Patent Description:
With the continuous improvement of electronic devices and smartphones, inherently there is also a need for advanced displays. One trend in the development of screens is extendable displays that provide devices having similar sizes but with larger screens. There are different types of extendable displays, such as bending, folding, rolling, and/or sliding displays.

It is apparent that, in order to be efficient, these displays need to have a support structure supporting the movement of the display, and also allowing the display to be flexible. Also, the display should be able to move, roll or slide as smoothly as possible, thus friction generated by movement has to be reduced. Currently, the most often used solution is to coat the sliding surfaces with a low-friction material, such as POM (Acetal, also known as Polyoxymethylene). However, this only partially reduces friction.

Patent application no. <CIT> comprises a belt-like display support. The tight bending radius of the display creates a bump near the bend, which bump effect is mitigated by means of a wire. This is a high-cost system which also adds unwanted weight to the device.

The document <CIT> also shows a slidable display arrangement for mobile communications devices.

The present invention is defined by the independent claim <NUM>.

It is an object to provide an improved support structure. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided a support structure for a slidable display, the support structure comprising a support arrangement configured to slide along a first sliding axis, at least two rotation arrangements, each rotation arrangement being fixedly arranged along the first sliding axis and configured to rotate around a rotation axis extending substantially perpendicular to the first sliding axis, each rotation arrangement being releasably interconnected to at least one support element of the support arrangement, such that the rotation arrangement rotates around the rotation axis with a tangential speed equal to a speed with which the support arrangement moves along the first sliding axis.

This solution provides a support structure with reduced sliding friction between the slidable display and the housing of the mobile device, since the use of the rotation arrangement almost entirely eliminates sliding friction by converting it into much smaller rotational friction. The rotation arrangement has a simple configuration and structure, and can be produced and replaced at low cost. The maintenance and/or replacement of worn rotation arrangements is easy, since the rotation arrangements are individual elements. In addition, the weight of the support structure, and/or the device into which it is mounted, is reduced.

In a possible implementation form of the first aspect, the support arrangement is configured to fold around a folding axis and slide along a second sliding axis, the second sliding axis extending at an angle to the first sliding axis, the folding axis extending substantially perpendicular to the first sliding axis, the second sliding axis, and the rotation axis, at least two rotation arrangements being fixedly arranged along the second sliding axis, each rotation arrangement being configured to rotate around a rotation axis extending substantially perpendicular to the second sliding axis. This facilitates continuous guiding of the sliding movement and provides smooth sliding with reduced friction.

In a further possible implementation form of the first aspect, a folded section of the support structure, extending between the first sliding axis and the second sliding axis, comprises at least two rotation arrangements. This facilitates guiding of the sliding movement even after the fold of the display. Having rotation arrangements along the whole length of the display helps reduce or completely eliminate the bump of the display.

In a further possible implementation form of the first aspect, the number of rotation arrangements is even, preferably between <NUM>-<NUM>.

In a further possible implementation form of the first aspect, the interconnection between the rotation arrangement and the support element is achieved by means of at least partially complementary shapes. This facilitates a constraint in the movement of the display to be only in the direction of the sliding axis, thus reducing the display bump effect.

In a further possible implementation form of the first aspect, a first end of the support arrangement is interconnected to at least one first rotation arrangement, and a second end of the support arrangement is interconnected to at least one second rotation arrangement. This facilitates the same guiding and equal speed on both sides of the support arrangement, which supports even and smooth sliding of the display.

In a further possible implementation form of the first aspect, the support arrangement comprises a plurality of support elements, each support element being a protrusion extending from a sheet.

In a further possible implementation form of the first aspect, the support arrangement comprises a sheet and a plurality of support elements, each support element comprising a rod arranged to support the sheet, center axes of the support elements extending in parallel with each other and with the folding axis.

In a further possible implementation form of the first aspect, the interconnection between the rotation arrangement and the support element prevents translation of the support element in all directions except along the first sliding axis and/or the second sliding axis.

In a further possible implementation form of the first aspect, the rotation arrangement comprises a transmission wheel being in sliding contact with the support element.

In a further possible implementation form of the first aspect, the rotation arrangement comprises a transmission wheel comprising a plurality of slots arranged around a circumference of the transmission wheel, each slot being configured to engage with one end of one support element. This facilitates a simple connection between the rotation arrangements and the support elements.

In a further possible implementation form of the first aspect, there is at least one contact point between the rotation arrangement and the support element at any time during interconnection, a maximum contact area achieved when the rotation axis and the center axis are aligned.

