Display device and preparation method thereof

Abstract

The embodiment of the invention provides a display device and a preparation method thereof. The display device is in a curved surface shape, and the display device comprises a backlight module which is in a first curved surface shape bent towards the light emitting side in the first direction; the display module is located on the light emitting side of the backlight module and is in a second curved surface shape matched with the shape of the backlight module, the display module comprises a display panel, the display panel comprises a first substrate, a second substrate and liquid crystals, the first substrate and the second substrate are oppositely arranged, the liquid crystals are located between the first substrate and the second substrate, and the first substrate is close to the backlight module relative to the second substrate; wherein the display module comprises a long side, a short side and an angular point; the display device further comprises corner areas close to the corner points, the corner areas extend from the corner points to the center of the display panel along the long edges and the short edges, and when the display device is in a dark state, the light leakage level of the corner areas is smaller than or equal to L3. The problem of light leakage at four corners of the curved-surface liquid crystal screen is solved, and the quality of the display device is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of display technologies, and in particular, to a display device and a method for manufacturing the same. Background Art

[0002] Curved display screens have characteristics such as a real sense of presence, low distortion that is more in line with the spherical structure of the human eye, equal viewing distance at the center, and optimized overall picture quality for side viewing, making curved display screens widely used in usage scenarios such as gaming, film and television, and multi-screen displays.

[0003] Figure 1 FIG. is a schematic diagram showing a comparison effect between a curved display screen and a flat display screen in the related art. Figure 1 The lower middle part shows the effect of the flat display screen in the dark state. Figure 1 The upper middle part shows the effect of the curved display screen in the dark state. As can be seen from Figure 1 it, the curved display screen has a problem of light leakage at the four corners. Summary of the Invention

[0004] Embodiments of the present disclosure provide a display device and a method for manufacturing the same to solve or alleviate one or more technical problems in the prior art.

[0005] As a first aspect of the embodiments of the present disclosure, the embodiments of the present disclosure provide a display device. The display device is in a curved shape that bends toward the light-emitting side along a first direction. The display device includes:

[0006] A backlight module, which is in a first curved shape that bends toward the light-emitting side along the first direction;

[0007] A display module, which is located on the light-emitting side of the backlight module. The display module is in a second curved shape that matches the shape of the backlight module. The display module includes a display panel. The display panel includes a first substrate and a second substrate that are oppositely arranged, and liquid crystal located between the first substrate and the second substrate. The first substrate is closer to the backlight module than the second substrate;

[0008] Wherein, the display module includes a long side, a short side, and corner points. The corner points are the intersection points of the long side and the short side; the display module further includes a corner region near the corner points. The corner region extends from the corner points along the long side and the short side toward the center of the display panel. When the display device is in the dark state, the light leakage level in the corner region is less than or equal to L3;

[0009] Wherein, the light leakage region in the corner region is a region enclosed by extending from the brightest position in the corner region toward the surrounding to a preset position. The ratio of the brightness of the brightest position to the brightness of the preset position is k. The preset position is a position with a preset brightness;

[0010] For the light leakage level L3, k is (3, 5];

[0011] For the light leakage level L2, k is in the range of (1.3, 3];

[0012] For the light leakage level L1, k is less than or equal to 1.3;

[0013] The light leakage levels of L3, L2, and L1 decrease in sequence.

[0014] In some embodiments,

[0015] The first substrate includes a first base, the material of the first base includes glass, and the thickness range of the first base is 2.0 mm to 3.0 mm; and / or,

[0016] The second substrate includes a second base, the material of the second base includes glass, and the thickness range of the first base is 2.0 mm to 3.0 mm.

[0017] In some embodiments, the corner region includes a sunken region, the sunken region includes a triangular region defined by a corner point, a third preset edge, and a fourth preset edge. The third preset edge is an edge extending from the corner point along the long side towards the center for a third length, and the fourth preset edge is an edge extending from the corner point along the short side towards the center for a fourth length. The connection line between the end of the third preset edge far from the corner point and the end of the fourth preset edge far from the corner point forms the demarcation line of the sunken region;

[0018] The sunken region bends towards the backlight module side along the demarcation line.

[0019] In some embodiments, the third length is less than the length of the corner region along the long side, and the fourth length is less than the length of the corner region along the short side;

[0020] The third length is the same as the fourth length, and the numerical range of the third length or the fourth length is 80 mm to 120 mm.

[0021] In some embodiments, the sinking distance of the corner point is 0.6 mm to 3.4 mm.

[0022] In some embodiments, the sinking distance of the corner point is 1.5 mm to 2.5 mm.

[0023] In some embodiments, the display module further includes a first polarizer and a second polarizer. The first polarizer is attached to the side of the first substrate facing the backlight module, and the second polarizer is attached to the side of the second substrate facing away from the backlight module. The thickness of the first polarizer is less than the thickness of the second polarizer.

[0024] In some embodiments,

[0025] The ratio of the difference between the thickness of the first polarizer and the thickness of the second polarizer to the thickness of the second polarizer is 26.5% to 37.8%; and / or,

[0026] The difference in thickness between the first polarizer and the second polarizer is 45 μm to 65 μm.

