Patent Description:
The size of electronic devices, such as tablets and mobile phones, is an important consideration when designing electronic devices. The user oftentimes requests the outer dimensions of the device to be as small as possible while still providing a display which is as large as possible.

This problem may be solved, e.g., by means of a foldable electronic device comprising one or several support bodies, e.g. interconnected by means of hinges, covered by a display. The support body/bodies and the display can be folded together to provide an as small electronic device as possible, and unfolded to provide an as large display as possible.

Preferably, the hinge can be locked in both an unfolded position and a folded position. However, stacking up of manufacturing tolerances for any locking components affects the flatness of the electronic device in the unfolded position, and movement between several pivot points have to be synchronized in order to provide enough locking force.

<CIT> provides a flexible display device including a base support of structurally flexible, a flexible display which is supported by and bendable with the base support, and at least one positioning mechanism disposed leftward or rightward of the base support.

<CIT> provides a hinge device including a housing, a cam, a cam follower to interact with the cam, and a resilient member. The housing contains the cam, cam follower and resilient member. The cam moves linearly, and the cam follower rotates.

It is an object to provide an improved foldable electronic device. The foregoing and other objects are achieved by the features of the independent claim. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided a hinge assembly for an electronic device, the hinge assembly being moveable between an unfolded position and a folded end position,
the hinge assembly comprising a row of interconnected and abutting hinge blades and at least one linear actuator, the hinge blades being aligned in a common plane when the hinge assembly is in the unfolded position, each hinge blade being rotated relative neighboring hinge blades around a hinge assembly rotation axis when the hinge assembly is moved to the folded end position, the linear actuator comprising a rotation shaft and a linear drive arrangement, a first end of the linear drive arrangement being interconnected with the rotation shaft, a second, opposite end of the linear drive arrangement being connected to at least one hinge blade, an actuator axis extending between the first and second ends and perpendicular to the hinge assembly rotation axis, the linear actuator further comprising a locking arrangement for locking the hinge assembly in at least one of the unfolded position and the folded end position, the locking arrangement comprising a cam element interlocking with a cam section located on the rotation shaft.

This solution allows the sections of the electronic device, which are interconnected by the hinge assembly, to be pivoted easily without effort, while still being securely locked into place in one of the desired positions, i.e. in the unfolded position or a folded end position. Furthermore, by having only one locking arrangement, there is no stacking up of individual manufacturing tolerances, providing better flatness in the unfolded position, while avoiding having to synchronize movement between several pivot points in order to provide enough locking force.

In a possible implementation form of the first aspect, the rotation shaft extends in parallel with the hinge assembly rotation axis and the linear drive arrangement extends along the actuator axis, the cam element enclosing a section of the rotation shaft such that the cam element and the rotation shaft share a center axis, providing a reliable locking arrangement which nevertheless takes up very little space.

In a further possible implementation form of the first aspect, the rotation shaft extends perpendicular to the hinge assembly rotation axis and the actuator axis, the cam element being arranged adjacent one end of the rotation shaft, the cam element comprising a circular element extending in a first plane perpendicular to a center axis of the rotation shaft, a center axis of the cam element extending in parallel with said center axis of the rotation shaft, the cam section comprising a circular section extending in the first plane and comprising at least one peripheral notch adapted for receiving the circular element. This allows the required locking forces on the cam element and the cam section to be significantly reduced while keeping the device locking forces the same. Furthermore, the locking position accuracy is improved.

In a further possible implementation form of the first aspect, the hinge assembly further comprises a resilient element biasing the cam element towards the cam section.

In a further possible implementation form of the first aspect, the resilient element comprises a spring.

In a further possible implementation form of the first aspect, the hinge assembly comprises a neutral axis, a center axis of the rotation shaft intersecting the neutral axis, a first end of the linear drive arrangement engaging the rotation shaft, a second end of the linear drive arrangement engaging a first location and a second location of an individual hinge blade, the first location and the second location being located on opposite sides of, and with equidistant spacing from, the neutral axis. This allows the actuation of the linear actuator to be synchronized along both main surfaces of the electronic device.

