A headset with an electrically conducting headband

Technical Field

The invention relates to a headset comprising a first earphone housing, a second earphone housing and a headband for attaching the headset to a user's head, which headband is electrical conducting in order to electrically connect the first earphone housing and the second earphone housing on the other side of the user's head.

Background Art

Headsets for communication and listening purposes can be embodied en may different ways. This disclosure relates to type of headsets that comprises a headband which extends from an earphone positioned at a user's ear, over the head to the opposite site of the head, where a second earphone is positioned at the other ear. Earphones and microphones require electric power and means to receive and transmit signals. With cordless headsets, power are supplied by batteries and signal transmitted via a transceiver. Corded headsets communicate via cords. If the headset is a so-called duo headset with two earphones, a cord can be bifurcated to define two pair of leads, where one pair is connected to one earphone and the other pair is connected to the other earphone. Another solution is to connect the cord to only one earphone, and connect the two earphones via conductors running along the headband. This solution is normally more comfortable for the user as he only has to manage a single cord whereby the risk of entanglement is reduced. Cordless headsets with two earphones normally comprise a single wireless transceiver in on of the earphones, whereby an electrical connection must be established between the two earphones.

Headbands for headsets are normally adjustable so that the headset can be adjusted to the size of the user's head. They can therefore comprise individually pieces which are telescopically connected, such that the length of the headband can be adjusted to the size of the user's head. This can lead to challenges regarding the conductors connecting the two earphones. They are often embodied as flexible cords which are fixed to parts of the headband but comprise loop like parts bridging the parts which are moved way from each other or closer to each other when the headband is adjusted. These loop-like parts can be provided outside or inside the headset construction. If they are provided outside they must be sturdy to withstand wear and this may destroy the overall design of the headset. If they are encapsulated in the headset construction, precautions must be taken to avoid jamming or squeezing of the cords.

US 3,356,797 discloses a headset comprising two earphones and a headband, where each end of the headband comprises a pair of parallel bare metal rods which can slide in grooves in the earphones which grooves comprise spring contacts. By sliding the rods in the grooves the headband can be adjusted to the size of the user's head. A problem with this headset is that the rods are non-insulated, whereby short circuit is a risk. It is also problematic that the user easier can get electric shock if a lightening strikes a phone line and travel to the user.

US 5,185,807 discloses a headset comprising two earphones and a headband, where an external cord attached to the outer side of the headband connects the two earphones.

A headset sold under the brand Jabra BIZ 2400 Duo comprises two earphones, and a headband connecting the two earphones. The headband, which is somewhat C-shaped, comprises a first headband housing attached to the first earphone and a second headband housing attached to the second earphone housing. A headband part interconnects the two headband housings and is slidably received in the headband housings such that the length of the headband can be adjusted to the size of the user's head. Two thin wires run in grooves in the headband part, through the headband housings to the earphones, where excessive wire is "accumulated" when the headband is adjusted to a size that is smaller than the most extracted size.

Disclosure of Invention

It is an object of the invention to provide a new and improved headset with an electrical conducting headband. This disclosure provides a headset for delivering audio to a user's ears, the headset comprising a first earphone housing, a second earphone housing and an electrically conducting headband for attaching the headset to the head of a user, wherein the first earphone housing is attached to a first end of the headband and the second earphone housing is attached to the second end of the headband, the headband comprising at least a first headband part with electrical conductors covered by electrical insulating material and at least a first hollow headband housing covering electrical conductors, wherein a first end of the first headband part is slidably received in a first end of the first headband housing, such that the length of the headband can be adjusted to a user's head by sliding the first headband part and the first headband housing relative to each other into any adjustment position between a first end position and a second end position, characterised in that a sliding contact assembly is provided in the first headband housing in order to provide electrical connection between the electrical conductors of the first headband part and the electrical conductors of the first headband housing in any adjustment position, which sliding contact assembly comprises at least two longitudinal conducting members, which are running in the longitudinal direction of the headband and are fixed in relation to either the first headband part or the first headband housing, and two sliding contact elements, which are fixed in relation to the other of the first headband part and the first headband housing) and slides along the longitudinal conducting members, when the headband is adjusted. With this headset, easy adjustment of the headband to the size of the user's head can take place without the risk of jamming excessive wire, short circuiting due to exposed electrical conductors and electric shock from lightning hitting the telephone line.

An embodiment of the invention is characterized in that the first headband housing at its second end is fixed to the first earphone housing, and wherein the headband comprises a second headband housing, which corresponds to the first headband housing, wherein the second end of the first headband part is slidably received in the first end of the second headband housing, and wherein the second end of the second headband housing is fixed to the second earphone housing. This ensures a more symmetric adjustment of the headband as it can be adjusted two places. The term "corresponds to" could be replaced by "embodied as" or "is similar to", as the second headband housing comprises the same features as the first headband housing. According to an alternative embodiment, the headband comprises a second headband part corresponding to the first headband part, wherein a first end of the second headband part is slidably received in a second end of the first headband housing, and wherein the second end of the first headband part is fixed to the first earphone housing and the second end of the second headband part is fixed to the second earphone housing. The term "corresponds to" could be replaced by "embodied as" or "is similar to", as the second headband part comprises the same features as the first headband part.

The two longitudinal conducting members may be provided as electric conductive pathways on a first side of a printed circuit board. This is an easy way of providing conducting members, as they can be obtained by etching a PCB as and plating the copper strips with gold in order to ensure a low contact resistance.

An embodiment may be characterized in that the longitudinal conducting members are fixed in relation to the headband housing(s) and the sliding contact elements are fixed in relation to the headband part(s).

According to en embodiment, the printed circuit board extends from the first earphone housing into the first headband housing, and wherein the headset comprises a microphone arm, which microphone arm is rotatably connected to the first earphone housing so that the microphone arm and the first earphone housing are mutually rotatable about a rotational axis, and wherein the printed circuit board comprises two concentric conductive contact rings, which are in electrical contact with two sliding contacts, which are fixed in relation to the microphone arm. In this ways, sliding contact members for an adjustable headband and a rotatable microphone arm can be obtained in a simple and cheap way.

The contact rings may be provided on a second side of the printed circuit board.

The longitudinal conducting members may be fixed in relation to the headband part(s) and the sliding contact elements may be fixed in relation to the headband housing(s). A single printed circuit board with two longitudinal conductive pathways may extend in the longitudinal direction of the headband part.

Brief Description of the Drawings

The invention is explained in detail below with reference to the drawing illustrating a preferred embodiment of the invention and in which Fig. 1 is a front view of a first embodiment of a headset according to the invention,

Fig. 2 is a cross-section through a first earphone housing and first headband housing of the headset according to the firs embodiment, Fig 3 is a cross section through a headband part of the headset according to the first embodiment,

Fig. 4 is a cross section through the first headband housing according to the first embodiment,

Fig. 5 a cross section through the first earphone housing according to the first embodiment,

Fig. 6 is a cross section through a the first headband housing according to a second embodiment of the invention,

Fig. 7 is a cross section through the headband part according to the second embodiment,

Fig. 8 is a front view of a headset according to a third embodiment of the invention, and

Fig. 9 is a front view of a headset according to a fourth embodiment of the invention. Modes for Carrying out the Invention

The following description of embodiments of the invention is only explaining non- limiting examples of embodiments. Furthermore, the drawings are schematic and only details necessary for explaining the invention are included. Due to the schematic nature of the drawings, inaccuracies can occur.

Fig. 1 is a front view of a first embodiment of a headset 1 according to the invention. The headset 1 is of the so-called duo-type comprising a first earphone housing 2 and a second earphone housing 3, which are interconnected by a headband 4. Thus the first earphone housing 2 is fixed to a first end 17 of the headband 4 and the second earphone housing 3 is fixed to a second end 18 of the headband 4. Both earphone housings 2, 3 comprise a protruding neck 37 with a speaker housing 36. A microphone arm 28 with a microphone 46 at its free end is rotatably connected to the outer side of the first earphone housing 2. By rotating the microphone arm 28 about the axis 29 the microphone arm 28 can be adjusted optimally in relation to the position of the user's mouth. The headset 1 is a corded headset 1 comprising a cord 48 connecting the first earphone housing 2 with external equipment, such as a desktop phone, a computer or a telephone system. The headband 4 interconnecting the two earphone housings 2, 3 serves two purposes: Firstly, it is used to secure the headset 1 to the user's head and secondly it provides electrical connection between the two earphone housings 2, 3. The headband 4 comprise a first headband housing 6, a first headband part 5 and a second headband housing 20. A first end 7 of the first headband part 5 is slidably received in a first end 11 of the first headband housing 6. A second end 23 of the first headband part 5 is slidably received in a first end 21 of the second headband housing 20. A second end 19 of the first headband housing 6 is fixed to the first earphone housing 2 and a second end 22 of the second headband housing 20 is fixed to the second earphone housing 3. Each end 7, 23 of the first headband part 5 can slide between two extreme positions in order to adjust the headset 1 to the size of the user's head. As the headset comprises earphones 2, 3 for supplying audio to the ears of a user and a microphone 46 for receiving audio from the user's mouth the headset can be used for two-way

communications such as telephone calls. Audio signals are transmitted to and from the headset via the cord 48, which as previously mentioned is connected to the first earphone housing 2. Thus, audio signals designated the second earphone housing 3 is transmitted via the headband 4.

