GB2457869A

GB2457869A - Earphone with rotatable in-ear section

Info

Publication number: GB2457869A
Application number: GB0724090A
Authority: GB
Inventors: James Strong; Stefan Andren; K K Ko
Original assignee: STRONG PACIFIC
Current assignee: STRONG PACIFIC
Priority date: 2007-12-10
Filing date: 2007-12-10
Publication date: 2009-09-02
Anticipated expiration: 2027-12-10
Also published as: GB0724090D0; GB2457869B

Abstract

The earphone comprises a speaker, a base defining a pivot axis, and a rotatable in-ear portion 18 that protrudes from the base. The in-ear portion 18 contains a sound tube 54 and is mounted asymmetrically about the pivot axis 36, thus its angular position can be adjusted. The earphone may also include a detent mechanism between the base and the in-ear portion 18. The detent mechanism defines a plurality of discrete relative positions between the in-ear portion and the base, and may be based on a pin or ball-bearing, and a spring. A window and markings may also be provided to indicate the relative positions of the in-ear portion and the base.

Description

Earphones The present invention relates to earphones, and in particular to earphones suitable for use with portable audio devices such as mp3 players, mobile phones and the like.

Earphones generally comprise a housing enclosing a speaker driver for converting electrical signals from an audio device into audible sound waves. Earphones are worn in close proximity to the ears and are either fully supported by the ears, or attached to a headband. Earphone devices may comprise a pair of earphones, one for each ear, in order to convey stereo audio signals. However, earphone devices comprising a single earphone are also used, for example as hands-free accessories for mobile phones.

A typical earphone comprises a generally circular speaker portion located at the end of an elongate stem. In use, the earphone is supported entirely by the outer ear, with the speaker portion located in the concha, outside the auditory canal, and the stem extending downwards, away from the ear, between the tragus and antitragus. Another type of earphone comprises a protruding portion that extends towards or partially into the auditory canal. The protruding portion directs sound into the auditory canal and in some cases increases the stability of the earphone. However, both types of earphone suffer from sound leakage problems and have poor dynamic range.

Recently, so-called "in-ear" earphones have been developed that comprise a protruding in-ear portion for direct insertion into the auditory canal. The protruding in-ear portion usually comprises a soft cap fitted over a cylindrical sound tube. The soft cap forms a seal with the auditory canal, which provides improved sound quality, particular at low frequencies. The seal also isolates the user from external noise, which enables in-ear earphones to be used at lower volumes than the earphones described above.

Many existing earphones, including in-ear earphones, suffer from losses in sound pressure caused by sound waves escaping from the earphone instead of being directed into the ear. Loss of sound pressure in this way can be antisocial because it enables others to hear whatever the user is listening to. It also limits the useful volume output of the earphone. The present invention aims to provide an earphone that minimises losses in sound pressure, and more generally an earphone having improved sound quality.

As ear shape and size varies from person to person, existing earphones may not be comfortable for all users. An aim of the present invention is to provide an earphone of universal comfort.

A further aim of the invention is to provide an earphone with visual or tactile appeal that maximises value perceived by a user.

It is against this background that the invention provides, in a first aspect, an earphone comprising: a base defining a pivot axis; a protruding in-ear portion asymmetric about the pivot axis, the in-ear portion being movable relative to the base about the pivot axis whereby the angular position of the in-ear portion about the pivot axis may be adjusted; and a speaker element mounted for pivotal movement with the in-ear portion about the pivot axis relative to the base.

The adjustability of the earphone enables a user to correctly position the earphone in the ear canal thus ensuring a comfortable and secure fit. The speaker element pivots with the in-ear portion, which ensures that sound quality is maintained as the in-ear portion is adjusted. The base is preferably made from a metal, such as stainless steel or aluminium to maximise the earphone's perceived value and intrinsic appeal.

The speaker element is preferably disposed in a driver housing mounted to the base.

The driver housing may be arranged for pivotal movement relative to the base about the pivot axis. The driver housing preferably includes the in-ear portion, and the in-ear portion preferably comprises a sound tube. The sound tube may be integrally formed with the driver housing, or it may be a separate component attached to the driver housing. A soft, flexible cap is preferably received over the sound tube to form a seal with the user's auditory canal when the in-ear portion is inserted in the user's ear. The soft cap may be removed to facilitate cleaning or replacement. Caps of various shapes or sizes may be placed over the sound tube according to the particular preference of the user. For increased comfort, the in-ear portion may be angled, such that a central longitudinal axis of the in-ear portion is inclined with respect to the pivot axis.

The earphone preferably includes an elongate stem. The stem may extend from the base, and may serve to support the earphone between the tragus and antitragus of the user's ear. Pivotal movement of in-ear portion relative to the base about the pivot axis varies the angular position of the in-ear portion relative to the stem. Since the relative position of the auditory canal, tragus and antitragus varies from person to person, this adjustment ensures that the earphone is comfortable, and correctly fits the majority of users. Furthermore, as sound quality is reliant on the earphone being positioned correctly within the ear, this adjustment ensures that all users benefit from the optimum sound quality of the earphone, irrespective of their ear shape, whilst also maintaining a comfortable fit and good support of the stem between the tragus and antitragus.

