Abstract: A pair of equilibrium output signals P(+) and P(-) from a 1-bit D/A converter IC, which is made up of an oversampling filter, noise shaper and a pulse converter, are supplied to a pair of field effect transistors connected in a common drain configuration. A constant current I.sub.0 is supplied to the common drain from a constant current source and at least one of the source output currents is converted by an output circuit into a voltage. In this manner, a 1-bit D/A converted output signal freed of fluctuations of the power source is provided at an output terminal.

Abstract: A screen cover opening device for a television receiver is provided with a screen cover openably closing left and right side portions or upper and lower side portions of a screen adapted for electively displaying plural different aspect ratio images. Two vertically extending rolls 5a, 5b are arranged at outwardly shifted positions from left and right lateral sideswrapped around of the screen 2 and an endless cover sheet 3 is wrapped around these rolls. Two windows 4a, 4b are formed at longitudinally spaced apart positions of the cover sheet 3. The rolls are rotated to run the cover sheet to change overlap of the two windows to change the transverse width W that may be viewed through overlapped portions of the two windows.

Abstract: In a thyristor ignition circuit, a forward voltage drop occurring in a signal path of an anode and a gate of a thyristor is reduced. An anode of a thyristor of the thyristor ignition circuit is connected to one signal terminal, and a gate thereof is connected to another signal terminal. The thyristor ignition circuit further comprises a transformer having a primary winding for receiving an ignition signal, and a first secondary winding having one end connected to a cathode of the thyristor and the other end connected to the other signal terminal. The thyristor is ignited via the cathode in response to the ignition signal applied to the transformer. A signal path is established between one signal terminal and the other signal terminal through the anode-to-gate path.

Abstract: A display device includes a beam index type cathode ray tube having a fluorescent screen on which red, green and blue fluorescent materials are formed in strip configurations and further index fluorescent materials are formed in strip configurations with a predetermined pitch, a sensor for converting light generated from the index fluorescent materials into an electric signal when an electron beam is impinged on the index fluorescent materials upon horizontal scanning of the electron beam with respect to the fluorescent screen, and for multiplying the converted electric signal, an index signal processing circuit for switching red, green and blue signals in accordance with the multiplied electric signal from the sensor, and for controlling luminance of the cathode ray tube in accordance with a luminance level control signal, and a driving voltage generating circuit for controlling a driving voltage applied to the sensor in accordance with the luminance level control signal to thereby control a multiplication r

Abstract: A method of forming a phosphor screen in which a color filter layer is formed between a phosphor layer and an inner surface of a panel having a slurry in which a fine particle pigment and transparent particles are dispersed into a photosensitive liquid coated on the inner surface of the panel. Then, the color filter layer is formed by exposure and development. When the color filter layer that constitutes one portion of a phosphor screen of a color cathode ray tube is formed in this manner, an adhesive force with which the color filter layer is bonded onto the panel can be increased and a transmittance of the color filter layer can be improved.

Abstract: A decoding method of Reed-Solomon code produces an error position polynomial .sigma.(x) and an error evaluation polynomial .omega.(x) by a Euclidean algorithm, whereby a syndrome polynomial S(x) is obtained, the highest degrees of the syndrome polynomial S(x) and of an initial polynomial x.sup.2t, which is determined by the number t of symbols to be corrected, are multiplied, while the degree is incrementally reduced, thereby obtaining polynomials h(x) and g(x) that satisfy the relation:f(x).multidot.B(x)+g(x).multidot.S(x)=h(x)(where the degree of h(x) is less than the degree of g(x).ltoreq.t). The polynomial g(x) is set to the error position polynomial .sigma.(x), and the polynomial h(x) is set to the error evaluation polynomial .omega.(x), thereby performing the decoding by real time processing.

Abstract: Apparatus is provided for switching between recording and playback modes of a tape recorder having a single input/output jack to which an output plug for an earphone, a headphone or the like, or an input plug for a microphone or the like can be connected. The jack is compatible with two channels. When a remote-control unit having a remote-control switch and connected to an input/output transducer is connected to the jack, one channel is used as an input channel for a remote-control signal, and the other channel is used as an input/output channel for an audio signal. In another embodiment, the tape recorder has a control circuit for discriminating between insertion of a 1-channel plug and insertion of a 2-channel plug into the 2-channel jack to control the operation of switches included in this tape recorder.

