Abstract:
The present invention provides an apparatus and method for characterizing the photometric and/or colourmetric properties of a light source. The apparatus comprises a detector system which generates data indicative of at least spectroradiometric data for at least a portion of the light emitted by the light source. The apparatus further comprises a manipulation stage configured to control the relative position between the detector system and the light source. In addition, the apparatus comprises a control and processing system configured to control operation of the detector system, operation of the manipulation stage and record the data and the relative position of the detector system associated therewith. The control and processing system is further configured to process the collected data for determination of the photometric and/or colourmetric properties of the light emitted by the light source.
Abstract:
Method for correction of the temperature dependency of a light quantity L emitted by a light emitting diode (LED), being operated in pulsed mode with substantially constant pulse duration tP, and measured in a light detector, using a predetermined parameter X, correlated to the temperature T of the LED in a predetermined ratio, whereby a correction factor K is determined from the parameter X, preferably using a calibration table, especially preferred using an analytic predetermined function, whereby the measured emitted light quantity L is corrected for the temperature contingent fluctuations of the emitted light quantity, whereby the parameter X is determined from at least two output signals of the LED, which are related to each other in a predetermined manner.
Abstract translation:用于校正由发光二极管(LED)发射的光量L的温度依赖性的方法,其以脉冲模式以基本上恒定的脉冲持续时间t P P运行,并且在光检测器中测量,使用 预定参数X,以预定比例与LED的温度T相关,由此,优选使用校准表,从参数X确定校正因子K,特别优选使用分析预定功能,由此测量的发射光量 根据发射光量的温度偶然波动来校正L,由此根据预定方式彼此相关的LED的至少两个输出信号来确定参数X.
Abstract:
The present invention provides a light source comprising one or more light-emitting elements, one or more photosensors and, a photosensor light guide, such as, for example, a substantially planar light guide. The photosensor light guide is generally configured to capture and guide some of the light emitted from the one or more light-emitting elements to one or more photosensors optically coupled thereto, the light sensed thereby being useable as a basis for controlling the respective outputs of the one or more light-emitting elements.
Abstract:
Disclosed are improvements in ellipsometer and the like systems capable of operating in the Vacuum-Ultra-Violet (VUV) to Near Infrared (NIR) wavelength range, and methodology of use.
Abstract:
In order to reduce the exposure of a detector surface 180 of a photo-multiplier 160 to stray charged particles, an off-axis structure is interposed between the resonant structure and the detector surface of the photo-multiplier. By providing the off-axis structure with at least one reflective surface, photons are reflected toward the detector surface of the photo-multiplier while at the same time absorbing stray charged particles. Stray particles may be absorbed by the reflective surface or by any other part of the off-axis structure. The off-axis structure may additionally be provided with an electrical bias and/or an absorbing coating for absorbing stray charged particles.
Abstract:
A machine and methods measure a characteristic of an optical signal incident upon a detector characterized by one or more dynamic response parameters. One method receives an output signal from the detector and compares that output signal and a computationally determined response of the detector to a known optical signal incident upon the detector. The response is based on said one or more dynamic parameters. The method determines the characteristic based on a relationship between the output signal and the computationally determined response. Another method observes an output signal from an optical detector detecting one or more optical signals, accesses a characteristic curve of detector response, compares the observed output signal to the characteristic curve, and calculates at least one characteristic of one or more optical signals based on a relationship of the observed output signal and the characteristic curve.
Abstract:
A system and method for detecting radiation indicative of fire, such as forest fire. In one embodiment, a threshold energy level is determined based on ambient sensor conditions. A sensor unit may be setup to scan a predetermined area for electromagnetic radiation. Any detected electromagnetic radiation may then be band pass filtered to a wavelength range centered about a predetermined frequency associated with the presence of fire. The resulting energy level signal may then be further filter to pass only those signals which exhibit a “flicker” frequency. If the resulting filtered signal exceeds the threshold signal, a fire notification signal may then be generated.
Abstract:
The invention relates to an arrangement with a panel of a flat display and with a graphics processor to which a digitized image signal can be supplied by an A/D converter, said image signal being generated from an analog image signal by the A/D converter. An amplification of the A/D converter can be set in such a manner that the A/D converter generates a maximum video step of the digital image signal from the highest video level of the analog image signal. Appropriate measures are used to reduce interfering influences upon the contrast of an image due to aging effects of the transparent portions of the panel, e.g. due to aging effects of the panel glass, the LCD liquid or of the diffuser films and/or polarization films, and permit the sensor to be seen via the display surface only during a calibrating phase. The contrast is automatically adjusted on site, e.g. when the flat display is used in the medical field, thereby eliminating the need for service personnel.
Abstract:
A system, method, and apparatus for determining the remaining time a user has before maximum natural UV radiation exposure is reached, and the clock time at which natural UV radiation exposure should end, based on measured irradiation and other parameters.
Abstract:
A semiconductor light source with optical feedback includes a vertical member extending upward from an upper horizontal surface of a header parallel to a vertical beam projected from a semiconductor light-emitting element mounted on the horizontal surface of the header wherein the vertical member supports a light-sensing element for receiving light reflected transversely from the vertical beam by a beam splitter supported by the vertical member. The vertical beam passing through the beam splitter passes through a window or filter in a cap mounted on the header and covering the light-emitting element, the light-sensing element, the beam splitter, and the vertical member. Substantially all of the transversely reflected light impinges on the light-sensing element and can be used to control the power to the light-emitting element. A simple lens can by used to collimate the beam. Interior portions of the unit are formed from light absorbing materials such as black ceramic, black plastic, anodized aluminum, etc. The combined effect of the non-reflective interior of the assembly, the orientation of the photo-diode to have an acceptance cone perpendicular to the beam axis, the small entrance pupil, and the optical filter reduces ambient radiation in the unit by as much as −75 dB of the level outside the device. This reduces noise and drift in the automatic power control loop to produce constant intensity in the output light beam.