CROSS REFERENCE TO RELATED APPLICATION

This application is based on and claims priority from Korean Patent Applications Nos. 10-2020-0048888 filed on Apr. 22, 2020, 10-2020-0079562 filed on Jun. 29, 2020 and 10-2020-0079563 filed on Jun. 29, 2020 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a foldable display device and, more particularly, to a foldable display device in which a first body and a second body of an electronic device having a folded display are rotatably connected to each other so that a rotation angle between the first and second bodies is efficiently set.

Description of the Related Art

Unless otherwise indicated herein, the descriptions set forth herein are meant to be related art to the claims of this application and, even though it is included in this section, are not to be admitted to related art.

Due to increasing industrial demand for portable electronic devices including portable terminals, portable electronic devices having various forms and functions meeting customer needs are being introduced.

General portable terminals, such as mobile phones, have a display part for displaying images, pictures, etc., and portable terminals having a function of watching TV through the display part or visually obtaining a variety of information over a wired or wireless Internet have appeared.

Furthermore, the portable terminals have been developed in various forms tailored to consumer demand and functional characteristics, and have been developed variously as a foldable type, a slidable type, a bar type, etc.

Herein, a foldable type portable terminal denotes a terminal in which two bodies are hinged together and opened in order to expand a usable area, and has continuously been developed due to its superior structural characteristics.

Particularly, in recent years, development of a thin film transistor-liquid crystal display technology and weight reduction of other components have become possible, and generally, most portable terminals have become slimmer, and their demand is increasing day by day.

However, because the external profile of portable terminals in the related art has been developed on the basis of forms more suitable for performing communication functions such as voice call, message transmission, etc., there is a disadvantage in that it may be inconvenient to use a multimedia service. For example, the display part of a general portable terminal has a vertically long shape and thus is inconvenient for viewing digital multimedia broadcasts, video files, etc.

In an effort to solve such a problem, Korean Patent No. 10-0909713 disclosed “Hinge device for mobile phone” as a registered patent of the present applicant. In order to solve the above-mentioned problem, the exemplary embodiment of the invention disclosed a hinge device for a mobile phone which is configured such that a cover of the mobile phone is rotatable by an open angle and a 360 degree angle with respect to a vertical direction while ultimately achieving structural stability of the entire device.

According to Korean Patent No. 10-0909713, there is a great advantage in that convenience of use can be enhanced and consumer demand to utilize the display part of the mobile phone in a relatively wide range can be satisfied. However, there is room for improvement, and thus it is necessary to develop a new type of hinge device and an electronic device using the same.

For example, in order to satisfy consumer demand for a large display screen even in the case of a small-size electronic device, it is necessary to provide an electronic device of a type in which a liquid crystal screen is provided on both of two bodies that are rotated together in a hinged manner, and two individual liquid crystal screens are combined to form a single large screen when the electronic device is opened from a closed state. In addition, it is necessary to develop a hinge device of a type suitable for the same.

On the other hand, in such type of foldable display device, the display part may not be fully folded like a paper sheet but leave an arc-shaped curved portion having a predetermined radius. Thus, there is a need to minimize the arc-shaped curved portion to prevent a gap between both bodies of the foldable display device from being generated when the device is folded.

SUMMARY OF THE INVENTION

Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and an objective of the present disclosure is to provide a hinge configured to allow a hinge structure to be located in an area where a flexible display is folded to correct a variable length deviation of the flexible display when folding or unfolding the flexible display, thereby preventing deformation and breakage of the display.

The objective of the present disclosure may be achieved by a foldable display device, including a first body and a second body formed in a plate shape to be arranged symmetrically; a display part attached to the first body and the second body to be folded or unfolded; and a hinge device coupled to the first body and the second body to connect the bodies to each other and allowing the first body and the second body to be folded and unfolded, wherein the hinge device includes a first bracket coupled to the first body and a second bracket coupled to the second body; first and second main shafts passing through one end of the first and second brackets and disposed in parallel respectively; a rotation inducing part fitted to outer surfaces of the first and second main shafts to guide linear motion when the first and second main shafts rotate; and a mobile part composed of first and second link connectors fitted to outer surfaces of the first and second main shafts and connected to the rotating induction unit, first and second links hinged to the first and second link connectors respectively, and first and second connection plates hinged to the first and second links and attached to the first and second bodies respectively, wherein when the first and second bodies are folded, the first and second connection plates are in proximity to each other, and the first and second link connectors move about the first and second main shafts to be in proximity to each other.

According to an embodiment, the device may further include first and second shaft pins fitted to the first and second tubular bodies respectively and first and second springs coupled to the first and second shaft pins respectively.

According to an embodiment, the device may further a first support plate supporting the first and second springs and coupled to the first and second shaft pins; a second support plate coupled in parallel with the first support plate and coupled to the first and second shaft pins; first and second gears interposed between the first and second support plates and coupled to the first and second shaft pins respectively; and multiple interlocking gears gear-engaged to the first and second gears.

According to the disclosed embodiment, it is possible to provide a hinge configured to allow a hinge structure to be located in an area where a flexible display is folded to correct a variable length deviation of the flexible display when folding or unfolding the flexible display, thereby preventing deformation and breakage of the display.

