Patent ID: 12222625

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

FIG.1is a cross-sectional view of a display device100according to one embodiment of the present disclosure. The display device100includes a driving substrate110, an electronic ink layer120, and a conductive barrier layer130. The electronic ink layer120is located on the driving substrate110. The conductive barrier layer130is located on the electronic ink layer120. The display device100of the present disclosure can be foldable display device.

FIG.2is a partial cross-sectional view of the display device100shown inFIG.1. The display device100further includes an adhesive layer140and a sealant150. The adhesive layer140is located between the electronic ink layer120and the conductive barrier layer130. The conductive barrier layer130includes a base layer132, a vapor barrier layer134, and a conductive layer136. The conductive layer136is located between the vapor barrier layer134and the electronic ink layer120. The vapor barrier layer134is located between the base layer132and the conductive layer136. In other words, the conductive layer136is separated from the electronic ink layer120.

The base layer132includes colorless polyimide (CPI). Since the ultraviolet transmittance of the colorless polyimide is lower, the base layer132can be ultraviolet resistant. Therefore, there is no need to dispose an ultraviolet resistant film on the conductive barrier layer130. The conductive layer136is configured to control the electrodes of the electronic ink layer120. Since the conductive layer136is formed on the vapor barrier layer134and the base layer132, and therefore the size of the conductive layer136is substantially the same as the sizes of the vapor barrier layer134and the base layer132.

In other words, since the base layer132, the vapor barrier layer134, and the conductive layer136of the display device100of the present disclosure are integrated as an integration film that can resist ultraviolet light and water and can drive the electronic ink layer120. Therefore, the conductive layer136of the conductive barrier layer130is not formed directly on the electronic ink layer120. As such, the size of the conductive barrier layer130can be greater than the size of the electronic ink layer120. As shown inFIG.2, an area of an orthogonal projection of the conductive barrier layer130on the driving substrate110is greater than an area of the orthogonal projection of the electronic ink layer120on the driving substrate110. In addition, a width W1 of the conductive barrier layer130is greater than a width W2 of the electronic ink layer120. With such design, there is no need to dispose a protection film covering the surface130T of the conductive barrier layer130facing away from the electronic ink layer120and a side wall130S of the conductive barrier layer130, and therefore the thickness of the display device100can be reduced. For example, in one embodiment, the thickness of the display device100can be reduced from about 163 um to about 107 um. As such, the display device100can have better foldability. For example, the folding radius of the display device100can be reduced from a value greater than about 10 um to a value smaller than or equal to about 4 um, and therefore the fatigue damage of the display device100due to repeated bending can be reduced.

Reference is made toFIG.2, the sealant150is located between the driving substrate110and the conductive barrier layer130, and the sealant150surrounds the electronic ink layer120. Specifically, the sealant150is located between the surface130B of the conductive barrier layer130facing the electronic ink layer120and the surface110T of the driving substrate110facing the electronic ink layer120, and the sealant150does not extend to the side wall130S of the conductive barrier layer130or the surface130T of the conductive barrier layer130facing away from the electronic ink layer120. As such, display device100a wedge-shaped protection film covering the electronic ink layer120(that is, the protection film covering the surface130T of the conductive barrier layer130facing away from the electronic ink layer120and a side wall130S of the conductive barrier layer130mentioned above), thereby preventing the peeling off of the protection film due to adhesive failure caused by stress when the display device100is bent.

In the present embodiment, a stiffness of the sealant150is smaller than 500 MPa·such that the sealant150can endure stress when the display device100is bent. The viscosity of the sealant150is smaller than 2000 Pa·s such that the sealant150can efficiently permeate to the gap G between the conductive barrier layer130and the driving substrate110, and the electronic ink layer120can be sealed through an edge sealing method. In some embodiments, the gap G between the conductive barrier layer130and the driving substrate110is about 55 um. The water vapor transmission rate (WVTR) of the sealant150is smaller than 12 g/m2/day such that an effective water resistant distance is smaller than 1.2 mm, and therefore vapor is prevented from permeating into the electronic ink layer120. With such design, the waterproof property of the display device100can be maintained.

Reference is made toFIG.1, the display device100further includes a functional thin film160disposed on the conductive barrier layer130, another functional thin film170disposed on the driving substrate110, and a housing180. The functional thin film160is a cover structure, and the functional thin film160includes a first cover structure162and a second cover structure164. The first cover structure162and the second cover structure164are adhered with each other through an optical adhesive layer166, and the first cover structure162and the conductive barrier layer130are adhered with each other through another adhesive layer166. The functional thin film170includes a protection layer172and another optical adhesive layer174adhering the protection layer172onto the driving substrate110. The functional thin films160,170mentioned above are merely examples, and the present disclosure are not limited in these regards.

In the present embodiment, a width W3 of the functional thin film160is smaller than or equal to a width W1 of the conductive barrier layer130(see FIG.2). The housing180surrounds the driving substrate110, the electronic ink layer120, the conductive barrier layer130, and the functional thin films160,170. The housing180extends onto a surface160S of the functional thin film160facing away from the conductive barrier layer130. In other words, the display device100of the present embodiment is not an overall planar design. Failure of the display device100caused by the stress applied by the shaft bearing and the housing180on each layers when the display device100is bent can be avoided through providing the functional thin film160of which the width W3 is smaller than the widths of the conductive barrier layer130and the driving substrate110.

FIG.3is a cross-sectional view of another display device100aaccording to one embodiment of the present disclosure. The display device100ais substantially the same as the display device100shown inFIG.1, and the difference is that a width W4 of the second cover structure164aof the functional thin film160aof the display device100ais smaller than a width W3 of the first cover structure162. Failure of the display device100acaused by the stress applied by the shaft bearing and the housing180on each layers when the display device100is bent can be avoided through reducing the width W4 of the second cover structure164a. The display device100ahas the same advantages as those of the display device100, and the description is not repeated hereinafter.

FIG.4is a cross-sectional view of another display device100baccording to one embodiment of the present disclosure. The display device100bis substantially the same as the display device100shown inFIG.1, and the difference is that a width W5 of the second cover structure164bof the functional thin film160bof the display device100bis smaller than a width W1 of the conductive barrier layer130(seeFIG.2), and the width of the first cover structure162bis substantially the same as the width W1 of the conductive barrier layer130. The difference D between the width W5 of the second cover structure164band the width W1 of the conductive barrier layer130is greater than 3 mm. The housing180asurrounds the driving substrate110, the electronic ink layer120, the conductive barrier layer130, and the first cover structure162b, and the housing180ais located below the second cover structure164b. In other words, the display device100bof the present embodiment is an overall planar design. Peeling off between the interfaces of the display device100bcaused by the wavy deformation due to bending stress when the display device100bis bent can be avoided, thereby avoid failure of the display device100b.

FIG.5is a cross-sectional view of another display device100caccording to one embodiment of the present disclosure. The display device100cis substantially the same as the display device100b, and the difference is that the first cover structure162cand the second cover structure164cof the functional thin film160cof the display device100chave the same width W5. The housing180bsurrounds the driving substrate110, the electronic ink layer120, and the conductive barrier layer130, and the housing180bis located below the first cover structure162c. The display device100chas the same advantages as those of the display device100b, and the description is not repeated hereinafter.

FIG.6is a flow chart of a fabrication method of a display device according to one embodiment of the present disclosure.FIG.7toFIG.9are cross-sectional views of intermediate steps of the fabrication method of display device shown inFIG.6. Reference is made toFIG.6andFIG.7simultaneously. The manufacturing method starts from step S1, of which the electronic ink layer120is formed on the driving substrate110. In step S2, the conductive barrier layer130is provided, and the conductive barrier layer130is located on the conductive layer136located on the base layer132. Step S2includes disposing the vapor barrier layer134on the base layer. In other words, the vapor barrier layer134is formed on the base layer first, and then the conductive layer136is formed on the vapor barrier layer134later. Sequence of step S1and step S2can be exchanged, and the technical advantages of the manufacturing method are not affected. As described above, since the conductive layer136is integrated in the conductive barrier layer130, the size of the conductive barrier layer130can be greater than the size of the electronic ink layer120.

Reference is made toFIG.6andFIG.8simultaneously. In step S3, the electronic ink layer120and the conductive layer136are adhered through the adhesive layer140. Since the size of the conductive barrier layer130is greater than the size of the electronic ink layer120, the gap G can be formed between the surface1306of the conductive barrier layer130facing the electronic ink layer120and the surface110T of the driving substrate110facing the electronic ink layer120.

Reference is made toFIG.6andFIG.2simultaneously. In step S4, the sealant150is disposed between the driving substrate110and the conductive barrier layer130, and the sealant150surrounds the electronic ink layer120. As described above, the electronic ink layer120can be sealed by the sealant150through the edge sealing method.

Reference is made toFIG.6andFIG.9simultaneously. In step S5, functional thin films160,170are disposed below the driving substrate110or above conductive barrier layer130. In the present embodiment, the cover structure of the display device100shown inFIG.1is used as an example. In other embodiments, the functional thin film160can be the cover structures shown inFIG.3toFIG.5.

Reference is made toFIG.6andFIG.1simultaneously. In step S6, the housing180is disposed to surround the driving substrate110, the electronic ink layer120, the conductive barrier layer130, and the functional thin films160,170. In the present embodiment, the housing180shown inFIG.1is used as an example. In other embodiments, the housing180ashown inFIG.4or the housing180bshown inFIG.5can also be used as the housing herein.

In summary, there is no need to dispose a protection film covering the surface of the conductive barrier layer facing away from the electronic ink layer and a side wall of the conductive barrier layer through the method of disposed the conductive barrier layer that can that can resist ultraviolet light and water and can drive the electronic ink layer, and therefore the thickness of the display device can be reduced. As such, the display device can have better foldability, and therefore the fatigue damage of the display device due to repeated bending can be reduced. In addition, such structure aforementioned can be applied in non-planar display device or overall planar display device so as to avoid failure of the display device caused by the stress applied on each layers when the display device is bent.

Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims.