TECHNICAL FIELD

The disclosure relates to a foldable assembly for an electronic device, the foldable assembly comprising a housing comprising a first section, a second section, and a third section.

BACKGROUND

The size of mobile devices, such as tablets and mobile phones, is an important consideration when designing mobile devices. In order to provide the best mobile device possible, the outer dimensions of the device have to be as small as is technically feasible, while still allowing the display of the device to be 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.

However, as the electronic device is folded, the display and/or the back cover will stretch on one side of the neutral axis and compress on the other side of the neutral axis. The neutral axis is the axis along which the display or the housing remains unchanged as it is folded, i.e. it neither stretches nor compresses. Furthermore, the continuous folding of the display and/or back cover may lead to permanent deformation due to fatigue, since the folded area is subject to very high stress. SUMMARY

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

According to a first aspect, there is provided a foldable assembly for an electronic device, the foldable assembly comprising a housing comprising a first section, a second section, and a third section, the first section and the second section being pivotally connected to opposing edges of the third section, a first hinge assembly connecting the first section and the third section, a second hinge assembly connecting the second section and the third section, the first section being pivotable relative the third section around a first assembly rotation axis by means of the first hinge assembly, the second section being pivotable relative the third section around a second assembly rotation axis by means of the second hinge assembly, the second assembly rotation axis extending in parallel with the first assembly rotation axis, the first section, the second section, and the third section being aligned in a common plane when the foldable assembly is in an unfolded position, the first section, the second section, and the third section being superimposed onto each other when the foldable assembly is in a folded end position, a synchronization arrangement connecting the first section and the second section operatively such that the first section and the second section are pivoted simultaneously, the simultaneous pivoting comprising the first section being pivoted clockwise and the second section being pivoted counterclockwise, or the first section being pivoted counterclockwise and the second section being pivoted clockwise.

Such a solution allows any dimensional changes, e.g. across the first hinge assembly, and generated by the folding or unfolding action, to be absorbed within the foldable assembly since the second hinge assembly folds correspondingly, in an opposite direction. In a possible implementation form of the first aspect, an outer face of the first section and an outer face of the second section extend in parallel with each other when the foldable assembly is in the folded end position.

In a further possible implementation form of the first aspect, the second section is superimposed on a first face of the third section, and the first section is superimposed on a second face of the third section when the foldable assembly is in the folded end position, such that they extend to provide only a minimum width.

In a further possible implementation form of the first aspect, a first dimension of an outer surface of the first hinge assembly is larger than a corresponding second dimension of an inner surface of the first hinge assembly, and a first dimension of an outer surface of the second hinge assembly is larger than a corresponding second dimension of an inner surface of the second hinge assembly, when the foldable assembly is in the folded end position, facilitating symmetrical folding.

In a further possible implementation form of the first aspect, the first dimension of the outer surface of the first hinge assembly is equal to the first dimension of the outer surface of the second hinge assembly, and the second dimension of the inner surface of the first hinge assembly is equal to the second dimension of the inner surface of the second hinge assembly, making any stretching of elements connected to these surfaces unnecessary.

In a further possible implementation form of the first aspect, the sum of the first dimension of the outer surface of the first hinge assembly and the second dimension of the inner surface of the second hinge assembly is constant.

In a further possible implementation form of the first aspect, the sum of the second dimension of the inner surface of the first hinge assembly and the first dimension of the outer surface of the second hinge assembly is constant. In a further possible implementation form of the first aspect, the first section and the second section are pivoted at identical speeds, such that the first section and the second section extend at substantially identical angles relative the third section when pivoted, facilitating a solution in which any elements connected to these sections maintains their outer dimensions also during folding.

In a further possible implementation form of the first aspect, the foldable assembly further comprises a first surface layer and a second surface layer attached to opposite faces of the housing, the first surface layer and the second surface layer extending in parallel with each other and with a main plane of the housing.

In a further possible implementation form of the first aspect, the housing has a first neutral axis, the first surface layer has a second neutral axis, and the second surface layer has a third neutral axis, superimposed sections of the first neutral axis, the second neutral axis, and the third neutral axis extending in parallel, and wherein the second neutral axis is offset in a first direction by a first offset distance from the first neutral axis along an offset axis extending perpendicular to the first assembly rotation axis and the second assembly rotation axis, the third neutral axis being offset in a second direction, opposite to the first direction, by a second offset distance from the first neutral axis, allowing said foldable assembly to be folded without affecting the dimensions of the first surface layer and the second surface layer.