In a further possible implementation form of the first aspect, the linear drive arrangement comprises a loop, a first loop section and a second loop section extending on opposite sides of, and with equidistant spacing from, the neutral axis, a first rotation of the rotation shaft rotating the loop in a first direction, and a second rotation of the rotation shaft rotating the loop in a second direction, providing a secure, simple, and reliable linear actuation.

In a further possible implementation form of the first aspect, the linear drive arrangement comprises a chain or a wire.

In a further possible implementation form of the first aspect, the wire is partially wound around the rotation shaft.

In a further possible implementation form of the first aspect, a first dimension of a first outer surface of the hinge assembly is larger than a corresponding second dimension of a second outer surface of the hinge assembly when the hinge assembly is in the folded end position, the linear actuator being actuated by a difference between the first dimension and the second dimension. This allows for a hinge assembly which has as small outer dimensions as possible, while having a sufficient range of motion.

According to a second aspect, there is provided an electronic device comprising a first frame section, a second frame section, a display connected to at least one of the first frame section and the second frame section, and a hinge assembly according to the above interconnecting the first frame section and the second frame section such that the first frame section and the second frame section are pivotable, relative each other, between an unfolded position and a first folded end position, the first frame section and the second frame section being aligned and releasably locked in a common plane when in the unfolded position, the second frame section being superimposed on the first frame section and releasably locked when in the first folded end position.

This allows for a hinge assembly which has as small outer dimensions as possible, while having a range of motion which allows, e.g., the first frame section and the second frame section to be moved between the unfolded position, in which the sections extend to provide a maximum electronic device width, and a folded position in which the two sections are superimposed onto each other such that they extend to provide only a minimum electronic device width.

In a possible implementation form of the second aspect, the hinge assembly interconnects the first frame section and the second frame section such that the first frame section and the second frame section are pivotable, relative each other, between an unfolded position and a second folded end position, the first frame section being superimposed on the second frame section and releasably locked when in the second folded end position.

This and other aspects will be apparent from and the embodiments described below.

<FIG> show an electronic device <NUM> comprising a first frame section <NUM>, a second frame section <NUM>, a display <NUM> connected to at least one of the first frame section <NUM> and the second frame section <NUM>, and a hinge assembly <NUM> interconnecting the first frame section <NUM> and the second frame section <NUM> such that the first frame section <NUM> and the second frame section <NUM> are pivotable, relative each other, between an unfolded position P1 and a first folded end position P2a. In a one embodiment, the hinge assembly <NUM> is also moveable between the unfolded position P1 and a second folded end position P2b. As the hinge assembly <NUM> is folded, the electronic device <NUM> is also folded from an unfolded position to a folded end position. The electronic device <NUM> may also comprise a back cover arranged oppositely to the display <NUM>.

As shown in <FIG>, the first frame section <NUM> and the second frame section <NUM> are aligned and releasably locked in a common plane when in the unfolded position P1, and
the second frame section <NUM> is superimposed on the first frame section <NUM> and releasably locked when in the first folded end position P2a. As shown in <FIG>, the first frame section <NUM> is superimposed on the second frame section <NUM> and releasably locked when in the second folded end position P2b.

The hinge assembly <NUM> comprises a row of interconnected and abutting hinge blades <NUM>, as shown in <FIG>, and at least one linear actuator <NUM>.

The hinge blades <NUM> may be tapered and interconnected by means of an elongated connection element extending along an actuator axis A2, as shown in <FIG>. The hinge blades <NUM> may be tapered in one direction, as shown in <FIG>, or in two directions, as shown in <FIG>. One-directional tapering allows the hinge assembly <NUM> to fold in only one direction, e.g. to first folded end position P2a, while bi-directional tapering allows the hinge assembly <NUM> to fold in two directions, i.e. to first folded end position P2a as well as second folded end position P2b.

