Abstract: A new calibration method for a spectrophotometer or a color sensor is provided using multiple color tiles with known reflectances. This procedure uses multiple reference standard tiles, in addition to, the standard white tile and substitutes a wavelength dependent adjustment constant instead of the dark noise reading. The constant is computed using measurements of multiple reference tiles with known reflectance spectra, and its purpose is to weight the sensor readings in order to avoid ill-posed scaling caused by physical limitations such as less than ideal light sources. A scaling factor may be calculated and also used to compute the reflectance of an arbitrary object. A device for carrying out the method is also provided.

Abstract: A Micro-Electro-Mechanical System (MEMS) based Fabry-Perot array may be used as a spectral filter to light sensing array, such as a CCD or CMOS photodetector. Applying different voltages to the electrodes of individual Fabry-Perot cells within the array allows a gradient in the Fabry-Perot air gap across the Fabry-Perot array. In this manner the MEMS Fabry-Perot array serves as a spectral filter of light passing through the Fabry-Perot array to the photodetector array. Embodiments of the disclosed sensor, used with LEDs that emit light outside the photosensitivity range of a photoreceptor belt, may be used to measure spectral information from toned patches and/or images placed upon a photoreceptor belt within a marking system. Other embodiments of the disclosed senor, used with LEDs that emit light of any wavelength, may be used to measure spectral information from toned patches or images placed by a marking system upon a non-photosensitive output substrate, such as an intermediate belt or paper.

Abstract: A multi-dimensional printer profile look-up table for color correction is generated. First, an initial estimate for a black (K) component in a four-color color space for received color signals in the device independent color space is generated by using a three-dimensional parametric function. Next, initial estimates for the three non-black color components of the four-color color space are generated from the generated initial estimate for the black (K) component and the received color signals. Then, a printer profile including a map that maps the device independent color space to the four-color color space is generated using the generated initial estimates for the black (K) and the three non-black color components in the four-color color space.

Abstract: An apparatus may include an illuminator, a controller, a display panel, a modulator, and a plurality of Fabry-Perot cavities. The plurality of Fabry-Perot cavities generated an image from light provided by the illuminator, each pixel of the image corresponding to a respective one of the plurality of Fabry-Perot cavities. The controller controls the modulator to provide image modulation data to the plurality of Fabry-Perot cavities for generating the image, the modulator providing color information to a first cavity of the plurality of Fabry-Perot cavities for setting a size of the first cavity to correspond to a color of a first pixel of the image, the modulator providing gray level information to the first cavity for time-division multiplexing to correspond to a gray level of the first pixel. The display panel display pixels of the generated image based on colors and gray levels of each pixel of the generated image.

Abstract: A color sensor monitors the output of a color producing process and produces a signal representative of a color produced by the color producing process. The signal can be used as feedback signal to control the process. Occasionally, the color sensor signal includes a component representing a transient error. A system model of the color producing process is used to predict reasonable sensor signals. A comparison of the sensor signal with the predicted sensor signals is used to determine if the sensor signal is reasonable. If the sensor signal is unreasonable, a substitute signal is used as the feedback signal to the control process. The substitute signal can be a predicted sensor signal or a signal based on historical system performance data.

Abstract: Linear transformations of L*a*b* color space are provided to minimize interpolation errors when performing multi-dimensional color space conversions involving lookup tables. Methods are provided for linear transformations (e.g., rotation and shear) to substantially fir the sampling grid to a given printer gamut.

Abstract: Disclosed is a microelectromechanically tunable Fabry-Perot device and method of manufacturing tunable Fabry-Perot device and method of manufacturing. The F-P device comprises a first and second substrate which has partially reflective planar surfaces, and the partially reflective planar surfaces are separated by a predetermined separation distance and aligned to provide a F-P cavity, where one or more piezoelectric members are adapted to displace the first and second substrates when an electric field is applied.

Abstract: Disclosed is an image color management system and method for controlling an image output device. The method for controlling the image output device comprises generating an image output device profile LUT (look-up-table) characterizing the color profile of the image output device for a plurality of drift states associated with the image output device; generating a set of basis vectors representing the LUT; storing the set of basis vectors in an image output device controller; and generating an image output device active profile associated with a current drift state of the image output device to convert image color data for display or printing by the image output device, wherein the image output device active profile is generated from the set of basis vectors.

Abstract: Disclosed is an image color management system and method for controlling an image output device. The method for controlling the image output device comprises generating an image output device profile LUT (look-up-table) characterizing the color profile of the image output device for a plurality of drift states associated with the image output device; generating a set of augmented basis vectors representing the LUT, L*a*b* values and multiple GCR/UCRs; storing the set of basis vectors in an image output device controller; and generating an image output device active profile associated with a current drift state of the image output device to convert image color data for display or printing by the image output device, wherein the image output device active profile is generated from the set of basis vectors.

Abstract: A color sensor monitors the output of a color producing process and produces a signal representative of a color produced by the color producing process. The signal can be used as feedback signal to control the process. Occasionally, the color sensor signal includes a component representing a transient error. A system model of the color producing process is used to predict reasonable sensor signals. A comparison of the sensor signal with the predicted sensor signals is used to determine if the sensor signal is reasonable. If the sensor signal is unreasonable, a substitute signal is used as the feedback signal to the control process. The substitute signal can be a predicted sensor signal or a signal based on historical system performance data.

Abstract: A spectral filter includes a two-dimensional array of Fabry-Perot cavity structures, a controller, and a sampling circuit used to switch the Fabry-Perot cavity. The filter receives an incoming image, the sampling circuit switches the cavity to generate a filter image, and the filtered image is detected by the photodetectors to convert a filtered image into digital data. The controller coordinates all the image capture functions of the spectral filter.

Abstract: The exemplary embodiment disclosed herein comprises several aspects of defining and using optimal color test patches for calibrating a printing system for various purposes (e.g., multi-media, gamut extension, drifting correction, etc.). One aspect is the creation and use of color patches where the color patches are selected optimally to result in minimum mean square error when those color patches are used to determine weights of a limited number of basis vectors that model the system (e.g., model the print engine response). A joint optimization technique is given as a method to select the optimal color test patches for calibration.

Abstract: Disclosed herein are optimal or near optimal algorithms implemented as software tools that will allow the user/machine to identify optimal media out of the job set automatically. There are at least two main process steps to the exemplary embodiment. The first step involves the off-line characterization of the printing/image rendering system that will be used to extract the principal basis vectors from the experimental data. The second step involves the run-time mode, in which the pre-characterized basis vectors are used in conjunction with an optimal algorithm that will identify the media for re-calibration/re-characterization from the group of media set that the customer is interested to print. The optimal algorithm performs the combinatorial search every time the customer wishes to select the media. Once the optimal media is selected, the customer or the machine can print color patches (which are also optimal set) and execute the rest of the processing to reconstruct the best color management LUTs.

Abstract: A low cost spectral camera may include a multiple Fabry-Perot cavity filter with silicon photodetectors distributed one beside another in a two-dimensional matrix fashion. Each cavity may be designed to capture a pixel from an image. The two-dimensional fabry-perot array may function as a sensor to capture an image in spectral form. Spectral information may be obtained to generate spectral displays.

Abstract: A new calibration method for a spectrophotometer or a color sensor is provided using multiple color tiles with known reflectances. This procedure uses multiple reference standard tiles, in addition to, the standard white tile and substitutes a wavelength dependent adjustment constant instead of the dark noise reading. The constant is computed using measurements of multiple reference tiles with known reflectance spectra, and its purpose is to weight the sensor readings in order to avoid ill-posed scaling caused by physical limitations such as less than ideal light sources. A scaling factor may be calculated and also used to compute the reflectance of an arbitrary object. A device for carrying out the method is also provided.

Abstract: An optical apparatus may include a plurality of Fabry-Perot cavities and a controller. The plurality of Fabry-Perot cavities receives an incoming image. The controller controls a group of adjacent Fabry-Perot cavities of the plurality of Fabry-Perot cavities to sample spectral information from a pixel of the incoming image. The group maybe designated to the pixel. Sizes of the cavities within the group may differ from one another. The sizes of the cavities within the group may be fixed during the spectral information synthesis operation.

Abstract: A Micro-Electro-Mechanical System (MEMS) based Fabry-Perot array may be used as a spectral filter to light sensing array, such as a CCD or CMOS photodetector. Applying different voltages to the electrodes of individual Fabry-Perot cells within the array allows a gradient in the Fabry-Perot air gap across the Fabry-Perot array. In this manner the MEMS Fabry-Perot array serves as a spectral filter of light passing through the Fabry-Perot array to the photodetector array. Embodiments of the disclosed sensor, used with LEDs that emit light outside the photosensitivity range of a photoreceptor belt, may be used to measure spectral information from toned patches placed upon a photoreceptor belt within a marking system. Other embodiments of the disclosed sensor, used with LEDs that emit light of any wavelength, may be used to measure spectral information from toned patches placed by a marking system upon a non-photosensitive output substrate, such as an intermediate belt or paper.

Abstract: A Micro-Electro-Mechanical System (MEMS) based Fabry-Perot array may be used as a spectral filter to light sensing array, such as a CCD or CMOS photodetector. Applying different voltages to the electrodes of individual Fabry-Perot cells within the array allows a gradient in the Fabry-Perot air gap across the Fabry-Perot array. In this manner the MEMS Fabry-Perot array serves as a spectral filter of light passing through the Fabry-Perot array to the photodetector array. Embodiments of the disclosed sensor, used with LEDs that emit light outside the photosensitivity range of a photoreceptor belt, may be used to measure spectral information from toned patches and/or images placed upon a photoreceptor belt within a marking system. Other embodiments of the disclosed senor, used with LEDs that emit light of any wavelength, may be used to measure spectral information from toned patches or images placed by a marking system upon a non-photosensitive output substrate, such as an intermediate belt or paper.

Abstract: Apparatus and methods are provided for implementing a full width array material scanning spectrophotometer by integrating a Fabry-Perot cavity filter with a silicon photodetector and a light focusing device (an optical guide or a SELFOC® lens). The material to be scanned is illuminated by a broad band illumination source (white LEDs or a fluorescence light source). The Fabry-Perot cavity gap can be tuned electromechanically to get multiple measurements to resolve the spectral distribution of the transmitted light signal. The array spectrophotometric architecture facilitates an elongated, substantially linear band detection and the associated spectral reconstruction technique resolves spectral distribution in the presence of multiple resonant peaks.

Abstract: A color marking device including a control system for calibration of the device based upon dynamic color balance control of an output image.