The present disclosure relates to display technologies and, in particular, to a display panel and a display apparatus.
With the development of display technology, organic light-emitting diode (OLED) displays are gradually replacing liquid-crystal display (LCDs). Because of a wide viewing angle, improved image quality, low power consumption, and general suitability of foldable displays, OLED displays start to become very popular among consumers, especially for use in portable and wearable applications.
The development of OLEDs expands their application from flat, rigid displays to flexible displays to meet emerging demands. Electronic components such as light-emitting diodes and their electrical connections can be fabricated on a flexible substrate that allows the displays to be bent.
One embodiment of the present disclosure is a display panel. The display panel may include a flexible substrate comprising a display region and a dummy region; the dummy region being at periphery of the display region; the display region comprising a plurality of display islands, a plurality of first openings surrounding each of the plurality of display islands, a plurality of first bridges connecting the plurality of display islands, and a plurality of display units on the plurality of display islands, respectively. The dummy region may further include a plurality of dummy islands, a plurality of dummy openings surrounding each of the plurality of dummy islands, and a plurality of dummy bridges connecting the plurality of dummy islands, and the dummy region may not include display units.
Optionally, an area of the first openings per unit area in the display region may be substantially the same as an area of the dummy openings per unit area in the dummy region.
Optionally, the plurality of first openings may be arranged in the display region in a substantially same pattern as the plurality of dummy openings in the dummy region.
Optionally, one of the plurality of dummy openings may have a substantially same shape and size as one of the plurality of first openings.
Optionally, a width of one of the plurality of dummy bridges may be larger than a width of one of the plurality of first bridges.
Optionally, a width of one of the plurality of dummy bridges located closer to the display region may be smaller than a width of one of the plurality of dummy bridges located farther away from the display region.
Optionally, widths of the plurality of dummy bridges may increase as distances of the plurality of dummy bridges from the display region increase.
Optionally, each of the plurality of first openings may have an oblong shape having a length less than 1000 μm and a width less than 100 μm, each of the plurality of display islands may have a square shape having a side approximately in a range of 200 μm to 600 μm, and a width of each of the plurality of first bridges may be approximately in a range of 10 μm to 50 μm.
Optionally, a width of the dummy region may not be less than 100 μm.
Optionally, each of the plurality of first bridges may include an arc shape connecting adjacent display islands and a force compensation area at an inner side and a middle part of the arc shape, and the force compensation area may be configured to reduce stress at the middle part of each of the plurality of first bridges.
Optionally, a width of each of the first bridges may be at a maximum at the middle thereof.
Optionally, an inner side of the force compensation area may be a straight line.
Optionally, the force compensation area may have a rectangular shape or a partial circular shape.
Optionally, a width of contact area between a first bridge and a first island may be larger than a width of the arc shape of the first bridge, and may not be more than an inner radius of the arc shape.
Optionally, the contact area between the first bridge and the first island may be reinforced by employing a fillet or a chamfer.
Optionally, the display panel may further include a non-opening region on a side of the dummy region opposite from the display region. The non-opening region may not include an opening.
Optionally, the flexible substrate may include a metal layer and a thickness of the metal layer may be approximately in a range of 0.1 μm to 0.5 μm.
Optionally, the flexible substrate may include a first flexible layer, a first barrier layer, the metal layer, a second barrier layer, and a second flexible layer in this order.
Optionally, a thickness of the first flexible layer or the second flexible layer may be approximately in a range of 0.2 μm to 0.6 μm, and a thickness of the first barrier or the second barrier may be approximately in a range of 0.05 μm to 0.3 μm.
Another embodiment of the present disclosure is a display apparatus including the display panel.
The drawings are intended to provide a further understanding of the technical solutions of the present disclosure, and are intended to be a part of the specification, and are used to explain the technical solutions of the present disclosure, and do not constitute a limitation of the technical solutions of the present disclosure.
The present disclosure will be described in further detail with reference to the accompanying drawings and embodiments in order to provide a better understanding of the technical solutions of the present disclosure for those skilled in the art. Throughout the description of the disclosure, reference is made to
In the description of the following embodiments, specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.
The following terms, used in the present description and the appended claims, have the following definition.
An “opening density ratio” of an area of a display substrate is defined as a percentage of an area of all openings in the area of the display substrate. The larger the opening density ratio of the area of the display substrate, the smaller the Young's modulus of the area of the display substrate.
A “width” of a bridge at a point on one side of the bridge refers to a shortest distance from the point on one side of the bridge to the other opposite side of the bridge.
A flexible OLED display meets requirement of bending on a two-dimensional plane. However, a stretchable OLED display also needs meet requirement of deformation in a third dimension for a flexible display apparatus such as wearables.
A display panel may be fabricated on a flexible substrate using an island-bridge configuration to achieve the stretchability of functional apparatuses. In the island-bridge configuration, active areas including thin film transistors (TFTs) and electroluminescent components may be fabricated on the islands. Wire connections to the active areas may be fabricated along the bridges.
The island-bridge configuration is usually formed by cutting out a pattern of openings in a flexible substrate, thereby forming a plurality of islands separated by the openings and a plurality of bridges connecting the islands. The openings may accommodate large and reversible deformation applied on the stretchable and flexible display substrate. The stretching of the flexible substrate may pull the islands further apart from one another and widen the sizes of the openings. In the current stretchable display substrate, the sizes of these openings are usually the same. Thus, the opening density ratio of the central area of the display substrate is usually larger than the opening density ratio of the edge area of the display substrate. Accordingly, the Young's modulus of the central area of the display substrate is less than that of the edge area. As a result, when stretched, the flexible substrate may undergo larger deformation in the central area than in the edge area, thereby causing non-uniform deformation of the display substrate. Such non-uniform deformation may distort display images, thereby resulting in display abnormalities.
