TECHNICAL FIELD

The disclosure relates to a hinge assembly comprising a first row of hinge plates and a second row of hinge plates being offset in relation to the first row of hinge plates such that a hinge plate of the second row partially overlaps a hinge plate of the first row.

BACKGROUND

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 an as large as possible display.

This problem may be solved by means of a foldable electronic device such as that of US 9,071,673, which discloses an electronic device comprising multiple housings interconnected by means of hinges and covered by one large display. The multiple housings, and the display, can be folded together to provide an as small device as possible, and unfolded to provide an as large display as possible.

The multiple housings are connected by means of hinge modules, which are configured to fold the multiple housings in such a way that the display is invisible, and hence the electronic device unusable, when the electronic device is in a folded configuration. Furthermore, the hinge modules of US 9,071,673 are bulky, complex, and comparatively heavy. SUMMARY

It is an object to provide an improved hinge assembly for a foldable 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 hinge assembly comprising a first row of hinge plates, a second row of hinge plates, a support rod, a pivot rod, the second row of hinge plates being offset in relation to the first row of hinge plates such that a hinge plate of the second row only partially overlaps a hinge plate of the first row, each hinge plate of the second row being pivotally connected to at least one neighboring hinge plate of at least one first row by means of a pivot rod, forming an interconnected hinge plate set, wherein each support rod passes through a hinge plate of an interconnected hinge plate set and borders the neighboring hinge plate of the interconnected hinge plate set, so that the neighboring hinge plate can fold around the support rod passing through the hinge plate of the interconnected hinge plate set.

Such a solution allows for a hinge assembly which has as small outer dimensions as possible, while having a range of motion which allows, e.g., two components interconnected by the hinge assembly, such as two electronic device frame sections, to be moved between an unfolded position, in which the frame 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. Furthermore, the solution provides support to any components which extend the two interconnected components across the hinge assembly.

In a possible implementation form of the first aspect, at least one first support rod passing through a hinge plate of a first row is arranged between two neighboring hinge plates of the second row so that the hinge plates of the second row can fold around the first support rod, and at least one second support rod passing through a hinge plate of a second row is arranged between two neighboring hinge plates of the first row so that the hinge plates of the first row can fold around the second support rod, facilitating a hinge assembly which has an as small width as possible while still allowing the hinge to fold the components, which the hinge assembly interconnects, completely together.

In a further possible implementation form of the first aspect,

the hinge plate of one row comprises at least one edge notch arranged to accommodate the support rod passing through a hinge plate of a neighboring row, such that the support rod and the hinge plate interlock when the hinge plate is unfolded around the support rod, allowing the hinge assembly to be locked in the unfolded position.

In a further possible implementation form of the first aspect,

the center axes of two neighboring support rods, connected to the hinge plates of one interconnected hinge plate set, are arranged at the same distance from the center axes of the pivot rod which interconnects the hinge plates of the interconnected hinge plate set regardless of whether a hinge plate is folded or unfolded around a support rod, such that any components which extend across the hinge assembly are not stretched beyond their limitations during folding.

In a further possible implementation form of the first aspect,

each hinge plate is tapered from a base section to an apex section, the apex sections of the hinge plates being moved towards each other when at least one hinge plate is being folded around a support rod, facilitating a hinge assembly which takes up minimal space and which is inherently stable when being folded together.

In a further possible implementation form of the first aspect,

each hinge plate is connected to one support rod and two pivot rods, the support rod being arranged closer to the apex section of the hinge plate than the pivot rods, allowing the hinge assembly to be folded together in one direction while being not foldable in the opposite direction. In a further possible implementation form of the first aspect,

the support rod comprises an axial center section and two axial end sections, the axial center section having larger outer dimensions than the axial end sections, providing secure attachment for the hinge plates in the longitudinal direction of the support rod such that a component supported by the support rods is not accidentally compressed due to movement of the hinge plates.

In a further possible implementation form of the first aspect,

each interconnected hinge plate set comprises at least one through-going passage extending through the hinge plates of the interconnected hinge plate set and accommodate a pivot rod, the through-going passage having variable inner dimensions allowing the pivot rod to spring, and subsequently an edge of a hinge plate to slide across the periphery of a support rod as the hinge plate is folded or unfolded around the support rod, allowing the pivot rods to bend slightly and hence the hinge assembly to be folded or unfolded.

