Flexible display with display support

A display device includes a flexible display and a support frame. The flexible display includes a first portion, a second portion, and a third portion there between. The support frame includes a first display support supporting the first portion, a second display support supporting the second portion, and a third display support supporting the third portion. The third display support is connected to the first display support and the second display support. The first display support and the second display support are rotatably connected between a configuration for maintaining the flexible display in a closed position and a configuration for maintaining the flexible display in an open position. The third display support includes a panel movable according to the rotation of the first display support and the second display support, such that the panel contacts the third portion of the flexible display in an open position of the flexible display.

TECHNICAL FIELD

The present invention generally relates to flexible displays. The present invention specifically relates to flexible displays provided with display supports.

Description of Related Art

Flexible and especially rollable displays are manufactured on an organic substrate and are very thin. This makes it possible to repeatedly bend them with a small radius, a requirement for a rollable display. The advantages of a rollable display are the small volume needed for storing in the closed position and the lack of glass making the display unbreakable and of light weight.

A number of product concepts have been developed for flexible displays. The most important concepts are the ‘book’, the ‘wrap’ and the ‘roll’. A ‘wrap’ concept is shown in WO 2008/054206 A2, a ‘roll’ concept in WO 2006/038171 A1.

The ‘book’ concept is the simplest implementation of a rollable display comprising two hingeably connected support halves with a continuous display. In the middle near the hinge mechanism is a hollow space to accommodate the curved segment of the display in the situation where the ‘book’ is in the closed position. The display size is at most twice the size of the closed display system. In practice, it will be around 1.8× the size due to the bezel of the support halves needed around the display.

The ‘wrap’ concept comprises a display, wrapped with its front side to the inside. Thus the display is protected when the ‘wrap’ is in the closed position. The display currently makes one complete turn around the device body when wrapped. Therefore, the size of the display will be about twice the size of the device. For larger displays compared to the device body more turns are required, which adds mechanical complexity.

Instead of rolling the display around the device body, especially if it is more than one turn, it could also be rolled around a tube and stored inside the system. This ‘roll’ concept has a very different product experience, as the display comes out of the system instead of being wrapped around it.

There are a lot of possibilities to realize the movement of the display with respect to the display system, but most of them result in an open position with unsupported parts of the display. This can result in problems when touch functionality has to be integrated into the display. The pressure from a touch on the display can result in tearing of the display due to the tensions and it can result in imprints along the edges of the unsupported display part.

Another problem is that for the end-user it is important to have a consistent feeling of touch across the whole display. In an unsupported location, touching the display will feel different than in a supported location and this could be confusing to the end-user.

It is an object of the invention to prevent unsupported locations in the display in its open position. It is also an object to improve the lifetime of the display.

SUMMARY

According to one aspect the invention provides a display system comprising a continuous flexible display, a support frame comprising two main display supports being hingeable with respect to each other and each structurally configured to support a respective portion of the flexible display, wherein the two main display supports are hingeable between a configuration for fixing the flexible display in a closed storage position and a planar configuration for fixing the flexible display in an open position, wherein at least one additional display support is configured to support substantially a segment of flexible display located between the said respective portions of the flexible display in the open position, said additional display support being movable with respect to the display segment between a non-operational position and a support position when the two main display supports are moved between the storage position and the open position of the flexible display, such that in the open position substantially the whole surface of the display is supported by the respective display supports.

According to another aspect the invention provides a display system comprising a continuous flexible display and a display support device structurally configured to support the flexible display, wherein the display is movable between a closed storage position and an open position, wherein the display support device comprises at least one display support being movable between a storage position and a support position when the display is moved between the storage position and the open position of the flexible display, such that in the open position substantially the whole surface of the display is supported by the display support. This configuration of the display support is applicable for supporting different kinds of the flexible displays, i.e. of rollable, wrappable or of book type.

According to yet another aspect the invention provides a display system comprising a continuous flexible display, a support frame comprising two main display supports being hingeable with respect to each other and each structurally configured to support a respective portion of the flexible display, a segment of the flexible display being located between the said respective portions of the flexible display, wherein the two main display supports are hingeable between a closed configuration for fixing the flexible display in a storage position and an open configuration for fixing the flexible display in an open position, in the storage position of the flexible display between the main display supports and the additional display support there is a free space enabling a partial curvature of said display segment without conflicting with the respective main display support wherein at least one additional display support is configured to support substantially said segment of the flexible display in the storage position of the flexible display, the additional display support facilitates the curvature of the display segment with a predefined curvature.

