CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and benefits of Korean Patent Application No. 10-2019-0131642 under 35 U.S.C. § 119, filed in the Korean Intellectual Property Office on Oct. 22, 2019, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

The disclosure relates to a foldable display device and a hinge device therefor.

2. Description of the Related Art

Display devices may serve to connect users and information. As information technology continues to develop, the importance of display devices is emphasized. Accordingly, use of display devices such as liquid crystal display devices, organic light emitting display devices, and plasma display devices has been increasing.

Recently, research and development of foldable display devices, bendable display devices, rollable display devices, and the like are in progress. Such devices provide advantages of a flexible display panel that may be bent or folded. Such display devices may be applied to a variety of devices, such as a television and a monitor as well as a portable electronic apparatus and a wearable apparatus.

A foldable display device may be implemented according to an in-folding method in which display surfaces may be folded to face each other, or according to an out-folding method in which the display surfaces may be folded outwardly.

A foldable display device may include a hinge device for assisting in folding and supporting a folded shape and/or an unfolded shape of the foldable display device. Research and development of hinge devices having reduced manufacturing cost while precisely assisting in the folding/unfolding of a foldable display device are in progress.

It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein.

SUMMARY

In an embodiment provided is a foldable display device that may control folding and unfolding of a display panel through a rotational movement of a rotor.

In another embodiment provided is a hinge device that may include a rotor that performs a smooth rotational movement using a groove and a follower that performs a linear movement by the rotor.

However, embodiments are not limited thereto. Other embodiment are disclosed and may be variously expanded within a range without departing from the spirit and scope of the disclosure.

In an embodiment, a foldable display device may include a display panel that may include a foldable display area, and a first panel support member supporting the display panel, the first panel support member overlapping a first area of the display panel. The foldable display device may include a second panel support member supporting the display panel, the second panel support member overlapping a second area of the display panel. The foldable display device may include a hinge device including base hinge devices coupled to the first panel support member and the second panel support member to guide folding and unfolding of the display panel with respect to virtual rotation axes.

In an embodiment, a hinge device may further include a first base plate coupled to the first panel support member, a second base plate coupled to the second panel support member, and a hinge cover supporting the base hinge devices.

Each of the base hinge devices may include a first rotor coupled to the first base plate to rotate along a first virtual rotation axis of the virtual rotation axes, and a second rotor coupled to the second base plate to rotate along a second virtual rotation axis of the virtual rotation axes.

Each of the base hinge devices may further include a bracket supporting the first rotor and the second rotor on an inner side surface of the hinge cover and guiding a rotational movement of the first rotor and the second rotor.

The bracket may include one of polyoxymethylene (POM) and stainless steel (STS).

The base hinge devices may include a first base hinge device including the first rotor that includes a curved surface having a diameter corresponding to the first rotation axis, and a groove recessed in an arc shape on the curved surface.

The groove of the first rotor may be fitted to the bracket.

The first rotor may have a shape bent along a rotation radius corresponding to the first rotation axis, and the first rotor may include a torque assist member extending in a direction parallel to the first rotation axis from a side surface of the first rotor.

At least one surface of the torque assist member may include grooves.

The second rotor included in the first base hinge device may have the same shape as the first rotor and may be disposed on the bracket so as to be rotationally symmetrical to the first rotor.

The first base hinge device may further include an auxiliary bracket disposed between the first rotor and the second rotor and overlapping at least a portion of the torque assist member of the first rotor and at least a portion of a torque assist member of the second rotor.

The first base hinge device may further include a lubricant applied between the auxiliary bracket and the torque assist member of the first rotor or the second rotor.

The base hinge devices may include a second base hinge device including a first rotor that includes a curved surface having a diameter corresponding to the first rotation axis, and a surface protruding in an arc shape on the curved surface.

The first rotor included in the second base hinge device may further include a torque assist member having a shape bent along a rotation radius corresponding to the first rotation axis and extending in a direction parallel to the first rotation axis from a side surface of the first rotor.

A side surface opposite to the side surface to which the torque assist member may be coupled in the first rotor may have a cross section of a spiral shape, which may be cut in a diagonal direction.

The cross section of the spiral shape may have a groove of an arc shape along the first rotation axis.

The second base hinge device may further include a follower that may be fitted to the groove of the cross section of the spiral shape of the first rotor, and may be pushed by the rotational movement of the first rotor to linearly move in a direction horizontal to the first rotation axis.

The second rotor included in the second base hinge device may have a shape symmetrical to the first rotor with respect to the follower, and may be disposed on a side opposite to the first rotor.

The second rotor may convert force according to the linear movement of the follower into a rotational force to rotate in a direction opposite to a rotation direction of the first rotor.

The first rotor and the second rotor may simultaneously rotate oppositely by a same angle.

An aspect of the disclosure for achieving the above provides a hinge device for a foldable display device.

The hinge device for the foldable display device may include a first base plate coupled to a first panel support member, a second base plate coupled to a second panel support member, and base hinge devices coupled to the first panel support member and the second panel support member. The hinge device may include a hinge cover supporting the base hinge devices, wherein each of the base hinge devices may include a first rotor coupled to the first base plate to rotate along a first virtual rotation axis, a second rotor coupled to the second base plate to rotate along a second virtual rotation axis, and

a bracket supporting the first rotor and the second rotor on an inner side surface of the hinge cover and guiding a rotational movement of the first rotor and the second rotor.

The foldable display device and the hinge device therefor according to the disclosure may be advantageous in assembly and production management through modularization by configuring an inside of the hinge device in a part of the base hinge devices.

Both screen angles by folding and unfolding operations may be linked and symmetric to each other by disposing a follower performing the linear movement between the rotors. The linear movement may be easily performed while minimizing wear due to friction by additionally disposing a fixed type bracket at a lower end the rotor and the follower.

The rotor may include a groove structure, and thus torque required for rotation may be easily generated. Thus, a natural folding or unfolding operation may be implemented.

However, the effects of the disclosure are not limited to the above-described effects, and may be variously expanded within a range without departing from the spirit and scope of the disclosure.