In a further possible implementation form of the first aspect, the synchronization arrangement comprises at least one linear drive extending in the direction of an actuator axis, the actuator axis extending substantially perpendicular to the first assembly rotation axis and the second assembly rotation axis, a first end of the linear drive being connected to the first section, a second end of the linear drive being connected to the second section. This allows for a linear drive which takes up little space and which can be fitted into any suitable, available location. In a further possible implementation form of the first aspect, pivoting one ofthe first section and the second section actuates the linear drive such that the linear drive urges the other of the first section and the second section to pivot simultaneously, at identical speed and in an opposite direction. As a result, the movement generated by the linear drive is synchronized at both ends of the housing.

In a further possible implementation form of the first aspect, the synchronization arrangement further comprises a rotation shaft arranged within the third section, the linear drive being connected to the rotation shaft.

In a further possible implementation form of the first aspect, the synchronization arrangement further comprises a motor adapted for rotating the rotation shaft, and wherein rotation of the rotation shaft initiates movement of the linear drive at least partially along the actuator axis, providing for automated folding of the foldable assembly and any electronic device into which it is mounted.

In a further possible implementation form of the first aspect, the rotation shaft extends in parallel with the first assembly rotation axis and the second assembly rotation axis.

In a further possible implementation form of the first aspect, the rotation shaft extends perpendicular to the first assembly rotation axis and the second assembly rotation axis.

In a further possible implementation form of the first aspect, the linear drive comprises at least one chain, wire, and/or sheet.

In a further possible implementation form ofthe first aspect, the linear drive comprises two wire sections extending on opposite sides of, with equidistant spacing from, the first neutral axis. This allows the actuation of the linear drive to be synchronized along both main surfaces ofthe electronic device. In a further possible implementation form of the first aspect, the synchronization arrangement further comprises at least one pinion enclosing a part of the rotation shaft, a first rack engaging the pinion at a first location, and a second rack engaging the pinion at a second location opposite the first location, the first rack and the second rack extending in the direction of the actuator axis, synchronizing movement on both sides of the rotation shaft.

In a further possible implementation form of the first aspect, the first rack is connected to and supports the first surface layer, and the second rack is connected to and supports the second surface layer.

In a further possible implementation form of the first aspect, the first surface layer and the second surface layer are adapted for sliding across the opposite faces of the third section of the housing.

In a further possible implementation form of the first aspect, the synchronization arrangement further comprises a locking arrangement for locking the foldable 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 arranged on the rotation shaft. This allows the foldable assembly to be securely locked into place in the unfolded position or the 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 further possible implementation form of the first aspect, the cam element encloses a part of the rotation shaft such that the cam element and the rotation shaft share a center axis, providing a reliable locking arrangement which takes up very little space.

In a further possible implementation form of the first aspect, the cam element is arranged adjacent an end of the rotation shaft and extends at least partially in a first plane perpendicular to a center axis of the rotation shaft, the cam section extending in the first plane and comprising at least one peripheral notch adapted for receiving a part of the cam 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.

According to a second aspect, there is provided an electronic device comprising the foldable assembly according to the above, wherein the first surface layer of the foldable assembly comprises a display, and the second surface layer of the foldable assembly comprises a further display or a back cover. Such a solution allows the display and/or the back cover to slide in relation to the housing, as the electronic device is folded, hence preventing surface layers, such as the display, from becoming wrinkled and/or permanently deformed since it neither stretches nor compresses as the device is folded.

In a possible implementation form of the second aspect, the linear drive of the foldable assembly extends at least partially through a first tunnel in the first hinge assembly and through a second tunnel in the second hinge assembly, preventing the trajectory of the linear drive from being shortened as the device is folded.

These and other aspects will be apparent from and the embodiment(s) described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments, and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which:

Fig. la shows a schematic side view of an electronic device in accordance with one embodiment of the present invention in an unfolded position; Fig. lb shows the embodiment of Fig. la in a folded end position;

Fig. lc shows a perspective view of the embodiments shown in Figs la and lb;

Fig. 2 shows a partial side view of a foldable assembly in accordance with one embodiment of the present invention;

Fig. 3a shows a schematic side view of the housing of a foldable assembly in accordance with one embodiment of the present invention;

Fig. 3b shows side view of an electronic device in accordance with one embodiment of the present invention, comprising the housing of Fig. 3a;

Fig. 4a shows a partial perspective view of a foldable assembly in accordance with one embodiment of the present invention;

Fig. 4b shows a side view of the embodiment shown in Fig. 4a;

Fig. 5 shows a partial perspective view of the linear drive of a foldable assembly in accordance with one embodiment of the present invention;

Fig. 6 shows a partial perspective view of a foldable assembly in accordance with one embodiment of the present invention;

Fig. 6b shows a partial perspective view of the linear drive of the embodiment shown in Fig. 6a;

Fig. 7 shows a partial perspective view of a linear drive of a foldable assembly in accordance with one embodiment of the present invention; Fig. 8a shows a top view of a linear drive of a foldable assembly in accordance with one embodiment of the present invention;

Fig. 8b shows a partial side view of the embodiment shown in Fig. 8a.