According to another aspect the invention provides a display system with a continuous flexible display, a support frame comprising two display supports located in respective housings being hingeable with respect to each other and each structurally configured to support a respective portion of the flexible display, a segment of the flexible display being located between the said respective portions of the flexible display, wherein the two display support housings are hingeable between a closed configuration for fixing the flexible display in a storage position and an open configuration for fixing the flexible display in an open position, in the storage position of the flexible display between the display supports there is a free space enabling a partial curvature of said display segment without conflicting with the respective display support, wherein in the storage position the flexible display is positioned in the system with its display segment in an asymmetrical configuration with respect to a plane between both display support housings.

The invention focuses in the different embodiments on the support of the display in parts of the construction where the display cannot be connected to a rigid underground. This can be the case near hinges, guiding mechanisms and other mechanical elements that facilitate the movement of the display and supporting frame between a closed storage and an open position. The invention provides technical solutions for applying touch functionality in a display system with a flexible/rollable display.

The advantages of the different embodiments are that in the open position the display is supported by an additional support when touched. This means that it is less likely to be damaged when touch functionality is added to the display. Another advantage is that the display will feel stiffer and gives a better quality perception of the product. The predefined curvature of the display segment in the closed position is advantageous for the lifetime of the display.

DESCRIPTION OF THE EMBODIMENTS

Reference is made to applicant's Provisional Application Ser. No. 61/506,180, filed on Jul. 11, 2011, which is hereby incorporated by reference.

The display system1schematically shown inFIGS. 1A and 1Bis a ‘wrap’ embodiment as disclosed in WO 2008/054206 A2 (herewith incorporated by reference). It comprises a flexible display2and a display support frame comprising two main display supports3,4. These supports3,4are connected via hinges5,6with a body7and are each structurally configured to support a respective portion of the flexible display2. At the other side of the respective hinge5,6each of the display supports3,4show an elongated portion configuring an additional display support3a,4a. The two main display supports3,4are rotatable in the direction of arrows a, b between a configuration shown inFIG. 1Afor fixing the flexible display in a closed storage position and a planar configuration shown inFIG. 1Bfor fixing the flexible display in an open position. The additional display supports3a,4aare moved with respect to a display segment2abetween a non-operational position and a support position when the two main display supports3,4are moved between the storage position and the open position of the flexible display. The combined supports3a,4asupport in the operational open position substantially the segment2aof the flexible display located between the said respective main display supports. In the open position the gap created by the hinge mechanism of hinges5,6between the main supports3,4is closed by the display supports3a,4aand substantially the whole surface of the display is supported.

In the storage position of the flexible display2between the main display supports3,4and the additional display supports3a,4athere is sufficient free space for enabling a partial curvature of the display segment2awithout conflicting with the respective main display supports.

In the open position between the hinges5,6the display segment2ais supported by the additional support3a,4awhen touched. This means that damage of the display is prevented when touch functionality is added to the display. Another advantage is that sagging of the display is prevented. The display will feel stiffer which gives a better quality perception of the display system.

InFIGS. 2A-2Eis schematically shown another ‘wrap’ embodiment. In this embodiment an additional display support is configured as a foil8which is attached to the hinges5,6and at least partly tensioned in the support position ofFIG. 2B, facilitating the support behind the whole surface of the display segment2ain the open position of the flexible display2. This will give a sufficient stiff underground for the display, enabling a touch functionality.

In the storage position of the flexible display2shown inFIG. 2Athe foil8facilitates the curvature of the display segment2ain a predefined way, in this embodiment shown as a combination of circular arches.

This well defined curvature is advantageous for the lifetime of the display. It enables opening/closing of the display system many times without damaging the display segment2a. Another advantage of this curvature in the storage position is that the display system can be designed with favourable dimensions.

A sufficiently stiff underground for the display by using a foil8is obtained for example by rotating the main display supports3,4around the hinges5,6by more than 90 degrees, thus tensioning the foil8. If (as shown inFIG. 2A, 2B) the main display supports3,4rotate equal or less than 90 degrees, the foil8would have a travel difference that is smaller than that of the flexible display2. This is solved in this embodiment by using a stretchable foil8as support of the display segment2a.

