Patent Description:
This disclosure relates to an audio device that is configured to be worn on the ear.

Wireless headsets deliver sound to the ear. Most wireless headsets include an earbud that is placed into the ear canal opening. Earbuds can inhibit or prevent the user from hearing speech and ambient sounds. Also, earbuds send a social cue that the user is unavailable for interactions with others.

<CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose prior art audio devices.

The present invention relates to an open audio device according to claim <NUM>. Advantageous embodiments are set forth in the dependent claims.

Various aspects of at least one example are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. The figures are included to provide illustration and a further understanding of the various aspects and examples, and are incorporated in and constitute a part of this specification, but are not intended as a definition of the limits of the inventions. In the figures, identical or nearly identical components illustrated in various figures may be represented by a like reference character or numeral. In the figures:.

Disclosed herein is an open audio device, such as a wireless headset, that delivers sound close to an ear canal opening but does not block or obstruct the ear canal. The open audio device is carried on the ear and portions of the head adjacent to the ear. The open audio device is configured to be positioned such that it lightly and comfortable clamps on the upper ear and locates an acoustic module against the ear above the ear canal such that the ear canal remains open to receive speech and environmental sounds. The open audio device engages with the ear such that it remains in place even as the user moves the head.

Exemplary open audio device <NUM> is depicted in <FIG>. Open audio device <NUM> is specifically designed to be carried on the right ear. The open audio device for the left ear is a mirror image; see <FIG> for an example. A right ear and adjacent head regions are shown in <FIG>, which help in an understanding of how the open audio device is engaged with the ear and head.

Open audio device <NUM> is carried by outer ear <NUM> and portions <NUM> and <NUM> of the head <NUM> that are behind and just in front of (i.e., adjacent to) the ear, respectively, as is further described elsewhere herein. Open audio device <NUM> comprises acoustic module <NUM> that contains in its interior an electro-acoustic transducer or audio driver (not shown). Acoustic module <NUM> is configured to locate sound-emitting opening <NUM> above the ear canal opening <NUM>, which is behind (i.e., generally underneath) ear tragus <NUM>. Acoustic module <NUM> has inner face <NUM> and opposed outer face <NUM>. In some examples faces <NUM> and/or <NUM> are generally flat, as shown in <FIG>. Advantageously, positioning the acoustic module <NUM> above the ear canal opening <NUM> leaves the ear canal opening unobstructed when viewed from both the side and front, which visually signals to others around the user that the user is open and able to interact with his or her environment. According to an embodiment of the invention, acoustic module <NUM> has a second sound-emitting opening <NUM> that is farther from the ear canal than opening <NUM>. Openings <NUM> and <NUM> emit sound from opposite sides (e.g., front and back) of an audio driver and so the sounds are out of phase. The out of phase sounds will tend to cancel in the far field and so the openings act like a low-frequency dipole. However, opening <NUM> is close enough to the ear canal that much of its sound is not cancelled before it reaches the ear. In this embodiment, acoustic module <NUM> carries at least two microphones. <FIG> illustrates openings <NUM> and <NUM> that lead to microphones (not shown, located inside of acoustic module <NUM>). In an example an axis through both of the microphone openings will be within about +/- <NUM> degrees of the expected location of the user's mouth so that the microphones can be arrayed/beamformed, as is known in the field.

Audio device <NUM> further includes body <NUM> that is configured to be worn on or abutting outer ear <NUM> such that body <NUM> contacts the outer ear and/or the portion of the head that is just behind and abuts the outer ear, at two or more separate, spaced contact locations. Audio device <NUM> is configured to gently grip the outer ear, the portion of the head just in front of (anterior to) the ear, and the portion of the head just behind the rear of outer ear <NUM>, as explained in more detail below.

<FIG> illustrate aspects of the ear <NUM>, especially the outer ear <NUM> (sometimes referred to as the pinna) and adjacent parts of the head that are useful in understanding the open audio device of this disclosure and its engagement with the ear and head. Outer ear <NUM> includes helix <NUM> (with its upper end <NUM> where it meets the head), anti-helix <NUM>, fossa <NUM>, concha cymba <NUM>, crus of helix <NUM>, tragus <NUM>, ear canal opening <NUM>, and earlobe <NUM>. Line <NUM> represents the intersection of the outer ear <NUM> and the head <NUM>. Intersection <NUM> has an upper end <NUM> termed the otobasion superius, and a lower end <NUM> termed the otobasion inferius, while the most posterior part <NUM> of intersection <NUM> is termed the otobasion posterius. Intersection <NUM> typically exhibits an arch <NUM> between area <NUM> close to otobasion superius <NUM> and area <NUM> where the intersection begins its descent toward otobasion posterius <NUM>. The outer ear comprises rear portion 82b that abuts intersection <NUM>. The head <NUM> comprises portion <NUM> just behind the ear and abutting the ear's rear portion 82b. The head also comprises portion <NUM> just in front of the upper portion <NUM> of the outside 82a of outer ear <NUM>. Also, the head typically includes a dimple or depression <NUM> (<FIG>) adjacent to the otobasion inferius and the earlobe; dimple <NUM> is typically but not necessarily located in most heads very close to or abutting or just posterior of the otobasion inferius <NUM>, as shown in <FIG>.

Turning back to <FIG>, open audio device body <NUM> comprises curved bridge portion <NUM>, and housing <NUM> with free distal end <NUM>. Bridge <NUM> merges smoothly into acoustic module <NUM>, e.g., as shown in <FIG>, such that the beginning of the outer surface <NUM> of bridge <NUM> is tangent to the front curved portion <NUM> of acoustic module <NUM>. Bridge <NUM> is thinner than housing <NUM>. One reason is so that room is available for eyeglass temple pieces to still fit on the ear when a user is wearing the open audio device, as shown in <FIG>. In an example body <NUM> is an integral molded plastic member. In an example body <NUM> is made of a non-plastic stiff material, such as metal. Body <NUM> is in an example relatively stiff, but may have some compliance in bridge portion <NUM> as described below.

Body <NUM> is generally configured to be located behind the outer ear, as shown in <FIG>. Gap <NUM> between body <NUM> and acoustic module <NUM> is generally sized and shaped to allow the upper portion <NUM> of outer ear <NUM> to fit through the opening, with the upper or closed end <NUM> of gap <NUM> located such that the upper end of the helix <NUM> is fitted in gap portion <NUM>. The upper end of the helix <NUM> thus becomes a point about which open audio device <NUM> can pivot or rotate.

Almost all of body <NUM> sits behind the ear, along the intersection of the back of the ear and the head. See <FIG>, which illustrates body <NUM> behind the left ear. Note that the open audio device illustrated in <FIG> is designed for the left ear <NUM> and so is a mirror image of open audio device <NUM> illustrated in <FIG>. Body <NUM> is sized, shaped, contoured and angled relative to acoustic module <NUM> such that body <NUM> generally follows the shape and contour of the ear-head intersection and contacts the ear and/or head along much of the length of body <NUM>, most of the way to, or almost to, free distal end <NUM>. At the same time, for most ears body <NUM> is thick enough such that it slightly pushes the back 82b of the outer ear out or away from the head. This bend of the ear causes a slight force against body <NUM> that tends to push it against the head. In an example acoustic module <NUM> has an inner face <NUM> that is configured to sit against the front portion 82a of outer ear <NUM> (e.g., against one or more of fossa <NUM>, anti-helix <NUM>, crus of helix <NUM>, and helix <NUM>) as well as the portion <NUM> of the head <NUM> that is located immediately anteriorly of upper ear portion <NUM>. The portion of acoustic module <NUM> proximate the uppermost point <NUM> of inside surface <NUM> of body <NUM> may sit under helix <NUM>.

The head and the upper portion <NUM> of the ear that lies on or very close to the head are stiffer than is the protruding back 82b of the outer ear. Since acoustic module <NUM> is at least in part sitting against a hard surface (the head and parts of the ear that lie against or very close to the head), it is not able to move closer to the head. This forces body <NUM> to push out into outer ear <NUM>, which creates an opposing force that tends to rotate open audio device <NUM> about point <NUM>. This results in three constraining device anchoring locations, which include the device contacting the helix around point <NUM>, the acoustic module <NUM> resting against the ear and head, and the body <NUM> pushing toward the head due to the slightly bent soft part of the ear. The flexibility of the outer ear loads/preloads these three points to ensure they are always experiencing a normal force. The flexibility of the outer ear thus contributes to a stable yet comfortable fit of open audio device <NUM>. Also, since the three anchoring locations are not linear they generally define the apices of a triangle, which creates greater stability than if the anchor locations were aligned. Open audio device <NUM> is thus gently but firmly held on the head, even when the head moves.

<FIG> illustrates one spatial relationship of the bridge <NUM> and the acoustic module <NUM> of open audio device <NUM>. A first generally vertical plane, seen from above as in <FIG>, appears as line "A. " This plane is coplanar with some or all of the flat or substantially flat inner face <NUM> of acoustic module <NUM>. Where this first plane bisects the width of bridge <NUM>, a second generally vertical plane that bisects the bridge across its width along its longitudinal extent is placed, and appears from above as line "B. " The planes represented by lines A and B intersect at an acute angle, which in one example is about <NUM> degrees. Angling bridge <NUM> at about <NUM> degrees (perhaps within +/- <NUM> degrees of <NUM> degrees) helps the bridge to follow the upper part of the ear/head intersection while ensuring the acoustic module inner face <NUM> sits against the ear and head. It also places housing <NUM> behind the ear on or very close to the ear/head intersection, along most of the length of the housing. Open audio device <NUM> is thus held to the ear and head at a plurality of spaced locations. Also, in some examples the thickness of housing <NUM> (which may be from about <NUM> to about <NUM>) is sufficient such that it will push the outer ear slightly away from the head, as described above. In an example the housing has a generally teardrop cross-sectional shape that becomes progressively wider when moving from a top end of the housing to a bottom end of the housing toward free distal end <NUM>. A teardrop shape has a wider end and a narrower end. In an example the housing is configured such that the wider end of its teardrop cross-sectional shape is located against the ear so that the ear is slightly bent outward, while the narrower end is not in contact with the head or ear for improved comfort.

<FIG> illustrates another spatial relationship between bridge <NUM> and acoustic module <NUM>. Plane A is the same plane A illustrated in <FIG>. Line C represents the contact rotational axis of bridge <NUM>. In an example line C is angled at (<NUM>, <NUM>, <NUM>) degrees from the normal vector of plane A (to a tolerance of approximately +<NUM>, - <NUM> degrees). This angle allows acoustic module <NUM> to closely match the orientation of the ear flesh in that area without pinching or crushing the flesh.

<FIG> and <FIG> illustrate and describe the radii of curvature of an example body <NUM>. Inside surface <NUM> of body <NUM> lies generally along a decaying helix. A helix is a smooth curve in three-dimensional space. Surface <NUM> is not strictly helical but does curve in three-dimensional space, in that free distal end <NUM> (which is at the distal end of housing <NUM>) is offset from uppermost point <NUM> of inside surface <NUM>, such that end <NUM> is closer to the mid-sagittal plane than is point <NUM>. The curve is decaying because its radius of curvature increases when moving from the beginning of the curve at point <NUM> to its end near free distal end <NUM> (accordingly, its curvature is greatest at the beginning of the curve at point <NUM> and decreases when moving down the body towards its end <NUM>). In an example the approximate dimensions of the radius of curvature at several points along surface <NUM> are as follows: point <NUM>, <NUM>; point 42a, <NUM>; point 42b, <NUM>; point 42c, <NUM>.

<FIG> is a plot of the radius of curvature along the length of surface <NUM> (which in one non-limiting example is about <NUM>). The sharp jump and drop starting at between <NUM>-<NUM>% of the length and ending at <NUM>% is due to the rounded end <NUM>. Surface <NUM> is configured to generally follow the ear-head intersection behind the ear in an "average" person, while the length of the housing ensures that in almost every ear anatomy the body will lie on or close to this intersection to a point at least as far down as the otobasion posterius, and in many cases lower than that, close to the lower end of the helix. The thickness of housing <NUM> is designed to push the outer ear slightly away from the head at least in most anatomies, as described above. In an example the housing has a generally uniform width. Accordingly, the inner <NUM> and outer <NUM> curved surfaces of the housing will have approximately the same radii of curvature. The housing is sized and shaped so as to accommodate a traditional cylindrical rechargeable battery, although other battery shapes can be accommodated.