The stem may be integrally formed with the base or a separate component attached to the base. Preferably the stem is formed from a metal such as stainless steel or aluminium. However, the stem may alternatively be formed from a flexible material, for example silicone rubber or a thermoplastic polyurethane elastomer (TPU).

Preferably the speaker element is sealed around its periphery to the driver housing. This seal minimises sound leakage between the front and the rear of the speaker element.

The driver housing preferably substantially encloses the speaker element on its reverse side to minimise sound leakage from the earphone. This also serves to maximise sound pressure provided to the user, which enables the earphones to be used at low volumes.

The driver housing may define a substantially enclosed chamber behind the speaker element. The chamber may however include one or more vent openings for allowing air into and out of the chamber to ensure that the speaker element does not act against a fixed volume of air. The one or more vent openings may communicate with a gap defined between the base and the driver housing. The gap is preferably defined in an overlap region where the base overlaps the driver housing. The gap is suitably dimensioned to allow air to flow between the base and the driver housing, but to minimise dust ingress into this region. The gap may be between 0.05mm and 0.2 mm in width, and is preferably about 0.1 mm. The gap is preferably substantially enclosed, and a seal is preferably provided between the base and the driver housing to further guard against dust ingress into the gap.

A vent may be provided in the base to allow airflow into and out of the gap. The vent in the base may be provided by a window defined in the base. The window is preferably provided in the region where the base overlaps the driver housing. The window may also serve as an indicator window. For this purpose, the driver housing preferably bears indicia selectively displayed through the indicator window depending upon the angular position of the in-ear portion about the pivot axis. It will be appreciated that a visual indication of the angular position of the in-ear portion about the pivot axis may be provided by any other suitable indicator means.

The base may comprise a sleeve and a skirt depending from the sleeve, with the pivot axis being substantially coincident with a central longitudinal axis of the sleeve. The driver housing may comprises a trunnion that may be pivotably received within the sleeve, such that the pivot axis is defined by a common central longitudinal axis of the sleeve and the trunnion within the sleeve. The region of overlap between the base and the driver housing may be defined by the skirt of the base overlapping the driver housing.

The driver housing may comprise opposed first and second sections that are assembled to enclose the speaker element. The first and second sections may together locate the speaker element within the driver housing upon assembly. The driver housing may be substantially lenticular in shape.

Preferably the earphone comprises a detent mechanism defining a plurality of discrete relative positions between the in-ear portion and the base. The detent mechanism preferably acts between the base and the driver housing. The detent mechanism suitably includes bias means whose bias must be overcome to move between the discrete relative positions.

The bias means preferably biases the driver housing toward the base. The bias means may comprise a compression spring acting between the base and the driver housing, or between an extension of or attachment to the driver housing. For example, the compression spring may be received within the sleeve and may act between an inwardly protruding portion within the sleeve, and an extension of the trunnion. The extension of the trunnion may be a screw that extends coaxially from an end of the trunnion. In that case, the compression spring preferably acts between the protruding portion within the sleeve and a head of the screw.

The detent mechanism may comprise engagement means associated with one of the base or the driver housing. The engagement means suitably engage complementary formations provided on the other one of the base or the driver housing. The formations may be defined by recesses, whereas the engagement means may comprise at least one protrusion. The or each protrusion preferably engages a respective recess in each of the angular positions of the in-ear portion. The recesses may ride over the protrusions when the driver housing is turned relative to the base. This causes the driver housing and the base to move apart against the bias of the bias means.

The or each protrusion may be defined by the head of a pin. The pin may be disposed in a bore, and the bore may be defined in a side wall of the sleeve. The bore preferably opens to an annular wall of the base surrounding an opening of the sleeve. The heads of the pins protrude from the bores at the annular wall of the base. Instead of being defined by pins, the or each protrusion may be defined by a ball bearing, in which case the or each ball bearing may be biased by a spring disposed in a respective bore. The pin heads or the ball bearings are preferably disposed between the annular wall of the base and a collar of the driver housing facing that annular wall. The collar preferably surrounds the trunnion and includes the formations with which the protrusions engage. The formations are preferably angularly spaced about the collar. Preferably the formations are defined by countersunk holes in the collar.

The collar is preferably substantially annular and comprises a pair of raised opposed arcuate segments and a pair of recessed opposed arcuate segments. The raised and recessed arcuate segments preferably alternate around the trunnion. A plurality of formations is preferably provided on each of the recessed opposed arcuate segments.

Each formation may have a twin formation diametrically opposite on the other recessed segment. Each pair of twinned formations preferably represents a discrete relative position between the in-ear portion and the base. Preferably a shoulder is defined at each end of a segment, between adjacent recessed and raised segments. The shoulders delimit the pivotal movement of the driver housing relative to the base about the pivot axis.

According to a second aspect of the present invention there is provided an earphone comprising: a base defining a pivot axis; a protruding in-ear portion asymmetric about the pivot axis, the in-ear portion being movable relative to the base about the pivot axis whereby the angular position of the in-ear portion about the pivot axis may be adjusted; and a detent mechanism between the base and the in-ear portion, the detent mechanism defining a plurality of discrete relative positions between the in-ear portion and the base and including bias means whose bias must be overcome to move between the discrete relative positions.