In a further possible implementation form of the first aspect,

the hinge plate of one row comprises at least one further edge notch arranged to accommodate the support rod passing through a hinge plate of a neighboring row, such that the support rod and the hinge plate interlock when the hinge plate is folded around the support rod, allowing the hinge assembly to be locked in the folded position.

In a further possible implementation form of the first aspect,

the hinge plate comprises of at least two sheets of metal and a locking spring, the locking spring being interspersed between the metal sheets and carried by the support rod and pivot rod connected to the hinge plate, the edge notch being arranged in the locking spring, allowing the hinge assembly to be folded and unfolded without the pivot rod having to bend.

According to a second aspect, there is provided a foldable electronic device comprising a first frame section and at least one second frame section, a foldable display attached to a front face of the first frame section and a front face of the second frame section, a hinge assembly according to the above, the hinge assembly connecting the first frame section to the second frame section such that the first frame section and the second section are pivotable relative each other, the second frame section being superimposed on the first frame section when pivoted to a folded end position,

the front face of the second frame section being aligned with the front face of the first frame section when pivoted to an unfolded end position. A foldable electronic device provided with a hinge assembly according to the present disclosure has a range of motion which allows the frame sections of the electronic device to be moved between an unfolded position, in which the electronic device has a maximum width, and a folded position in which the two sections are superimposed onto each other such that the electronic device has a minimum width. Furthermore, the solution provides support to the display which extends from one frame section to the other frame section, across the hinge assembly.

In a possible implementation form of the second aspect, a distance between a center axis of the support rod and center axes of the pivot rods, connected to a hinge plate, is such that a neutral axis of the foldable display extends as close to the center axis of the pivot rods as possible, hence minimizing the stress on the display during folding.

In a further possible implementation form of the second aspect, any misalignment between the neutral axis of the foldable display and the center axes of the pivot rods is compensated for by means of adjusting the distance between the center axes of the pivot rods and the center axis of the support rod, allowing the display to be arranged on the frame sections in a position wherein the stress on the display during folding is minimal.

In a further possible implementation form of the second aspect, the foldable electronic device further comprises a spring mechanism arranged between each frame section and each hinge assembly, allowing a distance between the first frame section and the second frame sections, and hence the stress on the display, to vary when necessary. In a further possible implementation form of the second aspect, the foldable electronic device further comprises a flexible support sheet arranged to support a folding section of the foldable display, the support rod(s) being arranged to support the flexible support sheet.

This and other aspects will be apparent from the embodiments 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. 1 shows a side view of a hinge assembly in accordance with one embodiment of the present invention;

Fig. 2 shows a perspective view of the embodiment of Fig. 1;

Fig. 3a shows a side view of a hinge assembly in accordance with a further embodiment of the present invention, the hinge assembly being in an unfolded position;

Fig. 3b shows the embodiment of Fig. 3b in a folded position;

Fig. 4 shows the embodiment of Figs. 3a and 3b in further detail;

Fig. 5 shows a cross-sectional perspective view of a hinge assembly in accordance with a further embodiment of the present invention;

Fig. 6 shows a cross-sectional top view of a hinge assembly in accordance with a further embodiment of the present invention; Fig. 7a shows a perspective view of a hinge assembly in accordance with a further embodiment of the present invention;

Fig. 7b shows a cross-sectional perspective view of the embodiment of Fig. 7a;

Fig. 8 shows a perspective view of an interconnected hinge plate set in accordance with one embodiment of the present invention;

Fig. 9 shows a schematic side view of a hinge plate and a support rod in accordance with one embodiment of the present invention, the support rod being arranged in first and second edge notches, respectively;

Fig. lOa shows a schematic side view of an interconnected hinge plate set in accordance with one embodiment of the present invention, the hinge plate set being in an unfolded position;

Fig. lOb shows the embodiment of Fig. lOb in a folded position;

Fig. l la shows a perspective view of a foldable electronic device in accordance with one embodiment of the present invention, the foldable electronic device being in an unfolded position;

Fig. 1 lb shows the embodiment of Fig. l la, the foldable electronic device being in a folded position;

Fig. 12 shows a perspective view of a hinge assembly in accordance with one embodiment of the present invention;