The hinge blades <NUM> are aligned in a common plane when the hinge assembly <NUM> is in the unfolded position P1, as shown in the middle drawings of <FIG>. Each hinge blade <NUM> is rotated relative neighboring hinge blades <NUM> around a hinge assembly rotation axis A1 when the hinge assembly <NUM> is moved to one of the folded end positions P2a, P2b, as shown in the lowermost drawings of <FIG>, as well as in the uppermost drawing of <FIG>.

As shown in <FIG>, the linear actuator <NUM> comprises a rotation shaft <NUM>, extending within the second frame section <NUM>, and at least one linear drive arrangement <NUM>. The first end of the linear drive arrangement <NUM> is interconnected with the rotation shaft <NUM>, and the second, opposite end of the linear drive arrangement <NUM> is connected to at least one hinge blade <NUM> or to the first frame section <NUM>. The actuator axis A2 extends between the first end and the second end, and perpendicular to the hinge assembly rotation axis A1. Actuation of the linear actuator <NUM> along the actuator axis A2 urges each hinge blade <NUM> to rotate relative neighboring hinge blades <NUM> around the hinge assembly rotation axis A1.

A first dimension of a first outer surface 8a of the hinge assembly <NUM> may be larger than a corresponding second dimension of a second outer surface 8b of the hinge assembly <NUM> when the hinge assembly <NUM> is in the first folded end position P2a, as shown in <FIG>. The linear actuator <NUM> is actuated by a difference between the first dimension and the second dimension.

The linear actuator <NUM> further comprises a locking arrangement <NUM> for locking the hinge assembly <NUM> in at least one of the unfolded position P1 and the folded end positions P2a, P2b. The locking arrangement <NUM> comprises a cam element <NUM> interlocking with a cam section <NUM> located on the rotation shaft <NUM>.

As shown in <FIG>, the rotation shaft <NUM> may extend in parallel with the hinge assembly rotation axis A1 while the linear drive arrangement <NUM> extends along the actuator axis A2. The cam element <NUM> may be arranged on the rotation shaft <NUM>, enclosing a section thereof, such that the cam element <NUM> and the rotation shaft <NUM> share a center axis A3. The cam element <NUM> is at least partially stationary such that it does not rotate around the shared center axis A3, such that the cam section <NUM> of the rotation shaft <NUM> interlocks with different parts of the cam element <NUM> as the rotation shaft <NUM> is rotated. For example, if the cam element <NUM> has two locking positions, i.e. at each <NUM>-degree rotation, then the hinge assembly <NUM> as well has locking positions at each <NUM>-degree rotation, e.g. when in the first folded end position P2a wherein the electronic device may be closed, then in the unfolded position wherein the electronic device may be in tablet mode, and after a further <NUM>-degree rotation when in the second folded end position P2b, wherein the electronic device may be in phone mode.

The cam element <NUM> may be moveable in opposite directions along the shared center axis A3, such that the cam element <NUM> may oscillate along the shared center axis A3 in response to rotation of rotation shaft <NUM> and cam section <NUM>. The hinge assembly <NUM> may in this case comprise a resilient element <NUM>, such as a spring, sharing the same center axis A3 as the rotation shaft <NUM> and the cam element <NUM>. The resilient element <NUM> is arranged such that it biases the cam element <NUM> towards the cam section <NUM>, keeping the interlock between the cam section <NUM> and the cam element <NUM> for at least as long as there is no actuation of the linear actuator <NUM>.

In a further embodiment, shown in <FIG>, the rotation shaft <NUM> extends perpendicular to the hinge assembly rotation axis A1 and the actuator axis A2, with a center axis A3b. The cam element <NUM> is arranged adjacent one side or end of the rotation shaft <NUM>.

The cam element <NUM> comprises a circular element <NUM> which may be plate shaped, and extend in a first plane perpendicular to the center axis of the rotation shaft <NUM>. The center axis A3a of the cam element <NUM> extends in parallel with the center axis A3b of the rotation shaft <NUM>.

