US-12619285-B2 - Support plate, foldable display module, and foldable display device

US12619285B2US 12619285 B2US12619285 B2US 12619285B2US-12619285-B2

Abstract

A support plate, including at least one bendable area and a non-bendable area connected to the bendable area. The bendable area includes a first bendable zone and a second bendable zone located between the first bendable zone and the non-bendable area. The first bendable zone includes a first etching pattern, and the second bendable zone includes a second etching pattern. The flexural rigidity of the second bendable zone is greater than the flexural rigidity of the first bendable zone, and is less than the flexural rigidity of the non-bendable area. In the first bendable zone, the closer a region to the second bendable zone, the greater the flexural rigidity of the region.

Inventors

Gusheng XU
Guizhou QIAO
Bo Yuan
Chang Lin

Assignees

Hefei Visionox Technology Co., Ltd.

Dates

Publication Date: 20260505
Application Date: 20231020
Priority Date: 20220129

Claims (17)

1 . A support plate, comprising at least one bendable area and at least one non-bendable area connected to the bendable area; wherein the bendable area comprises a first bendable zone and a second bendable zone, the second bendable zone is located between the first bendable zone and the at least one non-bendable area; the first bendable zone comprises a first etching pattern, and the second bendable zone comprises a second etching pattern, such that the flexural rigidity of the second bendable zone is greater than the flexural rigidity of the first bendable zone, and is less than the flexural rigidity of the non-bendable area; and the first etching pattern comprises a plurality of first strip-shaped recesses, and the second etching pattern comprises a plurality of second strip-shaped recesses; wherein the at least one non-bendable area comprises two non-bendable zones, the at least one bendable area is connected between the two non-bendable zones, and a bending axis of the support plate is located in the first bendable zone; taking the bending axis of the support plate as a reference, the first bendable zone comprises a plurality of first sub-bendable zones continuously arranged along a first direction and located on the same side of the bending axis of the support plate, and each of the first sub-bendable zones comprises at least one row of the first strip-shaped recesses extending along a second direction; wherein the first strip-shaped recesses in two adjacent rows are staggered with each other along the first direction; a projection of each of the first strip-shaped recesses, projected along a thickness direction of the support plate, has a first symmetrical axis along the first direction; and in the plurality of first sub-bendable zones on the same side of the bending axis of the support plate, the first symmetrical axes of the first strip-shaped recesses in row M coincide with the first symmetrical axes of the first strip-shaped recesses in row M+2, where M is a positive integer; wherein the first strip-shaped recess in the extension direction comprises a first recess section and second recess sections, the second recess sections are located at two ends of the first recess section; and each of the first recess section and the second recess sections is an equal-width structure, and the width of the second recess sections is larger than the width of the first recess section.
2 . The support plate of claim 1 , wherein in the first bendable zone, the closer a region to the second bendable zone, the greater the flexural rigidity of the region; and the depth of the first strip-shaped recesses is greater than the depth of the second strip-shaped recesses.
3 . The support plate of claim 2 , wherein all of the first strip-shaped recesses in each of the first sub-bendable zones are equal in length; and in the plurality of first sub-bendable zones located on the same side of the bending axis of the support plate, the closer the first sub-bendable zone to the second bendable zone, the less the length of the first strip-shaped recesses in the first sub-bendable zone; wherein the first direction is a direction from the first bendable zone to the second bendable zone, and the second direction is parallel to the bending axis of the support plate and perpendicular to the first direction.
4 . The support plate of claim 3 , wherein the first bendable zone is an axisymmetric structure with the bending axis of the support plate as a symmetrical axis.
5 . The support plate of claim 3 , wherein a projection of each row of the first strip-shaped recesses, projected along the thickness direction of the support plate, has a symmetrical axis along the second direction; and a projection of the bending axis of the support plate, projected along the thickness direction of the support plate, coincides with the symmetrical axis along the second direction of the projection of one row of the first strip-shaped recesses, projected along the thickness direction of the support plate.
6 . The support plate of claim 5 , wherein the row of the first strip-shaped recesses corresponding to the bending axis of the support plate is located in one first sub-bendable zone, and the first strip-shaped recesses of the first sub-bendable zone have the largest length.
7 . The support plate of claim 3 , wherein in the plurality of first sub-bendable zones on the same side of the bending axis of the support plate, along the first direction, the lengths of the first strip-shaped recesses are decreased in accordance with a first preset pattern.
8 . The support plate of claim 7 , wherein in the plurality of first sub-bendable zones on the same side of the bending axis of the support plate, along the first direction, the length of any one of the first strip-shaped recesses in the N-th first sub-bendable zone is L N , and the length of any one of the first strip-shaped recesses in the (N+1)-th first sub-bendable zone is L N+1 , where N is a positive integer; and the first preset pattern is L N −L N+1 =m, where m>0 and m is a constant.
9 . The support plate of claim 7 , wherein in the plurality of first sub-bendable zones on the same side of the bending axis of the support plate, along the first direction, the length of the first strip-shaped recesses in the 1-st first sub-bendable zones is L 1 , and the length of the of the first strip-shaped recesses in the N-th first sub-bendable zone is L N , where N is a positive integer; and the first preset pattern is: L N =L 1 −(N−1)×d 1 , where d 1 >0; or L N =L 1 +(N−1)×b 1 +(N−1)×(N−2)×d 2 /2, where d 2 =b 2 −b 1 , b 1 =L 2 −L 1 <0, and b 2 =L 3 −L 2 <0; or L 1 =L N ×q N−1 , where q>0, and L 1 >0.
10 . The support plate of claim 1 , wherein the first recess section is provided with a transition section in a middle position thereof, and a side wall of the first strip-shaped recess in the transition section protrudes outwardly, such that the width of the first strip-shaped recess in the transition section is larger than the width of the first recess section; and a projection of a side wall of the transition section of any one of the first strip-shaped recesses, projected along the thickness direction of the support plate, is symmetrical with respect to the first symmetrical axis of the first strip-shaped recess.
11 . The support plate of claim 7 , wherein in the same first sub-bendable zone, an equal first spacing is defined between two adjacent first strip-shaped recesses in a row; and in the plurality of first sub-bendable zones on the same side of the bending axis of the support plate, the first spacing is gradually increased along the first direction.
12 . The support plate of claim 11 , wherein the support plate comprises a third side and a fourth side, the third side and the fourth side are perpendicular to the bending axis of the support plate, at least some of the plurality of the first sub-bendable zones on the same side of the bending axis of the support plate comprise a marginal strip-shaped recess, and each of the marginal strip-shaped recesses is arranged in a row with corresponding first strip-shaped recesses, having one end running through the third side or the fourth side; and a spacing between the marginal strip-shaped recess and one adjacent first strip-shaped recess in the same row is equal to the first spacing between two adjacent first strip-shaped recesses in the same row.
13 . The support plate of claim 7 , wherein along the first direction, all of the first strip-shaped recesses are equal in width, and/or a second spacing between the first strip-shaped recesses in two adjacent rows is equal.
14 . The support plate of claim 3 , wherein in the second bendable zone, the closer a region to the non-bendable area, the greater the flexural rigidity of the region.
15 . The support plate of claim 14 , wherein the second bendable zone comprises a plurality of second sub-bendable zones continuously arranged along the first direction, each of the second sub-bendable zones comprises at least one row of second strip-shaped recesses extending along the second direction, and all of the second strip-shaped recesses in each of the second sub-bendable zones are equal in length; the closer the second sub-bendable zone to the non-bendable area, the less the length of the second strip-shaped recesses in the second sub-bendable zone; and in the plurality of second sub-bendable zones, along the first direction, the lengths of the second strip-shaped recesses are decreased in accordance with a second preset pattern.
16 . The support plate of claim 3 , wherein the second bendable zone comprises a plurality of second sub-bendable zones continuously arranged along the first direction, each of the second sub-bendable zones comprises a second strip-shaped recess extending along the second direction, the support plate comprises a third side and a fourth side, the third side and the fourth side are perpendicular to the bending axis of the support plate, and the second strip-shaped recess run through the third side and the fourth side.