[0027] In some embodiments, the display module further includes a first polarizer and a second polarizer. The first polarizer is attached to one side of the first substrate facing the backlight module. The first polarizer includes a first polarizing film, and the material of the first polarizing film includes polyvinyl alcohol.

[0028] The second polarizer is attached to one side of the second substrate facing away from the backlight module. The second polarizer includes a second polarizing film, and the material of the second polarizing film includes polyvinyl alcohol.

[0029] The thickness of the first polarizing film is less than the thickness of the second polarizing film.

[0030] In some embodiments,

[0031] The ratio of the difference in thickness between the first polarizing film and the second polarizing film to the thickness of the second polarizing film is 0 to 45%; and / or,

[0032] The difference in thickness between the first polarizing film and the second polarizing film is 0 to 10 μm.

[0033] As a second aspect of the embodiments of the present disclosure, the embodiments of the present disclosure provide a method for manufacturing a display device, which is applied to the display device of any embodiment of the present disclosure. The method includes:

[0034] Setting the flat display module on a jig having a preset curvature radius;

[0035] Setting the temperature of the jig at a preset temperature, and the display module deforms to form a second curved shape at the preset temperature and for a preset time, and the curvature of the second curved shape corresponds to the preset curvature radius;

[0036] Attaching the display module in the second curved shape to the backlight module. The display module is located on the light-emitting side of the backlight module, and the backlight module is in a first curved shape that bends toward the light-emitting side along a first direction, and the second curved shape matches the first curved shape.

[0037] In some embodiments, the preset curvature radius is R1000 mm to R1900 mm; and / or,

[0038] The preset temperature is 65°C to 75°C; and / or,

[0039] The preset time is 48 hours to 72 hours.

[0040] In the technical solution of the embodiments of the present disclosure, in the curved liquid crystal display device of the embodiments of the present disclosure, in the dark state, the light leakage level in the corner area is less than or equal to L3, which greatly reduces the light leakage level at the four corners compared with the related art, improves the problem of light leakage at the four corners of the curved liquid crystal screen, and improves the quality of the display device.

[0041] The above summary is for the purpose of the specification only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present disclosure will be readily apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In the drawings, unless otherwise specified, the same reference numerals throughout the several views denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments in accordance with the present disclosure and should not be regarded as limiting the scope of the present disclosure.

[0043] Figure 1 Schematic diagram of the comparison effect between a curved display screen and a flat display screen in the related art;

[0044] Figure 2 Showing a schematic diagram of the bending of the display panel and a schematic diagram of the force on the substrate;

[0045] Figure 3 Showing the optical path difference distribution diagram of the upper substrate and the optical path difference distribution diagram of the lower substrate;

[0046] Figure 4 Showing the light leakage mechanism after the display panel is bent and stressed;

[0047] Figure 5 Showing the Bongard sphere light leakage schematic diagram of the flat display panel;

[0048] Figure 6A Cross-sectional schematic diagram of a curved display device;

[0049] Figure 6B For Figure 6A Schematic diagram of side D in

[0050] Figure 7 Schematic diagram of the comparison effect between the light leakage level L3+ and the light leakage level L3;

[0051] Figure 8 Schematic diagram of the comparison of the light leakage levels of curved display panels corresponding to glass substrates of different thicknesses;

[0052] Figure 9A Cross-sectional schematic diagram of a display module in a display device according to another embodiment of the present disclosure;

[0053] Figure 9B For Figure 9A Schematic diagram of side D in

[0054] Figure 10Schematic diagram of the comparison effect of the curved display panel in another embodiment of the present disclosure;

[0055] Figure 11 Cross-sectional schematic diagram of the display panel before bending in a display device according to an embodiment of the present disclosure;

[0056] Figure 12 Schematic diagram of the polarizer attached to the glass substrate;

[0057] Figure 13 Schematic diagram of the display module;

[0058] Figure 14 For Figure 13 Schematic diagram of the bent display panel shown in;

[0059] Figure 15 Schematic diagram of the light leakage effect comparison of a curved liquid crystal display screen. Detailed implementation manners

[0060] In the following, only some exemplary embodiments are briefly described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present disclosure, and different embodiments can be arbitrarily combined without conflict. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0061] The curved liquid crystal display panel includes a first substrate and a second substrate disposed opposite to each other, and liquid crystal located between the first substrate and the second substrate. The curved liquid crystal display panel is usually bent toward the second substrate side along the length direction. Thus, the display side of the curved liquid crystal display panel is usually the side of the second substrate facing away from the first substrate. Exemplarily, the first substrate can be called the lower substrate or the array substrate, and the second substrate can be called the upper substrate or the color filter substrate. The first substrate may include a first substrate, and the material of the first substrate may be glass. For example, the first substrate may be a glass substrate. The second substrate may include a second substrate, and the material of the second substrate may be glass. For example, the second substrate may be a glass substrate. Thus, both the upper substrate and the lower substrate are glass substrates.

