Abstract: A backlight liquid crystal display including a collimated backlight for illuminating a display panel having a liquid crystal layer sandwiched between rear and front polarizers, the panel including an optical refracting film and a diffuser laminated adjacent the front surface of the panel. The refracting film and light scattering diffuser may be either exterior or interior the front polarizer, but on the viewer side of the liquid crystal layer. The optical system of the refracting faceted film along with the diffuser maintains the resolution of the display, improves the contrast ratio over a wide range of viewing angles, reduces its ambient light reflectively, reduces color shifting, substantially eliminates inversion, and enlarges the effective viewing zone of the display.

Abstract: To identify the boundary pixels of a number of particles in the same field of view, an electrical image of the field of view is formed by a CCD raster scan device. The electrical signal from the CCD device is segmented and is digitized. The signals are processed such that the boundary pixels have non-zero values and are linked to one another. The values of the pixels are stored in a boundary memory addressable by a row signal and column signal. In an addressable index memory, a plurality of values are stored with each value being an address to the boundary memory where the pixels having the boundary are located. Finally, a location memory has the same addressable dimensions as the boundary memory. The location memory stores, in address locations corresponding to address locations in the boundary memory where the pixels having characteristics of interest are located, addresses to the addressable index memory.

Abstract: A method and apparatus for selecting the best focal position of an image in a field of view is based upon pixel values located in the image that correspond to locations defining an invariant optical property of the image. In the preferred embodiment, the invariant optical property of the image are pixels that form a "halo" that surround the boundary of an object and are contiguous and immediately adjacent thereto. It has been determined that a certain relationship should exist for this "halo" that surround the boundary of an object when the best focal position is selected.

Abstract: A thin film transistor (TFT) array in an active matrix liquid crystal display (AMLCD) including a centrally located round source electrode completely surrounded by a substantially annular or circular shaped drain electrode. The geometric design of the TFT of this invention provides for a thin film transistor having a reduced parasitic capacitance and decreased photosensitivity. The TFTs of this invention are located at the intersections of gate and drain lines of an active matrix LCD array thereby increasing the size of the pixel display openings of the matrix array.

Abstract: A method of separating red blood cells within a volume of blood provides rapid separation of the red blood cells to permit efficient analysis of the white blood cells. First, a container is filled with the volume of blood while the container is in a substantially vertical position. The container has an open top portion, a side wall, and a closed bottom portion. The volume of blood in the container defines a first surface region having a particular spatial relationship to the side wall. Then, the container is moved to a first position, away from the substantially vertical position. The container is maintained at the first position for at least a first predetermined time such that red blood cells within the volume of blood settle substantially to the side wall of the container. The cross sectional area of the container at the first surface region of the volume of blood is such that the particular spatial relationship is maintained between the first surface region and the side wall.

Abstract: A normally white twisted nematic liquid crystal display is disclosed having a pair of retardation films disposed between the liquid crystal layer and an adjacent polarizer, both retardation films being on one side of the liquid crystal layer. Both retardation films, if uniaxial, have retardation values of from about 100-200 nm. Optionally, biaxial retarders (n.sub.X >n.sub.Y >n.sub.Z) may be used, such biaxial retarders having retardation values from about .DELTA..sub.ZX =-100 to -200 nm, and .DELTA..sub.ZY =-10 to -100 nm. Accordingly, inversion is reduced and contrast rations are improved at large viewing angles.

Abstract: A longitudinal position translator includes a probe drive module and a linear translation module. The probe drive module is coupled operatively to an ultrasonic imaging probe assembly having a distally located ultrasound transducer subassembly in such a manner that longitudinal shifting of the transducer subassembly may be effected. The probe drive module is preferably mounted to the linear translation unit so as to be moveable between a condition whereby longitudinal shifting of the transducer subassembly can be conducted either manually or automatically. When in the automatically-operable condition, the probe drive module will be engaged with a motor-driven screw associated with the linear translation module so as to cause the probe drive module to be longitudinally displaced at a constant motor-driven rate. In this manner, the distally located ultrasound transducer is longitudinally shifted during an ultrasound scan of surrounding intravascular (or other) tissue to thereby allow axially-spaced 360.degree.

Abstract: A catheter is provided for insertion into the blood vessel of a patient for ultrasonically imaging the vessel wall. The catheter includes a tubular element and an internally housed drive cable for effective a circumferential scan about the catheter of an ultrasonic generating means. Both the tubular element and the drive cable are of a size and flexibility sufficient to permit their introduction into the vessel and subsequent advancement through the vessel to the location of the vessel wall where imaging is desired.

Abstract: A liquid crystal display and corresponding method are provided for reducing display image reflections off of a reflection point on an external medium (e.g. cockpit canopy or automotive windshield). A retarder is provided on the front side of the display so that the polarization direction of the display image is substantially parallel to the plane of incidence when the image reaches the reflection point. Additionally, the angle of incidence .THETA..sub.i is substantially matched to the Brewster angle .THETA..sub.P in order to maximize the reduction of reflection at the reflection point. The retarder has a retardation value of from about 220-320 nm according to certain embodiments, and is a 1/2.lambda. retarder according to preferred embodiments.

Abstract: A normally white liquid crystal display is provided with a positively birefringent uniaxial retardation film having a retardation value of from about 100-200 nm. The retardation film is provided on one side of the liquid crystal layer, the liquid crystal being sandwiched between a pair of orientation or buffing films which orient the liquid crystal molecules adjacent thereto in predetermined directions. The optical axis of the retardation film is rotated from about 2.degree.-20.degree., most preferably from about 6.degree.-10.degree.relative to the buffing direction on the opposite side of the liquid crystal layer. This rotation of the retardation film optical axis allows for the high contrast ratio viewing zone of the display to be shifted vertically into either the positive or negative vertical viewing region depending upon the direction of rotation of the retardation film optical axis.

Abstract: A catheter for ultrasonic imaging has a transducer fixed to a cutter. The transducer is moved longitudinally within an artery while in a fixed radial position. Ultrasonic reflections are received and processed to display a planer or rectangular field of view image area of the artery. Other axial planes of the artery can be imaged by radially turning the transducer to a different angular orientation within the artery and then longitudinally moving the transducer to obtain an image of another planer field of view.

Abstract: A normally white twisted birefringent liquid crystal display having first and second retardation films having retardation values of about 80-200 nm on opposite sides of a liquid crystal layer for the purpose of expanding the viewing angles of the display. Also, the viewing zone of this normally white display can be shifted vertically by rotating the optical axes of the retardation films so as to position the viewing zone away from an inversion area.

Abstract: Front-end and side-on intravascular catheters are described that comprise an abrasive head contained substantially within a housing. Aspiration means and flushing means are connected to the region of grinding to remove dislodged debris. A preferred embodiment has the abrasive surface of a rotatable head comprised of diamond powder. Another preferred embodiment has an ultrasonic transducer affixed to the head to permit transluminal imaging of the site of occlusion.

Abstract: A guidewire imaging catheter includes a catheter body, housing secured to the distal end of the catheter body, a drive cable extending through a central lumen of the catheter body, and an imaging system disposed within the housing and coupled to the drive cable. A fixed guidewire is secured to the distal tip of the housing, and the catheter body is highly flexible while retaining sufficient torsional stiffness to allow the entire catheter to be used as a guidewire. Thus, the imaging guidewire can be used to first image a desired region within a patient's vascular system and subsequently as a guidewire to allow placement of a desired interventional catheter.

Abstract: A liquid crystal display including an array of thin film transistors. Each thin film device in the array includes gate, source and drain electrodes. At least one of the source and drain electrodes include first and second metal layers offset with respect to one another so as to reduce the channel length of the transistors. Because of the reduced TFT channel length, the TFT channel width can also be reduced while maintaining the same ON current. Thus, the gate-source capacitance is reduced which in turn reduces pixel flickering and image retention and improves gray level uniformity. The first and second source-drain metal layers are of different materials so that the etchant for the second metal does not etch the first metal layer deposited. The TFT may be either a linear TFT or a ring-shaped TFT according to different embodiments of this invention.

Abstract: A high-speed document verification system includes a document which is printed with a pattern having a predetermined arrangement of different reflectivity due to varying densities, line resolutions, or fluorescence. The arrangement represents information about the document. The document is fed into a high-speed document scanner sensitive to the varying ink densities or line resolutions. A graphic image of the document is produced by the scanner and this image or a graphic file of the image is checked to see if the proper pattern exists. A comparison unit, such as an optical character recognition system may be used to compare the scanned document's image with known density arrangements of valid documents to determine what information, if any, is represented by the arrangement. The graphic image may be sent to an operator's work station to be visually checked rather than being compared by the comparison unit or the image may be sent to the operator after it has been rejected by the comparison unit.

Abstract: A catheter is provided having a catheter body with a proximal end and a distal end. The catheter body has a proximal region having a first diameter and a distal region having a single lumen and a second diameter which is less than a first diameter. A distal guide wire exit port is disposed in the distal region of the catheter body within about 5 cm of the distal end. This allows the catheter to be used as a short lumen rapid exchange catheter. The catheter can also be provided with a proximal guide wire exit port in the proximal region so that the catheter can also be used as a long lumen rapid exchange catheter.

Abstract: A thin film transistor (TFT) having a reduced channel length and method of making same are disclosed for liquid crystal display (LCD) applications. The method of making the TFT includes the following process steps: (i) depositing and patterning the gate on a substrate; (ii) depositing and patterning an intrinsic a-Si layer, a n+ a-Si layer, and a source metal layer (e.g. Cr) over the gate; (iii) depositing and patterning an ITO layer to form a pixel electrode portion and a TFT source portion; (iv) etching the source metal layer so that it remains only under the ITO source portion so as to form the TFT source electrode; (v) depositing and patterning a metal (e.g. Mo) to form the drain of the TFT; and (vi) etching the n+ a-Si layer in the TFT channel area so that only the intrinsic semiconductor layer remains between the source and drain. The resulting TFT has a reduced channel length (e.g. less than about 4 .mu.m) less than the feature size of the lithography used so as to maximize I.sub.ON /C.sub.

Abstract: Character recognition processing wherein each of a batch of documents is scanned to produce corresponding scan data signals forming a rectilinear data array of binary bits at the intersections of a rectangular coordinate grid. These signals are stored and processed by a recognition algorithm to produce identity signals for recognized characters. Groups of non-recognized characters are presented simultaneously to permit rapid identification by inspection. The identification of recognized characters is verified at high speed by simultaneously presenting the character images as respective groups sorted to have the same recognized identities.

Abstract: In an intraluminal ultrasound imaging system, ultrasound echoes representing vessel walls are distinguished from ultrasound echoes from blood by detecting and examining the phase of all received ultrasound echoes, extracting selected parameters from the phase information and utilizing the extracted parameters to suppress ultrasound echoes representing blood, thereby to enhance the lumen-to-vessel wall contrast. In a first embodiment, parameters are derived from a phase difference between echoes in approximately the same spatial location, including comparisons between neighboring image vectors of the same image frame or comparison between vectors on successive image frames. Selected parameters may be extracted based on statistics of the phase signal or the phase difference signal or from the slope of the phase difference or the phase signal, either between neighboring image vectors in the same image frame or between images of successive image frames.