Abstract: A process and an apparatus for recycling resin scrap including a thermosetting resin paint film and a thermoplastic resin substrate as its major components, wherein the resin scrap is supplied into a passage of a cylinder, melted, and delivered by delivering means from an upstream side to a downstream side of the passage of the cylinder, and hydrolyzed by a hydrolyzing agent while forming a highly packed region with a resistor. The resistor restricts the resin scrap to flow from the upstream side to the downstream side in a short period of time, and forms the highly packed region where a contact efficiency is enhanced between the resin scrap and the hydrolyzing agent.

Abstract: An optical disk reproducing apparatus for reproducing at a high access-speed an optical disk on which data has been recorded at a constant linear velocity (CLV) includes a control circuit for controlling reading of the disk recorded at a CLV to be rotated at a constant angular velocity (CAV), and a processor for changing the frequency of a reference clock to determine the processing timing of the reproduced digital signal in accordance with a transmission speed of the digital information signal picked up from the disk. A motor for driving the disk can be rotated at a constant revolution rate upon access to the disk, and thus it is possible to remove one of the factors for determining the access time in the conventional CLV type reproduction system, or the time for controlling the motor to rotate for a constant linear velocity in accordance with the position of the optical pickup.

Abstract: A method of reclaiming a plastic product having a paint film, including the steps of: obtaining crushed particles by crushing a plastic product having a paint film into particles of a predetermined size; supplying the crushed particles to a screw-type extruder; kneading and fusing the crushed particles while supplying water thereto; and obtaining a plastic by discharging a gas produced by decomposing the paint film and vaporized water.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.

Abstract: A method of producing fiber reinforced plastic moldings.

Abstract: A method of forming a composite material involves feeding materials to a kneader, kneading the materials, and injecting them from the kneader into a mold. The kneader is formed by a screw-type extruder having an ejection outlet at one end for extrusion into the mold. Various input ports are located axially along the extruder. Materials are fed into the kneader beginning at the inlet port most remote from the outlet end and proceeding successively to the inlet port nearest the outlet end. The materials are fed in successive order from those with the highest viscosity and lowest reactivity relative to the materials with the highest reactivity and lowest viscosity. For example, thermoplastic is fed to the inlet most remote from the outlet, and thermosetting resin is fed to the inlet nearest the outlet. In another aspect of the invention, in which thermoplastic and thermosetting resins are employed in roughly comparable amounts, an "island-in-sea" structure is desired.

Abstract: In a disc playback apparatus using an optical pickup or the like, any flaws on a track of the disc are detected using: a first level detector for detecting a maximum value level of a recording information signal of an output of the pickup; a second level detector for detecting a change of the maximum value level of the recording information signal; and a comparator for comparing outputs of the above first and second level detectors. When any flaws are detected, a driving signal of a driving device for the pickup is held to a fixed reference potential.

Abstract: A tracking servo circuit for controlling an optical pickup is used in a tracking error detecting device including an optical system for forming on an optical disc a main light spot for illuminating a pit on the optical disc and forward and backward sub-light spots. The forward and backward sub-light spots are disposed before and behind the main light spot in the moving direction of a track with a small distance between each of the sub-light spots and the main light spot and are shifted from the center line of the track, so that a half of each sub-light spot area is placed on the pits of the track.

Abstract: A servo circuit for a signal reproducing apparatus for reproducing signals from a record medium such as a disc utilizing an optical pickup, wherein a variable gain amplifier is arranged in a servo loop between a pickup and an actuator so that the pickup is caused to track a signal track in accordance with a servo error signal produced by the variable gain amplifier. A playback condition of a disc is discriminated by detecting the number of errors in a signal reproduced from a recorded signal on the disc by the pickup, and a gain of the variable gain amplifier is controlled by the discrimination output so that the variation of the servo error signal caused by a difference in reflectance between individual discs is eliminated and a loop gain appropriate to an individual disc is automatically set.

Abstract: In a pulse width detector circuit, a high-level pulse width and a low-level pulse width of a digital signal derived by slicing an analog signal reproduced from a disc at a predetermined level are independently measured and maximum or minimum values thereof in a predetermined time interval are stored, and an average value, sum or difference of the maximum or minimum high-level pulse width and the maximum or minimum low-level pulse width is calculated to detect a correct pulse width of original data recorded on the disc.

Abstract: An information reproducing apparatus having a tracking servo control loop for causing an information reading unit including device for detecting a tracking error signal for tracking an information bearing track on a disc, to track the information bearing track in accordance with the tracking error signal so as to reproduce information in accordance with an information signal read by the information reading unit. A circuit for extracting a discrimination signal for discriminating a negative feedback region of the tracking error signal is provided so that a tracking servo control loop is closed in the negative feedback region.

