Audio system for vehicle

• US 5,218,643 A
• Filed: 05/12/1992
• Issued: 06/08/1993
• Est. Priority Date: 10/29/1991
• Status: Expired due to Fees

• Current Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Original Assignee: Pioneer Electronic Corporation (Pioneer Corporation)
• Inventors: Nagashima, Akira
• Primary Examiner(s): Isen, Forester W.
• Application Number:
  US07/881,655
• Time in Patent Office: 392 Days
• Field of Search: 381/86, 381/98, 381/102, 381/103, 381/28
• US Class Current: 381/86
• CPC Class Codes: H03G 9/02 in untuned amplifiers

Abstract

An audio system for a vehicle wherein the feeling of a passenger on the rear seat of the vehicle in listening to sound can be improved only by operation of a sound volume switch of a manually operating section without the necessity of operation of any other switch. A microcomputer detects an attenuation amount from an operating section and outputs to an equalizer, when the attenuation amount is lower than a predetermined value, a medium and high frequency sound region controlling signal for attenuating sound in the medium and high frequency sound regions in a substantially inversely proportional relationship at least to the attenuation amount. A plurality of rear loudspeakers receive the medium and high frequency sound region controlling signal from the equalizer and output sound of an attenuation information signal wherein sound in the medium and high frequency sound regions is attenuated.

Claims

1. An audio system for a vehicle, comprising:

a signal source for outputting an information signal;

an electronic volume for attenuating the information signal from said signal source in accordance with an attenuation signal and outputting an attenuation information signal obtained by the attenuation;

a plurality of front loudspeakers for outputting sound of the attenuation information signal from said electronic volume;

an equalizer for attenuating components for medium and high frequency sound regions of the attenuation information signal from said electronic volume in accordance with a medium and high frequency sound region controlling signal;

a plurality of rear loudspeakers for outputting sound of the attenuation information signal from said equalizer;

operating means for manually designating an attenuation amount; and

controlling means for detecting an attenuation amount from said operating means to output an attenuation signal to said electronic volume and for outputting to said equalizer, when the attenuation amount from said operating means is lower than a predetermined value, a medium and high frequency sound region controlling signal for attenuating sound in the medium and high frequency sound regions in a substantially inversely proportional relationship to the attenuation amount.

2. An audio system for a vehicle as claimed in claim 1, wherein said controlling means detects an attenuation amount from said operating means to output an attenuation signal to said electronic volume and outputs to said equalizer, in response to the attenuation amount, a medium and high frequency sound region controlling signal for varying at least the cut off frequency of said equalizer.

3. An audio system for a vehicle as claimed in claim 2, wherein said equalizer includes a plurality of low-pass filters and switching means for selecting one of said low-pass filters.

4. An audio system for a vehicle as claimed in claim 1, wherein said electronic volume includes a front electronic volume and a rear electronic volume which attenuate the information signal from said signal source in accordance with a front attenuation signal and a rear attenuation signal, respectively, and output a front attenuation information signal and a rear attenuation information signal respectively, and said audio system for a vehicle further comprises a second equalizer for attenuating components for a low frequency sound region of the attenuation information signal from said front electronic volume in accordance with a low frequency sound region controlling signal and outputting the attenuated attenuation information signal to said front loudspeakers, said controlling means outputting to said second equalizer, when the attenuation amount from said operating means is lower than the predetermined value, a low frequency sound region controlling signal for attenuating sound in the low frequency sound region in a substantially inversely proportional relationship to the attenuation amount.

5. An audio system for a vehicle as claimed in claim 1, wherein said electronic volume is a manually adjustable volume and said equalizer is operatively coupled to said volume, and further comprising a fader connected to said volume such that the attenuation information signal from said volume is transmitted to said front loudspeakers and said equalizer.