In a further possible implementation form of the first aspect, the plurality of slots comprises at least a first slot and a neighboring second slot, and the plurality of support elements comprises at least a first support element and a neighboring second support element, the first slot engaging the first support element, and wherein, as the support arrangement slides along the first sliding axis and the rotation arrangement rotates around the rotation axis, the first slot disengages from the first support element and the second slot engages the second support element.

In a further possible implementation form of the first aspect, the neighboring slots are delimited by a joint shoulder, the shoulder extending into a gap between two neighboring support elements, as the support arrangement slides along the first sliding axis and the rotation arrangement rotates around the rotation axis.

In a further possible implementation form of the first aspect, the support structure further comprises a motor operatively connected to the rotation arrangement, the motor being configured to drive the sliding movement of the support arrangement via the rotation arrangement. In this way, the support structure also works as actual drive means for moving the display.

According to a second aspect, there is provided a slidable display arrangement for an electronic device, the slidable display arrangement comprising a slidable display and a support structure, the support structure supporting the slidable display, and being configured to slide the slidable display along the first sliding axis of the support structure, and/or fold the slidable display around the folding axis of the support structure, simultaneously with the support arrangement of the support structure. This solution facilitates a display arrangement with reduced sliding friction, where the bump of the display near the fold is avoided.

According to a third aspect, there is provided an electronic device comprising a housing, two end cap modules arranged at opposite sides of the housing, and the slidable display arrangement. The end caps help guide the slidable display and help the slidable display stay in the direction of the sliding axis.

In a possible implementation form of the third aspect, the end cap module comprises an outer end cap and an inner end cap, the rotation arrangement of the support structure of the slidable display arrangement being at least partially enclosed between the outer end cap and the inner end cap, such that the support arrangement of the support structure is interconnected with the end cap modules via the rotation arrangement. This facilitates simple placement of the rotation arrangements. The placement of the rotation arrangements between the outer end cap and the inner end cap (such that a part of rotation arrangements may protrude) makes simple maintenance and/or replacement of the rotation arrangements possible. Furthermore, there is no need for other fixtures for placing the rotation arrangements. The low number of additional elements in the device also reduces the risk of malfunction and mechanical failures.

In a further possible implementation form of the third aspect, the slidable display arrangement may be in one of a retracted position and an extended position in relation to the housing and the end cap modules.

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

<FIG> illustrates a slidable display arrangement <NUM> for an electronic device <NUM>, which comprises a slidable display <NUM> and a support structure <NUM> for a slidable display <NUM>. The electronic device <NUM> may be for example a mobile phone or a tablet. The slidable display <NUM> is able to extend the screen size of the electronic device <NUM>. The enlarged slidable display <NUM> can be used when the display arrangement <NUM> is in extended position P2 shown in <FIG>, which extended position <NUM> is achieved by a sliding movement of the slidable display <NUM>. The slidable display <NUM> and its support structure <NUM> is flexible and able to fold so that it can be stored in the electronic device <NUM> while the display arrangement <NUM> is in retracted position P1. The support structure <NUM>, which will be described in further detail below, assists the slidable display <NUM> in this sliding movement so that it supports and slides the slidable display <NUM> along the first sliding axis A1a. Instead of or in addition to sliding it may also assist in folding the slidable display <NUM> around the folding axis A3. In one embodiment, the slidable display arrangement <NUM> moves simultaneously with the support arrangement <NUM>, which is a part of the support structure <NUM>. The support structure <NUM> also comprises at least two rotation arrangements <NUM> which help reduce the friction of the movement and thus the sliding movement go smoothly. The rotation arrangement <NUM> will also be described in more detail below.

The electronic device <NUM> of the embodiment shown in <FIG> and <FIG> comprises a housing <NUM> and two end cap modules <NUM> arranged at opposite sides of the housing <NUM>. The end cap modules <NUM> may be part of the housing <NUM>, or may be separate elements. The end cap modules <NUM> may be positioned within the housing <NUM> or outside the housing <NUM>. The electronic device <NUM> may also comprise the slidable display arrangement <NUM> according to the embodiment described above.

The above-described end cap modules <NUM> of the electronic device <NUM> are illustrated in <FIG>. The end cap modules <NUM> may comprise an outer end cap <NUM> and an inner end cap <NUM>. In one embodiment, the outer end cap <NUM> may be of metal, while the inner end cap <NUM> may be of plastic. The rotation arrangement <NUM> is at least partially enclosed between the outer end cap <NUM> and the inner end cap <NUM>, as <FIG> shows. In this embodiment the support arrangement <NUM> is interconnected with the end cap modules <NUM> only via the rotation arrangement <NUM>. This helps reducing the friction further, as the connection between elements of the support structure <NUM> and the electronic device <NUM> or the housing <NUM> of the electronic device <NUM> is minimal.