[0062] In the related art, the curved surface effect of the curved liquid crystal display panel is achieved by hard bending the assembled liquid crystal display panel. For example, the assembled flat display panel is adhered to a backlight module with a certain curvature through a foam by hard bending, so as to obtain a curved display panel. Stress is generated when the liquid crystal display panel is bent and deformed. According to the photoelastic theory and the light leakage mechanism, the greater the stress, the greater the light leakage intensity, and the light leakage is concentrated in the four corner regions of the display panel. Herein, the corner region can be understood as the region near the corner position in the display surface of the display panel, and the area of the corner region is not limited herein.

[0063] Figures 2 - 4 Schematic diagram of force analysis and light leakage mechanism of a curved liquid crystal display panel. Figure 2 It shows a schematic diagram of the display panel bending and a schematic diagram of the substrate stress. As Figure 2 shown, after the display panel is bent, it can be seen from the schematic diagram of the display panel bending that the upper substrate is subjected to a compressive force and the lower substrate is subjected to an expansion force. It can be seen from the schematic diagram of the substrate stress that in the upper substrate, from the neutral line (Neutral line) of the display panel towards the outside (from bottom to top), along the thickness direction of the upper substrate, the compressive force received by the upper substrate gradually increases; in the lower substrate, from the neutral line (Neutral line) of the display panel towards the outside (from top to bottom), along the thickness direction of the lower substrate, the expansion force received by the lower substrate gradually increases. Thus, it can be seen that the principal stress of the upper substrate is compressive force and the principal stress of the lower substrate is expansion force.

[0064] Figure 3 It shows the retardation distribution diagram of the upper substrate and the retardation distribution diagram of the lower substrate. In the two retardation distribution diagrams, the abscissa is the length dimension of the display panel and the ordinate is the width dimension of the display panel. The retardation delay direction of each position of the substrate is shown in the retardation distribution diagram of the upper substrate, and the retardation delay direction of each position of the substrate is shown in the retardation distribution diagram of the lower substrate. Substrate bending generates stress, causing the passing light to have a phase delay. Through the retardation (Retardation) relation formula (1) and Figure 3 it can be seen that the magnitude of the retardation generated at the same position of the upper substrate and the lower substrate is the same, and the retardation delay directions are perpendicular to each other.

[0065]

[0066] Among them, T1 and T2 are the thicknesses of the glass substrates in the upper substrate and the lower substrate respectively, SOC is the photoelastic coefficient of the glass, E is the Young's modulus of the glass, and R is the radius of curvature of the curved display screen.

[0067] From Figure 3 it can be seen that the angles formed by the retardation delay directions of the four corner regions with the liquid crystal alignment direction are neither 0° nor 90°, which causes the phase delay amount of the backlight light passing through the liquid crystal layer in the corner regions to increase, resulting in light leakage, and the light leakage amount is positively correlated with the substrate retardation value.

[0068] Figure 4 It shows the light leakage mechanism after the display panel is bent and stressed. Among them, Glass on the lower side represents the lower substrate, Glass on the upper side represents the upper substrate, LC in the middle represents the liquid crystal layer, POL on the lower side is the lower polarizer, and POL on the upper side is the upper polarizer.

[0069] Figure 5Shows the Bonger sphere light leakage schematic diagram of a planar display panel. Figure 5 In it, the polarized light passing through the lower POL passes through the lower substrate glass, liquid crystal, and upper substrate glass in sequence without obvious changes, and is finally absorbed by the upper POL. By comparing Figure 4 and Figure 5 It can be seen that after the display panel is bent and stressed, the light phase delay amount increases, resulting in light leakage. Dark state light leakage is the result of the combined action of the glass delay amount and liquid crystal arrangement. When the angle formed by the glass stress direction and the liquid crystal orientation direction is neither 0° nor 90°, the light passes through the liquid crystal layer to increase the phase delay amount, resulting in light leakage.

[0070] Exemplarily, the curved display panel includes a long side and a short side, and the intersection point of the long side and the short side is a corner point. In the related art, there is a problem of light leakage at the four corners of the curved liquid crystal screen. The light leakage level in the corner area near the corner point 20c position in the curved liquid crystal screen is higher than L3, which greatly reduces the display quality.

[0071] In order to improve the problem of light leakage at the four corners of the curved screen, an embodiment of the present disclosure proposes a display device.

[0072] Figure 6A Is a cross-sectional schematic diagram of a curved display device; Figure 6B Is Figure 6A The D-side schematic diagram in. As Figure 6A Shown, the display device is in a curved shape bent toward the light-emitting side along the first direction. In Figure 6A In, the light-emitting side is the upper side of the display device, and the first direction can be the length direction of the display device.

[0073] As Figure 6A Shown, the display device may include a backlight module 10 and a display module 20. The backlight module 10 is in a first curved shape bent toward the light-emitting side along the first direction. The display module 20 is located on the light-emitting side of the backlight module 10, and the display module 20 is in a second curved shape matching the shape of the backlight module 10.

[0074] As Figure 6A and Figure 6BAs shown, the display module 20 includes a display panel. The display panel includes a first substrate 21 and a second substrate 22 which are oppositely arranged, and liquid crystal (not shown in the figure) located between the first substrate 21 and the second substrate 22. The first substrate 21 is closer to the backlight module 10 than the second substrate 22. The display module 20 may include a long side 20a, a short side 20b, and a corner point 20c. The corner point 20c may be the intersection point of the long side 20a and the short side 20b. The display module 20 may include a corner region near the corner point 20c. The corner region extends from the corner point 20c along the long side 20a and the short side 20b towards the center of the display module 20. Exemplarily, in actual implementation, a rectangular region defined by a first preset edge and a second preset edge may be defined as the corner region. The first preset edge is an edge that extends a first length from the corner point 20c along the long side 20a towards the center, and the second preset edge is an edge that extends a second length from the corner point 20c along the short side 20b towards the center.

[0075] In the display device according to the embodiment of the present disclosure, when the display device is in the dark state, the light leakage level in the corner region is less than or equal to L3. In a liquid crystal display device, when the display device is in the dark state, the electric field used to drive the liquid crystal to deflect in the display device is 0. The light leakage level of the light from the backlight module 10 in the corner region is less than or equal to L3.

[0076] It should be noted that in this article, the long side 20a and the short side 20b of the display module 20 can be understood as the long side 20a and the short side 20b of the display surface of the display module 20. Correspondingly, the corner point 20c is the corner point 20c of the display surface. When the display surface is rectangular, the corner point 20c is the vertex of the rectangular display surface. It can be understood that the display surface of the display module 20 is determined by the display surface of the display panel. Therefore, the long side 20a, the short side 20b, and the corner point 20c of the display module 20 can be understood as the long side 20a, the short side 20b, and the corner point 20c of the display panel.

[0077] When the display module 20 is rectangular, the display module 20 includes two relatively arranged long sides 20a, two relatively arranged short sides 20b, and four corner points 20c. Correspondingly, the display module 20 includes four corner regions. The four corner points 20c correspond to the four corner regions one by one. Figure 6B The boundary line 20d of a corner region is shown.

[0078] In this text, the light leakage level in the corner area can be understood as the light leakage level in the light leakage area within the corner area. In a curved display device, the light leakage area is usually located in the corner area. The light leakage area can be an area enclosed by extending from the brightest position in the corner area towards the surrounding to a preset position, and the ratio of the brightness at the brightest position to the brightness at the preset position is k. Exemplarily, the preset position can be a position with a preset brightness. The preset brightness can be the brightness at the center of the display module, or the preset brightness can be set as needed. For example, the preset brightness can be the minimum brightness that the human eye can distinguish relative to the center of the display module. In the light leakage area, the preset position forms the boundary of the light leakage area.

[0079] In a curved display device, the brightness of the light leakage area in the corner area changes gradually. For example, the brightest position in the light leakage area is usually the corner point position, and the brightness gradually decreases from the corner point position in the light leakage area to the boundary of the light leakage area. Therefore, the light leakage level can be determined by using the ratio k of the brightness at the brightest position in the corner area to the brightness at the preset position. For example, for the light leakage level L3, k is in the range of (3, 5]; for the light leakage level L2, k is in the range of (1.3, 3]; for the light leakage level L1, k is less than or equal to 1.3. The light leakage levels L3, L2, and L1 decrease in sequence. When k is greater than 5, the light leakage level is L3+, that is, greater than L3.

[0080] In another embodiment, the light leakage level in the corner area can be L, where L = the sum of the areas of the light leakage areas / the area of the display area, that is, L is the ratio of the sum of the areas of the light leakage areas to the area of the display area.

[0081] For example, for a 34-inch QHD R1900 curved LCD screen, where for L3, k is in the range of (3, 5], that is, 3 < k ≤ 5, the value of L3 is in the range of [17%, 23%), that is, 17% ≤ L3 < 23%; for L2, k is in the range of (1.3, 3], the value of L2 is in the range of [16%, 22%); for L1, k is less than or equal to 1.3, the value of L1 is in the range of [13%, 18%).

[0082] For example, in Figure 1 in, Figure 1 the product is a 34-inch LCD screen. Through visual observation, obviously, Figure 1 in the corner area of, the k of the light leakage area is greater than 5, so Figure 1 the light leakage level in is L3+, that is, greater than L3.

[0083] For example, the ratio of the sum of the areas of the light leakage areas to the area of the display area can be used to determine Figure 1The light leakage level of the middle curved display screen. Pictures of the curved display device in the dark state can be taken. Through the pictures, the size of the light leakage area in the corner area is measured, the area of the light leakage area is calculated, and then the ratio of the sum of the light leakage area of the four corner areas to the display area is calculated. Figure 1 The L ratio of the middle curved display screen is greater than 33%, so its light leakage level is L3+, that is, greater than L3.

[0084] It should be noted that for curved LCD screens of different sizes, the L value (the ratio of the sum of the light leakage area to the display area) corresponding to each light leakage level can be determined as needed. Usually, for curved LCD screens of different sizes, there are specific values recognized by those skilled in the art for the L values of each light leakage level.

[0085] In another embodiment, the light leakage area in the corner area can be an area in the corner area where the brightness is greater than or equal to a preset brightness. Or, it can be understood as the area composed of positions in the corner area where the brightness is greater than or equal to the preset brightness. The area of this area can be called the light leakage area. The larger the light leakage area, the higher the light leakage level, and the smaller the light leakage area, the lower the light leakage level.

[0086] It can be understood that when the display device is in the dark state, the preset brightness can be the brightness at the center of the display module, or the preset brightness can be set as needed. For example, the preset brightness can be the minimum brightness that the human eye can distinguish relative to the center of the display module. When the brightness at this position is greater than or equal to the preset brightness, the human eye recognizes that there is light leakage at this position.

[0087] In addition, in the art, the light leakage level of the corner area can be determined according to the light leakage standard in the art. Or, the light leakage level of the corner area can be determined according to the samples of each light leakage level. For example, the light leakage level usually includes five levels from L1 to L5. From L1 to L5, the higher the level, the higher the light leakage level and the more serious the light leakage. The light leakage of light leakage level L4 is more serious than that of light leakage level L3. It should be noted that in this article, "L" is Level, and L3 represents the third level of light leakage level. The higher the level, the more serious the light leakage.

[0088] For example, for a certain specification of curved display device, the light leakage level of the prepared curved display device can be judged according to the samples of each light leakage level; or, the light leakage level of the prepared curved display device can be judged according to the light leakage standard of this specification product.

[0089] Figure 7 It is a schematic diagram of the comparison effect between the light leakage level L3+ and the light leakage level L3. From Figure 7It can be seen that the light leakage area in the light leakage level L3+ is larger than that in the light leakage level L3, and the light leakage in the light leakage level L3+ is more serious than that in the light leakage level L3. It should be noted that in the art, when the light leakage level is greater than L3, it is usually denoted as L3+, and the specific light leakage level is not specified anymore.

[0090] In the related art, in the dark state, the light leakage level at the four corners of the curved liquid crystal display screen is higher than L3. In the curved liquid crystal display device of the present disclosure embodiment, in the dark state, the light leakage level in the corner area is less than or equal to L3, which greatly reduces the light leakage level at the four corners compared with the related art, improves the light leakage problem at the four corners of the curved liquid crystal display screen, and improves the quality of the display device.

[0091] In one embodiment, the first substrate 21 may include a first base, and the material of the first base may include glass. For example, the first base may be a glass base. The thickness range of the first base is 2.0 mm to 3.0 mm. For example, the thickness of the first base may be 2.0 mm, 2.5 mm, or 3.0 mm.

[0092] In one embodiment, the second substrate 22 may include a second base, and the material of the second base may include glass. For example, the second base may be a glass base. The thickness range of the second base is 2.0 mm to 3.0 mm. For example, the thickness of the second base may be 2.0 mm, 2.5 mm, or 3.0 mm.

[0093] Through the research of the inventors of this patent, it is found that in the curved display panel, the first substrate 21 and the second substrate 22 generate optical anisotropy with mutually perpendicular optical axes under force. The degree of light leakage is positively correlated with the optical path difference of the display panel. In the case where the radius of curvature R and the base material are both glass, the light leakage level is positively correlated with the thickness of the glass base. Therefore, reducing the thickness of the glass base can effectively reduce the light leakage at the four corners of the curved display panel.

[0094] Figure 8 It is a schematic diagram for comparing the light leakage levels of curved display panels corresponding to glass bases with different thicknesses. From Figure 8 it can be seen that when the thickness of the glass base is 0.5T, the light leakage level of the display panel is L3+; when the thickness of the glass base is 0.4T, the light leakage level of the display panel is L3+, and the light leakage level corresponding to 0.5T is greater than the light leakage level corresponding to 0.4T; when the thickness of the glass base is 0.25T, the light leakage level of the display panel is L3; when the thickness of the glass base is 0.2T, the light leakage level of the display panel is L2. Thus, it can be seen that the smaller the thickness of the glass base, the lower the light leakage level of the curved display panel and the better the display effect.

[0095] It should be noted that "T" is in mm. For example, 0.25T can be understood as 0.25 mm.

[0096] The thickness range of the first substrate is set to be 2.0 mm to 3.0 mm; and / or, the thickness range of the second substrate is set to be 2.0 mm to 3.0 mm, which can not only effectively improve the light leakage at the four corners of the curved display panel, but also reduce the fragment rate in the process and ensure the process yield.

[0097] Figure 9A The following is a schematic cross-sectional view of a display module in another embodiment of the present disclosure. Figure 9B It is Figure 9A a schematic view of side D in . In one embodiment, the corner region includes a sinking region, and the sinking region includes a triangular region defined by the corner point 20c, the third preset edge, and the fourth preset edge. The third preset edge is an edge extending from the corner point 20c along the long side 20a towards the center for a third length. The fourth preset edge is an edge extending from the corner point 20c along the short side 20b towards the center for a fourth length. The connection line between the end of the third preset edge far from the corner point 20c and the end of the fourth preset edge far from the corner point 20c forms the demarcation line 20e of the sinking region. The sinking region bends towards the backlight module side along the demarcation line 20e.

[0098] Through the research of the present inventor, it is found that the curved display panel is spherical in shape, with concentrated shear stress at the four corners and serious light leakage. In the curved display panel, as Figure 2 shown, the first substrate is located on the lower side and is subjected to an expansion force, and the second substrate is located on the upper side and is subjected to a compression force. In the embodiment of the present disclosure, by setting the sinking region to bend towards the backlight module side along the demarcation line 20e, the part of the first substrate located in the sinking region is subjected to a compression force, which can weaken the expansion force received by the part of the first substrate located in the sinking region; and the part of the second substrate located in the sinking region is subjected to an expansion force, which can weaken the compression force received by the part of the second substrate located in the sinking region. Therefore, by setting the sinking region to bend towards the backlight module side along the demarcation line 20e, the light leakage level can be reduced and the light leakage can be improved.

[0099] Figure 10 The following is a schematic diagram of the comparison effect of a curved display panel in another embodiment of the present disclosure. Figure 10 In , the left figure is a curved display panel without a sinking region, and the right figure is a curved display panel with a sinking region. By comparing the display effects of the two display panels in the dark state, it can be seen that after setting the sinking region, the light leakage level is greatly reduced.

[0100] Exemplarily, the third length may be less than the length of the corner region along the long side 20a, that is, the third length may be less than the first length, and the fourth length may be less than the length of the corner region along the short side 20b, that is, the fourth length may be less than the second length. The third length and the fourth length may be the same or different. For example, the third length and the fourth length are the same, and the numerical range of the third length or the fourth length may be 80 mm to 120 mm. For example, the numerical value of the third length or the fourth length may be 80 mm, 100 mm, or 120 mm.

[0101] Exemplarily, the sinking distance H of the corner point 20c may be 0.6 mm to 3.4 mm, such as Figure 9A shown. The sinking distance of the corner point 20c is related to the thicknesses of the first substrate and the second substrate. For example, when both the first substrate and the second substrate are glass substrates and the thicknesses are both 0.2 mm, the sinking distance H of the corner point 20c may be 0.6 mm; when both the first substrate and the second substrate are glass substrates and the thicknesses are both 0.25 mm, the sinking distance H of the corner point 20c may be 2 mm. When both the first substrate and the second substrate are glass substrates and the thicknesses are both 0.3 mm, the sinking distance of the corner point 20c may be 3.4 mm.

[0102] In one embodiment, the sinking distance H of the corner point 20c may be 1.5 mm to 2.5 mm. For example, the sinking distance of the corner point 20c may be 1.5 mm, 2.0 mm, or 2.5 mm.

[0103] It is proved by experiments that by setting the sinking area to bend toward the backlight module 10 along the boundary line, the light leakage problem of the curved display panel can be improved, and the light leakage level in the corner area of the display panel can be improved by 0.5 to 1 Level.

[0104] It should be noted that the sinking distance of the corner point 20c can be understood as the distance between the position of the corner point 20c before the sinking area bends and the position of the corner point 20c after the sinking area bends in the central normal direction of the curved display panel, such as Figure 9A shown.

[0105] During the preparation process of the display panel, when the curved display panel on the left side as shown in Figure 10 is obtained, a force toward the backlight module side can be applied to the corner point (as shown by the downward arrow in the right figure in Figure 10 ) to make the sinking area bend toward the backlight module side along the demarcation line 20e.

[0106] Figure 11This is a schematic cross-sectional view of a display panel before bending in a display device according to an embodiment of the present disclosure. The display panel is a planar display panel before bending. The display module may further include a first polarizer 23 and a second polarizer 24. The first polarizer 23 is attached to one side of the first substrate 21 facing the backlight module 10, that is, the first polarizer 23 is attached to the side of the first substrate 21 facing away from the second substrate 22. The second polarizer 24 is attached to the side of the second substrate 22 facing away from the backlight module 10, that is, the second polarizer 24 is attached to the side of the second substrate 22 facing away from the first substrate 21. The thickness of the first polarizer 23 is less than the thickness of the second polarizer 24.

[0107] Those skilled in the art understand that the basic structure of a polarizer includes: PVA (polyvinyl alcohol) in the middle, and TAC (triacetyl cellulose) on both the upper and lower sides of the PVA.

[0108] The formula for the deformation of the polarizer under force is as shown in formula (2).

[0109] F = Y × ΔV,

[0110] λ = F × D = Y * T * W * ΔL * D, formula (2)

[0111] Wherein, F is the magnitude of the force, Y is Young's Modulus, ΔV is the volume change, λ is the deformation amount, T is the thickness, W is the width, ΔL is the dimension change, and D is the distance from the center to the substrate surface.

[0112] Figure 12 This is a schematic diagram of the polarizer attached to the glass substrate. Figure 12 The basic structural layers of the polarizer are shown, namely Layer1 (TAC1), Layer2 (PVA), Layer3 (TAC2), Figure 12 The thickness T of each film layer and the distance D from the center of each film layer to the substrate surface are also shown. Figure 12 The λ of each film layer is also shown. TAC1 corresponds to λ1, PVA corresponds to λ2, and TAC corresponds to λ3. The total λ_total of the polarizer = λ1 + λ2 + λ3.

[0113] Figure 13 This is a schematic diagram of the display module. It should be noted that the polarizer is formed by stretching and attaching multiple layers of thin films. Therefore, the deformation effects of the second polarizer 24 (upper polarizer) and the first polarizer 23 (lower polarizer) on the display panel are as Figure 13As shown in the figure. Among them, for the second polarizer 24 (i.e., the upper polarizer), λ_total1 = λ11 + λ12 + λ13, and for the first polarizer 23 (i.e., the lower polarizer), λ_total 2 = λ21 + λ22 + λ23.

[0114] Figure 14 is Figure 13 The schematic diagram after the display panel is bent as shown. After the display panel is bent, the second polarizer 24 (i.e., the upper polarizer) is subjected to a compressive force, and the first polarizer 23 (i.e., the lower polarizer) is subjected to an expansion force. Therefore, the deformation effects of the second polarizer 24 and the first polarizer 23 on the liquid crystal cell are different. When λ_total 1 of the second polarizer 24 is greater than λ_total 2 of the first polarizer 23, the overall deformation of the liquid crystal cell presents a curved surface state. The polarizer and the liquid crystal cell are surface-fitted, and the whole surface is uniformly stressed.

[0115] It can be seen from formula (2) that λ_total of the polarizer is positively correlated with T and D, that is, positively correlated with the thickness of the polarizer. Therefore, in the embodiments of the present disclosure, the thickness of the first polarizer 23 is set to be less than the thickness of the second polarizer 24, that is, the thickness of the upper polarizer is greater than the thickness of the lower polarizer, which is more likely to make λ_total 1 of the second polarizer 24 greater than λ_total 2 of the first polarizer 23, so that the overall deformation of the liquid crystal panel presents a curved surface state, and the polarizer and the display panel are surface-fitted, and the whole surface is uniformly stressed. In this way, the shear stress generated by the polarizer on the display panel can be reduced, and the light leakage at the four corners of the curved display module 20 can be improved.

[0116] Exemplarily, the ratio of the difference between the thickness of the first polarizer 23 and the thickness of the second polarizer 24 to the thickness of the second polarizer 24 is 26.5% - 37.8%; and / or, the difference between the thickness of the first polarizer 23 and the thickness of the second polarizer 24 is 45μm - 65μm. For example, the difference between the thickness of the first polarizer 23 and the thickness of the second polarizer 24 is 45μm, 50μm, 60μm or 65μm.

[0117] In one embodiment, the first polarizer 23 includes a first polarizing film, and the material of the first polarizing film includes polyvinyl alcohol. For example, the first polarizing film is a PVA layer. The second polarizer 24 includes a second polarizing film, and the material of the second polarizing film includes polyvinyl alcohol. For example, the second polarizing film is a PVA layer. The thickness of the first polarizing film is less than the thickness of the second polarizing film.

[0118] It can also be seen from formula (2) that λ_total of the polarizer is positively correlated with ΔL. The dimensional change amount in the polarizer, such as the shrinkage amount, mainly comes from the PVA layer. By setting the thickness of the first polarizing film to be less than that of the second polarizing film, it is easier to achieve λ_total 1 of the second polarizer 24 being greater than λ_total 2 of the first polarizer 23, enabling the overall deformation of the liquid crystal panel to present a curved surface state. Moreover, since the polarizer and the display panel are surface-to-surface bonded, the entire surface is uniformly stressed. In this way, the shear stress generated by the polarizer on the display panel can be reduced, and the light leakage at the four corners of the curved display module 20 can be improved.

[0119] Exemplarily, the ratio of the difference between the thickness of the first polarizing film and the thickness of the second polarizing film to the thickness of the second polarizing film is 0 to 45%; and / or, the difference between the thickness of the first polarizing film and the thickness of the second polarizing film is 0 to 10 μm. For example, the difference between the thickness of the first polarizing film and the thickness of the second polarizing film is 0, 5 μm or 10 μm.

[0120] For example, for a 34-inch QHD R1900 curved liquid crystal screen, the thickness of the first polarizer 23 is 45 μm to 65 μm smaller than the thickness of the second polarizer 24. The thickness of the first polarizing film in the first polarizer 23 is 0 to 10 μm smaller than the thickness of the second polarizing film in the second polarizer 24. Experiments have proved that the light leakage at the four corners of the curved liquid crystal screen has been improved, and the light leakage level has been reduced by 0.5 to 1 Level.

[0121] The embodiment of the present disclosure also provides a method for manufacturing a display device, which is applied to the display device in any embodiment of the present disclosure. The display device includes a backlight module 10 and a display module 20. The backlight module 10 is in a first curved surface shape that bends toward the light-emitting side along the first direction. Before the display device is manufactured, the display module 20 is flat. The display module 20 may include a display panel. The display panel includes a first substrate 21 and a second substrate 22 that are oppositely arranged, and liquid crystal located between the first substrate 21 and the second substrate 22. The display module 20 may also include a first polarizer 23 and a second polarizer 24. The first polarizer 23 is bonded to the side of the first substrate 21 facing away from the second substrate 22, and the second polarizer 24 is bonded to the side of the second substrate 22 facing away from the first substrate 21.