Abstract: Disclosed is a disc or tape signal reproducing apparatus having a first speed control loop in which the duration of a specific pulse in the PCM signal recorded on the disc or tape is detected and the current sync signal interval is anticipated from the duration of the pulse so that the motor speed is pulled into the operation range of the sync signal detector, and a second speed control loop which controls the motor speed basing on the sync signal reproduced by the sync signal detector. The motor speed is controlled by the first speed control loop until the sync signal detector detects the sync signal, thereafter the motor speed is controlled by the second speed control loop basing on the reproduced sync signal.

Abstract: In a power amplifier having a power circuit of a switching control system, a protective device for the power amplifier has connected to the amplifier a means for detecting an abnormal signal produced at the amplifier, and a control means connected between the detecting means and the power circuit to the amplifier so as to cut off a switching control signal to the power circuit when an abnormal signal is generated at the amplifier, thereby stopping the power circuit from operating to cut off power to the power amplifier. The detecting means is formed of a detecting circuit connected to the output end of the amplifier so as to detect the DC output voltage or excessive current from the amplifier, and a driving circuit connected to the detecting circuit so as to be operated by the output signal from the detecting circuit.

Abstract: A power supply controlled stereophonic amplifier system of a simplified circuit configuration which includes an analog logic circuit that generates a larger one of the input signals for left and right channels thereby to control the output voltage of the DC-DC converter as a power supply by means of a pulse train of pulse widths that change according to the output of the logic circuit. The output of the analog logic circuit is compressed by a signal compression means which functions to compensate for the non linear response of the DC-DC converter.

Abstract: An improved antenna tuning circuit for a long and a medium wave AM radio receiver is disclosed. The antenna tuning circuit of the present invention comprises a tuning coil wound around a ferrite core, a variable capacitor connected in parallel with the tuning coil, and a field effect transistor. One end of the tuning coil is connected to the gate electrode directly or through an impedance means, while the other end of the tuning coil is grounded. The output signal of the antenna tuning circuit is taken out from a selected one of the source or drain electrode of the field effect transistor, whereby the signal to noise ratio may be remarkably improved.

Abstract: A stereo demodulation system for an FM stereo broadcast receiver having frequency dividing means receiving the output of the voltage controlled oscillator in the phase locked loop and producing the first and the second switching signals which are supplied to the first and the second switch and decoder circuit for switching and decoding the stereo composite signal, wherein said first and second switching signals are produced with the fixed phase relationship therebetween.

Abstract: An automatic gain control for a receiver includes a gain controller for controlling the gain of the receiver, a control device connected to the tuning device of the receiver for varying and controlling the tuning frequency of the tuning device, and a level detector connected to the control device and the receiving signal system of the receiver for detecting the receiving level. The control device includes a calculation processor connected to the tuning device, the level detector and the gain controller, and the calculation processor includes a detector for detecting the absence or presence of other broadcasting waves (interference waves) in a predetermined relation with the receiving frequency of the receiver and for controlling the gain controller in such a manner as to reduce the gain thereof when the signal intensity of the interference broadcasting waves exceeds a predetermined level predetermined by the level detector.

Abstract: An audio frequency power amplifier circuit comprising a voltage detector for detecting the voltage between the gates of output MOS FETs in Class B push-pull connection, and a bias generator for applying a quiescent bias voltage to the MOS FETs. The bias voltages applied to the MOS FETs are changed in proportion to the output current in such a manner that the output MOS FET to be cut off is impressed with a substantially equal bias voltage in the absence of signal. In this way, the cut off of the push-pull transistor of Class B operation is prevented, thus preventing a switching distortion.

Abstract: In a stereo demodulator circuit, there is provided a phase-locked loop in which a comparison signal is produced by frequency-dividing an oscillation signal of an oscillator, and the phase of the comparison signal is compared with the phase of the pilot signal to phase-lock the phase of the oscillation signal and the phase of the pilot signal. The output signal of the oscillator is frequency-divided to produce a first switching signal. The first switching signal and a composite signal are supplied to a first decoder at which left and right channel signals are separated. The output of the oscillator is also frequency-divided to produce a second switching signal having a frequency which is three times the sub-carrier frequency. The composite signal and the second switching signal are supplied to a second decoder at which the left and right channel signals are separated.

Abstract: The emitters of a pair of transistors are connected to each other. A voltage/current converter circuit for converting an AC voltage into an AC current is inserted between ground and the junction point of said emitters, thus making up a first differential amplifier. With an input signal applied to the voltage/current converter circuit, an output signal is produced from one of the transistors of the first differential amplifier. With a fixed bias voltage applied to the other transistor of the first differential amplifier, the bias voltage for said one of said transistors is changed, thus controlling the amplitude of the output signal. A second differential amplifier has first and second input terminals.