In two alternative ‘wrap’ embodiments, respectively shown inFIG. 2Cand inFIG. 2D, 2E, a gear-actuated solution in the mechanism of the hinges5and/or6is applied for enlarging the travel difference of the foil8. InFIG. 2Ca gear mechanism5A is shown in the hinge5, that can be compared with the mechanism in a ballpoint pen. An example of such a mechanism is disclosed in GB 635144 (herewith incorporated by reference). The mechanism5A comprises a pin5E of which the axis coincides with the axis of the hinge5. Gears5F and5G are coaxially arranged around the pin5E, such that gear5F is connected with the support3whereas gear5G, connected with the stretchable foil8, is slidable and rotatable with respect to the pin5E. In the gears a series of ratchet-like teeth5H,5I respectively is cut. The teeth5I are continuously urged by a spring5J located around the pin5E in the direction of the teeth5H and cooperate with the teeth5H as the teeth of a gear-coupling. An abutment5K limits the pivotal movement of the supports3,4from the closed to the planar open position to 90 degrees. A shaft5L is coaxially arranged around and connected with the pin5E. The stretchable foil8is rolled with its end portion around the shaft5L and is with its end connected with the shaft5L. The cooperation of the inclined sides of the teeth5H,5I under the spring reaction ensures that the gear5G and the shaft5L rotate over an extra angle and thus tension the foil8.

This 90 degrees rotation is by way of example. This gear solution shows the same favorable additional rotation with main display supports3,4rotating by other angles of rotation.

InFIGS. 2D, 2Eis shown another solution with gears5B, C and6B, C. The axis of gear5B,6B coincides with the hinge axis of hinge5,6respectively. Due to the connection with the supports3,4respectively, the gear5B,6B drives the intermediate gear5C,6C respectively during movement of the support. The intermediate gear5C,6C drives an axle5D,6D respectively, configured as a shaft. The stretchable foil8is rolled with its end portions around the shaft5D and6D and is with its ends connected to the shaft. The gear ratios between the gears5A,5B and the shaft5D and between the gears6A,6B and the shaft6D are chosen in accordance with the required amount of travel difference between the foil8and the flexible display2, rotating the shaft5D,6D over an extra angle and thus tensioning the foil during the movement of the display from the closed to the planar open position.

The embodiment shown inFIGS. 3A-3Iis a ‘book’ display system9. It consists of a flexible display10and a support frame, comprising two main display supports11,12being connected by a hinge13with respect to each other and each structurally configured to support a respective portion of the flexible display. As shown inFIGS. 3A-3G, the two main display supports11,12are hingeable between a configuration for fixing the flexible display in a closed storage position (FIGS. 3E and 3F) and a planar configuration (FIGS. 3A and 3B) for fixing the flexible display10in an open position. In this embodiment the additional display supports consist of four support panels14a,14band15a,15b. SeeFIGS. 3D, 3Fshowing pairs of two mutually pivotable connected support panels14a,14band15a,15brespectively, with the panels14aand15apivotably connected by pivots18,19with the display support11,12respectively. As shown inFIG. 3Bthe panels are being positioned under the display when the main display supports are opened. In this open state the support panels are “pulled flat” by bars16,17(seeFIG. 3D) at the respective sides of the display. With the panels14a,14band15a,15bin the planar configuration as shown inFIGS. 3A and 3B, a segment10aof flexible display, located between the said respective main display supports11,12in the open position, is supported in an effective way. As shown inFIG. 3Fin the closed storage position the pair of panels is positioned at both respective sides of the curved display segment10a.

The embodiment ofFIGS. 3A-3Gis a symmetrical version of a ‘book’ in accordance with the invention with equally shaped housings of display support panels and in the storage position with a display segment10asymmetrically curved with respect to a plane s between both display supports11,12and their housings.

InFIG. 3His shown an alternative version of this embodiment in accordance with the invention in the storage state, in which the display support housings have different dimensions measured perpendicular to the plane s between both display support housings. In the closed position the display segment is curved into the housing of the support12. This solution can be applied in asymmetrical ‘book’ systems, in which the display segment10ais asymmetrically curved with respect to the plane s between both display supports11,12and their housings. A second asymmetrical version in accordance with the invention is shown inFIG. 3Iwith a curved profile11cof the support11. In the asymmetrical ‘book’ systems ofFIGS. 3H and 3Ithe area of the flexible display10supported by the display support12in the opened position is larger than in the symmetrical ‘book’ system ofFIG. 3G. Another advantage is that the lower book housing part with the support12is the housing part with a larger thickness, and thus has a higher volume and weight, enabling a stable positioning of the ‘book’ in the opened position in the hand or on a desk. As shown at the left side inFIGS. 3G, 3H and 3Iin an alternative embodiment these versions of a ‘book’ are provided with display supports11and12with two hinges13a,13b. With the use of two hinges in the opened position the hinges are located favorable in the plane of the surface of the flexible display10. Further the dimension of the display system9in the closed position (measured in the view ofFIGS. 3G/3H from the left to the right side) is smaller compared to the dimension of the system with only one hinge13.

