CA2822822A1

CA2822822A1 - Stereo headset with noise suppression

Info

Publication number: CA2822822A1
Application number: CA2822822A
Authority: CA
Inventors: Vladimir Walter Kukurudza
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-08-02
Filing date: 2013-08-02
Publication date: 2015-02-02
Anticipated expiration: 2033-08-02
Also published as: CA2822822C

Abstract

A headset, having ear phones for respective ears, and reproducing audio signals in a stereophonic manner, and comprising; two ear components; a head band connected between the two ear components, by which the two ear components can be fitted over the ears; a high frequency speaker and a low frequency speaker in each ear component; a signal separator circuit in each ear component; and, two bifilar noise reduction coil assemblies.

Description

FIELD OF THE INVENTION
The invention relates to a headset for enjoying audio sounds and in particular to a stereo headset for enjoying high fidelity audio sound signals, incorporating stereophonic speakers and signal separation components and electronic noise reduction circuits in both sides of the headset.
BACKGROUND OF THE INVENTION
Headsets for listening to audio signal sounds have been available since almost as early as the invention of radio, or morse code. Most headsets simply incorporate a simple miniature speaker in each side. Each speaker receives exactly the same audio signal and attempts to reproduce the signal in both sides simultaneously. Generally speaking the quality of such miniaturized speakers is not as great as could be desired.
The speakers receive audio signals containing the full spectrum of wave lengths from low to high. It has been considered to be impractical to incorporate speakers similar to full size speaker systems which incorporate two or three speakers, and a cross over circuit, which systems can then reproduce high, medium and low frequencies in a stereophonic manner. Cross over circuits could only be designed with difficulty in such headsets.
Even with such a cross-over there would still be noise signals generated in the circuit.
Clearly it is desirable from the viewpoint of both clarity, and also enjoyment of the quality of the sound signals, that sounds shall be reproduced in such headsets in a stereophonic manner. Preferably such result will be achieved by providing a headset which is of compact design and not excessively large or cumbersome. In addition, it is desirable to provide such a system which can be made in an economical manner, and which is as far as possible free from servicing problems, which might result from providing multiple frequency speakers in opposite sides of a headset. It is well known that the fidelity of simple speakers is impaired by the development of electronic noise signals generated in the speaker coils themselves. Clearly it is desirable if possible to provide a headset with stereophonic speaker systems for each ear and in which the signal separation circuits incorporate circuits which reduce or substantially eliminate the electronic noise generated within the circuits, so as to greatly increase the clarity of reproduction.
BRIEF SUMMARY OF THE INVENTION
With a view to providing a headset, having ear phones for respective ears, and reproducing audio signals in a stereophonic manner, the invention comprises:
two ear components; a head band connected between the two ear components, by which the two ear components can be fitted over the ears; a hi frequency speaker and a low frequency speaker in each ear component; a signal separator circuit in each ear component; and, two bifilar noise reduction coil assemblies in each ear component.
Preferably, the invention provides such a head set, wherein there are two such speakers namely a high frequency speaker and a low frequency speaker in each ear component, and a respective noise reduction assembly in respective ear component which effectively suppress electronic noise developed in the system.
Preferably the invention further provides such a head set wherein the high frequency speaker and the low frequency speaker are secured on a common mounting plate, and in which the common mounting plate is secured to the interior of the headset itself.

2 Preferably, the invention provides such a headset in which the mounting plate defines a central opening and a series of radial arms extending inwardly and supporting an inner mounting disc, and wherein the high frequency speaker is mounted on the mounting disc on one side of the mounting disc, and wherein the low frequency speaker is mounted on the opposite side spaced from the high frequency speaker.
Preferably the invention provides a circuit support member separate from the mounting plate wherein the noise reduction and signal separation circuit is mounted on the support member.
Preferably each ear phone has a shell defining a hollow space behind the low frequency speaker...
The various features of novelty which characterize the invention are pointed out with more particularity in the claims annexed to and forming a part of this disclosure.
For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
IN THE DRAWINGS
Figure 1 is a perspective illustration of a typical headset illustrating the invention;
Figure 2 is an exploded view of one ear component of Figure 1;
Figure 3a is a perspective of a bifilar coil noise reduction and signal separator, in a protective housing;

3 Figure 3b is an end elevation of Figure 313;
Figure 3d is a side elevation of Figure 3b;
Figure 3e is a circuit diagram of the separator circuit;
Figure 4 is a schematic diagram showing the arrangement of a bifilar coil; and Figure 5 is a side elevation of a bifilar coil, partly cut away.
DESCRIPTION OF A SPECIFIC EMBODIMENT
The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word "exemplary" or "illustrative" means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" or "illustrative" is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms "upper", "lower", "left", "rear", "right", "front", "vertical", "horizontal", and derivatives thereof shall relate to the examples as oriented in the drawings. Furthermore, thereis no intention to be bund by an expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments (examples), aspects and / or concepts defined in the appended claims.

4 I

Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. It is understood that "at least one" is equivalent to "a".
Referring first of all to Figure 1, it will be seen that this illustrates what appears to be at first sight to a conventional headset, having two ear phone components (10 and 12) , and a resilient band (14) connecting the two ear components and a wire harness (16) , which would be adapted to be connected to a source of audio signals (not shown). The resilient band (14) is flexible, and permits the two ear components (10 &
12) to be spread apart and fitted over the head. The resilient band (14) incorporates sliders (18) which enable the user to extend the band or retract it, depending upon the size of the head. Each of the ear components (10 & 12) is substantially identical with its main components being similar.
Thus each ear component has a housing shell (20) (Fig 2) supported in a generally semi circular shaped spring support (22). Studs (24) engage recesses (26).
Supports (22) are connected to the resilient band (14). The shell (20) is of generally cup shaped formation, typically being formed of thermo plastic material in known manner.
A wire harness opening (28) (in one shell) permits wire harness (16) to enter the shell. Shell (20) has an oval shape and a circumferential rim (29).
A hole (30) is formed in shell (20), for reasons to be described .below.
A harness extension wire (32) (Fig 1) extends from the one shell, around the resilient band (14), and in to the opposite shell.
Each ear component (10 & 12) is as explained above, substantially identical, although with minor variations. Accordingly only the contents of one such ear component will be

5 described, it being understood that the same components will be contained in the opposite component.
Within the shell (20), an annular circuit support member (34) is secured by screws (36), received in suitable screw receiving recesses in the shell. The support member (34) has a collar (38 ) formed thereon, around an opening, and a notch (40 ) is formed in the collar (38). Collar (38) forms a funnel, allowing low frequency sound waves to flow in and out of the shell (20).
A speaker mounting plate (42) is provided, which will also be secured by screws (36).
Speaker mounting plate (42 ) defines a central opening and has a spider formation defining spokes (44) and a central support disc (46). A high frequency speaker (48) is mounted on the forward side of the disc (46) . A low frequency or bass speaker (50) is mounted adjacent the rearward side of the disc (46).
Forward and rearward simply refer to delivery of sound to the ear of the user.
An annular ear pad (52) , encloses the exterior of the circuit support member ( 34) and the speaker mounting plate (42) and fits directly over the rim (29) of the shell (20) . The pad is typically made of resilient soft material such as foam rubber or synthetic plastic.
The high frequency speaker (48) and the low frequency speaker ( 50) are connected to a noise reduction and signal separator circuit (54). The circuit (54) is secured in the notch (40 ) of the circuit support member ( 34) by a screw.
The circuit (54) has a housing (56) (Fig 3), and a circuit board (58), held together by means of screw (60). Each circuit board (58 ) supports noise reduction assemblies namely a low frequency bifilar coil (62) and a high frequency bifilar coil (64). Each circuit board also supports a high frequency input capacitor ( 66) and high frequency

6 return capacitor (68).
It will be understood from the following explanation that bifilar coils are coils which are two lengths of wire, wound together side by side, carrying signals in the same direction.
Bifilar coils are described in U.S. Patents:
11/260,458 (pending ; 08/555,187 - Patent 5615272; 08/784,065 - Patent 5917922;
07/917985 - Patent 5373563;
Such a bifilar coil is illustrated in Figures 4 and 5.
As will be seen from Figure 4, a bifilar coil is two lengths of wire, which have been wound together side by side on a common core forming an input coil (IC) and a return coil (RC).
Figure 5 merely illustrates the way in which the input and return coils are wound together, with the windings of the two coils being side by side on a common core.
The input coil is connected to receive the input signal from the signal source. The signal passes through the input coil (IC) and then into the speaker (Sp) and then returns from the speaker to the return coil (RC) and then to ground. It will thus be seen that the signals pass through both the input coil and the return coil in the same direction. However the return signal will be slightly delayed relative to the input signal due to its passage through the speaker coil. This ensures that the unwanted electromagnetic fields created by the passage of the signals through the speaker and the two coils are substantially suppressed thus reducing electronic noise.
For the sake of simplicity the circuit board illustration , (Figure 3e), illustrates what appear to be four separate coils namely a low frequency input coil (62a) and a low frequency return coil (62b), and a high frequency input coil (64a) and a high frequency

7 return coil (64b). In fact however, the coils form two bifilar coils illustrated in Figures 3b, 3c and 3d namely low frequency bifilar coil (62) and high frequency bifilar coil (64).
The design of the circuit board ( Fig 3e) is of such a compact nature that the entire circuits consisting of high frequency bifilar coil and low frequency bifilar coil and the two capacitors can all be contained within a housing (56) (Figure 3d.) It will be noted that the two bifilar coils (62, 64) are secured to the board, with their central axis lying parallel to the board. This provides for secure attachment of teach coil at each end, thereby ensuring that the coils remain securely fastened notwithstanding the development of electromagnetic fields around them.
On the other side that the two capacitors are supported on the board on end, so that their central axis are normal to the board, thereby enabling the provision of the circuit which is compact and easily contained within the housing and secured within the interior of each ear component.
The function of the capacitors in the high frequency side of the circuit is simply to block the incoming low frequency signals from passing through the high frequency bifilar coils (64). This provides effective separation pf the high frequencies from the low frequencies.
An annular flexible resilient pad (52) is provided and adapted to rest against the head of the wearer around the ear. In this way, extraneous exterior sounds are reduced or excluded as far as possible.
The operation of the foregoing circuits is believed to be self evident and proceeds by the supply of a regular audio signal to wire harness (16 ) and to the first ear component.
The signal is communicated to the second ear component by the harness extension

8 (32). The operation in both ear components is the same.
The input signal is supplied to the circuit board (58)( Fig 3e) and is communicated to the input side (62a) of the respective low frequency bifilar coil (62 ) and the input side (64a) of the high frequency bifilar coil (64). The signals from the input side (62a) of the low frequency bifilar coil (62), pass directly to the speaker (50).
From the speaker (50 ) the low frequency signals pass back through the return side (62b) of the low frequency bifilar coil (62) and to ground.
The signals from the input side (64a) of the high frequency bifilar coil (64), pass through input capacitor (66) to the speaker ( 48) The high frequency signals, after passing through the speaker (48) pass back to the return capacitor (68 ) and then through the return side (64b) of the high frequency bifilar coil (64), and then to ground.
As the sounds in the low frequency speaker (50) are reproduced, low frequency sounds will flow rearwardly ie. away from the ear of the user, into the hollow space of the shell where the sounds can reverberate and develop full volume and will then flow back through the funnel defined by the collar. They will pass around the spokes (44), around the high frequency speaker (48) and into the ears of the user. The high frequency sound signals reproduced in the high frequency speaker (48) will pass directly to the ear of the user. The net result is a great increase in clarity, since the low frequency sounds and high frequency sounds are reproduced in separate speakers, resulting in three-dimensional sound.
The resulting sounds will be considerably amplified in comparison with the sounds generated by conventional circuits and speakers. This is because the sound waves as

9 they pass through their respective bifilar coils, are formed into regular wave forms with abrupt definition.
In addition the noise signals normally produced by audio signals passing through speaker coils at the lower frequencies will be greatly reduced, by the cooperation of the input and return sides of the low frequency bifilar coil with one another.
Similarly, the noise normally created by the high frequency signals going the through speaker coil, although of a less aggravating nature than the low frequency noise signals, will also be greatly reduced by passage of the high frequency signals through the high frequency bifilar coils.
The shell (20) provides a chamber in which the low frequency sounds can resonate.
The hole (30) functions to allow greater resonation. This result is a greater volume and greater clarity of sound. The sounds are not merely stereophonic, but, since they are communicated to each ear simultaneously, the sound appears to surround the listener.
The hole (30) can optionally be covered over (eg. by tape) if the user desires less low frequency or bass sound development.
The foregoing is a description of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims.
')0

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A headset, having ear phones for respective ears, and reproducing audio signals in a stereophonic manner, and comprising;
two ear phone components;
a head band connected between the two ear components, by which the two ear components can be fitted over the ears;
a hi frequency speaker and a low frequency speaker in each ear component;
a signal separator circuit in each ear component; and, respective high and low frequency noise reduction bifilar coil assemblies in each separator circuit.

2. A headset as claimed in claim 1, including high frequency input and return capacitors connected to respective high frequency bifilar coil assemblies in each separator circuit.

3. A headset as claimed in claim 2 including a circuit support member in each ear component, and each said signal separator circuit being secured to a respective said circuit support member.

4. A headset as claimed in claim 3 including a speaker support plate, a central opening defined by said speaker support plate, a central speaker support disk mounted in said support plate, and said high frequency speaker being mounted to a forward side of said speaker support plate and said low frequency speaker being mounted adjacent the rear side of said speaker support plate in each said ear component.

5. A headset as claimed in claim 4 including radial spider members connecting said central speaker support disk to said speaker support plate.

6. A headset as claimed in claim 5 including an opening in said circuit support member, a collar around said opening, and a notch formed in said collar receiving a respective said signal separator circuit therein.

7. A headset as claimed in claim 6 including an audio signal harness connection in one of said ear components, for connecting to an audio signal source, and a harness extension extending from said first ear component through said headband to said second ear component.

8. A headset s claimed in claim 2 wherein said high frequency bifilar coil assemblies define a high frequency input coil and a high frequency return coil, and wherein said high frequency input capacitor is connected between said high frequency input coil and said high frequency speaker, and wherein said high frequency return capacitor is connected between said high frequency speaker nd said high frequency return coil.

9. A headset as claimed in claim 1 wherein each ear component includes a shell defining a resonating chamber.

A headset as claimed in claim 9 including a hole formed in each said shell.

11. A headset as claimed in claim 6 wherein said collar defines a funnel, communicating sound waves into and out of said shell.

12. A headset as claimed in claim 8, and including a circuit board, and wherein said high frequency and low frequency bifilar coils are attached to said circuit board with their respective central axis aligned with the plane of the circuit board, and including input and return capacitors, wherein said capacitors are supported on said board with their respective central axis normal to said board.