The cam section <NUM>, arranged on the rotation shaft <NUM>, may comprise a circular section <NUM> extending in the first plane, e.g. in the form of a circular plate or two parallel circular plates, and having an outer diameter which is significantly larger that the diameter of the rotation shaft <NUM>, allowing the required locking forces on the cam element <NUM> and the cam section <NUM> to be significantly reduced while keeping the device locking forces the same. The circular section <NUM> comprises at least one peripheral notch <NUM> adapted for receiving the circular element <NUM>.

The circular element <NUM> may be moveable in opposite directions in the first plane, such that the circular element <NUM> may oscillate in response to rotation of rotation shaft <NUM> and cam section <NUM> around center axis A3b, as indicated by means of arrows in <FIG>. The hinge assembly <NUM> may comprise a resilient element <NUM>, such as a spring, extending within or in parallel with the first plane. The resilient element <NUM> is arranged such that it biases the circular element <NUM> towards the cam section <NUM>, keeping the interlock between the cam section <NUM> and the circular element <NUM> for at least as long as there is no actuation of the linear actuator <NUM>.

The hinge assembly <NUM> comprises a neutral axis N, and the center axis of the rotation shaft <NUM> may intersect the neutral axis N. The first end of the linear drive arrangement <NUM> engages the rotation shaft <NUM>, extending within e.g. the second frame section <NUM> and the second end of the linear drive arrangement <NUM> engages a first location and a second location of an individual hinge blade <NUM>. The second end of the linear drive arrangement <NUM> may also engage the first frame section <NUM>. The first location and the second location are located on opposite sides of, and with equidistant spacing from, the neutral axis N, as is clear from <FIG>. The above-mentioned elongated connection element, connecting the hinge blades <NUM>, may extend along the neutral axis N.

In the embodiment shown in <FIG>, the center axis A3 of the rotation shaft <NUM> extends within e.g. the second frame section <NUM> in the same plane as the neutral axis N. In the embodiment shown in <FIG>, the center axis A3b of the rotation shaft <NUM> extends within e.g. the second frame section <NUM> perpendicular to the neutral axis N, however, the longitudinal extent of the rotation shaft <NUM> along its center axis A3b is limited to extending between the display and the optional back cover of the electronic device.

The linear drive arrangement <NUM> may comprises a loop, a first loop section 13a and a second loop section 13b extending on opposite sides of, and with equidistant spacing from, the neutral axis N. The loop may be open at the second end of the linear drive arrangement <NUM>, as shown in <FIG>, and <FIG>. A first rotation of the rotation shaft <NUM>, in a first direction around the center axis A3, A3b of the rotation shaft <NUM>, rotates the loop in the first direction, and a second rotation of the rotation shaft <NUM>, in a second direction around the center axis A3, A3b of the rotation shaft <NUM>, rotates the loop in the second direction.

The linear drive arrangement <NUM> may comprises a chain, as indicated in <FIG>, or a wire, as indicated in <FIG>.

When the linear drive arrangement <NUM> comprises a wire it may be partially wound around the rotation shaft <NUM>, as shown in <FIG>, and extend through the hinge blades <NUM> along the actuator axis A2 and on opposite sides of, with equidistant spacing from, the neutral axis N.

The linear drive arrangement <NUM> may comprise two separate chain sections 13a, 13b extending in parallel with equidistant spacing from the neutral axis N and on opposite sides of the elongated connection element as suggested in <FIG>. The chain sections extend through the hinge blades <NUM> along the actuator axis A2, when the hinge assembly <NUM> is in the unfolded position P1.