The stretchability of the display substrate also depends largely on the deformation of the bridges. The openings divide the flexible display into separate display islands or areas on which thin film transistors and electroluminescent components are fabricated. The separate display areas or islands are interconnected through the bridges. Large strains are usually generated on the bridges when the flexible substrate is stretched. Since the opening density ratio is greater in the central area than in the edge area of the display substrate, the Young's modulus of the central area is less than that of the edge area of the display substrate. As a result, the deformations of the bridges in different areas of the flexible substrate are not uniform. The bridges in the central area of the display substrate may experience larger deformation or strain than those in the edge area of the display substrate.
In the existing design, the bridge generally has a uniform width along the whole length of the bridge. Furthermore, sharp corners are usually formed at the junctions between the bridges and the islands. Such existing design tends to generate large strain or stress concentrations in different locations of the bridge, which tend to cause fracture or mechanical failure of the bridges.
In one embodiment, the display panel includes a flexible substrate.
In one embodiment, the dummy region also includes a plurality of dummy islands, a plurality of dummy openings surrounding each of the plurality of dummy islands, and a plurality of dummy bridges connecting the plurality of dummy islands. The dummy region does not include any display units on the dummy islands.
In one embodiment, as shown in
In one embodiment, with reference in
In one embodiment, an area of the first openings per unit area in the display region may be substantially the same as an area of the dummy openings per unit area in the dummy region. In one embodiment, the first openings may be arranged in the display region in a substantially same pattern as the dummy openings in the dummy region.
In one embodiment, the dummy openings may have a substantially same shape and size as the first openings. In one embodiment, each of the first openings has an oblong shape having a length in a range of 200 to 1000 μm and a width less than 100 μm. The length and width of the oblong shape refers to a length of the major axis and a length of the minor axis of the oblong shape, respectively. Each of the display islands may have a square shape having a side approximately in a range of 200 μm to 600 μm. A width of each of the first bridges may be approximately in a range of 10 μm to 50 μm. In one embodiment, a width of the dummy region is not less than 100 μm. A “width” of the dummy region refers to a shortest distance from a point at a boundary of the display region and the dummy region to an opposite boundary of the dummy region and the non-opening region.
In one embodiment, a width of each of the dummy bridges may be larger than a width of each of the first bridges.
The flexible substrate is usually made of polyimide (PI). The flexible substrate is usually first fabricated on a rigid substrate 29 such as a glass substrate and later removed from the rigid substrate. Currently, most of the flexible substrates adopt a flexible film structure having a single PI layer or a PI/barrier/PI layer. When stretched, the single PI layer or the three layered structure lacks sufficient ductility and flexibility.
In one embodiment, as shown in
In one embodiment, as shown in
Furthermore, as shown in
In one embodiment, widths of the plurality of dummy bridges in the dummy region may increase as distances of the plurality of dummy bridges from the display region increase. A width of one of the dummy bridges located closer to the display region may be smaller than a width of one of the dummy bridges located farther away from the display region.
According to some embodiments of the present disclosure, a stretchable display substrate is provided. The stretchability of the stretchable display substrate is improved from both macro and micro levels. At the macro level, both a display region and a dummy region are provided on the display substrate. The dummy region can effectively improve the uniformity of the display substrate. Furthermore, a metal layer or an inorganic film layer having a large Young's modulus in the middle of the PI substrate can improve the uniformity of Young's modulus of the display substrate. At the micro level, the contacting areas at the junctions of the islands and the bridges are reinforced to improve the reliability of the stretchable display substrate. Furthermore, force compensation areas are added at the inner sides and the middle parts of the bridges to reduce strain or stress levels thereto.
Another embodiment of the present disclosure further provides a display apparatus including the display panel according to one embodiment of the present disclosure.
Compared with the existing technique, the beneficial effects of the display apparatus provided in some embodiments of the present disclosure are the same as those of the display panel described above and are not repeated herein.
In one embodiment, the display apparatus may be any product or component having a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, or a navigator.
Unless otherwise defined, technical terms or scientific terms used in the present disclosure are intended to be in the ordinary meaning of those of ordinary skill in the art. The words “first,” “second” and similar words used in the present disclosure do not denote any order, quantity or importance, but are merely used to distinguish different components. The words “including” or “comprising” and the like mean that the element or the item preceding the word includes the element or item listed after the word and its equivalent and do not exclude other components or objects. “Upper,” “lower,” “left,” “right,” etc. are only used to indicate the relative positional relationship. When the absolute position of the object being described is changed, the relative positional relationship may also change accordingly.
The principle and the embodiment of the disclosure are set forth in the specification. The description of the embodiments of the present disclosure is only used to help understand the method of the present disclosure and the core idea thereof. Meanwhile, for a person of ordinary skill in the art, the disclosure relates to the scope of the disclosure, and the technical embodiment is not limited to the specific combination of the technical features, and also should covered other technical embodiments which are formed by combining the technical features or the equivalent features of the technical features without departing from the inventive concept. For example, technical embodiments may be obtained by replacing the features described above as disclosed in this disclosure (but not limited to) with similar features.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/093902 | 6/2/2020 | WO | 00 |