Abstract: A geometry adjustment device for a color video projector having three monochrome tubes each projecting an image of a given color on a screen, comprising a geometry correction circuit adjustable by the user for providing, by acting on a single signal, vertical amplitude, vertical linearity and horizontal trapezoid corrections of the images projected on the screen by the tubes.

Abstract: A device for receiving dual polarized microwave signals, including a first waveguide connected to a receiving antenna and to a first substrate bearing a first sensor perpendicular to the longitudinal axis of the first waveguide, a second waveguide having the same longitudinal axis and the same dimensions as the first waveguide, and which is connected to a second substrate having a second sensor perpendicular to the longitudinal axis of the second waveguide. Surrounding the second waveguide is a tube having tongues at opposed ends which cooperate with slots formed in the first and second substrates. The opposed tongues of the tube are staggered by 90.degree. so that upon insertion of the opposed tongues of the tube within the slots of the first and second substrates, sensors formed on these substrates are arranged orthogonally with respect to one another. The tongues and cooperating slots assure mechanical integrity.

Abstract: Selected interference frequency signals are inserted into the video or RF signal at the transmitter for scrambling purposes, either singly or in pairs. At the receiving end the signals are decoded by use of filters matched to the transmitted signal. The system allows different scrambling for each pay program thereby increasing the security relative to the prior art single frequency system.

Abstract: The video image projection system of the invention includes two projecting devices formed by cathode ray tubes for projecting a green color onto a projection surface and two other projecting devices for projecting red and blue colors. The two green projecting devices project superimposed images. A circuit is provided for processing a video signal to supply a background signal without fine details to one of the green projection devices and a sharp contour signal to the other green projection device.

Abstract: The card is particularly intended to give a card-holder access to a service such as pay-TV (broadcast or cable), but in principle could be adapted to any lock-and-key type of system, e.g. credit cards, cards giving access to computer terminals or rooms, etc. The data is encoded on the card in the form of data-significant marks and spaces (2, 3). For example, the marks (2) may be distributed along two parallel tracks with marks in one track representing "1" bits and marks in the other track representing "0" bits. Dummy marks (20, 21, 30, 31, 32, 33) are also made on the card. The dummy marks have the same appearance to the human eye and to photographic and photocopying equipment as the data-significant marks. However, they are printed using inks having a different response in an invisible part of the spectrum, so that card reading equipment can be made to treat dummy marks differently from the way it treats data-significant marks. This makes the cards difficult to fake using commonly available equipment.

Abstract: In television reception, the sound intercarrier signal is detected by mixing the composite sound intermediate frequency signal, which is taken from an output of the video IF amplifier, with a clean, unmodulated signal, which is extracted from the oscillator output of the video synchronous detector and, accordingly, phase locked to the composite video intermediate frequency signal. Complementary amplifier stages, having highly selective tuned matching networks and traps, provide necessary gain and further purification of the respective signals before input to the intercarrier coincidence detector.

Abstract: A high performance video clamp and self-balancing inverter circuit for providing the DC coupling of a video signal together with substantially perfect inversion of any portion of a composite television signal. Under the control of synchronously timed pulses, two switches are alternately turned on and off to selectively apply the video signal to either the inverting or non-inverting input terminal of a video amplifier, thus separating signal portions selected to be inverted from those portions selected to remain non-inverted. To ensure perfect balance between inverted and non-inverted output signals, prior to processing, at least two reference pedestals are added to each field of the composite video signal to raise selected blanking level portions thereof to a level equal to 50% of the reference white level.

Abstract: Each decoder has a random access memory storing program code numbers, a security number, a customer identification number, and program identification numbers utilized for billing purposes. Communication between each decoder and a central computer is subscriber-initiated. The program code numbers must be updated periodically by means of a computer-decoder transmission which takes place only after the program identification numbers have been transmitted from the decoder to the computer. During predetermined cycles in the system sequence, the read-out of the random access memory takes place in reverse order and starting at an arbitrary start point hard-wired into each decoder. Confusion signals are transmitted while program identification numbers already transmitted to the computer are erased in the decoder memory. The communication through the telephone network takes place by frequency shift keying.

Abstract: At the television transmitting end, the program audio signals to be encoded are limited to a range of 50 to 7,500 Hz. A 202 KHz signal is modulated by the so-limited audio signal and the resultant upper side-band is heterodyned against an upper side-band derived from modulating the 202 KHz signal by video horizontal drive signals. Only the lower side-band created by the heterodyning process is transmitted. At the receiver, the received single sideband signal is applied to a product detector whose other input receives the output of a horizontal drive oscillator operating in synchronism with the corresponding oscillator at the transmitter. The baseband audio signal is separated from the upper sideband signal at the product detector output by means of a low pass filter.

Abstract: The standard composite television signal is modulated onto an intermediate frequency carrier signal. The so-modulated signal is applied to the input of a first and second frequency converter for conversion respectively to a first or second UHF or VHF output frequency. The two converters are enabled alternately, each for a predetermined number of frames. The resultant signals are summed and transmitted to a receiver location. At the receiver location, the power is split along two channels. Two tuner-mixers, one in each channel, and tuned, respectively, to the first and second output frequency, respectively convert the incoming signal components having the first and second frequency to the same intermediate frequency. The two intermediate frequency signals are summed and converted to the proper frequency for reception on standard television receiver.

