Electrical audio signal processing systems and devices – Having microphone
Patent
1985-08-29
1988-04-26
Isen, Forester W.
Electrical audio signal processing systems and devices
Having microphone
381168, H04R 300
Patent
active
047410418
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to an apparatus for shielding an audio signal circuit.
BACKGROUND OF THE INVENTION
With a recent significant improvement in the reproduced sound quality of audio equipment, a large power supply circuit, which was once regarded to be of poor economy and technically disadvantageous, has once again been taken into account for audio equipment. The introduction of high-quality wire material, particularly oxygen-free copper wire, linear-large-crystal oxygen-free copper wire and the like, for a signal conductor of audio signal circuits, has come to be recognized as indispensable. Even when most of the generally known methods of improving the sound quality, as described above, are adopted, however, it is pointed out not only by those skilled in the art but also by a number of enthusiastic users, that there still remains a delicate difference between the original sound and the reproduced sound, which difference can be discriminated by the human ear.
Generally, in order to further improve the reproduced sound quality, various attempts have hitherto been made with respect mainly to the material used in the signal circuits of audio equipment, as described above. In addition, to prevent a signal current flowing through a signal conductor from being adversely affected by an external electromagnetic field, it has been considered that the signal conductor should be shielded as completely as possible by means of a shielding member. On the other hand, as far as the inventor knows, the fact that undesirable influences, such as increase in the distortion of the signal current, are caused by the shielding member has not been completely recognized, and therefore, no particular attention has been paid to eliminate the undesirable influences.
If it is assumed to be possible to practically neglect the undesirable influences caused by the external electromagnetic field, then it is obvious that the shield member can be dispensed with, and a bare signal conductor can be used. However, such a use environment is quite uncommon and extraordinary. Consequently, provision of a shielding member for the signal conductor of domestic-use audio equipment has been regarded as being indispensable.
DISCLOSURE OF THE INVENTION
The present invention is based on a practical recognition obtained as a result of a thorough investigation, which has been carried out with respect to the structure of the shielding member to be provided for a signal conductor, without prejudice of general knowledge. More particularly, the inventor has made a careful consideration on the mechanism whereby the shielding member affects the signal current, and concluded as follows. Namely, when a signal current flows through a signal conductor an electromagnetic field is formed around the circumference thereof, a secondary current is induced in the shielding member surrounding the signal conductor as a closed circuit within the cross section thereof. A secondary electromagnetic field is formed by the secondary current, in response to which a current is induced within the signal conductor and superimposed on the signal current. The induced current causes distortion, noise, and the like, to appear in the signal current, significantly impairing high-fidelity. On the basis of such a recognition, a trial has been made therein the shielding member in the cross section of the signal conductor is arranged so that a non-closed, discontinuous circuit is formed, except for locally closed circuit, which resulted in a complete elimination of the undesirable influence of the signal current caused by itself through the shielding member, while at the same time sufficiently maintaining the required shielding effect against the external electromagnetic field. Accordingly, the present invention is characterized in that a shielding member has an electrically discontinuous portion, and is provided outside a signal conductor for an audio signal circuit so as not to form a closed circuit within the cross section of the signal conductor.
BRIEF DES
REFERENCES:
patent: 1370731 (1921-03-01), Chase
patent: 2433181 (1947-12-01), White
patent: 2515333 (1950-07-01), Buffington
patent: 2718542 (1955-09-01), Lapsley
patent: 3291891 (1966-12-01), Sharp
patent: 4365109 (1982-12-01), O'Loughlin
Isen Forester W.
Stax Industries Limited
LandOfFree
Apparatus for shielding audio signal circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for shielding audio signal circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for shielding audio signal circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-825323