17 . A foldable display module, comprising a flexible display panel and the support plate of claim 1 ; the support plate comprises a first side and a second side opposite to each other, the first etching pattern and the second etching pattern are disposed on the second side, and the flexible display panel is disposed on the first side.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of international patent application No. PCT/CN2022/129556, filed on Nov. 3, 2022, which itself claims priority to Chinese patent application No. 202210111830.6, filed on Jan. 29, 2022, and titled “SUPPORT PLATE, FOLDABLE DISPLAY MODULE, AND FOLDABLE DISPLAY DEVICE”, the content of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present application relates to the field of display technology, and particularly to a support plate, a foldable display module and a foldable display device. BACKGROUND A foldable terminal device is one of the ongoing development trends in the field of terminal devices, as it not only can meet the users' demands for a large-sized screen, but can also avoid the problems of bulkiness and inconvenience to carry due to the large screen size. The foldable terminal device commonly includes a flexible display. Due to the pliable nature of the flexible display, the surface flatness of the flexible display is inadequate, resulting in the presence of waviness on the surface, which would affect the quality of the displayed images. In the related art, in order to improve the surface flatness of the flexible display, one approach involves arranging a support plate on one side of the flexible display to support the flexible display. However, if the support plate is excessively thick, it would limit the bending of the flexible display; and if the support plate is excessively thin, its mechanical strength is not enough to effectively improve the surface flatness of the flexible display. SUMMARY In view of the above, there is a need to provide a support plate, a foldable display module, and a foldable display device. One aspect of the present application is to provide a support plate. The support plate includes at least one bendable area and at least one non-bendable area connected to the bendable area. The bendable area includes a first bendable zone and a second bendable zone, the second bendable zone is located between the first bendable zone and the non-bendable area. The first bendable zone includes a first etching pattern, and the second bendable zone includes a second etching pattern, such that the flexural rigidity of the second bendable zone is greater than the flexural rigidity of the first bendable zone, and is less than the flexural rigidity of the non-bendable area. In the first bendable zone, the closer a region to the second bendable zone, the greater the flexural rigidity of the region. In the above support plate, the flexural rigidities of the first bendable zone, the second bendable zone and the non-bendable area are decreasingly varied, and the flexural rigidity of the first bendable zone is regional and decreasingly varied, so that the bending ductility and fatigue resistance of the region corresponding to the support plate are improved, and the difference in curvature radius of each position of the support plate in the folded state is reduced, thereby allowing the bendable area to have a smooth transition and making the overall curvature of the bendable area more continuous. As such, it not only mitigate the bending stress concentration in the bendable area of the support plate, thereby reducing the risk of fracture or failure of the support plate, but also diminishes the stress exerted by the support plate on the flexible display panel, thereby protecting the flexible display panel from the risk of film debonding or cracking. In an embodiment, the thickness of the support plate is ranged from 50 μm to 200 μm. In an embodiment, the first etching pattern includes a plurality of first strip-shaped recesses, and the second etching pattern includes a plurality of second strip-shaped recesses. The depth of the first strip-shaped recess is larger than the depth of the second strip-shaped recess. In an embodiment, the depth of the first strip-shaped recess is equal to the thickness of the support plate to form a hollow structure in the first bendable zone, and the depth of the second strip-shaped recess is less than the thickness of the support plate. In an embodiment, the depth of the second strip-shaped recess is larger or equal to half of the thickness of the support plate, and is less than the thickness of the support plate. In an embodiment, each of the bendable area is connected between two non-bendable areas, and a bending axis of the support plate is located in the first bendable zone. Taking the bending axis of the support plate as a reference, the first bendable zone includes a plurality of first sub-bendable zones continuously arranged along a first direction and located on the same side of the bending axis of the support plate. Each of the first sub-bendable zones comprises at least one row of first strip-shaped recesses extending along a second direction, and all of the first strip-shaped recesses in each of the first sub-bendable zones are equal in length. In the plura