As shown in <FIG>, and already mentioned above, the slidable display arrangement <NUM> in the electronic device <NUM> may be in a retracted position P1 or in an extended position P2 in relation to the housing <NUM> and the end cap modules <NUM>. The slidable display <NUM> and the electronic device <NUM> are able to function in both positions.

The support structure <NUM> shown in <FIG> and <FIG> comprises a support arrangement <NUM> and at least two rotation arrangements <NUM>. The support arrangement <NUM> contains at least one support element <NUM> and/or a sheet <NUM>, and is configured to slide along a first sliding axis A1a. As already mentioned, the support arrangement <NUM> may move simultaneously with the slidable display arrangement <NUM>. Different embodiments of the support arrangement <NUM> are illustrated for example in <FIG> and <FIG>. Embodiments of the rotation arrangement <NUM> are shown in <FIG> and also in <FIG>.

Each rotation arrangement <NUM> is fixedly arranged along the first sliding axis A1a. The placement, in one embodiment, is assisted by the outer end cap <NUM> and the inner end cap <NUM>, such that no more fixtures are necessary. During the sliding movement, the rotation arrangements <NUM> rotate around their rotation axes A2. The rotation axes A2 extend substantially perpendicular to the first sliding axis A1a, as is shown in <FIG>. Each rotation arrangement <NUM> is releasably interconnected to at least one support element <NUM> of the support arrangement <NUM>. The rotation arrangement <NUM> rotates around the rotation axis A2 with a tangential speed equal to the speed with which the support arrangement <NUM> moves along the first sliding axis A1a.

As shown in <FIG>, the support arrangement <NUM> may be configured to fold around a folding axis A3 and slide along a second sliding axis A1b. This movement occurs for example when the electronic device changes its position from a retracted position P1 to an extended position P2 or vice versa. The second sliding axis A1b extends at an angle to the first sliding axis A1a, but in some embodiments first sliding axis A1a and second sliding axis A1b are parallel, as shown in <FIG>. The folding axis A3 extends substantially perpendicular to the first sliding axis A1a, the second sliding axis A1b, and the rotation axis A2. There are at least two rotation arrangements <NUM> arranged also along the second sliding axis A1b, the same way as along the first sliding axis A1a. The direction and axis of rotation of the rotation arrangements <NUM> arranged along the second sliding axis A1b is the same as of the rotation arrangements <NUM> arranged along the first sliding axis A1a. Thus, the second sliding axis A1b is also substantially perpendicular to the rotation axis A2.

In the folded section of the support structure <NUM>, illustrated in <FIG>, there are also at least two rotation arrangements <NUM> positioned. The frequent provision of rotation arrangements <NUM> provides better support for the slidable display arrangement <NUM> and the slidable display <NUM>. The folded section extends between the first sliding axis A1a and the second sliding axis A1b. The sliding axes A1a and A1b can be seen in <FIG>.

The number of rotation arrangements <NUM> in the support structure <NUM> is, according to one embodiment, an even number, preferably between <NUM>-<NUM>. This number depends on the size of the electronic device in which the structure is to be mounted, and on the size, thickness and type of the display. Furthermore, the number of rotation arrangements <NUM> can vary based on the size of the rotation arrangement <NUM> as well.

The rotation arrangement <NUM> may comprise, or may be, a transmission wheel, a sprocket, a gear, or a pulley wheel, and may be in sliding contact with the support element <NUM>.

The interconnection between the rotation arrangement <NUM> and the support element <NUM> can be achieved by different methods and differently shaped features. Some embodiments are illustrated in <FIG>, achieved by means of at least partially complementary shapes.

The support arrangement <NUM> may also have different parts and/or shape, but preferably two ends of the support arrangement <NUM> are in contact with at least two rotation arrangements <NUM>, one on each side. In one embodiment, the support arrangement <NUM> comprises a plurality of support elements <NUM>, each end of each support element <NUM> comprising a protrusion extending from a sheet <NUM>, the sheet <NUM> supporting the slidable display <NUM> and each protrusion interacting with one rotation arrangement <NUM>. An illustration of this embodiment is <FIG>.

The support arrangement <NUM> according to the embodiment shown in <FIG> comprises a sheet <NUM> and a plurality of support elements <NUM>. In one embodiment, each support element <NUM> comprises a rod arranged to support the sheet <NUM>. The number of rods depends on the size of the slidable display arrangement <NUM> and/or the slidable display <NUM>. The center axes A4 of the support elements <NUM> are parallel with each other and with the folding axis A3, and are perpendicular to the direction of the sliding movement.