The rotation shaft <NUM> may comprise at least one pinion and chain of the linear drive arrangement <NUM> may be connected to a first rack engaging the pinion at a first location, as shown in <FIG>. A first rotation of the rotation shaft <NUM> and the pinion moves the rack in a first direction along the actuator axis A2, hence pulling the chain in the first direction, and an opposite, second rotation of the rotation shaft <NUM> and the pinion moves the rack in a second direction along the actuator axis A2, hence pushing the chain in the second direction. The chain, or a second chain section, may be connected to a second rack engaging the pinion at a second location opposite the first location and extending along the actuator axis A2. The first rack and the second rack extend on opposite sides of, and with equidistant spacing from, the neutral axis N. A first rotation of the rotation shaft <NUM> and the pinion simultaneously moves the first rack in the first direction and the second rack in the second direction, such that the first rack pulls the chain in the first direction and the second rack, simultaneously, pushes the chain in the second direction. An opposite, second rotation of the rotation shaft <NUM> and the pinion simultaneously moves the first rack in the second direction and the second rack in the first direction, such that the first rack pushes the chain in the second direction and the second rack, simultaneously, pulls the chain in the first direction.

As previously mentioned, the present disclosure also relates to an electronic device <NUM> comprising the above described hinge assembly <NUM>. The display <NUM> and/or the back cover of the electronic device may be fixedly connected to the first frame section <NUM>, and pivoting the first frame section <NUM> or the second frame section <NUM> will actuate the linear actuator <NUM>. The linear actuator <NUM> urges the display <NUM> and/or the back cover to slide in relation to the hinge assembly <NUM> such that an overlap between the display <NUM> and/or the back cover and the second frame section <NUM> varies. The overlap between the display <NUM> and the second frame section <NUM> is at a minimum when the foldable assembly <NUM> is in the first folded end position P2a. Correspondingly, the overlap is at a maximum when the hinge assembly <NUM> is in the second folded end position P2b, as shown in, e.g., <FIG>.

In a further embodiment, the display <NUM> or the back cover 2b may be fixedly connected to the first frame section <NUM> and the second frame section <NUM>. The linear actuator <NUM> urges the second frame section <NUM> to slide, e.g. on sliding rails, in relation to the hinge assembly <NUM> such that the distance between the hinge assembly <NUM> and the second frame section <NUM> varies, as shown in <FIG>. The distance between the hinge assembly <NUM> and the second frame section <NUM> is at a minimum when the foldable assembly <NUM> is in the first folded end position P2a, and
the distance between the hinge assembly <NUM> and the second frame section <NUM> is at a maximum when the foldable assembly <NUM> is in the second folded end position P2b.

The various aspects and implementations have been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

Claim 1:
A hinge assembly (<NUM>) for an electronic device (<NUM>), said hinge assembly (<NUM>) being moveable between an unfolded position (P1) and a folded end position (P2a, P2b),
said hinge assembly (<NUM>) comprising a row of interconnected and abutting hinge blades (<NUM>) and at least one linear actuator (<NUM>),
said hinge blades (<NUM>) being aligned in a common plane when said hinge assembly (<NUM>) is in said unfolded position (P1), each hinge blade (<NUM>) being rotated relative neighboring hinge blades (<NUM>) around a hinge assembly rotation axis (A1) when said hinge assembly (<NUM>) is moved to said folded end position (P2a, P2b),
characterized in that
said linear actuator (<NUM>) comprising a rotation shaft (<NUM>) and at least one linear drive arrangement (<NUM>),
a first end of said linear drive arrangement (<NUM>) being interconnected with said rotation shaft (<NUM>),
a second, opposite end of said linear drive arrangement (<NUM>) being connected to at least one hinge blade (<NUM>), an actuator axis (A2) extending between said first end and said second end and perpendicular to said hinge assembly rotation axis (A1),
said linear actuator (<NUM>) further comprising a locking arrangement (<NUM>) for locking said hinge assembly (<NUM>) in at least one of said unfolded position (P1) and said folded end position (P2a, P2b),
said locking arrangement (<NUM>) comprising a cam element (<NUM>) interlocking with a cam section (<NUM>) located on said rotation shaft (<NUM>).