| 摘要 |
PURPOSE:To change automatically a sound image with a control of the sound volume to maintain an optimum state for a controller for a mobile audio device, by controlling the sound volume of 2 speakers provided in a car in accordance with the seating state at the seat, the level of the external weight and the time of continuation respectively. CONSTITUTION:The presence or absence of a fellow rider at the left seat is supplied to a CPU17 by means of seat switch 1 and 2 provided at the front and rear parts of the left side. The output of a car stereo set 3 is amplified 4 and 5 to drive speakers 6 and 7 and at the same time rectified 10 and 11 through HPF8 and 9 to be fed to the CPU17 after an A/D conversion. The voice of the conversation is fed through a mike 12 provided near a handle and amplified 13 and rectified 15 with the engine noise eliminated through HPF14 to be fed to the CPU17 after an A/D conversion. The CPU17 controls the sound volume of the right and left speakers by the presence or absence of a fellow rider to shift the sound image. Then the amplification factor is controlled for amplifiers 4 and 5 respectively in response to the sound volume of the conversation, and the level of the speaker sound volume is controlled so as not to disturb the conversation. In such way, the optimum state is maintained for a car stereo set. |