DETAILED DESCRIPTION

Figs la to lc disclose an electronic device 13 comprising a foldable assembly 1 , which is described in more detail below. The display of the electronic device 13 may comprise a first surface layer 4 of the foldable assembly 1, while a further display, or back cover, of the electronic device 13 may comprise a second surface layer 5 of the foldable assembly 1. The first surface layer 4 and the second surface layer 5 are carried by a housing 2 comprising a first section 2a, a second section 2b, and a third section 2c. The first section 2a and the second section 2b are pivotally connected to opposing edges of the third section 2c, by means of a first hinge assembly 14 and a second hinge assembly 15.

The first surface layer 4 and a second surface layer 5 of the foldable assembly 1 may be attached to opposite faces of the housing 2, such that the first surface layer 4 and the second surface layer 5 extend in parallel with each other and with a main plane of the housing 2. The first surface layer 4 and the second surface layer 5 are preferably fixed to opposite faces of both the first section 2a and the second section 2b. The first surface layer 4 and the second surface layer 5 may be adapted for sliding across the opposite faces of the third section 2c of the housing 2.

The housing 2 comprises most other components of the electronic device, such as battery, electronic circuits, optics, audio etc. One or several of the first section 2a, the second section 2b, and the third section 2c may have a tapered shape, as shown in Figs. 3a and 3b. Correspondingly, one or several of the first section 2a, the second section 2b, and the third section 2c may have surfaces which extend in parallel, i.e. the section(s) has/have the shape of a rectangular parallelepiped as shown in Fig. 2. Regardless of the shape of the sections, an outer face of the first section 2a and an outer face of the second section 2b may extend in parallel with each other when the foldable assembly 1 is in a folded end position P2, as shown in Figs lb, 2, 3b, and 4b.

A linear drive 7 of the foldable assembly 1 may extend at least partially through a first tunnel 16 in a first hinge assembly 14 and through a second tunnel 17 in a second hinge assembly 15, as shown in Fig. 5. This supports and maintains the linear drive 7 in the correct position as the foldable assembly 1 is being folded.

The first section 2a, the second section 2b, and the third section 2c are aligned in a common plane when the foldable assembly 1 is in an unfolded position PI, and are superimposed onto each other when the foldable assembly 1 is in the folded end position P2. The second section 2b may be superimposed on a first face of the third section 2c, the first surface e.g. comprising the display of the electronic device 13, and the first section 2a may be superimposed on a second face of the third section 2c, the second surface e.g. comprising the back cover of the electronic device 13, when the foldable assembly 1 is in the folded end position P2, as shown in Figs lb and lc. In the folded end position P2, only approximately one third of the display may be visible to the user, while the entire display is visible in the unfolded position PI .

The foldable assembly 1 comprises the above-mentioned housing 2, first hinge assembly 14, and second hinge assembly 15, as shown in Figs. 2 and 3b. The first section 2a is pivotable relative the third section 2c around a first assembly rotation axis A1 by means of the first hinge assembly 14. The second section 2b is pivotable relative the third section 2c around a second assembly rotation axis A2 by means of the second hinge assembly 15, the second assembly rotation axis A2 extending in parallel with the first assembly rotation axis Al.

A synchronization arrangement 3 connects the first section 2a and the second section 2b operatively such that the first section 2a and the second section 2b are pivoted simultaneously, as shown in Figs. 4a and 6a. The simultaneous pivoting comprises the first section 2a being pivoted clockwise and the second section 2b being pivoted counterclockwise, or the first section 2a being pivoted counterclockwise and the second section 2b being pivoted clockwise.

Neither the first surface layer 4 nor the second surface layer 5 change dimensions as the foldable assembly 1 is pivoted between the unfolded position PI and the folded end position P2, wherefore the first surface layer 4 and the second surface layer 5 are preferably made of materials which are bendable but not necessarily stretchable. Instead, all dimensional changes may be absorbed by the simultaneous movement of the first section 2a and the second section 2b, sliding movement of the first surface layer 4 and the second surface layer 5 across the third section 2c, and/or the symmetrical action of the synchronization arrangement 3 across the first hinge assembly 14 and second hinge assembly 15.

As shown in Fig. 2, a first dimension D14a of an outer surface 14a of the first hinge assembly 14 may be larger than a corresponding second dimension D14b of an inner surface 14b of the first hinge assembly 14, when the foldable assembly 1 is in the folded end position P2. Correspondingly, a first dimension D 15b of an outer surface 15b of the second hinge assembly 15 may be larger than a corresponding second dimension D 15a of an inner surface 15a of the second hinge assembly 15, when the foldable assembly 1 is in the folded end position P2.

