Abstract:
An authentication system uses the unique distribution of an invisible taggant as a “signature” to identify an item. The verification is error tolerant. The taggant is made visible to a camera by special illumination. Inert taggants, with no optical activity, can be made visible by their thermal properties.
Abstract:
A flexographic press of conventional design is used to print on a container, with the container to be printed upon replacing the web and the impression roll of the conventional press. In order to maintain the registration between the print stations, the container is placed into a carrier and stays registered to the carrier until all colors are printed. The carrier is moved between the different print stations and is registered to each print station independently. All print stations are set up to print in exactly the same place relative to the carrier, thus registration is achieved.
Abstract:
A method of adding authentication material during printing by dispensing the authentication material in powder form over the articles being printed before the ink used for the printing is fully cured. The method can be combined with the spray powder step during the printing process.
Abstract:
A deformable mirror element with a high natural frequency has elongate ribbons attached along a longitudinal portion thereof to a support. The ribbon is transversely slit to divide each ribbon into at least two individual wing portions. The wing portions extend laterally from the support and are capable of deforming in response to a force applied to the wing. The deformable mirror element is used in a light valve for modulating one or more beams of incident light. The high natural frequency of the element ensures that the light valve is useful in applications requiring fast response time.
Abstract:
An inkjet printing method ejects fluid droplets onto a transfer surface. On the transfer surface the droplets are treated. The droplets are then transferred to a substrate. The treatment decreases the sizes of the dots and increases their viscosity. Adjacent dots in the pattern may be printed in separate passes to retain dot integrity. The droplets may comprise UV-curable inks. The droplets may be partially cured by exposure to UV radiation while on the transfer surface.
Abstract:
An interferometric optical torque sensor senses the torque transmitted by a rotating shaft without requiring physical contact with the shaft. A diffraction grating is provided on the shaft with its grating lines parallel to the longitudinal dimension of the shaft. A laser beam is split in two and reflected from two axially-separated points of the grating. As the shaft twists, the phase of the light in the diffracted orders of the light reflected from the grating changes. By superimposing the diffracted beams an interference pattern is created. The motion of the interference fringes in this pattern is proportional to the twist, therefore the torque, in the shaft. The power transmitted by the shaft may be computed from the torque and shaft speed.
Abstract:
An imaging device and a camera with an imaging device for imaging and digital photography are provided. The imaging device includes an imaging die having an electrical circuit on a surface thereof, a glass cover having a first surface and a second surface, and connecting means for connecting the first surface of the glass cover to the surface of the imaging die, wherein the connecting means have a refractive index substantially equal to the refractive index of the glass cover. The connecting means may include spectral filtering means. The first surface of the glass cover may be coated with spectral filtering means.
Abstract:
Apparatus for high resolution imaging of integrated circuits and flat panel displays uses a pulsed laser source, a thermoresist coated image receiving surface and a pair of masks. A primary mask carries the principal image and a secondary mask containing an array of lenslets which concentrate light from the source onto a subset of the features of the primary mask. The secondary mask lenslets are dimensioned so as to illuminate a subset of the features with a known pitch and form an image corresponding to the subset on the thermoresist. After creating a subset image, the secondary mask is moved so as to expose another subset of the features and form another subset image. In this manner the entire principal image is reconstructed on the thermoresist from subset images. The secondary mask is moved on two axes by a plurality of piezo-electric actuators. Registration and position control of the secondary mask are accomplished by including positioning marks on the primary mask and a photo-detector to resolve the positioning marks and provide position feedback. To increase the power density imparted on the image receiving surface, the laser source may be focused into a concentrated scanning line, which is scanned across the secondary mask so as to further divide the imaging process, while providing additional power density.
Abstract:
A method for compensating for image distortion imparted on a flexographic printing plate is disclosed. The compensation scheme reduces the distortion effect caused by stretching of the image when the printing plate is wrapped around the cylindrical drum of a printing press. The compensation scheme predicts the localized distortion on different parts of the image caused by variations in the undercut depth and density of the image features on the plate. By so doing, the scaling factor is varied in accordance with the predicted localized distortion in the different parts of the image, so as to minimize the distortion effect over the entire printing plate.
Abstract:
A method and apparatus for an improved autofocus in an optical system is presented. The improved autofocus system uses distinct optics from those of the primary optical system. Although optically distinct, physically, the autofocus optics are mechanically linked to the optical output stage of the primary optical system. The optical separation of the autofocus optics from those of the primary optical system overcomes the trade-offs associated with trying to combine the primary optical function and focus in the same beam. In particular, the autofocus beam is not blinded by a more powerful write beam. The physical integration of the autofocusing optics with the optical output stage of the primary optical system overcomes the difficulties associated with using external distance sensors. In particular, the autofocusing system is not susceptible to steady state error because the autofocus sensor is a true null detector.