Fig. 2 is a cross-section through the first earphone housing 2 and first headband housing 6 of the headset according to the first embodiment. The first earphone housing 2 and the first headband housing 6 is formed in one piece and encloses a sliding contact assembly 12. The functioning of this sliding contact assembly 12 will be explained in the following. A PCB (printed circuit board) 25 comprises a wide area 50 situated in the first earphone housing 2 and a narrow area 51, that extends from the first earphone housing 2 into the first headband housing 6. The PCB's 24 first side 26 facing the ear of user during use comprises two electrically conductive pathways 13, 14, which extends in the narrow area 51 in the longitudinally direction of the first headband housing 6. The first headband part 5, which is slidably received in the uppermost first end 11 of the headband housing 6, comprises two electrical wires which are connected to two spring contacts 15, 16 that are biased against the conductive pathways 13, 14. The headband part 5 can slide in relation to the first headband housing 6 between two extreme positions, and the spring contacts 15, 16 are in electrical contact with the conductive pathways 13, 14 in these two extreme positions and in any position between them. And end wall 43 is closing the end face of the first headband housing 6 with the exception of a narrow slot 44 that the first headband part 5 extends through. The PCB's 25 second side 27 comprises in the wide area 50 two concentric circular electrically conductive pathways 30, 31 which are used for a further sliding contact assembly used for the microphone arm 28. The longitudinal conductive pathways 13, 14 and the circular pathways 30, 31 are preferably made by well known PCB manufacturing processes, where f. ex. the board is laminated with thin copper foil on both sides, which copper foils are masked and etched to leave the pathways 13, 14, 30, 31. Subsequently, the copper pathways are plated with gold in order to provide a low contact resistance. Fig 3 is a cross section through the first headband part 5 of the headset 1 according to the first embodiment. The headband part 5 comprises steel band 38 with two

longitudinally extending grooves 54. A wire 8, 9 with wire isolation 55 is embedded in each groove 54. Heat-shrinkable tubing 10 is used as electrical isolation material, that encloses the steel band 38 and the wires 8, 9

Fig. 4 is a cross section through the first headband housing 6 according to the first embodiment. Only one of the two spring contacts 15, 16 is visible in the drawing. The spring contacts 15, 16 which are made of bent resilient metal plate, such as copper plate, are biased towards the longitudinally conductive pathways 13, 14, where only one of them is visible in the drawing. The spring contacts 15, 16 are connected to the wires 8, 9 in the headband part 4. A first positioning member 39 with a resilient cam 35 is fixed to the inner side of the wall of the first headband housing 6. The cam 35 engages a positioning recess 40 in a second positioning member 45 which is fixed to the inner side of the first headband part 5. By moving the first headband housing 6 and the first headband part 5 in relation to each other the cam 35 can be forced out of engagement with one positioning recess 40 and into engagement with another positioning recess 40 in order to adjust the length of the total headband 4 to the size of a user's head. During such adjustment, the contact springs 15, 16 will slide along the longitudinal conductive pathways 13, 14 and maintain electrical contact. Fig. 4 is only showing the first headband housing 6 and the first end 7 of the first headband part 5. However, the second headband housing 20 and the second end 23 of the first headband part 5 are embodied the same way, whereby the total length of the headband 4 can be adjusted at both headband housings 6, 20.

Fig. 5 is a cross section through the first earphone housing 2 according to the first embodiment. In the centre of the earphone housing 2 the PCB 25 is visible. Three pairs of wires 34 lead from the cord 48 to the longitudinally conducting pathways 13, 14, the circular contact rings 30, 31 and the speaker 49. The speaker 49 is located in the speaker housing 36, which is attached to the neck 37, such that it can tilt in relation to the earphone housing 6. This tilting provides a more comfortable engagement with the ears. As previously mentioned, the microphone arm 28 is made rotatable about the axis 29 by being rotatably attached to the earphone housing 6. An inner sliding contact element 32 and an outer sliding contact element 33 are fixed in relation to the microphone arm and biased against the inner and outer contact rings 31, 32. The contact elements 32, 33 are connected by wires 47 to the microphone 46 arranged in the outer end of the

microphone arm, which is not visible in fig. 5.

Fig. 6 is a cross section through the first headband housing 6 of a headset 1 according to a second embodiment of the invention. This embodiment differs primarily from the first embodiment by the PCB 25 with longitudinal conductive pathways 13, 14 being provided in the first headband part 5 and the spring contacts 15, 16 being fixed in relation to the headband housing 6. Wires 34 run from the contact elements 15, 16 to first earphone housing 2 and further to the cord 48, which are not visible in Fig. 6. An end face 42 of the second positioning member 45 abuts a stop member 41, when the first headband part 5 is pulled to the outermost extreme position.

Fig. 7 is a cross section through the headband part 5 according to the second

embodiment. The headband part 5 comprises a steel band 38, a PCB 25 with two longitudinally conductive pathways 13, 14 and a heat-shrinkable tubing 10 as electrical isolation material. The PCB 25 extends from the first end 7 of the headband part 5 to the second end 23 of the headband part 5.

Fig. 6 is only showing the first headband housing 6 and the first end 7 of the first headband part 5. However, the second headband housing 20 and the second end 23 of the first headband part 5 are embodied the same way, whereby the total length of the headband 4 can be adjusted at both headband housings 6, 20.

Fig. 8 is a front view of a headset according to a third embodiment of the invention. This headset 1 differs from the first end second embodiments by only having one headband housing 6. The headband housing 6 and the headband part 5 can be embodied as the headband housing and the headband part according to the first or the second

embodiment. Fig. 9 is a front view of a headset according to a fourth embodiment of the invention. This embodiment differs from the first embodiment by having a first headband part 5 a second headband part 24 and a intermediate first headband housing 6. The first end 7 of the first headband part 5 is received in the first end 11 of the first headband housing 6. The second end 23 of the first headband part 5 is fixed to the first earphone housing 2. The first end 52 of the second headband part 24 is received in the second end 19 of the first headband housing 6 and the second end 53 of the second headband part 24 is fixed to the second earphone housing 3. In this embodiment the first earphone housing 6 comprises two sliding contact assemblies. The two headband parts 5, 24 can be embodied as in the headband parts 5 of the first or the second embodiment. Thus the first headband housing 6 can comprise either two pairs of sliding spring contacts 15, 16 or a PCB extending in the longitudinally direction of the headband housing and comprising two longitudinally conductive pathways which are in electrical contact with two pairs of spring contact elements fixed to the two headband parts 5, 24.

A suitable type of PCB is a standard 0.4-0.5 mm thick glass fibre board. The construction makes it possible to prevent short circuits and electrical shocks due to lightning strokes. A rule of thumb is that there should at least 1 mm distance pr. kilovolt between conducting parts, in practice at least 5-6 mm. Thus, according to a preferred

embodiment, there is at least 5 mm between the outer side of the headset and the conducting parts inside the headset, which means the longitudinal conducting parts and the spring contacts.

The headband housings are made of electrically isolating material such as plastics.

The invention is net restricted to the embodiments shown disclosed here.

The term headset could be replaced by the term headphones, especially if it does not comprise a microphone. Reference signs

I headset

2 first earphone housing

3 second earphone housing

4 headband

5 first headband part

6 first headband housing

7 first end of first headband part

8, 9 wires

10 electrical insulating material

I I first end of first headband housing 12 sliding contact assembly

13, 14 longitudinal conducting members

15, 16 sliding spring contacts

17 first end of headband

18 second end of headband

19 second end of first headband housing 20 second headband housing

21 first end of second headband housing

22 second end of second headband housing

23 second end of first headband part

24 second headband part

25 PCB (printed circuit board)

26 first side of printed circuit board

27 second side of printed circuit board

28 microphone arm

29 rotational axis of microphone arm 30 inner contact ring

31 outer contact ring inner sliding contact element outer sliding contact element wires

cam

speaker housing

neck

steel band

positioning member

positioning recess

stop member

abutment face

end wall

slot

second positioning member microphone

microphone wires

cord

speaker

wide area of PCB

narrow area of PCB

first end of second headband part second end of second headband part groove

wire isolation