Abstract: A reception clock signal used for a data sampling unit to sample received data is generated by a reception clock generator based on a reference clock signal, which is generated by a reference clock generator based on a reference bit rate frequency. The reference bit rate frequency is produced by a reference oscillator which is controlled by a control voltage. The control voltage is generated by a phase difference-to-voltage converter depending on the phase difference, detected by the reception clock generator, between the timing of a change in the received data and the reference clock signal. If good reception sensitivity is not available due to a phase difference, then the phase difference-to-voltage converter generates a control voltage in a manner to eliminate the phase difference, and applies the generated control voltage to a variable capacitor connected to the reference oscillator for automatically adjusting the reference bit rate frequency.

Abstract: A vapor deposition apparatus and method in which pulse waveform light is applied to a sample sealed in a reaction chamber. The sample is exposed to gaseous material while the pulse waveform light is applied creating one or plural atomic layers. Alternate layers of plural substances or alternate multiple layers of plural substances can be formed by alternating the introduction of gaseous materials with the application of pulse waveform light.

Abstract: A repeater which is installed as measures for silent zones, which automatically compensates for a variation in a light loss caused by a difference in length among optical cables interconnecting a master device and a plurality of slave devices which are allocated and installed in an underground shopping center or the like. The master device and the slaves devices both have current detectors for detecting current values of O/E transducers which transduce received lights to electric signals. Based on the detected current values, gain control signals are applied to variable gain amplifiers to change their amplification factors so that the levels of output RF signals for transmission to a radio base station and a portable station have a prescribed value, thereby compensating for the variation in the light loss of the optical cables. The present invention greatly facilitates the installation of the repeater and additional installation of slave devices.

Abstract: A wafer transfer plate adapted to be disposed on a wafer transfer unit for transferring a wafer within a wafer manufacturing system, which comprises at least one wafer contact portion designed to be held in contact with the wafer as the wafer transfer plate is loaded with the wafer, a coated film being formed of a material which does not contain harmful elements and provided at a region including the wafer contact portion.

Abstract: A splashproof construction for a portable electronic device, comprising an electronic device main unit, and a battery pack to be mounted on the electronic device main unit, whereby one of either the electronic device main unit or the battery pack has a boundary surface formed along a combined surface and a peripheral edge and with a graded step with respect to the combined surface, and a guide rail provided adjacent to the boundary surface, and the other of either the electronic device main unit or the battery pack has a peripheral wall aligned with the boundary surface and a guide groove to be slidably engaged with the guide rail, or a bottom wall of the peripheral wall has a notch abutting on a lower surface of the graded step on the boundary surface, or a water-repellent sheet is provided at the bottom of the guide groove, or a seal plate made of a highly elastic material is provided either on an end surface of the battery pack abutted on the electronic device main unit at an end point of sliding when the

Abstract: A speech circuit is disclosed which solves the serious problem of the degradation of the articulation of received speech voice in conventional circuits and permits pleasant communications at places where the background noise level is high. The circuit has a construction in which an input signal from a microphone is attenuated in correspondence to the background noise level to form a sidetone signal and a received speech signal from a speech channel is amplified in correspondence to the background noise level to form a new received speech signal.

Abstract: A thermal treatment furnace for use with a semiconductor system is provided. The thermal treatment furnace includes a scavenger which sealingly encloses a lower end of a reaction tube so as to diminish gas leakage from the reaction tube.

Abstract: A speech coding transmission system is disclosed in which a coder of a differential coding system quantizes a difference between a predictive value from an adaptive predictor and an input speech signal by an adaptive quantizer in accordance with the level of the latter and to send out the resulting coded signal to transmission medium, and a decoder outputs a reproduced speech signal on the basis of a residual signal obtained by inversely quantizing a received coded signal with an inverse adaptive quantizer and a predictive value from an adaptive predictor. Both or either one of the coder and the decoder includes a comparator-attenuator which attenuates the amplitude of the input signal or reproduced speech signal to a value smaller than a predetermined threshold value and applies to the amplitude-attenuated speech signal to the adaptive predictor.

Abstract: In an improved image data transmission system, an image data partitioning unit is provided at the transmitter section to partition an input image data into a predetermined number of picture elements (blocks) so that same picture elements of the image data can be subject to source image encoding and forward error correction encoding. At the receiver section, picture elements in each of the data blocks are subject to error correction decoding and source image decoding. The receiver section is provided with an image data interpolator which works, when an transmission error is detected, to interpolate with a substitution data the data in a block in which the error has been detected or data in other block to which the error has been propagated as it is. After the interpolation, a reconstructed image data is delivered.

Abstract: Duplicate optical fibers connect between a base station controller and a radio base station for each route. The duplicate optical fiber is connected to each of the radio base stations for each route through a star coupler. The radio base stations are arranged in each of areas so that the radio base stations for different routes are arranged adjacent to each other.

Abstract: A voice decoding apparatus of an adaptive PCM coding system in which an auxiliary controller is provided between a controller and a prediction coefficient holder. The controller receives a voice activity detection flag b separated from a received demodulated signal a and, at the time of transition from the voice-active duration to the voice-nonactive duration and vice versa, outputs a reset signal d and a signal e indicating whether the voice activity detection flag is voice-active or voice-nonactive. The prediction coefficient holder extracts, from an ADPCM decoder for decoding a coded signal c, a prediction coefficient g, calculates and stores its average value for each frame and updates the old value with the new one and, at the time of transition from the voice-nonactive duration to the voice-active duration, outputs an immediately stored value h.

Abstract: A voice coding communication system in case of applying an adaptive differential PCM system in which a discontinuous transmitter is provided at the transmitting side to reduce its power consumption, transmission is suspended during a silent duration, and a pseudo-noise is generated at the receiving side and is used as the reproduced output during the silent duration. Discomfort is avoided in hearing the reproduced voice which is caused by the difference between the level of the pseudo-noise and the level of a background noise at the transmitting side.

Abstract: A voice encoder using a voice activity detector in which two predictive coefficients available from an adaptive predictor in the voice encoder are received for each sample of a input voice signal of the voice encoder. Average values of the predictive coefficients are calculated for each fixed period to decide whether the period is a voice active period or a voice non-active period as a result of comparing the average values with respective ranges of predictive coefficient threshold values predetermined from respective distributions of the two predictive coefficients. Voice active/non-active flags indicative of the voice active period and the voice non-active period are obtained for voice operate switch exchange of encoded of the voice encoder.

Abstract: A low-delay code excited linear prediction (LD-CELP) voice coding systemapplied to a scheme, in which the transmitting side interrupts transmission during the voice-nonactive period and the receiving side generates and outputs a comfort noise during the voice-nonactive period. At the transmitting side, when voice non activity is detected by the voice activity detector, the CN flag indicating the interruption of transmission is sent from the CN flag generator and shortly thereafter a background noise from the LD-CELP encoder is sent, followed by the interruption of transmission. At the receiving side, when the background noise following the CN flag is decoded by the LD-CELP decoder, the internal gain and synthesis filter coefficients are held, which is subsequently used to decode the input from the pseudo-noise generator.

Abstract: A speech encoder circuit of a waveform coding system. An analog speech input signal having coded data therein is received by a buffer and split into two branches. In a first branch the input signal is applied to a subtractor of an adaptive predictor to obtain a predicted residual signal subjected to an orthogonal transformation in a discrete cosine transform unit to convert the residual signal into a frequency domain of each of the frames of the individual blocks. An adaptive encoder in the first branch quantizes the frequency domain frame and branches its digital coded output to a branch for output to a transmission line and to a decoding branch. In the second branch of the split input signal a first sample delay element delays the split input signal for a given number of samples and a first attenuator in the second branch delays the output of the first sample delay element a given amount of each frame received for application to the subtractor for obtaining the predicted residual signal.

Abstract: A method of controlling the time constant of a filter for use in a radio receiver which receives a signal, transmitted from a transmitting station at a predetermined period, intermittently at the predetermined period and demodulates and delivers the received signal, a filter circuit having the time constant control function based on the method, and a radio receiver having the filter circuit. Preferably, the filter has its time constant switchable stepwise and specifically, parallel connection of capacitors or shortcircuiting of resistors is controlled by turning on/off switches.

Abstract: In the semiconductor manufacturing apparatus according to the present invention, there are provided a cassette stocker for accommodating wafer cassettes loaded with wafers, a reaction furnace provided with heating means, a reaction gas introducing means for introducing reaction gas into the reaction furnace, a gas discharging means for discharging exhaust gas in the reaction furnace, a boat for supporting wafers, a buffer cassette stocker for storing unprocessed wafers, a boat elevating means for inserting the boat into and retrieving the boat from the reaction furnace, a wafer transfer means for transferring wafers between the boat and the wafer cassette accommodated on the cassette stocker, and a wafer cassette transfer means for transferring wafer cassettes between the buffer cassette stocker and the cassette stocker, and the buffer cassette stocker is enclosed to provide an antioxidation area to prevent natural oxidation of the wafers in standby status.