Abstract:
An illumination system comprises at least two light sources (101,102,103) having different emission spectra to one another; a detection circuit (131,132,133) for sensing a light intensity using at least one of the light sources as a photosensor; and driving means (161,162,163) for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.
Abstract:
A method for providing an intensity or brightness measurement using a digital image-capturing device comprising: selecting a target area within a field of view of the image-capturing device, the target area containing pixels; determining the brightness of pixels in the target area; accumulating the brightness values of the pixels in the target area; and determining a pixel value representative of the pixels in the target area. A device for making color measurements comprising an image-capture device, a processor or logic device, and a memory location for accumulating color data, and the processor or logic device is programmed to perform color measurements by accumulating the data for pixels located in the target area in memory, and determining a representative color value.
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 radiation detector is disclosed with a detector arrangement, which has a plurality of detector elements, by means of which a detector signal is obtained during operation of the radiation detector, and with a control device, wherein the detector elements each have a spectral sensitivity distribution, and are suited for generating signals. At least one detector element includes a compound semiconductor material, and this detector element is designed for detecting radiation in the visible spectral region. The radiation detector is designed such that the sensitivity distributions of the detector elements are used to form different spectral sensitivity channels of the radiation detector. A channel signal assigned to the respective sensitivity channel can be generated in these sensitivity channels using the detector elements, and the control device is designed such that the contributions of different channel signals to the detector signal of the radiation detector are differently controlled.
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 method for providing data useful in procedures associated with the oral cavity, in which at least one numerical entity representative of the three-dimensional surface geometry and color of at least part of the intra-oral cavity is provided and then manipulated to provide desired data therefrom.
Abstract:
A liquid crystal display apparatus according to the present invention includes: a liquid crystal panel; a backlight provided on a rear face of the liquid crystal panel; a detector which detects RGB output light levels of the backlight; a first controller which controls backlight current for driving the backlight so that a prescribed luminance is attained based on the RGB output light levels detected by the detector; and a second controller which controls display signals supplied to the liquid crystal panel so that a prescribed chromaticity is attained based on the RGB output light levels detected by the detector.
Abstract:
An illumination system (1) comprises a plurality of lamps (11, 12, 13) for generating light (R, G, B) with mutually different colors; in an embodiment, the lamps are fluorescent lamps. A sensing system (50) comprising a color sensor (51) provides a sensor output signal (Ss) that indicates the color of the light received by the color sensor. The sensing system comprises a light guide arrangement (60) interposed between the lamps and the sensor, which is arranged in a service room (74) shielded from ambient light. Each light guide captures light from one lamp only, and the sensor receives a mixture of the captured lights. The color sensor and light guide are used in a feedback system that corrects for tolerances, lamp aging, ambient temperature etc.
Abstract:
The measuring device comprises a lighting system, a photoelectric receiver unit and optical means. The lighting system applies light to image elements disposed in strip-shaped lighting regions (15) at a standardized angle of incidence range. The photoelectric receiver unit comprises several photoelectric line sensors (21) disposed parallel at a distance apart which are sensitized to different wavelength ranges by color filters (22) connected upstream. The optical means comprise linear optical arrays (31) which pick up the measurement light reflected by the image elements at a standardized range of angle of reflection and direct it to one of the respective line sensors (21). By means of optical screening and other structural features, cross-talk effects between adjacent image elements are largely reduced.
Abstract:
A handheld color measurement device includes a housing in which an optoelectronic measurement unit is located which receives measurement light originating from a measurement object, converts it into corresponding electrical measurement signals and processes these measurement signals into preferably digital measurement data characterizing the color of the measurement object. It further includes passive components required for the realization of different application functions, such as measurement windows and reference standards, which can be selectively positioned into the measurement beam path of the measurement unit. The passive components are positioned in a first housing block (100) and the opto-electronic measurement unit as a whole in a second housing block (200). The second housing block is adjustable into several defined application positions relative to the first housing block, in which application positions respectively one of the passive components is located in the measurement beam path of the opto-electronic measurement unit.This special division into two mutually relatively adjustable housing blocks allows an easy realization of a compact color measurement device suitable for many application functions, which is distinguished by a particular user friendliness.