Abstract: Techniques are disclosed herein for estimating parameters of a model of a thermal print head for use in performing thermal history control. In particular, techniques are disclosed for use in conjunction with a thermal print head having a plurality of print head elements and an associated heat sink. A sensitivity of a thermal print media to a temperature of the heat sink is identified. A sensitivity of the thermal print medium to a temperature of the plurality of print head elements is then identified based on the identified sensitivity of the thermal print medium to the temperature of the heat sink. Techniques are also disclosed for deriving conditions on estimated parameters of the print head model that determine the stability of the resulting thermal history control algorithm. Techniques are also disclosed for iteratively optimizing the values of those parameters.

Abstract: A method for controlling the print density of individual heating elements of a thermal print head array determines respective energy values for each heating element in response to image pixel data to be printed, multiplies determined energy values by a respective predetermined correction factor for one or more respective heating elements for improving print density consistency between individual heating elements, and dithers adjusted energy values from the step of multiplying as a function of adjacent image pixels.

Abstract: A printing device that includes a platen for supporting an imaging member during a printing operation and at least one print head subassembly for direct thermal printing on the imaging member. The print head subassembly is configured to be movable independently of the platen for printing on a first surface of the imaging member in a first transport path and on a second surface of the imaging member in a second transport path. The printing device also includes at least one driving roller for driving the imaging member during the printing operation that is configured to drive the imaging member through a driving nip created by the driving roller with a substantially constant degree of wrap wherein the distance of transport of said imaging member for a given angular rotation of said driving roller is substantially the same for the first transport path and the second transport path.

Abstract: A printing device that includes a platen for supporting an imaging member during a printing operation and at least one print head subassembly for direct thermal printing on the imaging member. The print head subassembly can be configured to be movable independently of the platen for printing on a first surface of the imaging member in a first transport path and on a second surface of the imaging member in a second transport path. Alternatively, the printing device can include two print head subassemblies, each positioned to print on a different side of the imaging member. The position of the print line of the print head in each printing position is offset from a dead center alignment with respect to a platen.

Abstract: A sharpening filter is disclosed for performing density-dependent sharpening on digital images. In one embodiment, a digital image to be sharpened is decomposed into a plurality of high-pass versions of the image at different resolutions. These high-pass images are gained at each resolution and recombined with the original image to produce a sharpened version of the image. The gains that are applied at each resolution are density-dependent. As a result, the effects of density-dependent blurring are counteracted, such that the sharpness of the final printed image is independent of the print density. Techniques are disclosed for performing such density-dependent sharpening with a high degree of computational efficiency.

Abstract: A printing device that includes a platen for supporting an imaging member during a printing operation and at least one print head subassembly for direct thermal printing on the imaging member. The print head subassembly is configured to be movable independently of the platen for printing on a first surface of the imaging member in a first transport path and on a second surface of the imaging member in a second transport path. The printing device also includes an element movable with said print head subassembly for ensuring that the wrap of the imaging member around the platen is substantially symmetrical about the print line such that the thermal heating elements of the thermal print head are substantially parallel to the surface of the imaging member when printing on each side of the imaging member.

Abstract: A method for controlling the print density of individual heating elements of a thermal print head array determines respective energy values for each heating element in response to image pixel data to be printed, multiplies determined energy values by a respective predetermined correction factor for one or more respective heating elements for improving print density consistency between individual heating elements, and dithers adjusted energy values from the step of multiplying as a function of adjacent image pixels.

Abstract: Techniques are disclosed for performing thermal history control in a thermal printer in which a single thermal print head prints sequentially on multiple color-forming layers in a single pass. Each pixel-printing interval may be divided into subintervals, which may be of unequal duration. Each sub-interval may be used to print a different color. The manner in which the input energy to be provided to each print head element is selected may be varied for each of the subintervals. For example, although a single thermal model may be used to predict the temperature of the print head elements in each of the subintervals, different parameters may be used in the different subintervals. Similarly, different energy computation functions may be used to compute the energy to be provided to the print head in each of the subintervals based on the predicted print head temperature.

Abstract: A model of a thermal print head is provided that models the thermal response of thermal print head elements to the provision of energy to the print head elements over time. The amount of energy to provide to each of the print head elements during a print head cycle to produce a spot having the desired density is calculated based on: (1) the desired density to be produced by the print head element during the print head cycle, (2) the predicted temperature of the print head element at the beginning of the print head cycle, (3) the ambient printer temperature at the beginning of the print head cycle, and (4) the ambient relative humidity.

Abstract: Techniques are disclosed for performing color registration estimation and correction in a multi-head printer. A registration target is printed by the printer and captured by an image capture device (such as a camera) within the printer. The registration target includes a plurality of shapes, each of which is printed by a single one of the print heads in the printer, and which are arranged in a pattern designed to enable cross-web and down-web registration estimates to be generated. The printer analyzes the captured target to generate such cross-web and down-web registration estimates and thereby to generate cross-web and down-web registration corrections. The printer applies the registration corrections to subsequent print jobs, thereby reducing or eliminating misregistration in printed output. The techniques disclosed herein are suitable for use in printers having print heads that differ in resolution from each other.

Abstract: A model of a thermal print head is provided that models the thermal response of thermal print head elements to the provision of energy to the print head elements over time. The thermal print head model generates predictions of the temperature of each of the thermal print head elements at the beginning of each print head cycle based on: (1) the current ambient temperature of the thermal print head, (2) the thermal history of the print head, (3) the energy history of the print head, and (optionally) (4) the current temperature of the print medium. The amount of energy to provide to each of the print head elements during a print head cycle to produce a spot having the desired density is calculated based on: (1) the desired density to be produced by the print head element during the print head cycle, and (2) the predicted temperature of the print head element at the beginning of the print head cycle.

Abstract: A multi-resolution filter is provided that may be used to attenuate aliasing artifacts in a digital input signal, such as a digital image acquired by a digital camera. The multi-resolution filter reduces the resolution of the digital input signal and filters the reduced resolution signal using a median filter. The output of the median filter is provided to an interpolation filter, which increases the resolution of the median filter's output to produce a digital output signal in which aliasing artifacts from the digital input signal have been attenuated. The multi-resolution filter may be advantageously applied to the chrominance channels of digital images to attenuate aliasing artifacts without undesirably blurring sharp luminance and color boundaries in the digital image. Furthermore, the computational expense associated with the median filter is diminished by reducing the resolution of the digital input signal before filtering it using the median filter.

Abstract: We disclose an electronic imaging method and apparatus capable of effectively and accurately sensing and interpolating color image data received from a two-dimensional array of discrete image sensing elements, particularly, from a so-called “Bayer Pattern” array. In operation, the method and apparatus both extract one-color image data from the two-dimensional array and generate therefrom fully color-recovered image data by a combination of interpolation and non-linear filtering. Efficiency is accomplished, without departure from good accuracy, by performing two one-dimensional color recovery applications and essentially incrementally combining the results thereof. The first one-dimensional color recovery application generates a partially color-recovered image in which, for each row in that dimension, values are recovered for all of the colors present in that row. The second one-dimensional color recovery application then generates all the remaining colors at each pixel by operating along a second dimension.

Abstract: A system and method for monitoring performance of an electromechanical system include monitoring a plurality of predetermined system conditions, collecting monitored values of the plurality of predetermined system conditions over time, and calculating system maintenance needs from collected monitored values.

Abstract: There is described a protective overcoat material comprising from about 40 weight percent to about 85 weight percent of poly(methyl methacrylate) having a Tg above about 100° C., from about 10 weight percent to about 50 weight percent of poly(ethyl methacrylate) having a Tg of from about 52° C. to about 65° C. and about 1 weight percent of a melt flow modifier. Also described are thermal image recording members which include a protective overcoat layer.

Abstract: There is described a method for forming lenses having substantially no optical power. The method includes forming, via in situ polymerization, a layer of non-uniform thickness of an optically clear, high scratch-resistant polymeric material on the convex surface of the lens. The lenses provided by the method are characterized by having maximum thickness in the central region of the lens and gradually diminishing thickness radially towards the periphery of the lens.

Abstract: A system and method for using an e-commerce system to provide a user with the ability to order customized identification documents over the Internet is provided. The user can customize the layout of the identification document, including the use of company logos and trademarks. The user provides the demographic data and corresponding graphical representations, and is given the opportunity to approve a digital facsimile of the identification document that will be produced by the service bureau prior to the production of the identification documents. In addition, enhanced security is provided by verifying that the user is part of a legitimate organization and is authorized to use the identification documents being ordered.

Abstract: There is disclosed a thermal print head platen which includes a pair of support members separated by a gap wherein the support members are adapted to be oriented to press media against a thermal print head for printing purposes with the gap approximately aligned with a heating element located within the print head. There are also described a thermal printer which includes at least one thermal print head in conjunction with a thermal print head platen to pressure print media against the thermal print head for printing purposes and a thermal printing method utilizing such a thermal printer.

Abstract: To enable the use of a single use digital camera for acquiring, selecting and storing images, thereby providing the ability to delete unwanted images, a method is disclosed in which a customer is provided a single use digital camera, which the customer uses for acquiring, selecting and storing digital images, return of the digital camera is accepted from the customer after the storing of the images and the selected images are retrieved for the customer. The single use digital camera does not provide the customer the ability to retrieve the stored images. A system that provides the ability to perform the steps of the method for use of a single use digital camera is also described.

Abstract: There are described metal-complexed azo dyes which are useful in ink jet printing applications. Also described are ink jet ink compositions including a dye of the invention as well as ink jet printing methods and apparatus.