Abstract: An audio signal reproduction device of the invention has a seventh-order delta-sigma modulation circuit that receives a PCM signal and that performs delta-sigma modulation on the PCM signal, a PWM circuit that performs pulse width modulation on the signal outputted from the seventh-order delta-sigma modulation circuit to produce a one-bit digital signal, a switching amplifier that converts the one-bit digital signal into an analog signal and that then amplifies it, and a low-pass filter that eliminates high-frequency components of the analog signal. This configuration permits size and weight reduction.

Abstract: This invention is an anti-theft system that is capable of preventing theft of a vehicle-mounted device, and improving the convenience to a user. This invention creates current-position information for a vehicle that indicates the current position of the vehicle, and projects the created current-position information for the vehicle on map information that was stored beforehand, and when the current-position information for the vehicle matches specified position information that is created based on arbitrary conditions set by the user, it makes it impossible to detect a vehicle-mounted device that can seen from outside the vehicle.

Abstract: An audio signal reproduction device of the invention has a seventh-order delta-sigma modulation circuit that receives a PCM signal and that performs delta-sigma modulation on the PCM signal, a PWM circuit that performs pulse width modulation on the signal outputted from the seventh-order delta-sigma modulation circuit to produce a one-bit digital signal, a switching amplifier that converts the one-bit digital signal into an analog signal and that then amplifies it, and a low-pass filter that eliminates high-frequency components of the analog signal. This configuration permits size and weight reduction.

Abstract: To record and reproduce appropriately video signals of PAL system as still picture in a magnetic tape recording and reproducing apparatus. As still picture data, video signals for one field or two fields of PAL system recorded in a magnetic tape after once stored in memories at the time of recording are read out when reproducing and stored simultaneously once in the memories. When storing the still picture data for one field, the still picture data of one field, and the still picture data for one false field which excludes the data of specific scanning lines from the still picture data are repeatedly read out from the memories. When storing the still picture data for two fields, the still picture data for the two fields, and the still picture data for two false fields which excludes the data in specific scanning lines from the still picture data are repeatedly read out from the memories, so that the number of scanning lines in phase face to face in the still picture data may be an even number.

Abstract: A digital audio tape recorder memory or a DAT memory includes a buffer memory for absorbing the operating speed difference between the computer and the DAT memory, and a control circuit for controlling the buffer memory. This buffer memory includes a plurality of addressable sections. The control circuit causes the input and output data to and from the computer to be written into and read out from the buffer memory to synchronize the transmission and reception between the two devices. The addressing of the buffer memory by the control circuit is controlled from section to section to simplify the control circuit.

Abstract: Generally in the case that a rotary head type digital audio tape recorder is used as an auxiliary storage of a computer or the like, the R-DAT reads recorded data immediately after the data is recorded and inspects its recording state by comparing it with the original recorded data, and if the recording state is inferior, namely, if an error is detected, the R-DAT records the data again in order to improve reliability of the recorded data. Since an R-DAT according to the present invention re-records the original data of the error-detected data plural times, the R-DAT allows for reproduction of the data re-recorded immediately after, or further thereafter the error-detected data, in the case that the first re-recorded data cannot be reproduced correctly.

Abstract: An apparatus for controlling an articulated robot comprises coordinate transforming portions (5 to 8 and 18) and a calculating portion (9) for equation of motion. The coordinate transforming portions (5 to 8 and 18) perform coordinate transformation between the Cartesian coordinate system and the articular system with respect to the position data, speed data, acceleration data and force data. The coordinate transforming portions (5 to 8 and 18) are respectively formed of hardware and accordingly, the calculation speed therein is extremely high as compared with the case using software. The calculating portion (9) for equation of motion solves the inverse problem of an equation of motion using the speed data (d.alpha.) and acceleration data (d.sup.2 .alpha.) in the articular coordinate system, whereby predictive control is performed. The calculating portion (9) for equation of motion is also formed of hardware and accordingly, the calculation speed therein is extremely high.

Abstract: An automatic welding apparatus comprises a welding torch including an electrode and a fixture for fixing a workpiece, and a relative positional relation of the welding torch and the workpiece fixture is controlled such that the electrode of the welding torch is moved to trace the welding line of the workpiece, whereby automatic welding is achieved. The automatic welding apparatus further comprises a switch for selectively connecting the electrode of the welding torch to a welding power supply or a detecting power supply, and a sensor for sensing a current or a voltage between the electrode and the workpiece when the electrode is switched to the detecting power supply, whereby the relative positional relation between the welding torch and the workpiece is detected in response to the output of the sensor, and thus a welding point or a welding line is sensed.