications when the precise wavelength is needed in order to obtain accurate measurements. The present invention also provides a system in which it is not necessary to know precise wavelengths of LEDs where precise wavelengths were needed in the past. Finally, the present invention provides a method and apparatus for determining the operating wavelength of a light emitting element such as a light emitting diode.
Abstract:
A spectrophotometer (10) is provided having the capability to accurately measure spectral reflectance at relatively long sample distances. A first illumination optics arrangement (14) assures uniform illumination to a portion of the sample and a second optical arrangement (20) focuses the reflected image of part of the illuminated sample onto a polychromator (22). Reference beam means are provided so that the polychromator sequentially measures the spectral characteristics of the reference beam and the sample. Continuous monitoring of the illumination at select wavelengths provides illumination normalization data so that a microprocessor (40) can normalize the illumination and compare the reference beam and sample measurements to accurately determine the spectral reflectance characteristics of the sample. Angular and raster scanning capability is also provided.
Abstract:
Spectrum sensors can be continuously calibrated in a manufacturing environment employing a continuously moving platform that carries the spectrum sensors in combination with spatially separated light spectra illuminating a region of the platform. A plurality of spectrum sensors, each including multiple sensor pixels, can be placed on the platform. The spatially separated light spectra can be illuminated over an area of the platform. The plurality of spectrum sensors can be moved with the platform through a region of the spatially separated light spectrum. Each sensor pixel for each of the plurality of spectrum sensors can be calibrated based on response of each spectral channel during passage through the spatially separated light spectra. The entire spectra from a light source can be employed simultaneously to calibrate multiple spectrum sensors in the manufacturing environment.
Abstract:
A spectrometric device for optical analysis of material composition, coating thickness, surface porosity, and/or other characteristics uses several monochromatic light sources—e.g., laser diodes—to illuminate a sample, with a camera taking an image of the sample under each source's light, and with the various images then being combined to generate a (hyper)spectral image. To address the difficulty in obtaining uniform illumination intensity across the illuminated sample area with solid-state light sources, the output from the light sources may be supplied to an integrating sphere (preferably after being combined within a fiber combiner), and then to a fiber bundle whose output ends are configured as a ring light (a ring of fiber ends directing light at a common spot). The camera may then focus on the spot, at which the sample may be placed for illumination and imaging.
Abstract:
A spectroscopic measurement apparatus includes a light source, an integrator, a first spectroscopic detector, a second spectroscopic detector, and an analysis unit. The integrator includes an internal space in which a measurement object is disposed, a light input portion for inputting light to the internal space, a light output portion for outputting light from the internal space, and a sample attachment portion for attaching the measurement object. The first spectroscopic detector receives the light output from the integrator, disperses the light of a first wavelength region, and acquires first spectrum data. The second spectroscopic detector receives the light output from the integrator, disperses the light of a second wavelength region, and acquires second spectrum data. The first wavelength region and the second wavelength region include a wavelength region partially overlapping each other.