Yamaha Corporation

Hamamatsu-photonics K.k.

Masayoshi Sahara

Akira Miki

Kimitsugu Nakamura

Junichi Takeuchi

Chiyoshi Okuyama

Atushi Ishikawa

A sound reproducing apparatus which can be relatively inexpensive as a whole and also be simple in construction with reduced wiring even in the case where many speakers are used. Pulse-width modulated (PWM) pulses are generated based on respective audio signals for multiple-channel speakers. PWM pulses are time-division multiplexed and amplified, and then output as digital driving signals. The multiple-channel speakers are selectively turned on/off such that the digital driving signals are supplied to the respective multiple-channel speakers of corresponding channels.

Sound reproducing apparatus

Support electrodes are provided for individually supporting a plurality of dynodes arranged inside of a vessel of an electron tube, such as photomultiplier tube. A black spacer formed from a ceramic material is disposed between the support electrodes. The black spacers are formed with elemental composition having content of MnO suppressed to 3 wt % or less. Current leaks, which are the cause of dark current, and abnormal generations of light during photomultiplication can be reduced, thereby improving the signal-to-noise ratio of the electron tube.

Electron tubes using insulation material containing little alkali metal

Growing community of inventors

Hamamatsu, Japan

Masayoshi Sahara