Abstract: A portable set of electronic drums includes individual drum units which are attached to different parts of a musician's body to provide maximum mobility for a stage performance. An impulse analyzer with each of the drum units processes the outputs of the drum units for transmission to a synthesizer which further processes and amplifies the resulting sound for application to a loudspeaker. A wire, radio transmitter or optical link may be employed to communicate the signals from the musician's body to a stationary synthesizer and loudspeaker. A percussion transducer in the musician's shoe may be employed to further increase the flexibility of the system. The output of the percussion transducer in the musician's shoe is combined with the outputs of the remaining drum units to create a total drum signal. In addition, the outputs of the shoe percussion transducer and the drum units may be employed to control the energization of optical emitters on the person of the musician.

Abstract: A battery check device for checking a battery of a camera having at least a storoboscopic flash unit is disclosed, which functions to compare a first reference time with a charging time of a main capacitor of the flash unit and, when the charging time becomes longer than the reference time, to indicate it as showing a considerable consumption of the battery. The device may have a second reference time which is longer than the first reference time so that the battery is disconnected from the flash unit when the charging time is longer than the second reference time. Thus, the battery can be checked even during a usage of the flash unit and prevented from being discharged completely.

Abstract: Disclosed in an optical distance measuring apparatus using an observation lens and at least one reflector. Thanks to the use of reflectors the whole size of the apparatus reduced at least one half of a conventional distance measuring apparatus, still assuring the same exactness as the conventional apparatus in measuring a distance.

Abstract: The present invention relates to a camera capable of both bulb and self-timer photography. The feature of the present invention is that the indicating mode for indicating the time of the self-timer is made different from that of the bulb exposure when bulb photography is carried out after a lapse of time of the self-timer, thus clarifying the change-over operation from the self-timer to the bulb exposure, whereby the remaining time of the self-timer and the time lapse of the bulb exposure can be indicated clearly.