Abstract: The perceived quality of an audio signals obtained from very low bit-rate audio coding system is improved by using expanding quantizers and arithmetic coding in a transmitter and using complementary compression and arithmetic decoding in a receiver. An expanding quantizer is used to control the number of signal components that are quantized to zero and arithmetic coding is used to efficiently code the quantized-to-zero coefficients. This allows a wider bandwidth and more accurately quantized baseband signal to be conveyed to the receiver, which regenerates an output signal by synthesizing the missing components.

Abstract: A memory block is subject to an erasure operation by a batch operation. Subsequently, a read-out test is conducted upon the memory block to count the number of unerased memory cells. If the count FN is equal to or greater than a given number TF, a plurality of erasure operations are conducted consecutively next. If FN<TF, a single erasure operation is conducted next, subsequently followed by a read-out test. The erasure operations and the read-out tests are repeated.

Abstract: A movable contact is mounted on the vicinity of one end of a movable contact piece having a generally U-like shape and made of an elastic member. A recess of a generally circular arc-shape in section is formed on the vicinity of the other end of the movable contact piece to extend in the direction of the width thereof. The movable contact piece is swingably supported by the movable contact piece support member, and a generally circular arc-shaped tip in section of a movable contact piece actuator of an operation button is engaged with the recess. The movable contact piece actuator swingable with the swinging movement of the operation button causes the movable contact piece to be swung to the switch-on position where the movable contact thereof comes into contact with a fixed contact mounted on a fixed contact piece or the switch-off position where the movable contact is away from the fixed contact.

Abstract: A depolarizer 11 is inserted between an optical branch unit 2 and a polarization filter 3, a depolarizer 12 and a polarization filter 14 are inserted between an optical phase modulator 5 and a quarter-wave plate 16, and a depolarizer 13 and a polarization filter 15 are inserted between the other branch end of the optical branch unit 4 and a quarter-wave plate 17. The optical branch unit 2 and the optical phase modulator 5 are formed by single mode optical fibers, and single mode optical fibers are used to connect between optical elements, thus providing an arrangement which is inexpensive as a whole.

Abstract: An optical transmission system is provided, which permits high-precision optical transmission of a signal even if the signal has a high accurate timing, an indefinite period, and a DC component. The transmitting side is provided with a rise edge detecting circuit 1 for detecting the rise edge of a transmitting signal waveform, a transmitting pulse generating circuit 2 for generating a transmitting pulse signal (b) constituted by a pair of opposite-polarity pulses inverting their polarities at the detected timing, and a light intensity modulation circuit 3 for generating a light intensity modulated signal (c) based on the pulse signal (b). The receiving side is provided with an AC-coupled receiving circuit 4 for receiving the light intensity modulated signal (c) and extracting therefrom only an AC component, and a discrimination circuit 5 for discriminating the rise timing from the received signal.

Abstract: Outer ends of link members supported to a case and having their inner ends coupled to each other are coupled to a slider. A membrane sheet and a pusher are disposed one after the other on the slider, and a knob having molded therewith a surface sheet is fixed to the slider. On a bottom plate are mounted a tactile push-button switch and a light source. No matter which press area is depressed, the slider is uniformly translated by the link mechanism to actuate the push-button switch. The link mechanism, the slider, the membrane sheet except conductor portions, and the pusher are formed of a light transmitting material.

Abstract: A signal under measurement is transformed into a complex analytic signal using a Hilbert transformer and an instantaneous phase of this analytic signal is estimated. A linear phase is subtracted from the instantaneous phase to obtain a phase noise waveform. The phase noise waveform is sampled in the proximity of a zero crossing point of a real part of the analytic signal. A differential waveform of the sample phase noise waveform is calculated to obtain a differential phase noise waveform. An RMS jitter is obtained from the phase noise waveform, and a peak-to-peak jitter is obtained from the phase noise waveform.

Abstract: In a computer system, the controller of one or more primary data recording devices sends update information to the controller of one or more secondary data recording devices to maintain a remote copy of data stored on the primary data recording devices. The primary controller receives a command from a computer that specifies a prospective suspend time after which remote copy operation is to be suspended. After the suspend time passes, the primary controller stops sending the update information to the secondary controller and begins storing indicators of the updated information in cache memory. The primary controller may resume remote copy operation in response to a command received from the computer by first entering into a pending mode of operation in which cached indicators are used to identify update information that must be sent to the secondary controller to resynchronize the remote copy. When the information for all cached indicators has been sent, normal remote copy operation may be resumed.

Abstract: Data output from a semiconductor device under test and a reference clock output therefrom in synchronization with the data are sampled by slightly phased-apart multiphase strobe pulses. The phases of points of change of the output data and the reference clock are obtained from the sampled outputs, then the phase difference between them is measured, and a check is made to determine if the phase difference falls within a predetermined range, thereby evaluating the semiconductor device under test on a pass/fail basis.

Abstract: In a method of lossless processing of an integer value signal in a prediction filter which includes a quantiser, a numerator of the prediction filter is implemented prior to the quantiser and a denominator of the prediction filter is implemented recursively around the quantiser to reduce the peak data rate of an output signal. In the lossless processor, at each sample instant, an input to the quantiser is jointly responsive to a first sample value of a signal input to the prediction filter, a second sample value of a signal input to the prediction filter at a previous sample instant, and an output value of the quantiser at a previous sample incident. In a preferred embodiment, the prediction filter includes noise shaping for affecting the output of the quantiser.

Abstract: There is provided a swing type multi-way switch in which light irradiated from a light source built therein sufficiently illuminates substantially all over the rear surface of an operation knob. The switch comprises: a box-like operation knob; a square frame-shaped holder disposed in the inside of the operation knob; a case having an outer square tube-like member and an inner square tube-like member coaxially formed; and a base plate on which a light source and a plurality of switch elements are to be mounted. The operation knob is rotatably supported by the holder disposed in the inside of the operation knob, and the holder is rotatably supported by the inner square tube-like member of the case by a second axis for rotating movement orthogonal to the axis for rotating movement of the operation knob.

Abstract: Differential amplifiers and phase-splitting circuits incorporate voltage-transfer or current-transfer devices of different conductivity types that are connected in series between two different potentials. The current flowing through the two devices is responsive to input signals provided to either or both of the devices. The two devices may be of different types such as bipolar transistors, field-effect transistors, vacuum tubes, triacs and silicon controlled rectifiers. Specific implementations include amplifiers with very low input capacitance and very low second harmonic distortion, multi-state memory cells, detectors and voltage regulators.

Abstract: An optical transmission system is provided, which permits high-precision optical transmission of a signal even if the signal has a high accurate timing, an indefinite period, and a DC component. The transmitting side is provided with a rise edge detecting circuit 1 for detecting the rise edge of a transmitting signal waveform, a transmitting pulse generating circuit 2 for generating a transmitting pulse signal (b) constituted by a pair of opposite-polarity pulses inverting their polarities at the detected timing, and a light intensity modulation circuit 3 for generating a light intensity modulated signal (c) based on the pulse signal (b). The receiving side is provided with an AC-coupled receiving circuit 4 for receiving the light intensity modulated signal (c) and extracting therefrom only an AC component, and a discrimination circuit 5 for discriminating the rise timing from the received signal.

Abstract: A signal under measurement is transformed into a complex analytic signal using Hilbert transformation to estimate an instantaneous phase of the signal under measurement from the complex analytic signal. A least mean square line of the instantaneous phase is calculated to obtain a linear instantaneous phase of the signal under measurement, and a zero-crossing timing of the signal under measurement is estimated using an interpolation method. Then a difference between the instantaneous phase and the linear instantaneous phase at the zero-crossing timing is calculated to estimate a timing jitter sequence. A jitter of the signal under measurement is obtained from the jitter sequence.

Abstract: A lossless encoder and decoder are provided for transmitting a multichannel signal on a medium such as DVD-Audio. The encoder accepts additionally a downmix specification and splits the encoded stream into two substreams, such that a two-channel decoder of meagre computational power can implement the downmix specification by decoding one substream, while a multichannel decoder can decode the original multichannel signal losslessly using both substreams. Further features provide for efficient implementation on 24-bit processors, for confirmation of lossless reproduction to the user, and for benign behaviour in the case of downmix specifications that result in overload. The principle is also extended to mixed-rate signals, where for example some input channels are sampled at 48 kHz and some are sampled at 96 kHz.

Abstract: There is provided a magnetic sensor switch in which its magnetic sensor is responsive to approach of a magnet to turn its electrical switch on or off. A cylindrical magnetic sensor having magnetic poles contrary to each other at opposite ends thereof is mounted for rotation in clockwise and counter-clockwise directions. An auxiliary magnet is movably mounted on a longitudinal extension line of the magnetic sensor when the magnetic sensor is in the horizontal position so that the auxiliary magnet provides an attracting force and a repulsive force to the magnetic sensor to rotate it in one direction. The movement of the magnetic sensor is transmitted to a movable contact piece through a driving member to rotate the movable contact piece in one direction depending upon the rotation of the magnetic sensor. The movable contact piece is provided with a pair of contact blades one of which is contacted with one of a pair of fixed contact pieces disposed in opposition to the corresponding contact blades.

Abstract: In a triangular-sectioned prism 11 having a first plane 11a opposite an end face of an optical fiber 12, a second plane 11b opposite a light receiving element 13 and a third plane 11c which reflects received light 21 incident thereon from the optical fiber 12 toward the second plane 11b and transmits transmission light 22 emitted from a light emitting element toward the first plane 11a, a cylindrical member 32 of a refractive index larger than that of the prism 11 is embedded in that area of the prism 11 which is opposite the end face of the optical fiber 12. The cylindrical member 32 effectively suppresses the leakage therefrom of light, providing increased optical coupling efficiency as compared with that achievable by use of a mere prism structure.

Abstract: A sampling digitizer comprises a sampling head 11, a clock generator 12, a digitizer 13 and a trigger circuit 14. A clock signal from the clock generator is also supplied to a delay element 15, and a change-over switch 16 switches from an output from the delay element 15 to a clock signal which does not pass through the delay element 15 to feed the sampling head 11 in response to a trigger signal from the trigger circuit.

Abstract: In a substrate carrying optical devices housed in a case, there are formed positioning parts for defining the positions of optical axes of the optical devices. Flexible optical waveguides are provided which are fixedly held at one end in the positioning parts and connected at the other end to an optical connector ferrule mounted in the case, and deviations from proper alignment between the optical axes of the optical devices and the axes of optical fiber receiving holes of the optical connector ferrule are accommodated by deformation of the flexible optical waveguides.

Abstract: A clock signal xc(t) that has been converted into a digital signal is transformed into a complex analytic signal zc(t), and an instantaneous phase &THgr; of the zc(t) is estimated. A linear phase is removed from the &THgr; to obtain a phase noise waveform &Dgr;&phgr;(t). The &Dgr;&phgr;(t) is sampled at a timing close to a zero crossing timing of the xc(t) to extract the &Dgr;&phgr;(t) sample. A root-mean-square value &sgr;t of the &Dgr;&phgr;(t) samples is obtained, and a differential waveform of the extracted &Dgr;&phgr;(t) samples is also obtained to obtain a period jitter Jp. Then a root-mean-square value &sgr;p of the Jp is obtained to calculate a correlation coefficient &rgr;tt=1−(&sgr;p2/(2&sgr;t2)). If necessary, an SNRt=&rgr;tt2/(1−&rgr;tt2) is obtained. The &rgr;tt and/or the SNRt is defined as a quality measure of a clock signal.