Abstract:
An apparatus for imaging a tooth having a light source with a first spectral range and a second spectral range. A polarizing beamsplitter (18) light having a first polarization state toward the tooth and directs light from the tooth having a second polarization state along a return path toward a sensor (68), wherein the first and second polarization states are orthogonal. A first lens (22) in the return path directs image-bearing light from the tooth, through the polarizing beamsplitter (18), toward the sensor (68), and obtains image data from the redirected portion of the light having the second polarization state. A long-pass filter ( 15) in the return path attenuates light in the second spectral range. Control logic enables the sensor to obtain either the reflectance image or the fluorescence image.
Abstract:
A color measurement instrument and color measurement method for measuring a color of a surface are provided. The instrument includes a plurality of independently switchable light sources characterized by differing spectral ranges, and a plurality of light guides configured to receive light from the light sources and to direct the received light to a light emitting portion of the instrument for illuminating the surface. The instrument further includes a first light detector configured to receive a portion of the light reflected from the surface. The first light detector is a wideband light detector.
Abstract:
The invention relates to a method and to an electronic circuit for processing signals which as such are indicative of the features or characteristics of the spectral distribution of light which is supplied for spectrometric measurements combined with an LED light source. The problem of the invention is to provide solutions which allow the informative value of spectrometric measurements to be increased. For this purpose, a reference curve for the spectral emission is calculated based on a reference measurement and at least two additional measurements on the same reference, said spectral emission being used as a reference when carrying out measurements of practically any objects. This curve is determined in such a manner that it corresponds to a curve of the spectral emission at a temperature that is outside or far outside the temperature range of the actual temperatures of the LED during the measurements.
Abstract:
An optical system comprising an optical instrument and a processing unit. The optical instrument may comprise an illumination source and a sensor. The processing unit may comprise a data storage having stored thereon a characterization of the illumination source and a characterization of the sensor. The processing unit may also comprise a computer configured to calculate a system response of the illumination source and the receiving element considering the characterization of the illumination source and the characterization of the receiving element.
Abstract:
In one embodiment, the invention is spectrophotometer with a light emitting diode illuminator. In one embodiment, a spectrophotometer for characterizing a reflectance spectrum of a specimen includes an optical assembly for illuminating the specimen, where the optical assembly includes at least one light emitting diode. A measurement head is coupled to the optical assembly for collecting light reflected by the specimen, and a spectrum analyzer is coupled to the measurement head for performing spectral analysis of the collected light into a plurality of spectral bands. A reference channel provides illumination from the optical assembly to the spectrum analyzer, while a test channel provides the collected light from the measurement head to the spectrum analyzer.
Abstract:
A system provides light of selectable spectral characteristic (e.g. a selectable color combination of light), for luminous applications such as signage and indicator lights. An optical integrating cavity combines energy of different wavelengths from different sources, typically different-color LEDs. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined light. Control of the intensity of emission of the sources sets the amount of each wavelength of light in the combined output and thus determines a spectral characteristic of the light output through the aperture. A deflector shaped like a number, character, letter, or other symbol, may be coupled to a similarly shaped aperture. By combining several such fixtures, it is possible to spell out words and phrases, with selectable color lighting. Disclosed fixture examples use an extruded body member with appropriately located reflective surfaces, to form both the cavity and deflector.
Abstract:
A color measurement instrument includes a housing and illuminators, a two-dimensional photodetector array, and an optics system within the housing. A UV filter wheel closes the housing to prevent contaminants from entering the housing. The filter wheel supports UV filters and non-UV glass that can be selectively aligned with the illuminators. The photodetectors can be read in parallel, and each photodetector includes a unique spectral filter. The optics system delivers light from the sample target area equally to each of the photodetectors.
Abstract:
An object (206) to be imaged or detected is illuminated by a single broadband light source or multiple light sources emitting light at different wavelengths. The light is detected by a detector (200), which includes a light-detecting sensor (400) covered by a hybrid filter. The hybrid filter includes a multi-band narrowband filter (516) mounted over a patterned filter layer (508). The light strikes the narrowband filter (516), which passes light at or near the multiple wavelengths of interest while blocking light at all other wavelengths. The patterned filter layer (508) alternately passes the light at one particular wavelength while blocking light at the other wavelengths of interest. This allows the sensor (400) to determine either simultaneously or alternately the intensity of the ligth at the wavelengths of interest. Filters (902) may also be mounted over the light at the light sources to narrow the spectra of the light sources.
Abstract:
A handheld, portable color measuring device (10) for measuring the primary colors of red, green and blue in a color target (22) and connected to a built-in LCD display (30) or connected to a separate personal computer (38). The color measuring device (10) includes an elongated color measuring probe housing (12). A hollow cone shaped probe tip (18) is attached to one end of the probe housing (12). Inside the probe housing (12) is a battery powered white LED light source (42) connected to a color measurement switch (26). A light pipe (44) is centered inside the probe housing (12) and a portion of the probe tip (18). The light pipe (44) captures the light reflected off the color target (22) and projects the captured light onto a 3 color sensor (54). The light signal is amplified and converted to a digital signal using an A/D converter. The A/D converter is part of a microprocessor mounted on a printed circuit board (56) inside the probe housing (12).