CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean Patent Application No. 10-2016-0103290, filed on Aug. 12, 2016, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

Field

The invention relates generally to organic light emitting display devices, and, more particularly, to organic light emitting display devices that are flexible and resistant to damage or defects due to static electricity.

Discussion of the Background

Flat panel display (FPD) devices are widely used as a display device of an electronic device because the FPD device is lightweight and thin compared to a cathode-ray tube (CRT) display device. Typical examples of the FPD devices are a liquid crystal display (LCD) device and an organic light emitting display (OLED) device.

Recently, a flexible OLED device has been developed that is capable of bending or folding a portion of a display device by including lower and upper substrates which have flexible materials. For example, the lower substrate included in the display panel may be formed of a flexible substrate, and the upper substrate included in the display panel may have a thin film encapsulation structure. In addition, the flexible display device may further include an upper structure that is located on an upper surface of the display panel and a lower protection film that is located on a lower surface of the display panel. Here, the lower protection film may include an adhesive layer and a protection film that protects the adhesive layer.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concepts, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY

Applicants have discovered that when the lower protection film of a flexible OLED adheres to the lower surface of the display panel, it may adhere after the protection film has become detached from the adhesive layer. In this case, static electricity may be generated as the protective film is detached from the adhesive layer, and the flexible display device may be damaged by the static electricity. Additionally, the presence of non-uniform static electric may cause a displayed image to be non-uniform.

One or more exemplary embodiments of the invention provide an organic light emitting display device having an adhesive layer that includes an antistatic material having a surface resistance that enables static electric charges to achieve a uniform distribution in the adhesive layer and/or migrate to a grounded process device. Accordingly, the performance of the device may be improved by reducing or eliminating some or all of the problems caused by static electricity. Further, a weight ratio the antistatic material with respect to the total weight of the adhesive layer may be in a range that enables some or all of problems caused by the static electricity to be overcome without adding much weight to the device.

Additional aspects or benefits will be set forth in the detailed description which follows, and, in part, will be apparent from the disclosure, or may be learned by practice of the inventive concepts.

According to a one aspect of the invention, an organic light emitting display (OLED) device includes a flexible display panel, an upper structure, and a lower protection film. The display panel has a display region where a plurality of pixels are disposed and a pad region where pad electrodes that are electrically connected to an external device are disposed. The pad region is located at a side of the display region. The display panel is configurable to have a curved shape where a flexible portion of the display region is bent. The upper structure is disposed in the display region of the display panel. The lower protection film is disposed on a lower surface of the display panel, and includes an adhesive layer and a protection layer. The adhesive layer is in direct contact with the lower surface of the display panel, and includes an antistatic material. The protection layer is disposed under the adhesive layer.

In example embodiments, the display region may have a first width extending in a first direction, and the pad region may have a second width extending in the first direction when viewed in a plan view of the OLED device. The second width may be less than the first width.

In example embodiments, the display region may include a first sub-display region having opposed lateral portions, second and third sub-display regions, a fourth sub-display region, and a fifth sub-display region. The first sub-display region may be located in a center of the display region. The second sub-display region may be located at one of the opposed lateral portions of the first sub-display region and the third sub-display region may be located at the other opposed lateral portion. The second and third sub-display regions may be configured to have a shape that is bent on an axis with respect to a second direction. The second direction may be perpendicular to the first direction. The fourth sub-display region may be located adjacent to the second sub-display region, and may extend in a third direction that is orthogonal to both the first direction and the second direction. The fifth sub-display region may be located adjacent to the third sub-display region, and may extend in the third direction.

In example embodiments, the second and fourth sub-display regions and the third and fifth sub-display regions may be symmetrical to each other with respect to the first sub-display region.

In example embodiments, the display region may include a light emitting region configured to emit light and a peripheral region surrounding the light emitting region. The first sub-display region, the second sub-display region, and the third sub-display region may be located in the light emitting region, and the fourth sub-display region and the fifth sub-display region may be located in the peripheral region.

In example embodiments, the lower protection film may be disposed on a portion of the lower surface of the display panel that is located in the first, second, third, fourth, and fifth sub-display regions or on substantially the entire lower surface of the display panel that is located in the first, second, third, fourth, and fifth sub-display regions.

In example embodiments, a neutral plane of the lower protection film, the display panel, and the upper structure in the second and third sub-display regions are located within the display panel.

In example embodiments, a thickness of the adhesive layer of the lower protection film may be in a range between about 11 and about 15 micrometers, and a thickness of the protection layer of the lower protection film may be in a range between about 74 and about 76 micrometers.

In example embodiments, a plurality of wirings may be disposed in the peripheral region, and the plurality of wirings may electrically connect the pad electrodes and the pixels.

In example embodiments, the pad region may include a bending region located in a first portion of the pad region that is adjacent to the display region and a pad electrode region where the pad electrodes are disposed in a second portion of the pad region.

In example embodiments, the OLED device may further include a bending protection layer and connection electrodes. The bending protection layer may be disposed in a portion of the display region, the bending region, and a portion of the pad electrode region. The connection electrodes may be disposed between the bending protection layer and the display panel, and may electrically connect the pixels and the pad electrodes.

In example embodiments, the lower protection film may expose a portion of the lower surface of the display panel that is located in the bending region.

In example embodiments, the lower protection film may include a first lower protection film pattern and a second lower protection film pattern. The first lower protection film pattern may be disposed in the display region. The second lower protection film pattern may be disposed in the pad electrode region of the pad region such that the portion of the lower surface of the display panel that is located in the bending region is exposed.

In example embodiments, the first lower protection film pattern and the second lower protection film pattern may be spaced apart from each other.

In example embodiments, the bending region may be bent on an axis with respect to the first direction, and the second lower protection film pattern may be disposed on a lower surface of the first lower protection film pattern.

In example embodiments, a bending radius of the bending region may be less than a bending radius of a portion of the display region where the display region is bent.

In example embodiments, the lower protection film may define a groove in the bending region.

In example embodiments, the adhesive layer included in the lower protection film may be entirely disposed on the lower surface of the display panel. The protection layer included in the lower protection film may include a first protection layer and a second protection layer. The first protection layer may be disposed in the display region. The second protection layer may be disposed in the pad region. The first protection layer and the second protection layer may define an opening exposing a lower surface of the adhesive layer located in the bending region. The first protection layer and the second protection layer may be spaced apart from each other on the lower surface of the adhesive layer.

In example embodiments, each of the pixels included in the display panel may include a substrate on the lower protection film, a semiconductor element on the substrate, a lower electrode on the semiconductor element, a light emitting layer on the lower electrode, an upper electrode on the light emitting layer, and a thin film encapsulation structure on the upper electrode.

In example embodiments, the semiconductor element may include an active layer, a gate insulation layer, a gate electrode, an insulating interlayer, and source and drain electrodes. The active layer may be disposed on the substrate. The gate insulation layer may be disposed on the active layer. The gate electrode may be disposed on the gate insulation layer. The insulating interlayer may be disposed on the gate electrode, and the gate insulation layer and the insulating layer may define an opening that exposes an upper surface of the substrate that is located in the bending region. The source and drain electrodes may be disposed on the insulating interlayer.

In example embodiments, the upper structure may include a touch screen electrode layer and a polarizing layer on the thin film encapsulation structure.

In example embodiments, the polarizing layer may be disposed on the touch screen electrode layer.

In example embodiments, the touch screen electrode layer may be disposed on the polarizing layer.

In example embodiments, the lower protection film may further include an antistatic layer under the protection layer.

In example embodiments, a thickness of the protection layer may be greater than a thickness of the adhesive layer, and the thickness of the adhesive layer may be greater than a thickness of the antistatic layer.

In example embodiments, a surface resistance of an upper surface of the lower protection film that is in direct contact with the display panel may be less than about 1×1011ohm/sq.

In example embodiments, a weight ratio the antistatic material based on a total weight of the adhesive layer may be in a range between about 1 wt % and about 3 wt %.

In example embodiments, the protection layer may further include a light blocking material.

In example embodiments, the light blocking material may include at least one material selected from the group consisting of carbon black, titanium nitride oxide, titanium black, phenylene black, aniline black, cyanine black, and nigrosine acid black.

According to another aspect of the invention, an OLED device includes a display panel, an upper structure, and a lower protection film. The display panel has a display region where a plurality of pixels are disposed and a pad region where pad electrodes that are electrically connected to an external device are disposed. The pad region is located at a first side of the display region. The display panel is configurable to have a curved shape where a flexible portion of the display region is bent. The upper structure is disposed in the display region of the display panel. The lower protection film is disposed on a lower surface of the display panel, and includes an adhesive layer and a protection layer. The adhesive layer is in direct contact with the lower surface of the display panel, and includes an antistatic material. The protection layer is disposed under the adhesive layer. The pad region includes a bending region located in a first portion of the pad region that is adjacent to the display region and a pad electrode region where the pad electrodes are disposed in a second portion of the pad region. The lower protection film includes a first lower protection film pattern and a second lower protection film pattern. The first lower protection film pattern is disposed in the display region. The second lower protection film pattern is disposed in the pad electrode region of the pad region such that the portion of the lower surface of the display panel that is located in the bending region is exposed. The antistatic material is included in the first lower protection film pattern, and the second lower protection film pattern does not include the antistatic material.

The foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed subject matter.