The embodiment shown inFIGS. 4A-4Fis a ‘book’ display system9comparable with that ofFIGS. 3A-3Ibut inFIGS. 4A-4Fthe additional display supports comprise two panels20,21being guided slidably in slots11a,12aat both sides of the display support11,12. They slide with respect to the display segment10aduring movement of the flexible display10between the open position (FIGS. 4A, B) via the position shown inFIGS. 4C, D to the closed storage position (FIG. 4E, F). In the position ofFIG. 4A, B the panels20,21are in a planar configuration for supporting the surface of the display segment10a. As in the previous embodiment these panels20,21are also pivotably connected respectively to an arm22,23that is attached by pivots22a,23arespectively to the opposite main display support11,12in order to enable the sliding movement during opening and closing of the system. As in the previous embodiment shown inFIG. 3Halso this solution can be applied one-sided in an asymmetrical book.

The embodiment shown inFIGS. 5A-5Fis a ‘book’ display system9provided with a lifting mechanism24comprising an additional display support that consists of a panel25that is lifted under the display segment10awhen the system is moved from the closed (FIGS. 5E, F) to the opened (FIGS. 5A, B) position. The lift panel25is constrained to a linear movement and is guided by a guiding element, comprising a protrusion26on the main display support11and parallel guiding walls25a,25bin a housing24aof the lift mechanism24.

The embodiment shown inFIGS. 6A-6Bis a ‘book’ or ‘wrap’ display system27. Each of the two main display supports28,29comprises a number of extended teeth like parts28a,29a, extending parallel to each other and perpendicular to a hinge axis30between the display supports28,29. Due to the mutually offset positioning of the parts28a,29a, when opening the system, from the position ofFIG. 6Athe extended parts28a,29aare rotated around the axis30and moved to a planar configuration, supporting as an additional display support in the position ofFIG. 6Bthe display segment10afor touch events.

In the embodiment shown inFIGS. 7A-7Bthe display system27has a construction with parts28b,29b, used comparable with the extended main display supports parts embodiment ofFIGS. 6A-6B. However a combination of two connected flat panels31,32, rotatable around the axis30, inside main display supports28,29is added as an additional display support for touch support. In the closed state these parts28b,29bare positioned as shown inFIG. 7A. The flexible display10has the free space to form a partial curvature without conflicting with the panels31,32. Upon opening the two main displays supports28,29, the extended parts28b,29bpush and support the supporting flat panels31,32to the flat position as shown inFIG. 7B. The detailed transition from the closed position ofFIG. 8Ais shown inFIGS. 8B and 8C. By pivots31a,32athe panels31,32are connected with panel parts31b,32b. For ensuring stable end positions this connection may be spring loaded. Between the two flat panels31,32the angle of rotation can be limited so that in open state the panels31,32and their parts31b,32bare parallel and therefore support the flexible display segment10ain the region of the hinge mechanism, seeFIG. 8C. In the opened position the panels31,32may fully support the display segment10aor be located (as shown inFIG. 8C) with a minimal play under the display segment in order to be able to compensate tolerances in the support mechanism.

It is noted that alternatively the two panels28,29are integrated into one plastic panel with a living hinge at the location of the axis30.

The embodiment shown inFIGS. 9A-9Fis a ‘book’ display system9comparable with that ofFIGS. 3A-3IandFIGS. 4A-4F. In this embodiment the display segment10ais supported by additional display supports comprising a central support plate33and two hingeably connected display support plates34,35. The central support plate33is used as dual guided hinge part for the two display supports11,12of the system by gear sets36,37. Alternatively (not shown) the central additional support plate33is separated from the two device halves in which case it is only attached to the two display support plates34,35, with a guidance for the central support plate33.

The support plates34,35each have a pin34a,35athat is guided in a slot11a,12ain each of the display supports11,12of the device body. These slots11a,12aguide the movement of the plates34,35in such a manner that in open position ofFIGS. 9A and 9Bthe display segment10ais completely supported and in closed position ofFIGS. 9E and 9Fthe curved display segment10ais not obstructed.FIGS. 9C and 9Dshow an intermediate situation. Preferably in the closed position the plates33,34and35facilitate by their positioning a pre-defined curvature of the display segment10awith the advantages described before for the embodiment ofFIGS. 2A-2E.