Abstract: At a horizontal deflecting circuit of bi-directional deflection, timings of deflection of forward scan path and backward scan path are respectively controlled. The timing of deflection of forward path or backward path is controlled at the first timing control circuit 22 so that it is synchronized with the horizontal synchronizing signal HD and timing of deflection of backward path or forward path is controlled at the second timing control circuit 24 so that deflection cycles of forward path and backward path are equalized.Further, timings of deflection of forward scan path and backward scan path are controlled respectively at first and second phase comparison circuits 22 and 24 so that the relation in phase between the image signal and the deflection takes a constant value on the basis of the horizontal synchronizing signal, to previously prevent occurrence of steady phase error.

Abstract: A display device comprising a CRT having a reduced number of components for automatic cutoff adjustment. The device needs an IC having a less number of connection pins. The device adds reference pulses to given portions within every field of video signals. The resulting cathode currents are converted into voltage pulses. These voltage pulses are compared with a reference voltage by a comparator. The output signal from this comparator is counted by forward-backward counters for three primary colors, respectively, and converted into analog form. Level shift circuits for the three primary colors, respectively, control the DC components of the video signals according to the output signals from the D/A converters. In this way, the cutoff characteristics of the CRT are controlled.

Abstract: A transmitter-receiver is simple in arrangement and can prevent a receiving circuit side from being disturbed; in which one channel is divided to provide a transmission slot and a reception slot. Transmission and reception are effected in the transmission slot and reception slot of one channel in a time division manner and a channel selection frequency synthesizer is commonly used both in the transmitting circuit and the receiving circuit. This transmitter-receiver includes a modulator circuit (40) of the transmitting circuit which has an oscillator (41) for modulating a signal into a predetermined frequency and a multiplier circuit (44) for converting an output signal of the oscillator (41) into a desired intermediate frequency. During the period of the transmission slot, the supply of a voltage to the multiplier circuit 44 is stopped.

Abstract: A magnetic recording apparatus comprises a time base compressing portion for causing a video signal to be subjected to time base compression, a recording signal producing portion for forming a recording video signal based on the video signal with compressed time base, a tape guide cylinder, a rotary magnetic head device disposed in the tape guide cylinder, and a recording signal supplying portion for supplying the rotary magnetic head device with the recording video signal, wherein assuming that .alpha. represents the diameter of a standard tape guide cylinder employed in a standard apparatus, .beta. represents a tape wrapping angle on the standard tape guide cylinder, .gamma. represents the revolving speed of a standard rotary magnetic head device disposed in the standard tape guide cylinder, and .delta. represents the number of magnetic gap portions of the standard rotary magnetic head device, the diameter of the tape guide cylinder is selected to be X.multidot..alpha.

Abstract: A copy guard processing detecting apparatus which can correctly judge whether or not a copy guard is applied to an input video signal and prevents copy guard processing from being applied to a video signal to which a copy guard is not applied. The copy guard processing detecting apparatus comprises a first circuit for receiving an input video signal which includes a plurality of false synchronizing signals for prevention of duplication inserted in a vertical blanking interval thereof and for counting the number of the false synchronizing signals, a second circuit for counting the number of synchronizing signals in an image interval of the input video signal except the vertical blanking interval, and a discriminator for discriminating whether or not copy guard processing is applied to the input video signal from the count values of the first and second circuits.

Abstract: A power control circuit for use in radio transmitters such as portable telephone sets includes a power amplifier for amplifying the power of a transmission signal to obtain an output signal; control circuits for controlling the amplitude of the signal output by the power amplifier; a limiter for partially limiting the amplitude of the signal from the power amplifier in order to obtain a limited signal; a multiplication circuit for multiplying the limited signal from the limiter and part of the signal from the power amplifier in order to acquire a multiplied signal; a low-pass filter for extracting a DC component of the multiplied signal from the multiplication circuit; and a comparison circuit for comparing the DC component from the low-pass filter with a reference voltage in order to obtain a comparison output.