Abstract: A target videogame employing a screen with a moving light spot symbol and a mechanically disjoint target detector. Signals generated by light received in the target detector and by discharging a trigger attached to the target detector are transmitted by wireless communication to the circuits providing for the screen display.
Abstract: A target videogame employing a screen with a moving light spot symbol and a target detector. A frequency selective circuit is provided for selecting the electrical signals generated by the light entering a photosensor in the target detector according to their frequency relationship with respect to the line scanning and frame scanning frequency.
Abstract: A television vertical deflection circuit is disclosed. A sawtooth generator is connected to a driver circuit and this circuit is in turn connected through a capacitor to an output amplifier, which powers vertical deflection coils of a television receiver. A first voltage source is connected through a forward diode to the output amplifier. A second voltage source is connected through switching means to the output amplifier. A signal from the driver circuit to the base of a transistor of switching means shuts the first voltage source off and turns the second voltage source on.
Abstract: A terminable scanning movement of a video tape track with respect to the scanning path of a playback head in a helical scan video recorder is provided with a staircase-type tracking control voltage. During each scanning cycle, in which each increment of the scanning voltage provides a monotonic, unidirectional translation of the tape track with respect to the scanning path by suitably altering the velocity of advance of the tape, the occurrence of a successive minimum and maximum in the resulting variation of detected video amplitude results in the generation of a stop signal. Such signal, which ideally coincides with the maximum amplitude of the detected voltage and thereby the desired registration position between the video tape track and the scanning path, is employed to stop the progression of the staircase voltage and to thereafter store the then-attained value for the maintenance of the tape drive servo at the optimum position.
Abstract: An arrangement for effectively excluding the effects of disturbance pulses in the operation of an infra-red remote control system (e.g., for channel switching of a television receiver) is described. Facilities are provided on the transmitting side of the remote control arrangement for encoding the pulse interval of a chain of pulses derived from a quartz crystal-controlled oscillator with the intelligence contained in a selected one of a plurality of command signals for the channel switching function. The resulting encoded pulses are converted into a form suitable for modulating a high-frequency chain of pulses from the same oscillator so that the infra-red transmitter emits intelligence in extremely short-duration bursts of energy.
Abstract: A compact and efficient design of a function switching and indication arrangement for a TV receiver or other communications apparatus is described. The functional setting, illustratively indicative of a selected one of a plurality of TV channels, is chosen by the depression of an associated one of a plurality of keys that are respectively connected to externally accessible first switching terminals of a corresponding number of transistorized binary multivibrators that are arranged in an integrated circuit. The outputs of the multivibrators are coupled, on the integrated circuit chip, to a corresponding plurality of multi-collector transistors, one of whose outputs is used to reset the multivibrators of the non-selected channels, and another of whose outputs is employed to set the selected channel itself.
Abstract: An arrangement for varying the triggering phase of a thyristor or other controllable switch employed to vary the excitation of a sweep deflection circuit during changes in the circuit load is described. The output of a winding of the deflection transformer is converted to a constant-amplitude sawtooth voltage which has a DC component proportional to the amplitude of the then-occurring forward sweep portion of the sweep voltage. A zener diode or other comparison element coupled to the output of a variable voltage divider whose input is fed by the resulting sawtooth voltage generates a trigger pulse for the controllable switch at the instant, during each cycle of the sweep waveform, that the constant-amplitude sawtooth voltage exceeds a predetermined value.
Abstract: An improved sweep generator circuit suitable for deflection circuits in television receivers conventionally includes a condenser chargeable through a resistance to establish the sweep. A resistive voltage divider and a threshold comparator circuit are each arranged parallel to the condenser. The comparator circuit is triggerable to establish a low impedance discharge path across the condenser when the charging voltage across the condenser exceeds a normal reference voltage from the voltage divider. The frequency of the generator is made variable in response to a synchronization frequency within predetermined limits by shunting a resistance of the voltage divider by a control resistance through an electronic switch that is triggerable by the sync pulse train.
Abstract: A first thyristor gate whose conductive state is determined by the polarity of a signal applied to its control electrode is connected in series with a flash tube for selectively coupling operating voltage from a flash capacitor to the tube. The first gate is opened by a signal of a first polarity derived from the operating voltage source and generated in synchronism with an ignition pulse, which is applied to the trigger electrode of the flash tube to energize the tube. An integrating circuit energized by a transformer coupled to the flash tube output contains a photosensitive element responsive to a portion of the emitted light for developing a control voltage that increases in proportion to the total light integrated. When the output voltage from the integrating circuit reaches a predetermined value, a second thyristor gate whose control electrode is coupled to the output of the integrating circuit is opened to apply a signal of the opposite polarity to the control electrode of the first thyristor gate.
Abstract: An arrangement for initiating and terminating a scanning movement of a video tape track with respect to the scanning path of a playback head is described for use in a helical scan video recorder. A disturbance detector is actuated when the detected video pulse envelope exceeds a predetermined amplitude indicative of a minimum displacement of the track from the scanning path. Such actuated detector operates to couple the servo unit of the tape velocity regulator to a tracking controller. The controller initiates a track scanning operation by applying to the tape drive servo a cyclic modulation which is superimposed upon an error signal derived from the detected video envelope.