Fig. l3a shows a cross-sectional side view of a foldable electronic device in accordance with one embodiment of the present invention; Fig. l3b shows a cross-sectional side view of a foldable electronic device in accordance with a further embodiment of the present invention;

Fig. 14 shows a perspective view of a support rod in accordance with one embodiment of the present invention;

Fig. 15 shows a cross-sectional side view of a foldable electronic device in accordance with an embodiment of the present invention;

Fig. l6a shows a cross-sectional side view of a foldable electronic device in accordance with one embodiment of the present invention, the foldable electronic device being in an unfolded position;

Fig. l6b shows the embodiment of Fig. l6a, the foldable electronic device being in a folded position.

DETAILED DESCRIPTION

Figs l la and l lb show a foldable electronic device 16 comprising a first frame section l7a and a second frame section l7b. A hinge assembly 1, shown more clearly in Fig. 12, connects the first frame section l7a to the second frame section l7b such that the first frame section l7a and the second frame section l7b are pivotable relative each other, between a folded end position Pl and an unfolded end position P2. In the folded end position Pl, shown in Fig. 1 lb, the second frame section l7b is superimposed on the first frame section l7a. In the unfolded end position P2, shown in Fig. 1 la, the front face of the second frame section l7b is aligned with the front face of the first frame section l7a.

The foldable electronic device 16 further comprises a foldable display 18, attached to the front face of the first frame section l7a and the front face of the second frame section l7b, and extending across the hinge assembly 1. In one embodiment, the foldable electronic device 16 further comprises a spring mechanism 19, shown in Fig. 15, which is arranged between the first frame section l7a and the hinge assembly 1, as well as a spring mechanism 19 arranged between the second frame section l7b and the hinge assembly 1. The flexible spring mechanism 19 allows the distance D2 between the first frame section l7a and second frame section l7b to vary slightly, reducing the stress on the foldable display 18 as it is being folded or unfolded.

The first frame section l7a may be a hollow housing which comprises the internal components of the foldable electronic device 16, such as battery, circuit board, etc., and the second frame section l7b may be either a similar hollow housing or a solid support plate. Furthermore, the foldable electronic device 16 may comprise two second frame sections l7b, one arranged at each longitudinal edge of the first frame section l7a.

The hinge assembly 1, shown in, e.g. Figs. 1 and 12, comprises at least one support rod 5, which, when mounted in a foldable electronic device 16, extends in parallel with the longitudinal edges of the first frame section l7a and the second frame section l7b, and is adapted for supporting the foldable section of the electronic device 16, e.g. the foldable display 18, as it extends across the gap between the first frame section l7a and the second frame section l7b. The support rods 5 may support the display 18 directly, or support a flexible support sheet 20 arranged to, in turn, support the foldable section of the foldable display 18.

The flexible support sheet, shown in Fig. 11 a, may rest on the support rods, as shown in Fig. l3a, or may enclose the support rods, as shown in Fig. l3b, in which case the support rods are either assembled separately onto the flexible support sheet 20 or insert molded together with the flexible support sheet 20. The flexible support sheet 20 is preferably made of elastomer or flexible metal. In addition to the support rods 5, the hinge assembly 1 comprises at least one first row 2 of hinge plates 3a, at least one second row 4 of hinge plates 3b, and at least one pivot rod 6, as shown in Figs. 1, 3a, 3b, and 5. The second row 4 of hinge plates 3b is offset in relation to the first row 2 of hinge plates 3a such that a hinge plate 3b of the second row 4 only partially overlaps a hinge plate 3a of the first row 2. Furthermore, each hinge plate 3b of the second row 4 is pivotally connected to at least one neighboring hinge plate 3a of at least one first row 2 by means of a pivot rod 6, forming an interconnected hinge plate set 7 as shown in Fig. 8. Fig. 8 shows two hinge plates 3a and one hinge plate 3b, but any number of hinge plates 3 a of the first row 2 and any number of hinge plates 3b of the second row 4 is possible.

The hinge assembly 1 may comprise only one first row 2 of hinge plates 3a and only one second row 4 of hinge plates 3b. The hinge assembly 1 may also comprise two first rows 2 of hinge plates 3a and only one second row 4 of hinge plates 3b, as shown in Figs. 2, 5, 6, 7b, and 8, in which case the second row 4 of hinge plates 3b is arranged between the two first rows 2 of hinge plates 3a. The hinge assembly 1 may also comprise multiple first rows 2 of hinge plates 3a as well as multiple second rows 4 of hinge plates 3b. The rows 2, 4 may be arranged such that every second row is a first row 2 of hinge plates 3a and every other row is a second row 4 of hinge plates 3b. The rows 2, 4 may also be arranged such that two or more adjacent rows are first rows 2 of hinge plates 3a and the next two or more adjacent rows are second rows 4 of hinge plates 3b. For the sake of simplicity, the description below will refer to an embodiment comprising one or two first rows 2 of hinge plates 3a and one second row 4 of hinge plates 3b between, however, the description below is applicable to all possible embodiments.

Each hinge plate 3a, 3b of the hinge assembly 1 may be connected to two neighboring hinge plates 3b, 3a of at least one neighboring row, to one neighboring hinge plate 3b, 3a of a neighboring row and the first frame section l7a or the second frame section l7b, or to the first frame section l7a and the second frame section l7b. The latter is shown, e.g., in Figs. 5, l3a, l3b, and l6a. The embodiment shown in Fig. 8, shows an interconnected hinge plate set 7 comprising two hinge plates 3a of first rows 2, a neighboring hinge plate 3b of the second row 4, and a pivot rod 6 pivotally connecting the three hinge plates. In such an embodiment, each support rod 5a will pass through two hinge plates 3a, and each support rod 5b will pass through one hinge plate 3b. Each support rod 5a, 5b will border at least one neighboring hinge plate 3b, 3a of the interconnected hinge plate set 7. Hence, the neighboring hinge plate 3b, 3a can fold around the support rod 5a, 5b passing through the hinge plate 3a, 3b of the interconnected hinge plate set 7.

This is shown more clearly in Fig. 3b, which shows two hinge plates 3a of the first rows 2 being folded around one support rod 5b of the second row 4. Fig. 3a shows the same embodiment when the foldable electronic device 16, and hence the hinge assembly 1, is unfolded, i.e. the frame sections l7a, l7b of the electronic device extend in one and the same main plane.

As shown in Fig. 5, a first support rod 5a, passing through a hinge plate 3a of a first row 2, is arranged between two neighboring hinge plates 3b of the second row 4 so that the hinge plates 3b of the second row 4 can fold around the first support rod 5 a, and a second support rod 5b, passing through a hinge plate 3b of a second row 4, is arranged between two neighboring hinge plates 3a of the first row 2 so that the hinge plates 3a of the first row 2 can fold around the second support rod 5b.

Each support rod 5a, 5b comprises an axial center section l la and two axial end sections l lb, the axial center section l la preferably having larger outer dimensions than the axial end sections 1 lb as shown in Fig. 14. The axial sections 1 la, 1 lb of the support rod 5a, 5b may be cylindrical. The axial center section l la of the support rod 5a, 5b may also be tapered from the base section 9 to the apex section 10, as shown in Figs. 14, l6a, and l6b. The widest outer surface of the base section 9 may be convex such that all neighboring support rods 5a, 5b together form a semicircular surface when the hinge plates 3a, 3b have been folded around the support rods 5a, 5b, as shown in Fig. l6b. The tapered shape may be achieved, e.g., by machining a metal rod or by molding plastic over a cylindrical metal rod.

As shown in Figs. 1 and 3b, each hinge plate 3a, 3b is tapered from a base section 9 to an apex section 10, the hinge plates 3a, 3b being arranged such that the apex sections 10 of the hinge plates 3a, 3b are moved towards each other when at least one hinge plate 3a, 3b is folded around a support rod 5b, 5a. Each individual hinge plate 3a, 3b is connected to one support rod 5a, 5b and two pivot rods 6, the support rod 5a, 5b being arranged closer to the apex section 10 of the hinge plate 3a, 3b than the pivot rods 6.

Each hinge plate 3a, 3b of one row 2, 4 comprises at least one edge notch 8a arranged to accommodate the support rod 5b, 5a passing through a hinge plate 3b, 3a of a neighboring row 4, 2, as shown in Figs. 4 and 5. The edge notch 8a allows the support rod 5b, 5a and the hinge plate 3a, 3b to interlock when the hinge plate 3a, 3b is unfolded around the support rod 5b, 5a, i.e., when the foldable electronic device 16 is in the unfolded end position P2.

