Abstract:
Optical properties of an object are determined via light provided to the object via a probe tip including a plurality of light source/light receiver pairs. Light is received from a first light source/light receiver pair, and the first light source/light receiver pair is arranged so that a first measurement generates data based on light from the object received from a first average optical depth or first thickness sensitivity. Light is received from a second light source/light receiver pair, and the second light source/light receiver pair is arranged so that a second measurement generates data based on light from the object received from a second average optical depth or a second thickness sensitivity. The second average optical depth is different from the first average optical depth. Optical properties of the object are determined based on the data generated by the first and second measurements.
Abstract:
A color image forming apparatus, when a white LED is made to emit light onto a color image so that the reflected light can be detected, changes a color measuring condition in adaptation to a reflectance predicted for the image from the forming condition of the color image to be detected. The amount of reflected light is detected by photodiodes, and the image forming condition is adjusted, based on the detected amount of reflected light of each color image. Thereby, irrespective of the reflectance of each color image, the color measurement of each color image is effected with good accuracy, and the hue and density of the color image to be detected are accurately detected, thereby to form a color image with excellent color reproduction.
Abstract:
A detector system, filter therefor, and method of making same is disclosed. The filter includes an interference element having a reflection band disposed primarily in the near infrared, and having a high transmission over most of the visible region. The filter also includes an absorptive element that absorbs light non-uniformly over the visible region. The filter when combined with a semiconductor photodiode or other suitable detector yields a detector system whose spectral responsivity closely matches the visual response of the human eye.
Abstract:
Disclosed is an apparatus and method for a compact, rugged, and inexpensive spectrometer that will make possible a range of new applications for optical spectroscopy including point-of-care medical devices, personal monitors, and ubiquitous environmental sensing. Embodiments of the disclosure include silicon photodetectors where incident light passes through a layer of an inexpensive, absorbing thin film. In one embodiment, one or more photodetectors may be used where a series of absorbing thin film layers are passed over the photodetectors. In another embodiment, an absorbing thin film layer is placed over one or more photodetectors where the absorptivity of the thin film layer is different for each photodetector.
Abstract:
In the color imaging system, multiple rendering devices are provided at different nodes along a network. Each rendering device has a color measurement instrument for calibrating the color presented by the rendering device. A rendering device may represent a color display in which a member surrounds the outer periphery of the screen of the display and a color measuring instrument is coupled to the first member. The color measuring instrument includes a sensor spaced from the screen at an angle with respect to the screen for receiving light from an area of the screen. A rendering device may be a printer in which the measuring of color samples on a sheet rendered by the printer is provided by a sensor coupled to a transport mechanism which moves the sensor and sheet relative to each other, where the sensor provides light from the sample to a spectrograph. The color measuring instruments provide for non-contact measurements of color samples either displayed on a color display, or printed on a sheet, and are self-calibrating by the use of calibration references in the instrument.
Abstract:
A tristimulus colorimeter on a single semiconductor chip having at least three detectors, each detector being coated by colorant filters, each filter having at least one layer and at least one filter having a double layer is provided. The colorimeter determines CIE tristimulus values of an incident light from inputs to the filters and detectors. Colorimeters having integral dye filters may be constructed on a single silicon chip embodying all the detectors and electronics, coated over each detector by a deposited filter layer. Colorants may be directly deposited on the detectors, rather than using a plastic substrate for a filter.
Abstract:
A method for determining the optimal colorant thicknesses for integral CIE color-matching filters is provided. According to a computational study, a four band filter of the present invention provides a best approximation to the CIE XYZ color-matching functions with the least cost.
Abstract:
A color calibration method for an imaging color measurement device utilizes a detector array, a plurality of optical elements, and multiple instances of irradiation of the detector array for a single measurement. A flat-fielding correction error correction matrix of the imaging color measurement device for each instance of irradiation of the detector array is obtained prior to color calibration. The response for each instance of irradiation of the detector array is flat-fielded with the corresponding error matrix to obtain a flat-fielded, spectrally weighted irradiance response for each instance of irradiation of the detector array. An illuminant light source with known spectral output or chromaticity coordinates is measured to obtain an irradiance response of the imaging color measurement device for each instance of irradiation of the detector array. A color correction coefficient is calculated using the known spectral output and chromaticity coordinates of the light source and the corresponding flat-fielded irradiance response.
Abstract:
Optical characteristic measuring systems and methods such as for determining the color or other optical characteristics of teeth are disclosed. Perimeter receiver fiber optics are spaced apart from a source fiber optic and receive light from the surface of the object/tooth being measured. Light from the perimeter fiber optics pass to a variety of filters. The system utilizes the perimeter receiver fiber optics to determine information regarding the height and angle of the probe with respect to the object/tooth being measured. Under processor control, the optical characteristics measurement may be made at a predetermined height and angle. Various color spectral photometer arrangements are disclosed. Translucency, fluorescence, gloss and/or surface texture data also may be obtained. Audio feedback may be provided to guide operator use of the system. The probe may have a removable or shielded tip for contamination prevention. A method of producing dental prostheses based on measured data also is disclosed. Measured data also may be stored and/or organized as part of a patient data base.
Abstract:
A color measuring head is provided with an illuminating unit, a light receiving optical system, a color image pickup unit, a drive controller and a measurement controller, and picks up an image of a test chart as a measurement specimen placed to face a specimen opening. A personal computer is provided with a monitor, a memory unit, and a CPU. The CPU calculates color values of color samples by reading and implementing a control program stored in the memory unit. The color of the test chart in which a plurality of color samples are arrayed can be automatically measured within a short period of time.