Abstract: A secure tag comprising: a carrier doped with one or more rare earth ions, and a barrier material associated with the carrier and substantially blocking low-wavelength radiation to shield the rare earth ions from low-wavelength radiation. This enables a secure tag to be fabricated that does not photoluminescence strongly in response to a low-wavelength excitation radiation source.

Abstract: A method of reducing receipt fraud comprises attempting to detect emission from a receipt associated with one or more luminescent markers that are incorporated in a valid receipt. The receipt is validated when the attempt is successful.

Abstract: A secure reader for reading a spatial code and a security feature. The secure reader comprises: (i) a security module, and (ii) a read engine for reading both a spatial code and a security feature carried by an item. The security module is operable to transmit a unique reader identification each time an authentication request is sent to a data management system. The spatial code may be a barcode, such as a two-dimensional barcode. The security module may include tamper responsive sensors for destroying any stored data in the event that the security module is tampered with. The security module may also include a unique identification conveyed to the data management system as part of an authentication request to allow the secure reader to be identified by the data management system.

Abstract: A device for validating a secure tag comprises: an optical source (such as one or more LEDs); a processor coupled to the optical source for controlling emissions therefrom; and a luminescence detector coupled to the processor. The processor is programmed to control the optical source to create a first and a second pulse sequence having first and second excitation parameters respectfully. The processor is also programmed to control the luminescence detector to measure first and second luminescence in response to the first and second pulse sequences respectively. The processor is programmed to validate the secure tag in the event that the first and second luminescence meet an acceptance criterion. A method of validating a secure tag is also described.

Abstract: A method of identifying a source of a marking fluid applied to a person or an object comprises applying a marking fluid including one or more security markers to a person or an object and illuminating the applied marking fluid to excite the security markers. Photoluminescent emission from the security markers in response to the excitation is measured and compared with one or more pre-defined photoluminescent signatures associated with the source of the marking fluid. The source of the marking fluid is identified based on a match between the detected photoluminescent emission and at least one of the pre-defined photoluminescent signatures.

Abstract: A reader for a secure tag. The reader comprises a first excitation source (such as one or more LEDs) that stimulates at least one transition in the secure tag. The reader also comprises a second excitation source that stimulates more transitions than were stimulated by the first excitation source. The reader has a detector for detecting luminescence from the secure tag in response to excitation from the first excitation source and in response to excitation from the second excitation source to ensure that luminescence is detected at a pre-determined wavelength in response to the second excitation source but not the first excitation source.

Abstract: A system and method are provided for identifying a one- or multi-dimensional spatial code comprising a plurality of security tags with one or more characteristic emission profiles. The spatial codes are identified on the basis of the combined spatial and spectral information. The system for identifying such spatial codes is comprised of a beam source, a detector, and a processor. The method includes illuminating the code, recording the light emission at a plurality of wavelengths, decoding the spatial information, resolving the spectral profiles, and identifying the code based on the spatial and spectral information. The system and method are applicable to validating a spatial code.

Abstract: A method of determining a component of a medium comprises illuminating the medium to excite a marker associated with the component. Detected photoluminescent emission from the marker in response to the excitation is compared with one or more emission profiles. The component is identified based on a match between the detected photoluminescent emission and at least one of the emission profiles.

Abstract: A data acquisition system is disclosed where a first communication device transmits a transmitted signal to a second communication device. The second communication device encodes the transmitted signal with a code generating a retransmitted signal. The retransmitted signal is then transmitted back to the first communication device. The code can be indicative of an environmental element, such as a traffic sign. The first communication device can determine a distance to the environmental element by monitoring a time for the retransmitted signal to arrive. The first communication device can also encode the transmitted signal with information, such as voice for example.

Abstract: A dwelling system having a housing which lacks plumbing. The housing is elevated so as to accept a portable unit below the housing. The housing uses a mating structure to provide bi-directional access through the roof of the portable unit that plumbing is provided by the portable unit.

Abstract: A light source is disclosed for use an optical printer illuminating a spatial light modulator to efficiently and uniformly project light onto a photosensitive medium while providing a simpler design of the spatial light modulator in the optical printer. The light source uses light emitting diodes opposed across a light pipe. The light from the light emitting diodes propagates in the light pipe until striking a redirection structure which redirects the light out of lateral surface of the light pipe.

Abstract: A synchronizing signal generator produces a PAL standard horizontal synchronizing signal using a PAL standard subcarrier signal as a timing reference. The synchronizing signal period is not an even multiple of the subcarrier signal period. To produce the synchronizing (sync) signal, the generator first frequency multiplies and divides the input signal to produce a reference signal having a period that is a rational multiple of the subcarrier signal period but smaller than the desired sync signal period. The generator then delays each successive pulse of the reference signal by increasingly longer delay times to produce the sync signal.

Abstract: A video converter converts an input video signal conveying pixel data representing an M.times.K pixel image to an output video signal conveying data representing an N.times.L pixel image. The converter samples the input video signal to acquire an M.times.K matrix of pixel data, re-encodes each pixel data value as necessary to meet color coding requirements of the output video signal standard, and then employs digital interpolation and/or decimation filters to convert the M.times.K data matrix to an N.times.L data matrix. A simple digital output encoder operating at four times the output video signal subcarrier frequency is then employed to process the N.times.L matrix to produce a digital output data sequence which, when applied to D/A converter, becomes the output video signal.

Abstract: An electrostatic discharge protection device is disclosed which selectively shunts charge accumulation across electrical conductors emplaced within the device housing. A grounding element is provided on the housing surface which maintains electrical contact with the enclosed electrical conductors so as to form a shorting shunt and place the conductors at substantially similar electrical potentials. The grounding element may be reversibly changed from the operative into an inoperative position to remove the grounding element from electrical contact with the electrical conductors.

Abstract: An optical system is disclosed wherein an arcuate mirror is used to redirect light in a compact optical printing system in which a cylindrical lens is used to converge light over a predetermined distance so that light transmission through air is enabled.

Abstract: A bilinear decimator converts an input data sequence representing a high resolution image formed by N horizontal pixel lines to an output data sequence representing a lower resolution image formed by P horizontal pixel lines where N>P. The decimation ratio P/N can be any rational fraction. When the decimation ratio reduces to the form 1-(1/n), the decimator computes the each output sequence data value as a simple weighted average of pixel data values for two vertically adjacent high resolution image pixels. When the decimation ratio is other than of the form 1-(1/n), the decimator adds additional terms to the computation of output pixel data values when necessary to compensate for aliasing errors.

Abstract: A data acquisition system is disclosed where a first communication device transmits a transmitted signal to a second communication device. The second communication device encodes the transmitted signal with a code generating a retransmitted signal. The retransmitted signal is then transmitted back to the first communication device. The code can be indicative of an environmental element, such as a traffic sign. The first communication device can determine a distance to the environmental element by monitoring a time for the retransmitted signal to arrive. The first communication device can also encode the transmitted signal with information, such as voice for example.

Abstract: An electrostatic discharge protection device is disclosed for use with a semiconductor chip package where the electrostatic discharge protection device establishes electrical connection between connector pins on the semiconductor chip package and ground, thereby creating a short circuit to protect the semiconductor chip package from electrostatic discharge. The electrostatic discharge protection device is manually operable to engage or disengage a ground connection while remaining attached to the semiconductor chip package. The electrostatic discharge protection device is also removable from the semiconductor chip package either prior to or subsequent to mating a semiconductor chip package with a printed circuit board or other receptacle.

Abstract: An electrostatic discharge protection device is provided for use with a magnetic read/write transducer. The electrostatic discharge protection device electrically interconnects the conductive elements of magnetoresistive (MR) and inductive heads to provide a low-resistance conductive path placing the conductive elements at a substantially equal electrical potential, thus minimizing electrostatic discharge. The electrostatic discharge protection device provides an electrical path between the conductive elements which is manually or automatically removable upon connection to a mating element. The electrostatic protection device has a resilient inward bias to connect electrically conductive elements such that a ground is established between them and is removed automatically upon insertion of the conductive elements into a mating receptacle which is interposed between the conductive elements and the electrostatic discharge protection device.