The embodiment shown inFIGS. 11A and 11Bis a ‘book’ or ‘wrap’ display system43with a flexible display44and main display supports45,46which are hingeably connected via hinges5,6like the supports in the embodiment ofFIGS. 2A-2E. In this embodiment, instead of the foil8, the additional display support comprises near both sides of the display a strip of spring tape47, cooperating with rods47a. The tape47may be of the kind of spring steel measuring tape, or alternatively a plastic spring tape. These rods47aare of the kind disclosed in WO 2009/148313 A1 (herewith incorporated by reference) and close in the open position ofFIG. 11B, supported by the tape47, the gap created by the hinge mechanism of hinges5,6between the main supports45,46and support substantially the whole surface of the display segment44ain a flat position.

The display system48schematically shown inFIGS. 12A-12Dis a ‘roll’ embodiment of the kind as disclosed in WO 2006/038171 A1 (herewith incorporated by reference). In the embodiment shown inFIG. 12A, both a rollable flexible display49and a pre-tensioned rolled foil50are provided with a spring49a,50a, respectively, on the inside of their roll and accommodated in a housing51. The ends of the flexible display49and the foil50are connected at a hold out mechanism52(only shown with its connection wall), enabling a common rolling out of both the display and the foil. In the open position preferably the force f2of the pre-tensioned foil spring50ais greater than the force f1of the display spring49a. These forces are indicated by the length of the arrows. In this way in the open position the rollable display is provided with an additional display support acting over its surface as an effective touch-support.

InFIGS. 12B and 12Csimilar embodiments are shown but with a different kind or thickness of foil50to achieve different levels of support. Also is shown that a force f2smaller than and/or equal to f1could be possible as well, depending on desired level of support.

In the embodiment ofFIG. 12Conly one spring53is used, provided in the display roll49, further using a gear belt54or a gear set (not shown) for linking the two rolls49,50. In the last case the gear ratio needs to account for any differences in radius between the two rolls.

In the embodiment ofFIG. 12Dis shown the combination of the flexible display49and the foil50in a single roll with only one spring53. Thus the dimensions of the housing51may be limited.

In the embodiments ofFIGS. 12A-12Da flexible display49is extended using a linear actuation mechanism52anot further described here and of the kind as for example disclosed in WO 2006/038171 A1, which also functions as the hold out mechanism52, such that in extended position the force f3exerted by the hold out mechanism52is equal to the forces of the pre-tensioned foil50and the flexible display49added together but oriented in the opposite direction.

An alternative solution in a display system for an additional display support55for the preceding ‘book’ or ‘wrap’ embodiments is shown inFIGS. 13A-13Cfor the embodiment ofFIGS. 2A-2Ein a storage position (FIG. 13A) and in an open flat position (FIG. 13B), respectively. This solution uses a number of specially designed segments56, inter-linked by hinges56a. An end segment56is coupled by a pivot4cwith the display support4and an abutment4blimits the pivotal movement of this end segment. These segments are substantially parallelogram-shaped with one rounded corner56band are mutually configured such that when a segment56is locally bent to a radius, its inter-linkage will make sure that other segments follow (see arrow g inFIG. 13C). The local radius can therefore never become small. The configuration and inter-linkage of the segments prevent that a segment56is bent in the direction of the arrow h inFIG. 13C. During the movement from the position shown inFIG. 13Ato the flat position shown inFIG. 13Ball segments56are pushed flat by their configuration and inter-linkage. A stable positioning towards the flat position of the segments is supported due to the length of the gap3dbetween the flexible display2and the support3. In addition, in the position shown inFIG. 13Aat the left side of the gap3dan end segment56may be stably positioned in an optional hook shaped recess3bin the support3. Further in addition, in the area of the gap3dan optional recess3cin the support may be applied for extra stabilization of the flat position of the segments56. Due to this stable positioning the flat position of the whole additional support55is ensured. In the flat position the combined segments56support substantially the whole surface of the display segment2ain an effective way.

It is noted that in addition a spring (not shown) may be applied between the left side segment56and the support3, urging the end segment56into the gap3dtowards its end position.

The minimum achievable radius of the curvature will be determined by the positioning of the individual hinges56a, the design of end stops near the corners of the segments and the distance between hinge points. This enables in the storage position a facilitation of the curvature of the display segment2awith a predefined curvature, in this embodiment shown as a combination of circular arches.

The detailed drawings, specific examples and particular formulations given, serve the purpose of illustration only. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims.