Abstract: An arrangement for protecting an electrical circuit such as a telephone circuit from a voltage transient comprises a voltage clamp or foldback device (3) arranged to be connected between a current-carrying line (1) and ground (1'), a capacitor (2) in series with it, and an inductance (4) series connected in the line. During normal operation the arrangement acts as an LC filter whose high frequency break-point is determined by the capacitance of the voltage clamp or foldback device (3) and the value of the inductance (4) which are chosen to give a break point of 1 kHz to 10 MHz. However, when the arrangement is subjected to a voltage transient, the voltage clamp or foldback device (3) fires causing the break-point to fall to a value determined by the values of the capacitor (2) and inductance (4). The arrangement may be used, for example, to protect the circuit against a rapid voltage drop caused by the firing of another circuit protection device such as a gas discharge tube 5.

Abstract: A method and device for testing the quality of a ground path, particularly although not exclusively for a telecommunications system. The device has terminals for connection to respective lines, such as tip and ring. A terminal is provided for connection to the local ground. Voltage-sensitive switches of increasing threshold voltage are alternatively connected between the local ground and each of the tip and ring lines via a rotary or other selector switch and the terminals. Current will flow if the local ground potential exceeds the threshold voltage of the voltage sensitive switches. A device responsive to mains frequency, e.g. a butt-in head set, provides an audible sound (mains hum) indicating the ground potential rise exceeds the threshold of the selected voltage-sensitive switch.

Abstract: A printing apparatus capable of using recording media of different widths expands the range of print head movement while limiting the movement of the mask plate, which press the recording media against a platen, to within the area of the recording media, thereby preventing interference between the mask plate and the recording media, as a means of assuring the minimum print head travel required to sufficiently advance the ink ribbon or prevent overheating of the print head.

Abstract: A method of and an apparatus for guiding a microrobot without the necessity of an operator is disclosed. The operation area for the microrobot can easily be enlarged, contracted or changed. Sensors of the microrobot are used to cause the microrobot to react to light, magnetism or sound through an arbitrary passage formed on a surface of a light transmissible base plate, on which the microrobot is moved. The passage is formed by projecting light emitted from a light source through a pattern mask from an opposite side of the base plate.

Abstract: An information recording/reproducing device is provided with design features permitting are reduction in device height making it readily suitable for compact utility in a computer assembly, such as, a laptop computer or the like as well as a simplification of parts to provide for a reduction in manufacturing and assembly costs. These features include a structure for miniaturization and simplification of the collet mechanism and its assembly for clamping the recording medium, and the employment of a light guide member in the recording medium detection system for detecting the instantaneous rotational position of the recording medium from which a timing signal is derived. With the improvement of the clamping mechanism and use of a light guide member, significant miniaturization and thinning or reduction in casing height of the device can be achieved.

Abstract: A laser emission unit for use in an optical head performs a plurality of functions which are integrated. A laser beam from the laser emission unit mounted in a lens holder is emitted through an objective lens and is focused on an optical medium. A reflected beam from the optical medium returns through the objective lens and a diffraction grating to a signal detection circuit in the laser emission unit. Since the laser emission unit performs a plurality of functions, the space for various elements otherwise required in the optical head can be eliminated. The space for an additional light path for the reflected beam is also eliminated. Therefore, the size of the optical head is very small. Since the optical head can be assembled by using a small number of parts, the production costs can be reduced. Furthermore, the optical head can shield the noises by using the housing and/or the lens holder itself.

Abstract: A magneto-optical recording and reproducing apparatus achieving an improvement in high density recording and bit error correction rate. The magneto-optical recording and reproducing apparatus comprises coding and modulating means for (1,7) RLL encoding and then NRZI encoding a digital information series {A.sub.i }; recording and reproducing means for recording the encoded series {a.sub.i } to a magneto-optical recording medium, and reproducing an analog signal from the medium as elementary waveform sequence e(t) using an optical head; a transversal filter type waveform equalizer for waveform equalizing elementary waveform sequence e(t) by applying the transfer function (1+2D+2D.sup.2 +D.sup.3) of the PR(1,2,2,1) encoding method to the elementary waveform of the encoded sequences, where delay operators D have a delay time of the encoded sequence cell width T.sub.

Abstract: A ferrite antenna is disclosed. The antenna includes a board on which a ferrite component is mounted. The board includes a plurality of slots and a conductive pattern extending between two of the slots. First and second metal bands are wound around the ferrite component and inserted into the slots. The metal bands are coupled together by the conductive pattern to form a coil. Thus, the interval between adjacent bands can be more accurately set and the antenna can be more easily fabricated. In another embodiment, a metal band partially encloses the ferrite component and covers an open area between the ferrite component and one end of the metal band. The sensitivity of the antenna is thus increased beyond the upper limit of a regular ferrite antenna. In still another embodiment, conductive patterns are formed on the periphery of the board and coupled to the metal bands to improve the directional sensitivity of the antenna.

Abstract: A signal voltage level conversion circuit has a configuration in which all transistors can be produced, during the semiconductor fabrication process, so that their gate-source, gate-drain, and gate-substrate voltages are within the 3v voltage tolerance range. The signal voltage level conversion circuit converts input signals with a narrow logical amplitude of 0.about.3v to output signals with a wide logical amplitude of 0.about.5v. The input signal Vin, 0.about.3v, is temporarily converted into a mediator signal Vm, approximately 3.about.5v by a mediator signal generation circuit. An output buffer circuit then converts mediator signal Vm to output signal Vout of 0.about.5v. In the mediator signal generation circuit and the output buffer circuit, application of voltage is relaxed on a plurality of transistors, so that all transistors are maintained within the 3v voltage tolerance range.

Abstract: A semiconductor device comprises an electrically insulating film having a device hole; a plurality of groups of leads, each group including of a large number of leads arranged in a predetermined pattern, in a plurality of lead formation regions on the surface of the film; an integrated circuit chip positioned within the device hole and with electrodes connected to inner lead portions of the leads; and a resin sealing portion that seals in at least the integrated circuit chip, the film, and the lead groups. The film comprises a first group of aperture portions including of aperture portions provided in regions outside the lead formation regions and a second group of aperture portions consisting of a plurality of aperture portions provided in the lead formation regions.

Abstract: A data expansion apparatus that performs data expansion operation for a data block unit in a constant period of time is provided. First and second memory devices are first initialized by storing zeroes at all of their addresses. Numeric data and number-of-zeroes data (i.e., data representing the number of successive zeroes) are input to the data expansion apparatus. A calculation circuit outputs a calculated value by combining the number-of-zeroes data, a previous calculated value and 1 together. A first selection circuit associated with the first memory device selects the calculated value and numeric data and output them to the first memory device for storing the numeric data at the address specified by the calculated value. This operation is then repeated. After the first memory device completes the expansion operation, it is switched to perform read operation and the second memory device begins to perform expansion operation through second selection circuit in a similar manner.

Abstract: The temperature dependence of the difference in oscillation frequency between two quartz resonators caused by the pressure difference between the two quartz resonators as well as the intrinsic physical properties between them can be compensated accurately and at low cost by calibrating the difference in oscillation frequency between the two quartz resonators by means of a quadratic formula with regard to temperature or by reducing the temperature dependence of the difference in oscillation frequency by connecting a thermistor to oscillation circuits. Pulses from each of an oscillation circuit (1) including a quartz resonator placed in vacuum and another oscillation circuit (2) including a quartz resonator placed in an atmospheric pressure are counted by pulse counters (3, 4). The difference between the pulse counts is obtained by a subtracter (5) and sent out to an MPU (6) as a measured value.

Abstract: A thin film transistor which has improved electric characteristics such as off current characteristics, and a manufacturing method of a thin film transistor. A thin film transistor has an n- source area and an n- drain area comprising an n- silicon film (low concentration area). The n- silicon film is made by performing a crystallization treatment such as an SPC method on an amorphous silicon. The crystallization treatment is carried out after the implantation of impurities but before a gate electrode is formed and activates the impurities at the same time. Accordingly, the activation of impurities is not restricted by the heat resistance of the materials for the gate electrode. A gate electrode made of metal is formed after the n- source area and n- drain area are formed. The gate electrode, n- source area and n- drain area are not formed by self-alignment.

Abstract: An optical recording regeneration apparatus with a compensation circuit is provided. In the apparatus, a recording state detection circuit detects the recording state of recorded data and generates state data indicative of the recording state. A modulation control circuit compares the state data with a specified value and generates the comparison results. A drive circuit adjusts the power level and/or the pulse width of the laser beam in accordance with the comparison results. Thus, the power level and/or the pulse width of the laser beam can maintain at an optimum value without being affected by variations in disk recording sensitivity resulting from temperature or other changes over time.

Abstract: A magneto-optical recording apparatus capable of maintaining decoding performance even if the recording density at the magneto-optical recording is high. The magneto-optical recording apparatus comprises a modulator for RLL (Run-Length Limited) encoding recording data, an NRZI encoder for NRZI-encoding a RLL code from the modulator, an equalizer for equalizing a read-out analog signal obtained from a magneto-optical recording medium into a waveform (1+D).sup.n (n is a positive integer) assuming that the delay time for one bit period of the read-out signal is D, a low pass filter, and a Viterbi decoder that uses the difference between a sample value obtained by quantizing an output from the low pass filter and an expected value obtained from a theoretical value of a data column to make the most probable path to be decoding data.

Abstract: A thin film transistor structure and methods of manufacture provide high ON/OFF current ratio and significantly reduce OFF state leakage currents. A doped thin film disposed on an insulating substrate is etched to form opposing source and drain regions. An undoped thin film is disposed between the opposing source and drain regions so that there is some overlap of the undoped thin film onto the top sides of the source and drain regions. Conventional photomasking, etching and ion implantation steps are then used to form a gate electrode offset from at least the drain region, and preferably offset from both source and drain regions, as well as conventional insulation and interconnect layers. The reduction in electric field intensity in the drain region, and the reduction in trap state density result from, performing heavy junction doping prior to deposition of the undoped thin film, and offsetting the gate electrode from the drain region.

Abstract: The invention provides an drive coil protection apparatus and method and a printer incorporating the apparatus. A rank memory stores a preset rank value associated with a reference drive coil in the print head of a printer. The preset rank value characterizes inherent deviations associated with the reference drive coil. The deviations result from manufacturing process, etc. A judgment value memory stores a plurality of sets of mode judgment values. Each set of mode judgment values corresponds to a particular rank value. Each mode judgment value represents a threshold value for determining the thermal condition of the print head and for selecting an appropriate operating mode for the print head. A head information detector detects the voltage drop across the reference drive coil to measure the change in the resistance of the reference drive coil. The voltage drop is digitized for accuracy measurement. The change in temperature of the reference drive coil can thus be determined.

Abstract: A leadframe for semiconductor devices is disclosed. The leadframe includes a die pad supported on the leadframe. A semiconductor chip is mounted on the die pad. The chip has a plurality of pads including at least one group of designated pads for communicating an identical signal, such as a power supply signal of the same level, with external circuits. A terminal on the leadframe is coupled to the group of designated pads. The terminal is attached to selected one or more leads on the leadframe for communicating the identical signal with the external circuits. The other pads on the chip, such as signal pads, are coupled to the corresponding leads on the leadframe. Thus, the total number of leads on the leadframe is reduced and more leads are available for the signal pads, resulting in efficient connections between the chip pads and the leads.

Abstract: An information storage medium having both a read-only optical storage portion and a magnetic storage portion that can be written and read is provided. There is also disclosed a drive unit for use with this information storage medium. To control the optical head of this drive unit, a system controller and a CLV servomechanism are provided and form a control portion. When information is written or read to or from the magnetic storage portion, this control portion commands a disk-rotating mechanism to control the magnetic head of the drive unit based on information read from the optical storage portion of the medium. The magnetic storage portion can have either a single track or plural tracks. Interference between the optical head and the magnetic head can be avoided. The drive unit can adapt itself to the information storage medium having the optical storage portion of a large storage capacity and the magnetic storage portion that can be easily rewritten.

Abstract: In the precision angular displacement mechanism of an optical record and playback apparatus, the elasticity coefficient of the supporting component is kept from fluctuating caused by changes in temperature and the fatigue strength is increased. This is accomplished by making the support component of the moving section a flat metal spring. The support component of the moving section is attached with a reflecting mirror. In addition, by forming the moving section so that the position of its gravity center is located near the center of the flat metal spring, it is possible to prevent secondary resonance and torque resonance. Finally, an assembly method is disclosed that makes such a precision angular displacement mechanism easy to assemble.