The interconnection between the rotation arrangement <NUM> and the support element <NUM> prevents translation of the support element <NUM> in all directions except along the first sliding axis A1a and/or the second sliding axis A1b.

The rotation arrangement <NUM> can have many different forms depending on the interconnection to the support arrangement <NUM>. One possible shape is illustrated in <FIG>. In this embodiment, the rotation arrangement <NUM> comprises a centrally symmetric transmission wheel. In the embodiment illustrated in <FIG>, the rotation arrangement <NUM> is also equipped with a pin.

The pin may be in sliding contact with the housing <NUM>, as indicated in <FIG>, or it may comprise a separate bearing arranged around the pin, at its top and/or bottom, the bearing being mounted in the end cap module <NUM>. Furthermore, the rotation arrangement <NUM> may be provided with an inner bearing, in which case the pin is stationary. Each rotation arrangement <NUM> may, in other words, be a single piece of low-friction material, or an assembly comprising also a separate pin, a wheel, and possibly one or several bearings.

A rotation arrangement <NUM> having this shape also comprises a plurality of slots <NUM>. These slots <NUM> are arranged around a circumference of the transmission wheel, and each slot <NUM> is able to engage with one end of one support element <NUM>. The number of slots <NUM> in each wheel is preferably <NUM>-<NUM>, more preferably <NUM>. The number of slots <NUM> in the wheels depend on the spacing of support elements <NUM>, and the diameter of the wheel. The slot <NUM> and the end of the support element <NUM> may both comprise a square frustum.

During interconnection, as illustrated in <FIG>, there is at least one contact point between the rotation arrangement <NUM> and the support element <NUM> at any time. The maximum contact area, which is shown in <FIG>, is achieved when the rotation axis A2 and the center axis A4 are aligned.

In an embodiment as shown in <FIG>, <FIG> and <FIG>, the plurality of slots <NUM> comprises at least a first slot 8a and a neighboring second slot 8b. Furthermore, the plurality of support elements <NUM> comprises at least a first support element 7a and a neighboring second support element 7b. As shown in <FIG> and <FIG>, when the first slot 8a engages the first support element 7a, the support arrangement <NUM> slides along the first sliding axis A1a and the rotation arrangement <NUM> rotates around the rotation axis A2. After this, the first slot 8a disengages from the first support element 7a and the second slot 8b engages the second support element 7b.

<FIG> depicts that the neighboring slots <NUM> may be delimited by a joint shoulder <NUM>. In this embodiment, the shoulder <NUM> extends into a gap <NUM> between two neighboring support elements 7a, 7b as the support arrangement <NUM> slides along the first sliding axis A1a and the rotation arrangement <NUM> rotates around the rotation axis A2.

The sliding movement can be achieved by different solutions, for example by driving the slidable display arrangement <NUM> and/or the support arrangement <NUM>. This way, the rotation of the rotation arrangements <NUM> is also started by the slidable display arrangement <NUM> and/or the support arrangement <NUM>. However, the support structure <NUM> may comprise a motor. In this case, the motor would be connected to the rotation arrangement <NUM>, thus driving the rotation arrangement <NUM>. Therefore, the sliding movement can be achieved by driving the sliding movement of the support arrangement <NUM> via the rotation arrangement <NUM> as well.

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 support structure (<NUM>) for a slidable display (<NUM>), said support structure (<NUM>) comprising
- a support arrangement (<NUM>) configured to slide along a first sliding axis (A1a), and
- at least two rotation arrangements (<NUM>), each rotation arrangement (<NUM>) being fixedly arranged along said first sliding axis (A1a) and configured to rotate around a rotation axis (A2) extending substantially perpendicular to said first sliding axis (A1a),
each rotation arrangement (<NUM>) being releasably interconnected to at least one support element (<NUM>) of said support arrangement (<NUM>), such that said rotation arrangement (<NUM>) rotates around said rotation axis (A2) with a tangential speed equal to a speed with which said support arrangement (<NUM>) moves along said first sliding axis (A1a),
wherein the support structure (<NUM>) is configured to support the display (<NUM>) and is configured to slide the display (<NUM>) along the first axis (A1a),
wherein said support arrangement (<NUM>) is configured to fold around a folding axis (A3), and
said folding axis (A3) extending substantially perpendicular to said first sliding axis (A1a) and said rotation axis (A2).