Abstract: A rotatable fastener of low torque application, the fastener being characterized by external fastener, bearing surface which comprises a hemispherical dome, said dome defining a head whereby a mating tool may apply torsional forces thereto, the fastener having formation in the dome of a blind cavity the horizontal cross-section of which appears to be concentric to the center axis of the fastener, an axis of the cavity being at an acute angle relative to the central axis of the fastening means, wherein the driving moment between the fastener and a tool is provided by the eccentric relationship of the cavity, relative to the exterior dome of the fastener.

Abstract: A computer carrier strip having perforated feed is slit longitudinally and a label price tag strip having a gummed back is adhered to the computer strip, after which the strips are perforated to form tear lines, and cutouts are made to make a composite strip form carrying T-shaped label-price tag sheets connected together by perforated tear lines only at the tops and bottoms of the labels and with the price tag portions separated by the cutouts and connected to the labels only by perforated tear or fold lines superimposed along the slit along the computer strip. A computer prints the names, addresses, contents of shipping cartons on the labels and prices on the price tags. Then, when a carton having merchandise therein is to be shipped, the label for that carton is peeled from the backing strip and carries with it the price tag portion and the portion of the backing strip under the price tag portion.

Abstract: A predetermined pattern of code signals is periodically inserted into the transmitted encoded television signal. The pattern is so chosen that a bistable circuit at the receiver changes state for each received signal. A counter counts the number of state changes and, if correct, a validation signal is furnished. The validation signal allows recording of the billing charge for the program and transmission of the decoded signal to the television receiver.

Abstract: The computer at the central office is connected to the automatic answering system either with or without ringing the subscriber's telephone. Tones sent by the computer to the subscriber system are filtered and compared to a reference signal and a connect signal is furnished when the comparator outputs indicate that the tones signifying the particular billing system have been received. The connect signal energizes a relay which connects the billing system to the telephone line. A holding circuit for the relay is also energized. A first time delay circuit furnishes a signal to start data transmission from the billing system to the computer a short time after receipt of the connect signal. A billing system furnishes an "access complete" signal deenergizing the holding circuit when billing data transmission is complete.

Abstract: An improved pay TV method and apparatus is disclosed, characterized in that the program to be broadcast is encoded to effect electrical inversion of selected groups of lines of the program, thereby to scramble and disguise the video and audio signals. Simultaneously with the encoding of the program, a card is marked with programming, subscriber and area/month identifying information, which card is transmitted to the subscriber. During the actual broadcasting of the program, the subscriber inserts his card into a punch/reader in the subscriber box unit that is connected with his television receiver. When the subscriber selects a program for paid viewing, his subscriber card is punched, and decoder means operable by information contained on the subscriber's card serve to electrically reinvert those lines which were initially inverted by the encoder means, whereby the program is unscrambled for unimpaired viewing, and the sound is made audible.

Abstract: Reference pulses of opposite polarity to the horizontal sync pulses are added to the composite television signal just preceeding each horizontal sync pulse. The video portion of the signal is inverted for randomly selected fields. Coding bursts are added to the composite signal to indicate whether subsequent field is inverted. Transmitter clamped to reference pulse level. Reference pulse used for AGC in decoder. Video portion of received signal inverted in accordance with coding bursts. Audio program signals encoded by modulation on suppressed carrier centered above audio range. Barker signals transmitted on normal audio frequencies.

Abstract: At the sending end randomly generated binary code number signals are inserted into predetermined lines of the vertical retrace interval. The code number signals are also processed in accordance with a program assignment code to change or leave unchanged a predetermined characteristic of the television signal. Periodically, program identification signals, each signifying a program identification number, are inserted into the television signal instead of the binary code number signals. At the receiving end, the program identification signals are utilized to address a random access memory which furnishes program assignment signals. The program assignment signals control logic circuits to process the code number signals in accordance with the same program assignment code utilized at the transmitter. The output of these logic circuits is then utilized to decode the received encoded signal.

Abstract: A clutch assembly for controlling the transfer of rotation from a rotatable driving member to a rotatably mounted driven member comprises a spider driven within a drum having an interior wall surrounding the spider. The spider has outwardly radiating arms which receive clutch shoes between alternate pairs of adjacently disposed arms. The clutch shoes are equipped with outrigger means providing anchors for the ends of springs which interconnect circumferentially adjacent clutch shoes. The outrigger means support the ends of the springs circumferentially outwardly from the clutch shoes in a position which enables centrifugal forces to bow the springs outwardly and thus change the direction of force exerted by the springs on the clutch shoes.

Abstract: At the sending end, a plurality of high-frequency oscillators each furnish a signal having a frequency different from the frequency of the other of the oscillators. Timing signals derived from the television signal and signals from a random pulse generator are combined to furnish enabling signals for enabling the high-frequency oscillators during predetermined time intervals of the television signal and in a random order. A logic circuit which includes externally operable switches for setting up a program code assignment receives the enabling signals and furnishes an encoder control signal only in response to certain selected enabling signals. The encoder control signal changes the polarity of the picture signals relative to the synchronizing signals in the television signal. A mixer mixes the oscillator signals into the encoded television signal.

Abstract: A predetermined pattern of code signals is periodically inserted into the transmitted encoded television signal. The pattern is so chosen that a bistable circuit at the receiver changes state for each received signal. A counter counts the number of state changes and, if correct, a validation signal is furnished. The validation signal allows recording of the billing charge for the program and transmission of the decoded signal to the television receiver.