Each hinge plate 3 a, 3b of one row 2, 4 may further comprise at least one further edge notch 8b also arranged to accommodate the support rod 5b, 5a passing through a hinge plate 3b, 3a of a neighboring row 4, 2. The edge notch 8b allows the support rod 5b, 5a and the hinge plate 3a, 3b to interlock when the hinge plate 3a, 3b is folded around the support rod 5b, 5a, i.e., when the foldable electronic device 16 is in the folded end position Pl .

The edge notches 8a, 8b, the support rods 5a, 5b and their interrelated positions are shown more clearly in Fig. 9, as well as Fig. lOa, which shows the foldable electronic device 16 in the unfolded end position P2, and Fig. lOb, which shows the foldable electronic device 16 in the folded end position Pl. Figs. 9, lOa, and lOb also show the circle of rotation along which the support rods 5a, 5b move, except for when the protrusion formed between the two edge notches 8a, 8b slides across the support rods 5a, 5b. At least one edge of each hinge plate 3a, 3b may further comprise at least one of a tooth or a recess, such that neighboring hinge plates 3a, 3b of one row 2,4 form a synchronized gear mechanism. Such a gear mechanism is shown in Figs. 3a and 3b.

Each interconnected hinge plate set 7 comprises at least one through-going passage 12 which extends through the hinge plates 3a, 3b of the interconnected hinge plate set 7 and accommodates a pivot rod 6. The through-going passage 12 may have the same inner dimensions throughout, or it may have variable inner dimensions as shown in Figs. 5 and 6. Such variable inner dimensions, e.g. provided by chamfering the through-going passage 12, allows sufficient space for the pivot rod 6 to bend within the hinge assembly 1 which subsequently provides the resilience needed for an edge 13 of a hinge plate 3a, 3b to slide across the periphery of a support rod 5b, 5a as the hinge plate 3a, 3b is being folded or unfolded around the support rod 5b, 5a.

The hinge plate 3 a, 3b may be made in one integral piece, or it may comprise of at least two sheets 14 of metal, e.g. stamped metal sheets. In the latter case, a locking spring 15 may be interspersed between the metal sheets 14 and carried by the support rod 5a, 5b and the pivot rods 6 connected to the hinge plate 3a, 3b, as shown in Figs. 7a and 7b. The opposing ends of the locking spring 15 are hook-shaped such that they partially surround and connect with the pivot rods 6, while the middle section of the locking spring 15 is pulled in a direction away from the pivot rods, and hence the ends of the locking spring 15, by the support rod 5a, 5b. The edge notches 8a, 8b are arranged in the locking spring 15. In this embodiment, the pivot rod 6 does not need to bend as the hinge plate 3a, 3b is being folded or unfolded around the support rod 5b, 5a, but rather, the locking spring 15 is sufficiently resilient to allow said folding and unfolding.

The center axes Cl of two neighboring support rods 5a, 5b, connected to the hinge plates 3a, 3b of one interconnected hinge plate set 7, are arranged at the same distance Dl from the center axis C2 of the pivot rod 6 which interconnects the hinge plates 3a, 3b of the interconnected hinge plate set 7 regardless of whether a hinge plate 3a, 3b is folded, as shown in Fig. 3b, or unfolded, see Fig. 3a, around a support rod 5b, 5a. The distance Dl between the center axis Cl of the support rod 5a, 5b and the center axis C2 of the pivot rod 6, connected to a hinge plate 3a, 3b, is such that a neutral axis N of the foldable display 18 extends as close to the center axis C2 of the pivot rod 6 as possible, as shown in Fig. 4. The neutral axis N corresponds to the section of display in which the stress on the display during folding is minimized. The neutral axis N of the foldable display 16 may correspond to the center line of the foldable display 18, however, it may also extend in parallel with, at a distance from, the center line of the foldable display 18. Any misalignment between the neutral axis N of the foldable display 18 and the center axes C2 of the pivot rods 6 is compensated for by means of adjusting the distance Dl between the center axis C2 of the pivot rod 6 and the center axis Cl of the support rod 5a, 5b.

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. 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.

The reference signs used in the claims shall not be construed as limiting the scope.