The invention may alternatively by expressed, within the same inventive concept, as an earphone comprising: a body defining a pivot axis; a protruding in-ear portion asymmetric about the pivot axis whereby the angular position of the in-ear portion about the pivot axis may be adjusted by turning the in-ear portion relative to the body about the pivot axis; and a detent mechanism between the body and the in-ear portion, the detent mechanism defining a plurality of discrete relative positions between the in-ear portion and the body and including bias means whose bias must be overcome to move between the discrete relative positions.

The invention may further be expressed, within the same inventive concept, as an earphone comprising: a base defining a pivot axis; and a driver housing mounted to the base for pivotal movement relative to the base about the pivot axis, the driver housing including a protruding in-ear portion asymmetric about the pivot axis whereby the angular position of the in-ear portion about the pivot axis may be adjusted by turning the driver housing relative to the base.

It will be appreciated that optional and preferred features of the first aspect of the invention apply equally to the second aspect of the invention, either alone or in combination. It will also be appreciated that optional and preferred features of the second aspect of the invention apply equally to the first aspect of the invention, either alone or in combination. Furthermore, it will be appreciated that optional and preferred features of both the first and second aspects of the invention also apply to the other expressions of the invention above.

The inventive concept extends to earphone devices comprising either a pair of earphones, or a single earphone, in accordance with the present invention.

Brief description of the drawings

Figure 1 is an outer schematic view of an earphone having a speaker housing assembly comprising an adjustable in-ear portion, in accordance with a variant of the invention; Figures la, lb and ic show the in-ear portion of the earphone of Figure 1 in different angular positions; Figure 2a is a perspective view of the earphone of Figure 1, in which a protruding sound tube is shown; Figure 2b is a partially exploded view corresponding to Figure 2a showing an internal housing and an external housing of the speaker housing assembly; Figure 2c is a fully exploded view of the internal housing shown in Figure 2b, in which a speaker element is shown between first and second sections of the internal housing; Figures 3a and 3b are views of the inner side of the earphone, which illustrate angular adjustment of the sound tube; Figures 4a and 4b are inner side perspective views of the earphone, in which Figure 4a shows the protruding sound tube, and Figure 4b shows a soft cap mounted on the protruding sound tube; Figure 5a is a partial cross section through the assembled earphone of Figure 2a, in a plane containing the longitudinal axes of a stem and a sleeve visible in Figure 2a, in which the soft cap illustrated in Figure 4b is shown mounted on the sound tube; Figure 5b is a partial cross section taken in a plane perpendicular to the plane of Figure 5a, in which a detent mechanism comprising a pair of pins is shown between the internal and external housings; Figure 6a is a perspective view of the second section of the internal housing, in which the pins of Figure 5b are shown engaging with complementary formations on the second section; Figure 6b is a perspective view of the second section of the internal housing, showing a set of indicia provided thereon; Figure 7 is a perspective view of the earphone, in which an indicator window to indicate the angular position of the internal housing with respect to the external housing is shown; Figure 8a is a perspective view showing the speaker element mounted to the first section of the internal housing, in which a metal grille of the speaker element is visible; Figure 8b is a further perspective view, similar to Figure 8a but in which the metal grille is removed from the speaker element in accordance with another variant of the invention; Figure 8c is a perspective view corresponding to Figure Sb but from an opposite angle to show features not visible in Figure 8b; Figure 9a is a perspective view of the internal housing within the external housing, in which the external housing is shown as transparent, and arrows are provided to represent airflow between the internal and external housings and out through the indicator window; Figure 9b is an enlarged detail perspective view that shows the airflow in Figure 9a from a different perspective; and Figure 10 is a side view of an earphone comprising a ball detent mechanism, in accordance with a further variant of the invention.

Detailed description of the preferred embodiments

Referring to Figure 1, the earphone 10 comprises a speaker housing assembly 12 of generally circular outline. The speaker housing assembly 12 encloses a speaker driver (not shown). A tubular stem 14 extends from the centre of the speaker housing assembly 12. A cable 16 extends through the stem 14 and connects the speaker driver to an adaptor (not shown), for example a 3.5mm stereo jack plug for connection to a portable audio player such as an mp3 player or the like.

The earphone 10 includes an in-ear portion 18 for insertion into the auditory canal of a user's ear. The in-ear portion 18 protrudes from an inner side 20 (shown in Figures 3a and 3b) of the earphone 10. A portion of the speaker housing assembly 12 is arranged for angular movement with respect to the remainder of the speaker housing assembly 12, to adjust the in-ear portion 18 for comfort between a number of predetermined positions, three of which are shown in Figures la to ic. Moreover, an indicator 20 is provided on the speaker housing assembly 12 to indicate the changing position of the in-ear portion 18. The aforementioned features of the earphone 10 are described in more detail below with reference to Figures 2 to 10.

Referring to Figures 2a, 2b and 2c, the speaker housing assembly 12 comprises a base, hereinafter referred to as the external housing' 24, and a driver housing, hereinafter referred to as the internal housing' 22. The internal housing 22 can be turned with respect to the external housing 24.

The external housing 24 is mounted at the end of the stem 14 and comprises a short tubular sleeve 26 and a frusto-conical skirt 28 depending from the sleeve 26 (Figure 2b).

