US4558460A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Audio apparatus for vehicle
Assignee: LMRC ACQUISITION Co C/O OLIVER RUBBER COMPANY 1200 65TH ST A CORP OF TX
•
Filing: 1984-06-12
•
Granted: 1985-12-10
•
Expires: 2004-06-12
Abstract
Abstract An audio apparatus for a vehicle is disclosed having an audio signal generator, an amplifier operatively connected to the generator for amplifying an audio signal received from the generator, a speaker for emitting sounds and which is driven by the amplifier, a vehicle speed detector, and a gain control operatively connected to the speed detector for generating a control signal and providing it to the amplifier, such that the control signal increases the gain of the amplifier according to an increase in the output of the vehicle speed detector.
Inventors
- 👤 Shuji Tanaka
- 👤 Shigehira Nakamura
- 👤 Tuneaki Sakamoto
- 👤 Yoshiaki Hirakata
- 👤 Tetsuo Yamagata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:17
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/32; B; B62; B62J; B62J45/00; B62J45/10; B62J50/00; B62J50/20; B62J50/21
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
196 words
An audio apparatus for a vehicle, comprising: means for generating an audio signal; amplifying means operatively connected to said generating means for amplifying an audio signal received from said generating means; sound emitting means for emitting sounds and which is driven by said amplifying means; means for detecting vehicle speed; and gain control means operatively connected to said speed detecting means for generating a control signal and providing it to said amplifying means, such that said control signal increases the gain of the amplifying means according to an increase in the output of said speed detecting means, wherein the output of said amplifying means, or the sound volume, is kept constant if the vehicle speed is below speed V 1 where V 1 is a predetermined, extremely low speed, and the output of said amplifying means is increased as the vehicle speed is increased above V 1 , and wherein said output of said amplifying means increases at a faster rate when the vehicle speed is above V 2 than when it is below V 2 where V 2 is a predetermined vehicle speed faster than V 1 and above which the wind noise greatly increases.
Claim 2
Dependent Claim
196 words
An audio apparatus for a vehicle, comprising: means for generating an audio signal; amplifying means operatively connected to said generating means for amplifying an audio signal received from said generating means; sound emitting means for emitting sounds and which is driven by said amplifying means; means for detecting vehicle speed; and gain control means operatively connected to said speed detecting means for generating a control signal and providing it to said amplifying means, such that said control signal increases the gain of the amplifying means according to an increase in the output of said speed detecting means, wherein the output of said amplifying means, or the sound volume, is kept constant if the vehicle speed is below speed V 1 where V 1 is a predetermined, extremely low speed, and the output of said amplifying means is increased as the vehicle speed is increased above V 1 , and wherein said output of said amplifying means increases at a faster rate when the vehicle speed is above V 2 than when it is below V 2 where V 2 is a predetermined vehicle speed faster than V 1 and above which the wind noise greatly increases.
Claim 3
Dependent Claim
23 words
The audio apparatus of claim 1, wherein said vehicle speed detecting means comprises means for generating vehicle speed pulses, and an integration circuit.
Claim 4
Dependent Claim
28 words
The audio apparatus of claim 1, wherein said gain control means comprises compensation circuit means for compensating gain characteristics of said amplifying means in relation to vehicle speed.
Claim 5
Dependent Claim
25 words
The audio apparatus of claim 1, wherein said gain control means has a manual adjusting means for adjusting the output of said gain control means.
Claim 6
Dependent Claim
35 words
The audio apparatus of claim 1, wherein said amplifying means comprises an amplifier adjustable in gain by a variable resistance, a gain control amplifier adjustable in gain by said control signal, and a power amplifier.
Claim 7
Dependent Claim
49 words
The audio apparatus of claim 2, wherein said vehicle speed pulse generating means comprises a magnet disposed on a wheel axle of the vehicle and a reed switch located promixal to said magnet, such that the rotation of the magnet causes said reed switch to be opened and closed.
Claim 8
Dependent Claim
16 words
The audio apparatus of claim 6, wherein said integration circuit comprises a resistance, capacitors and diodes.
Claim 9
Dependent Claim
23 words
The audio apparatus of claim 3, wherein said compensation circuit means comprises a first stage operational amplifier and a second stage operational amplifier.
Claim 10
Dependent Claim
15 words
The audio apparatus of claim 4, wherein said manual adjusting means is a variable resistor.
Claim 11
Dependent Claim
28 words
The audio apparatus of claim 4, wherein said gain control amplifier includes a negative feedback amplifier having a field effect transistor interposed in the negative feedback circuit thereof.
Claim 12
Dependent Claim
31 words
The audio apparatus of claim 4, wherein, when the output of said amplification means is increased, the output levels of the high and low bands of the sound volume are attenuated.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-09 | 1989-06-10 | 1989-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-09 | 1993-06-10 | 1993-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-09 | 1997-06-10 | 1997-12-10 | $7700.00 | Window Closed / Lapsed |