Abstract: Counting and division circuits include an input differential stage connected to a cross-coupled differential stage. The input stage includes first and second IGFETS whose gate electrodes are respectively connected to first and second inputs, whose drains are respectively connected to first and second outputs, and whose sources are connected to the drain of a third IGFET whose source is grounded. The cross-coupled stage includes fourth and fifth IGFETs which are cross-coupled in that the gate of the fourth IGFET and the drain of the fifth IGFET are directly connected to the first output and the gate of the fifth IGFET and the drain of the fourth IGFET are directly connected to the second output. The sources of the fourth and fifth IGFETs are connected in common to the drain of a sixth IGFET whose source is grounded.
Abstract: A bar code reader includes an optical system for storing a two dimensional image in memory, which stored two dimensional image contains a bar code symbol. A method and apparatus is disclosed for detecting the location of said bar code image by computing the accumulated sum of the products of the derivatives of respective first and second scan lines as a location score for the image under consideration. The higher the location score, the higher the probability that the area under consideration contains a bar code image. Also, a method and apparatus is disclosed for determining the fine orientation of a located bar code image by the cross-correlation of interpolated scan line data. The bar code image is filtered by shifting interpolated scan line data in accordance with the detected peak of the cross-correlation and combining the shifted scan line data.
Abstract: Tone values of a photographic image are stored in a frame store and retrieved from the frame store to produce a corresponding video display. A mouse or trackball is used to locate a point on display and a gamma correction curve look up table is used to interactively show the effect of color correction. Adjustment can be made via lighter and darker switches on the mouse or trackball. These switches subtract or add a bump function to the gamma correction curve in the selected color density plane. The bump function is displaced by the measured tone value in order to achieve more flexible control over the color correction.
Abstract: A multiple resolution optically encoded label is readable at two more optical resolutions, and is able to store two or more respective channels of optically encoded information. Low resolution information is encoded in a plurality of large cells arranged in a predetermined geometric pattern. Each of the large cells includes a plurality of smaller cells for storing high resolution information. Method and apparatus are disclosed for encoding both high resolution data, and low resolution data, as well as for finding and reading both high resolution and low resolution data.
Abstract: An omnidirectional bar code reader uses a virtual scan of raster scan digital image memory to create the equivalent scanning pattern of a mechanical laser scanner. A two dimensional image of bar code symbol at any random orientation is captured in a memory. In one embodiment, the image memory is scanned to create a virtual scan equivalent to the scan pattern of a laser scanner. In another embodiment, the image memory is divided into plurality of memory segments, and simultaneous virtual scan is provided in each of the respective memory segments. In yet another embodiment, the memory is divided into a plurality of overlapping memory segments and simultaneous virtual scan is provided in each of the respective overlapping memory segments. The overlap between the memory segments is made large enough so that a bar code symbol of the expected size will be entirely included in one or the other of the overlapping memory segments.
Abstract: In the generation of screened halftones of photographic images for low resolution marking devices, conventional screen techniques are too coarse, and adaptive dither techniques are too fine. The present invention preserves the advantages of the adaptive dither techniques, while creating screen patterns with an adjustable degree of coarseness. The invention applies a hysteresis constant and recursion techniques previously limited to adaptive screening with fixed dot patterns to vary the size of dots in the screened image, thereby allowing adjustment of the image coarseness by adjusting the hysteresis constant.
Abstract: A method and apparatus for reducing the low frequency electric and magnetic fields associated with electric blankets and mattress pads includes a power form converter inserted between the heating element of the electric blanket or mattress pad and the AC power source. In one embodiment, the power form converter is an AC to DC converter. In another embodiment, the power form converter is a full wave bridge rectifier circuit. The power form converter may either be built into the electric blanket or mattress pad, or may be external so that an existing electric blanket or mattress pad may be used in conjunction with the power form converter.
Abstract: A clothing image mirror projection system for producing a composite image of an article of clothing superimposed upon the reflected image of a viewer's face includes a two-way mirror, a rear projection screen, and apparatus for projecting an image of an article of clothing onto said rear projection screen. The present system includes an anamorphic lens assembly to adjust the dimensions of the clothing image along a horizontal axis. Further, the present system includes means by which the height and weight of the subject are measured by sensors, and used to automatically adjust the height and width of the clothing image so as to fit the height and general size of the subject viewer.
Abstract: A television converter includes a circuit for detecting scrambled signals and enabling the descrambler in response thereto. Scrambled signals are detected by sensing amplitude modulated digital tag information on the audio carrier. The descrambler is enabled if amplitude modulation is detected on the audio carrier during the portion of a horizontal line where digital information is expected, and also if no amplitude modulation is detected during a portion of the horizontal line where no data is expected. The scrambled signal detector of the present invention reduces the tendency for noise and other influences to enable the scrambler when viewing a clear, i.e. unscrambled, signal.
Abstract: A two way digital communication arrangement utilizes a CATV system to provide bidirectional data transport service between any two points within the CATV system. The headend receives an upstream message and selectively rebroadcasts such message on the downstream portion of the spectrum. System intelligence is thus distributed throughout the system as server and subscriber nodes can be located anywhere in the CATV network. In order to obtain access to the CATV communication resources, user equipment at each node must attach a frame verifier (FV) code to each respective message. The headend examines the FV and permits rebroadcast of messages only if the FV code indicates that the user is authorized.
April 30, 1982
Date of Patent:
August 6, 1985
General Instrument Corporation
Robert P. McNamara, Gregory B. Ennis, Richard J. Feiertag, Robert K. Bauer
Abstract: An Electrically Alterable Read Only Memory device including at least one cell in a substrate having source and drain channels with a memory gate region therebetween with the substrate in the memory gate region having therein a first impurity material of a first conductivity type to establish a desired write threshold voltage and a second impurity material of a second conductivity type opposite to said first type to tailor the surface concentration profiles of the impurity material in the memory gate region of the substrate.
Abstract: A cable TV security system utilizes three radio frequency signals as three data communication channels: one downstream channel and two upstream channels. The system includes a plurality of individual subscriber security units which transmit respective alarm messages on an upstream alarm channel essentially when an alarm condition is first detected. If two or more subscriber units attempt to transmit simultaneous alarm messages on the alarm channel, the resulting collision causes a garbled alarm message to be received at the headend. The present invention provides respective apparatus in each subscriber's security unit for responding to two unique headend search commands for identifying the respective addresses of the subscriber unit or units which originated the garbled alarm messages.
Abstract: A cable TV security system utilizes three radio frequency signals as three data communication channels. One downstream channel is provided as a polling channel in available spectrum space in the standard FM band. Two upstream channels are provided in the return portion of the cable spectrum. One of the upstream channels is a polling response channel, and the other is an alarm channel. Subscriber security units transmit on the polling return channel in response to downstream command messages on the polling channel. Alarm conditions are immediately transmitted on the alarm channel so that system response to an alarm condition is fast and substantially independent of the number of subscribers.
Abstract: A fault detection system is provided for detecting and locating faulty connections in a cable TV system. First and second signals are generated at the head end transmitter. The first signal is a continuous wave signal. The second signal is a pulse modulated sine wave signal. A fault is indicated by the reception of a beat frequency signal between the first and second signals generated at the location of the faulty connection and returned to the head end. The location of the fault is determined by measuring the time interval between the transmission of the first and second signal and the return of the beat frequency signal, and relating such time interval measurement to the corresponding distance between the head end and the faulty connection.
Abstract: A complementary symmetry amplifier having variable gain control is used in an automatic gain control (AGC) system. The amplifier includes first and second field effect transistors of opposite conductivity type. Variable gain control is achieved by applying first and second differential control signals to respective gate electrodes of said first and second field effect transistors.
Abstract: In addition to the usual field-effect transistor structures available in CMOS-type integrated circuitry, certain bipolar transistor structures are also available for use in linear amplifier circuits combining both bipolar and FET devices. One of the transistor structures available, i.e., a vertical transistor, has high current gain but its collector region, integral to the substrate, is committed to substrate potential. The other of the bipolar transistor structures available, i.e., a lateral transistor, has an uncommitted collector, but has low current gain. A cascade connection of both bipolar transistor types provides a composite transistor with high current gain and uncommitted collector useful in combination with field-effect transistor structures to form novel amplifier arrangements.
Abstract: Disclosed is an apparatus for adjusting an inductor that is mounted on a circuit board. The inductor is of the type comprising two extensible sections connected at one respective end to the circuit board and connected at the other respective end by a connecting portion integral to the inductor. The electrical value of the inductor is adjusted by mechanically engaging the connecting portion between first and second push rods and moving the connecting portion so as to simultaneously extend or compress the two extensible sections. The first push rod extends through an opening in the circuit board to apply mechanical force against the connecting portion and the second push rod extends from above the circuit board so as to clamp the connecting portion between the first and second push rods.
Abstract: A complementary field-effect transistor (FET) amplifier with means for controlling peak cross-over current. A substantially constant current is established in the drain-source conduction paths of a pair of reference transistors by degenerative feedback from the conduction paths to the respective gate electrodes thereof; wherein the reference transistors have similar characteristics to the respective amplifier transistors. The resulting sum of the gate-to-source voltages of the reference transistors is used to apply a bias voltage between the gate electrodes of the transistors in the FET amplifier so that the sum of the gate-to-source voltages of the amplifier transistors is equal to the sum of the respective gate-to-source voltages of the reference transistors during the cross-over current condition. Cross-over current is thereby limited to a predetermined value proportional to the substantially constant current established through the reference transistors.
Abstract: A temperature-sensitive voltage divider for monolithic i.c.'s using singly and doubly diffused resistors avoids the problems with tracking their resistance characteristics owing to diffusion process variations. This is done by using the pinch resistor in conjunction with the base-emitter circuit of a bipolar transistor arranged in common-collector amplifier configuration. The impedance transformation properties of the transistor ease the problems of scaling otherwise encountered in many potential divider arrangements of supply and doubly diffused resistors. The utility of the voltage divider is illustrated in the shunt regulation of the operating voltage of an AM radio receiver.
Abstract: A gated oscillator implemented with cascade-connected inverting logic circuits and resistor-capacitor timing elements generates oscillations so long as an inhibiting signal is not applied to one of the logic circuits. Means are provided to maintain potentials on the timing elements during application of inhibiting signal, which potentials are equivalent to steady-state operating potentials at the inception of a state transition. When the inhibiting signal is discontinued allowing oscillations to be generated, the initial pulse period is equal to the steady-state pulse period.
July 9, 1979
Date of Patent:
August 25, 1981
Nicholas Kucharewski, James E. Gillberg