The first dimension D 14a of the outer surface 14a of the first hinge assembly 14 may be equal to the first dimension D 15b of the outer surface 15b of the second hinge assembly 15, and the second dimension D 14b of the inner surface 14b of the first hinge assembly 14 may, simultaneously, be equal to the second dimension D 15a of the inner surface 15a of the second hinge assembly 15.

The sum of the first dimension D 14a of the outer surface 14a of the first hinge assembly

14 and the second dimension D 15a of the inner surface 15a of the second hinge assembly

15 may be constant. Correspondingly, the sum of the second dimension D 14b of the inner surface 14b of the first hinge assembly 14 and the first dimension D 15b of the outer surface 15b of the second hinge assembly 15 may be constant.

In one embodiment, the first section 2a and the second section 2b are pivoted at identical speeds, such that the first section 2a and the second section 2b extend at substantially identical angles ai, X2 relative the third section 2b when pivoted, as indicated in Fig. 4b. The foldable assembly 1, and hence the electronic device 13, folds to and from a Z-shape.

The housing 2 may have a first neutral axis Nl, the first surface layer 4 a second neutral axis N2, and the second surface layer 5 a third neutral axis N3. Superimposed sections of the first neutral axis Nl, the second neutral axis N2, and the third neutral axis N3 extend in parallel, and the second neutral axis N2 is offset in a first direction D1 by a first offset distance from the first neutral axis 1 along an offset axis extending perpendicular to the first assembly rotation axis Al and the second assembly rotation axis A2. Similarly, the third neutral axis N3 is offset in a second direction D2, opposite to the first direction Dl, by a second offset distance from the first neutral axis Nl , as shown in Fig. la.

The synchronization arrangement 3 may comprise at least one linear drive 7 extending in the direction of an actuator axis A3, the actuator axis A3 extending substantially perpendicular to the first assembly rotation axis Al and the second assembly rotation axis A2. A first end 7a of the linear drive 7 is connected to the first section 2a, and a second end 7b of the linear drive 7 is connected to the second section 2b. Pivoting one of the first section 2a and the second section 2b may actuate the linear drive 7 such that the linear drive 7 urges the other of the first section 2a and the second section 2b to pivot simultaneously, at identical speed and in an opposite direction.

The linear drive 7 may comprise at least one chain, wire, and/or sheet. The linear drive 7 may furthermore comprise two wire sections extending on opposite sides of, with equidistant spacing from, the first neutral axis N 1. The synchronization arrangement 3 may further comprise a rotation shaft 6 arranged within the third section 2c, the linear drive 7 being connected to the rotation shaft 6 as shown in Figs. 6a and 6b.

The synchronization arrangement 3 may further comprises a motor adapted for rotating the rotation shaft 6, such that rotation of the rotation shaft 6 initiates movement of the linear drive 7 at least partially along the actuator axis A3.

The rotation shaft 6 may extend in parallel with the first assembly rotation axis A1 and the second assembly rotation axis A2, as shown in Figs. 6a and 6b.

The synchronization arrangement 3 may further comprise at least one pinion 8 enclosing a part of the rotation shaft 6, a first rack 9 engaging the pinion 8 at a first location, and a second rack 10 engaging the pinion 8 at a second location opposite the first location, the first rack 9 and the second rack 10 extending in the direction of the actuator axis A3.

The first rack 9 may be connected to and support the first surface layer 4, and the second rack 10 may be connected to and support the second surface layer 5. Hence, as the rotation shaft 6 is rotated, the first rack 9 and the first surface layer 4 are moved in one direction along the actuator axis A3. Correspondingly, the second rack 10 and the second surface layer 5 may be moved in an opposite direction along the actuator axis A3.

The rotation shaft 6 may also extend perpendicular to the first assembly rotation axis A1 and the second assembly rotation axis A2, as shown in Figs. 8a and 8b.

The synchronization arrangement 3 may further comprise a locking arrangement 11 as shown in Figs. 7. The locking arrangement 11 locks the foldable assembly 1 in at least one of the unfolded position PI and the folded end position P2, the locking arrangement 11 comprising a cam element 11 a interlocking with a cam section 1 lb arranged on the rotation shaft 6. The cam element 11a may enclose a part of the rotation shaft 6 such that the cam element 11a and the rotation shaft 6 share a center axis. As shown in Figs. 8a and 8b, the cam element 1 la may be arranged adjacent an end of the rotation shaft 6 and extend at least partially in a first plane perpendicular to a center axis of the rotation shaft 6, the cam section l ib extending in the first plane and comprising at least one peripheral notch 12 adapted for receiving a part of the cam element 11a.

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. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the 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. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

The reference signs used in the claims shall not be construed as limiting the scope. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this disclosure. As used in the description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.