The skirt 28 splays out from an inner end 30 of the sleeve 26. An orifice 32 is provided in a side wall 34 of the sleeve 26 through which the stem 14 is inserted such that a central longitudinal axis 34 of the stem 14 is orthogonal to a central longitudinal axis 36 of the sleeve 26. The external housing 24, internal housing 22 and the stem 14 are made from stainless steel or aluminium, but other materials may of course be used.

The internal housing 22 is substantially lenticular in shape (Figure 2b), and comprises opposed first and second sections 38, 40 that come together to enclose a speaker element 42 (Figure 2c), otherwise known as a speaker driver. The sections 38, 40 come together on a join line 44 that lies in a plane perpendicular to the central longitudinal axis 36 of the sleeve 26. The first section 38 is on the inner side of the earphone 10 in that it faces towards a user's ear in use, whilst the second section 40 is on the outer side of the earphone 10 in that it faces away from the user's ear in use.

The first section 38 includes the protruding in-ear portion 18, as described in detail below, whereas the second section 40 comprises a frusto-conical body 46 that tapers towards a centrally mounted tubular trunnion 48. The second section 40 is complementary in external shape to the internal shape of the external housing 24. When the speaker housing assembly 12 is assembled (Figure 2a), the trunnion 48 is pivotably received within the sleeve 26 of the external housing 24, and the skirt 28 of the external housing 24 surrounds the body 46 of the second section 40.

The internal housing 22 can be turned with respect to the external housing 24 between a number of predetermined positions to vary the angular position of the in-ear portion 18.

As described in further detail later, this is achieved by grasping the external housing 24 in one hand and moving the protruding in-ear portion 18 with the other hand to turn the internal housing 22 within the external housing 24. The internal housing 22 turns about a pivot axis 50 coincident with the common central longitudinal axis 36 of the sleeve 26 and the trunnion 48 within the sleeve 26.

The lenticular shape of the internal housing 22 is defined, in part, by a convex curved wall 52 of the first section 38. A sound tube 54, which forms part of the in-ear portion 18 of the earphone 10, projects from the convex curved wall 52. The sound tube 52 extends from a generally elliptical root 56 at the curved wall 52, towards a tip 58 spaced apart from the curved wall 52. When the earphone 10 is assembled, the root 56 encompasses, but is asymmetrical about, the central longitudinal axis 36 of the sleeve 26. The sound tube 54 is angled, in the sense that a central longitudinal axis 60 of the sound tube 54 is inclined with respect to the central longitudinal axis 36 of the sleeve 26.

As described in further detail below, the earphone 10 can be adjusted to vary the angular position of the central longitudinal axis 60 of the sound tube 54 about the central longitudinal axis 36 of the sleeve 26, as shown in Figure 3a and 3b. The sound tube 54 is also shown in the perspective view of Figure 4a. Referring also to Figure 4b, a soft cap 62 is mounted on the sound tube 54 before use of the earphone 10. The soft cap 62 is formed from silicone rubber, and fits comfortably within the user's auditory canal to form a seal.

Referring to Figure 2c, the first and second sections 38, 40 of the internal housing 22 have snap-fit attachment formations, as exemplified by four equally-spaced tabs 64 formed in a castellated circular wall 66 of the first section 38 (Figure 2c). An annular seal 68 is provided between the first and second sections 38, 40. The seal 68 comprises inner and outer concentric rings 70, 72, and is made from a hard material such as polypropylene (PP), a thermoplastic polyurethane elastomer (TPU), or Acrylonitrile Butadiene Styrene (ABS). The inner and outer rings 70, 72 are joined together by four equally-spaced bridges 74 extending radially between an outer circumferential surface 76 of the inner ring 70 and an inner circumferential surface 78 of the outer ring 72. The bridges 74 define between them four equally-spaced gaps 80 between the inner and outer rings 70, 72 through which the tabs 64 of the castellated wall 66 of the first section 38 project to effect the snap fit with the second section 40.

Referring to the sectional view of Figure 5a, when the internal housing 22 is assembled, the inner ring 70 of the annular seal 68 (Figure 2c) seats upon an outer surface 80 of the speaker element 42. The inner ring 70 is substantially rectangular in cross section and is retained partially within the body 46 of the second section 40, such that the outer circumferential surface 76 of the inner ring 70 abuts an inner circumferential surface 82 of the body 46. The snap fit between the first section 38 and the second section 40 of the internal housing 22 causes the body 46 of the second section 40 to bear against the inner ring 70 to form a circular seal between the inner circumferential surface 82 of the body 46 and the outer circumferential surface 76 of the inner ring 70. In turn, the inner ring 70 bears against the outer surface 80 of the speaker element 42 to retain the speaker element 42 in place within the internal housing 22 and to maintain a seal around the periphery of the speaker element 42.

In cross section, the outer ring 72 of the annular seal 68 (Figure 2c) has a flat inner circumferential surface 84 and a convex curved outer circumferential surface 86. The outer ring 72 surrounds the first section 38 of the internal housing 22, such that the flat inner circumferential surface 84 of the outer ring 72 abuts an outer circumferential surface 88 of the castellated circular wall 66 of the first section 38. The outer ring 72 is retained by an annular rim 90 extending radially outwards form the circular wall. The annular rim 90 can be seen more clearly in Figure 2c. In this position, the curved outer circumferential surface 86 of the outer ring 72 slides against a free circular edge 92 of the skirt 28 to reduce dust ingress into a narrow clearance region 94 between the internal and external housings 38, 40.

The internal and external housings 38, 40 are coupled together by a screw 96. The screw 96 extends parallel to the central longitudinal axis 36 of the sleeve 26 and through a screw hole 98 in an outer end 100 of the sleeve 26 to engage a threaded bore 102 on the central longitudinal axis 36 of the trunnion 48. The screw hole 98 and threaded bore 102 can also be seen in the perspective view of Figure 9a.

Referring to Figure 5b, the earphone 10 includes a detent mechanism that defines a plurality of discrete angular positions of the internal housing 22 with respect to the external housing 24. In this variant, the detent mechanism comprises a pair of pins 104 associated with the external housing 24 that engage with complementary formations 108 on the internal housing 22. The pins 104 each have an elongate shaft 110 with an enlarged head 112 at one end facing the internal housing 22. The elongate shafts 110 are retained within respective blind bores 114 in the side wall 34 of the sleeve 26 of the external housing 24. The bores 114 extend parallel to the central longitudinal axis 36 of the sleeve 26. The pins 104 protrude from the bores 114 such that their enlarged heads 112 are outside the bores 114, thereby preventing the pins 104 from entering the bores 114 completely.

Parts of the detent mechanism are also shown in the perspective views of Figures 6a and 6b. Referring to Figures 6a and 6b, the second section 40 of the internal housing 22 includes an annular collar 116 that surrounds an inner end 118 of the trunnion 48, at the junction with the frusto-conical body 46. The annular collar 118 comprises a pair of raised opposed arcuate segments 120 and a pair of recessed opposed arcuate segments 122. The raised and recessed segments 120, 122 alternate around the trunnion 48. As shown best in Figure 6b, a shoulder 124 having an inwardly-inclined raised face 126 is defined at each end of a recessed segment 122, between adjacent recessed and raised segments 120, 122.

Four countersunk holes 128 are angularly spaced about each recessed segment 122.

The countersunk holes 128 define the formations 108 with which the pins 104 engage.

Each hole 128 has a twin hole diametrically opposite on the other recessed segment 122, and each pair of twinned holes 128 represents a discrete angular position of the internal housing 22 with respect to the external housing 24. As shown in Figure 6a, the pair of pins 104 engages a pair of twinned holes 128 to retain the internal housing 22 in a desired angular position. In this variant there are four pairs of twinned holes 128, corresponding to four discrete angular positions of the internal housing 22, and hence of the angled protruding in-ear portion 18 with respect to the remainder of the earphone 10.

Referring also to Figure 5b, the detent mechanism further comprises a compression spring that biases the internal and external housings 22, 24 together. The compression spring 130 is located within the sleeve 26, and acts between the head 132 of the screw 96 and a flange 134 that projects inwards from an internal surface 136 of the sleeve 26.

The flange 134 is annular and spaced apart from the outer end 100 of the sleeve 26 such that the screw 96 extends through the hollow centre of the annular flange 134 to engage the threaded bore 102 in the internal housing 22. The effect of the compression spring is such as to pull the internal housing 22 into the external housing 24, by pressing on the underside 138 of the screw head 132.

When the internal housing 22 is turned with respect to the external housing 24 between successive discrete angular positions, the countersunk surfaces 140 of the holes 128, ride over the heads 112 of the pins 104. This angular movement forces the internal and external housings 22, 24 to move slightly apart against the bias of the spring 130, causing the screw head 132 to compress the spring 130 against the annular flange 134.

Continuing to turn the internal housing 22 aligns the next pair of twinned holes 128 with the heads 112 of the pins 104, at which point the compression spring 130 extends to force the screw head 132 away from the annular flange 134 bringing the internal and external housings 22, 24 back together.

In addition to retaining the internal and external housings 22, 24 in each of the discrete angular positions, the pin heads 112 provide bearing surfaces between the housings 22, 24 as the housings 22, 24 move relative to one another between those angular positions.

By acting as bearings, the pins 104 ensure that the pivoting action of the internal housing 22 within the external housing 24 is smooth, thus minimising wear and adding to the perceived quality and ease of use of the earphone 10. As the internal housing 22 is turned from one discrete angular position to the next, a click can be heard and felt each time the internal and external housings 22, 24 spring back together, caused as the pins 104 engage the holes 128. The click serves as a tactile and aural indication to the user of each angular adjustment of the earphone 10, further adding to the perceived quality and ease of use of the earphone 10.

Referring to Figure 6b, the shoulders 124 at each end of the recessed segments 122 delimit the angular movement of the internal housing 22 with respect to the external housing 24. The inwardly inclined raised faces 126 of the shoulders 124 are not able to ride over the heads 112 of the pins 104, which prevents the inner housing 22 from turning in either direction past the extreme discrete angular positions.

Referring to Figures 6a and 6b, an opening 142 is defined in a side waIl 144 of the trunnion 48. As seen in Figure 5a, the opening 142 communicates with the orifice 32 in the sleeve 26 when the internal and external housings 22, 24 are assembled, such that a passageway is defined between the stem 14 and the internal housing 22. The cable 16 extends along the passageway and into the internal housing 22 where it is soldered to the speaker element 42. The opening 142 is wider than the orifice 32 in the sleeve 26 so that the cable 16 will not prevent the internal housing 22 turning within the external housing 24.

As best seen in Figure 6b, the frusto-conical body 46 of the internal housing 22 is provided with a set of indicia 146, in this case the numbers one to four. Each number corresponds to a respective angular position of the internal housing 22 with respect to the external housing 24. Referring to Figure 7, the indicator window 20, described above with reference to Figure 1, is provided in the frusto-conical skirt 28 of the external housing 24. The window 20 is arranged to overlie the indicia 146 corresponding to the present angular position of the internal housing 22, thereby providing the user with a visual indication of the angular configuration of the earphone 10. The remaining indicia 146 on the body 46 of the internal housing 22 are obscured by the skirt 28 of the external housing 24.

Referring to Figure 8a, in which an inner side 148 of the speaker element 42 is visible, the speaker element 42 comprises a speaker body 150 (Figure 8c) coupled to a diaphragm (not shown). A voice coil (not shown) is mounted to the diaphragm, and a metal grille 160 is located in front of the diaphragm. The speaker element 42 is mounted to the first section 38 of the internal housing 22, which ensures there is no loss of sound quality as the internal housing 22 is turned relative to the external housing 24 to adjust the angular position of the in-ear portion 18. Bass regulator holes 162 penetrate convex curved wall 52 of the first section 38 of the internal housing 22 as shown in Figures 8a and 8b.

Optionally, as shown in Figure 8b, the metal grille 160 can be removed from the speaker element 42. The metal grille 160 can block some high frequency signals, hence removing it allows more high frequency tones to be heard, thereby improving sound quality. This is particularly advantageous for in-ear earphones which tend to produce increased levels of bass as a result of the seal formed with the auditory canal. In addition, removing the metal grille 160 allows the unit to be made more compact. This is exemplified by the tabs 64 in Figure 8b, which project to a lesser extent than the tabs 64 in Figure 8a.

Furthermore, removing the metal grille 160 enables the speaker element 42 to be moved closer to the ear to further reduce losses in sound pressure.

Referring to Figure 8c, in which an outer side 164 of the speaker element 42 is visible, adhesive is provided around the periphery of the speaker element 42 to secure the speaker element 42 in place. The adhesive forms a seal between the speaker element 42 and the internal surface of the first section 38 of the internal housing 22 to substantially prevent sound leakage between the inner and outer sides 148, 164 of the speaker element 42. This reduces losses in sound pressure and benefits sound quality.

Referring again to Figure 5b, the body 46 of the second section 40 of the internal housing 22 defines a chamber 166 behind the speaker element 42. The countersunk holes 128 on the annular collar 116 between the body 46 and the trunnion 48 of the internal housing 22 allow air to pass into and out of the chamber 166 so that the diaphragm of the speaker element 42 does not act against a fixed volume of air. The narrow clearance region 94 defined between the body 46 and the skirt 28 provides a passage for air passing through the holes 128 to pass between the chamber 166 and the indicator window 20 in the external housing 24 as described in further detail below with reference to Figures 9a and 9b. The clearance between the body 46 and the skirt 28 is very small, about 0.1 millimetres, and is selected to minimise dust ingress, whilst still allowing air to pass.

Referring to Figures 9a and 9b, as the diaphragm of the speaker element 42 vibrates, air is pushed out of the chamber 166 (Figure 4b) through the countersunk holes 128 in the internal housing 22. The air passes between the internal and external housings 22, 24 as shown by the arrows in Figure 9b, and out through the indicator window 20 in the skirt 28. Although not shown, air also passes in the reverse direction, i.e. air is drawn in through the indicator window 20, between the internal and external housings 22, 24, through the holes 128 in the internal housing 22 and into the chamber 166 (Figure 4b).

A variant of the earphone is shown in Figure 10, in which a ball detent mechanism is used in place of the detent mechanism described above. The ball detent mechanism comprises a compression spring 168 disposed in one of the blind bores 114 and a ball bearing 170 disposed at the end of the spring 168, outside the blind bore 114. The ball bearing 170 is retained by an end coil 172 of the spring 168, and is prevented from entering the blind bore 114 by the tension in the spring 168. Similar countersunk formations 128 may be provided on the internal housing 22 as described above with reference to Figures 6a and 6b. Whilst only a single spring 168 and ball bearing 170 is shown in Figure 10, it will be appreciated that the ball detent mechanism would include a similar spring 168 and ball bearing 170 disposed in the other blind bore 114.

It will be appreciated that further variants of the earphone could employ a detent mechanism similar to those described above but comprising a single retaining means disposed in a single blind bore 114, for example a single pin 104 or a single spring 168 and baIl bearing 170. However, using a pair of pins 104 or a pair of springs 168 and ball bearings 170 is advantageous because it provides a better bearing surface to enhance the relative rotation of the internal and external housings 22, 24, thereby improving the feel of the earphone 10 and maximising its perceived quality.

Whilst countersunk holes have been specifically described for engaging the pins 104 or ball bearings 170 of the detent mechanisms, it will be appreciate that other formations could be used, for example chamfers or recesses on the internal housing 22.

Claims

CLAIMS1. An earphone comprising: a base defining a pivot axis; a protruding in-ear portion asymmetric about the pivot axis, the in-ear portion being movable relative to the base about the pivot axis whereby the angular position of the in-ear portion about the pivot axis may be adjusted; and a speaker element mounted for pivotal movement with the in-ear portion about the pivot axis relative to the base.
2. The earphone of Claim 1, wherein the speaker element is disposed in a driver housing mounted to the base for pivotal movement relative to the base about the pivot axis.
3. The earphone of Claim 2, wherein the driver housing includes the in-ear portion whereby the angular position of the in-ear portion about the pivot axis may be adjusted by turning the driver housing relative to the base.
4. The earphone of Claim 2 or Claim 3, wherein the speaker element is sealed around its periphery to the driver housing.
5. The earphone of any of Claims 2 to 4, wherein the driver housing substantially encloses the speaker element on its reverse side.
6. The earphone of Claim 5, wherein the driver housing defines a substantially enclosed chamber behind the speaker element.
7. The earphone of Claim 6, wherein the chamber includes one or more vent openings.
8. The earphone of any of Claims 2 to 7, wherein a gap is defined between the base and the driver housing.
9. The earphone of Claim 8 when dependent upon Claim 7, wherein the one or more vent openings communicate with the gap.
10. The earphone of Claim 8 or Claim 9, wherein the gap between the base and the driver housing is between 0.05mm and 0.2mm in width.
11. The earphone of Claim 10, wherein the gap is approximately 0.1 mm in width.
12. The earphone of any of Claims 8 to 11, wherein the gap is defined in an overlap region where the base overlaps the driver housing.
13. The earphone of Claim 12, wherein the base has an indicator window in the overlap region and the driver housing bears indicia selectively displayed through the indicator window depending upon the angular position of the in-ear portion about the pivot axis.
14. The earphone of Claim 13, wherein the indicator window communicates with the gap.
15. The earphone of any of Claims 2 to 14, wherein the base comprises a sleeve and a skirt depending from the sleeve, and the pivot axis is substantially coincident with a central longitudinal axis of the sleeve.
16. The earphone of Claim 15, wherein the driver housing comprises a trunnion, the trunnion being pivotably received within the sleeve, such that the pivot axis is defined by a common central longitudinal axis of the sleeve and the trunnion within the sleeve.
17. The earphone of Claim 15 or Claim 16 when dependent upon Claim 12, wherein the overlap region is defined by the skirt of the base overlapping the driver housing.
18. The earphone of any of Claims 15 to 17, wherein the driver housing comprises opposed first and second sections that are assembled to enclose the speaker element.
19. The earphone of Claim 18, wherein the first and second sections together locate the speaker element within the driver housing upon assembly.
20. The earphone of any one of Claims 2 to 19, wherein the driver housing is substantially lenticular in shape.
21. The earphone of any preceding claim, wherein the in-ear portion comprises a sound tube.
22. The earphone of any preceding claim, wherein a central longitudinal axis of the in-ear portion is inclined with respect to the pivot axis.
23. The earphone of any preceding claim, further comprising an elongate stem extending from the base, wherein pivotal movement of in-ear portion relative to the base about the pivot axis varies the angular position of the in-ear portion relative to the stem.
24. The earphone of any of Claims 2 to 23, further comprising a detent mechanism between the base and the in-ear portion, the detent mechanism defining a plurality of discrete relative positions between the in-ear portion and the base and including bias means whose bias must be overcome to move between the discrete relative positions.
25. The earphone of Claim 24, wherein the detent mechanism acts between the base and the driver housing.
26. The earphone of Claim 24 or Claim 25, wherein the bias means biases the driver housing toward the base.
27. The earphone of any of Claims 24 to 26, wherein the bias means comprises a compression spring acting between the base and the driver housing.
28. The earphone of Claim 27, wherein the compression spring acts between the base and an attachment to the driver housing.
29. The earphone of Claim 27 or Claim 28 when dependent directly or indirectly upon Claim 16, wherein the compression spring is received within the sleeve.
30. The earphone of Claim 29, wherein the compression spring acts between an inwardly protruding portion within the sleeve, and an extension of the trunnion.
31. The earphone of Claim 30, wherein the extension of the trunnion is a screw that extends coaxially from an end of the trunnion, and the compression spring acts between the protruding portion within the sleeve and a head of the screw.
32. The earphone of any of Claims 29 to 31, wherein the driver housing comprises a collar surrounding the trunnion, the collar facing an annular wall of the base surrounding an opening of the sleeve.
33. The earphone of any of Claims 24 to 32, wherein the detent mechanism comprises engagement means associated with one of the base or the driver housing for engaging complementary formations provided on the other one of the base or the driver housing.
34. The earphone of Claim 33, wherein the formations are defined by recesses and the engagement means comprise at least one protrusion, the or each protrusion engaging a respective recess in each of the angular positions of the in-ear portion, and the recesses riding over the or each protrusion when the driver housing is turned relative to the base causing the driver housing and the base to move apart against the bias of the bias means.
35. The earphone of Claim 34 when Claim 33 depends upon Claim 32, wherein the or each protrusion is defined by the head of a pin disposed in a bore that is defined in a side wall of the sleeve and opens to the annular wall of the base.
36. The earphone of Claim 34 when Claim 33 depends upon Claim 32, wherein the or each protrusion is defined by a ball bearing disposed between the collar and the annular wall of the base.
37. The earphone of Claim 36, wherein the or each ball bearing is biased by a spring disposed in a bore that is defined in a side wall of the sleeve and opens to the annular wall of the base.
38. The earphone of any of Claims 33 to 37 when dependent directly or indirectly upon Claim 32, wherein the formations are angularly spaced about the collar.
39. The earphone of Claim 38, wherein the collar is substantially annular and comprises a pair of raised opposed arcuate segments and a pair of recessed opposed arcuate segments, the raised and recessed arcuate segments alternating around the trunnion.
40. The earphone of Claim 39, wherein a plurality of formations is provided on each of the recessed opposed arcuate segments, such that each formation has a twin formation diametrically opposite on the other recessed segment, and each pair of twinned formations represents a discrete relative position between the in-ear portion and the base.
41. The earphone of Claim 39 or Claim 40, wherein a shoulder is defined at each end of a segment, between adjacent recessed and raised segments, the shoulders delimiting pivotal movement of the driver housing relative to the base about the pivot axis.
42. The earphone of any of Claims 33 to 41 when dependent directly or indirectly upon Claim 32, wherein the formations are defined by countersunk holes in the collar.
43. An earphone comprising: a base defining a pivot axis; a protruding in-ear portion asymmetric about the pivot axis, the in-ear portion being movable relative to the base about the pivot axis whereby the angular position of the in-ear portion about the pivot axis may be adjusted; and a detent mechanism between the base and the in-ear portion, the detent mechanism defining a plurality of discrete relative positions between the in-ear portion and the base and including bias means whose bias must be overcome to move between the discrete relative positions.
44. The earphone of Claim 43, wherein the in-ear portion protrudes from a driver housing mounted to the base for pivotal movement relative to the base about the pivot axis, whereby the angular position of the in-ear portion about the pivot axis may be adjusted by turning the driver housing relative to the base.
45. The earphone of Claim 44, wherein the detent mechanism acts between the base and the driver housing.
46. The earphone of Claim 44 or Claim 45, wherein the bias means biases the driver housing toward the base.
47. The earphone of any of Claims 44 to 46, wherein the bias means comprises a compression spring acting between the base and the driver housing.
48. The earphone of Claim 47, wherein the compression spring acts between the base and an attachment to the driver housing.
49. The earphone of Claim 47 or Claim 48, wherein the base comprises a sleeve, the driver housing comprises a trunnion, and the trunnion and the compression spring are received within the sleeve.
50. The earphone of Claim 49, wherein the compression spring acts between an inwardly protruding portion within the sleeve, and an extension of the trunnion.
51. The earphone of Claim 50, wherein the extension of the trunnion is a screw that extends coaxially from an end of the trunnion, and the compression spring acts between the protruding portion within the sleeve and a head of the screw.
52. The earphone of any of Claims 49 to 51, wherein the driver housing comprises a collar surrounding the trunnion, the collar facing an annular wall of the base surrounding an opening of the sleeve.
53. The earphone of any of Claims 44 to 52, wherein the detent mechanism comprises engagement means associated with one of the base or the driver housing for engaging complementary formations provided on the other one of the base or the driver housing.
54. The earphone of Claim 53, wherein the formations are defined by recesses and the engagement means comprise at least one protrusion, the or each protrusion engaging a respective recess in each of the angular positions of the in-ear portion, and the recesses riding over the or each protrusion when the driver housing is turned relative to the base causing the driver housing and the base to move apart against the bias of the bias means.
55. The earphone of Claim 54 when Claim 53 depends upon Claim 52, wherein the or each protrusion is defined by the head of a pin disposed in a bore that is defined in a side wall of the sleeve and opens to the annular wall of the base.
56. The earphone of Claim 54 when Claim 53 depends upon Claim 52, wherein the or each protrusion is defined by a ball bearing disposed between the collar and the annular wall of the base.
57. The earphone of Claim 56, wherein the or each ball bearing is biased by a spring disposed in a bore that is defined in a side wall of the sleeve and opens to the annular wall of the base.
58. The earphone of any of Claims 53 to 57 when dependent directly or indirectly upon Claim 10, wherein the formations are angularly spaced about the collar.
59. The earphone of Claim 58, wherein the collar is substantially annular and comprises a pair of raised opposed arcuate segments and a pair of recessed opposed arcuate segments, the raised and recessed arcuate segments alternating around the trunnion.
60. The earphone of Claim 59, wherein a plurality of formations is provided on each of the recessed opposed arcuate segments, such that each formation has a twin formation diametrically opposite on the other recessed segment, and each pair of twinned formations represents a discrete relative position between the in-ear portion and the base.
61. The earphone of Claim 59 or Claim 60, wherein a shoulder is defined at each end of a segment, between adjacent recessed and raised segments, the shoulders delimiting pivotal movement of the driver housing relative to the base about the pivot axis.
62. The earphone of any of Claims 53 to 61 when dependent directly or indirectly upon Claim 52, wherein the formations are defined by countersunk holes in the collar.
63. An earphone substantially as herein described with reference to or as shown in the accompanying drawings.