Body <NUM> can be shaped generally to follow the intersection of the outer ear and the head. Contact along this intersection and/or the head and/or ear abutting this intersection will be at a number of spaced locations along the ear and adjacent head regions. However, since the human head has many shapes and sizes, body <NUM> does not necessarily contact the intersection of the head and ear. Rather, it can be designed to have a shape such that it will, at least on most heads, contact the back of the outer ear and/or the portion of the head that abuts the back of the outer ear, and the front of the ear above the ear canal opening. These contacts occur at a plurality of spaced locations. These locations can include at least locations that are substantially or generally diametrically opposed.

In an example the bridge can be constructed to have some bending compliance (e.g., by making the bridge of a compliant material, or overmolding a compliant material, such as an elastomer, in a portion that is designed to be able to bend). The bending compliance can be about its longitudinal axis. The bridge can be configured such that the bridge bends slightly when it is pushed down over the top of the ear. The compliance can create forces that gently push the acoustic module and the housing against the head, to better hold the open audio device in place. The compliance can cause a slight compressive force at opposed locations of the open audio device and so can lead to a grip on the ear and head that is sufficient to help retain the open audio device in place as the head is moved.

Also, since at least two of the open audio device-to-ear/head contact points are in the vicinity of the upper part of the ear (due to the acoustic module and the bridge) and lower down on the back of the ear/the head (typically at or below the otobasion posterius <NUM> due to the shape and curvature of the housing), there are contact points that are generally diametrically opposed. The generally diametrically opposed locations create a resultant force on the open audio device that lies approximately in the line between the opposed contact regions. In this way, the open audio device can be considered stable on the ear. Contrast this to a situation where the lower contact region is substantially further up on the back of the ear, which would cause a resultant force on the open audio device that tended to push it up and rotate it forward, up and off the ear. By arranging contact forces roughly diametrically opposed on the ear, the open audio device can accommodate a wider range of orientations and inertial conditions where the forces can balance, and the open audio device can thus remain on the ear.

Open audio device <NUM> can be a mainly unitary molded plastic member. The plastic material may have some flexibility so that open audio device is less likely to break if it is sat on or the like. The material may be a nylon or a cellulose acetate (similar to the material used in the frames of some eyeglasses that are able to be bent to a degree without breaking, and then return to their original shape after being bent). Since acoustic module <NUM> holds an audio driver and electronics used to receive, process and supply audio signals to the driver, the design must account for the need to locate components inside of acoustic module <NUM>. Also, a rechargeable battery is typically contained in housing <NUM> and wiring needs to run from the battery to the acoustic module.

Claim 1:
An open audio device (<NUM>) arranged for delivering sound close to an ear canal opening (<NUM>) of a user without blocking or obstructing the ear canal, comprising:
a body (<NUM>) with an inner surface that is configured to be located behind an outer ear (<NUM>) of the user and in contact along a length of the body at multiple locations of at least one of the outer ear and the head (<NUM>) proximate the intersection (<NUM>) of the head and the outer ear, wherein the inner surface of the body lies generally along a decaying helix; and
an acoustic module (<NUM>) that contains in its interior an electro-acoustic transducer or audio driver, the acoustic module being carried by the body and configured to be located against the outer ear above the ear canal opening (<NUM>), wherein the acoustic module is configured to locate a first sound-emitting opening (<NUM>) above the ear canal opening, the open audio device is characterised in that the acoustic module further comprises a second sound-emitting opening (<NUM>) farther from the ear canal than the first sound-emitting opening, the first and second sound-emitting openings being arranged for emitting sound from opposite sides of the electro-acoustic transducer or audio driver and such that the emitted sounds are out of phase so as to cancel in the far field.