[0122] The manufacturing method of the display device may include: disposing the flat display module 20 on a jig having a preset radius of curvature; setting the temperature of the jig at a preset temperature, and deforming the display module 20 into a second curved shape at the preset temperature for a preset time, where the curvature of the second curved shape corresponds to the preset radius of curvature; attaching the display module 20 in the second curved shape to the backlight module 10, with the display module 20 located on the light-emitting side of the backlight module 10, and the backlight module 10 being in a first curved shape that bends towards the light-emitting side along a first direction, and the second curved shape matching the first curved shape. The process of deforming the display module 20 into the second curved shape through the jig may be called OC Aging.

[0123] In the related art, the flat display module 20 is adhered to the backlight module 10 in the first curved shape through a foam, and the display module 20 is deformed into a second curved shape that matches the first curved shape by hard bending. The hard bending process causes the display panel to be directly stressed around the perimeter with the backlight module 10, resulting in problems of uneven stress and stress concentration.

[0124] In the embodiments of the present disclosure, the display panel is disposed on a jig having a preset radius of curvature, and by setting the jig at a preset temperature for a preset time, the display module 20 is deformed into a second curved shape. In this way, before the display module 20 is attached to the backlight module 10, OC Aging is performed on the display module 20, enabling the display module 20 to release local stress in advance during the deformation process, reducing the stress at the four corners of the display panel, and improving the light leakage at the four corners of the display panel.

[0125] Exemplarily, OC Aging may be performed on the display panel, and then, the first polarizer 23 and the second polarizer 24 are respectively attached to the surface of the display panel; or, after the first polarizer 23 and the second polarizer 24 are attached to the surface of the display panel, OC Aging is performed on the display module 20.

[0126] Exemplarily, the preset radius of curvature is R1000mm to R1900mm (including the end values).

[0127] Exemplarily, the preset temperature may be 65°C to 75°C. Exemplarily, the preset time may be 48 hours to 72 hours.

[0128] The inventors of this case found through research that for a 34WQHD R1900 curved LCD screen, when the radius of curvature of the jig is R1000mm to R1900mm, the preset temperature is 65°C to 75°C, and the preset time is 48 hours to 72 hours, the light leakage level at the four corners of the curved LCD screen can be reduced by 0.5 to 1 Level.

[0129] Figure 15It is a schematic diagram for comparing the light leakage effects of a curved liquid crystal screen. Among them, the first column shows the light leakage effects of the curved liquid crystal screen in the related art. It can be seen from the first column that the smaller the thickness of the glass substrate, the smaller the light leakage problem. When the thickness of the glass substrate is 0.4T and 0.5T, the light leakage level in the corner area is greater than L3; when the thickness of the glass substrate is 0.25T, the light leakage level in the corner area is L3; when the thickness of the glass substrate is 0.2T, the light leakage level in the corner area is L2.

[0130] The second column shows the light leakage effects of the curved liquid crystal screen using OC Aging. For the glass substrate with a thickness of 0.25T, the light leakage level in the corner area is greater than L2 but does not reach L3, and the light leakage level is improved compared to without OC Aging. For the glass substrate with a thickness of 0.2T, the OC Aging light leakage level is L1.5, which is less than L2.

[0131] The third column shows the light leakage effects of the curved liquid crystal screen with a sunken area based on the second column. It can be seen from the figure that after the sunken area is bent along the boundary line towards the backlight module 10 side, for the glass substrate with a thickness of 0.25T, the light leakage level in the corner area is L2, which is improved compared to the second column. For the glass substrate with a thickness of 0.2T, the light leakage level in the corner area is L1, which is improved compared to the second column.

[0132] The fourth column shows the light leakage effects of the curved liquid crystal screen with a top-thick and bottom-thin polarizer based on the third column, that is, the thickness of the first polarizer 23 is less than the thickness of the second polarizer 24. It can be seen from the figure that for the glass substrate with a thickness of 0.25T, the light leakage level in the corner area is less than L1, and the light leakage level in the corner area is approximately L0.5, which is improved compared to the third column.

[0133] The display device in the embodiments of the present disclosure can be a liquid crystal display device. The liquid crystal display device of the present disclosure can adopt a horizontal electric field mode or a vertical electric field mode. The display device can be: an electronic paper, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, a wearable display device, or any other product or component with a display function.

[0134] In the description of this specification, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present disclosure.

[0135] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present disclosure, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0136] In the present disclosure, unless otherwise clearly defined and limited, terms such as "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0137] In the present disclosure, unless otherwise clearly defined and limited, the fact that the first feature is "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the fact that the first feature is "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The fact that the first feature is "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0138] The foregoing disclosure provides many different embodiments or examples for implementing the different structures of the present disclosure. To simplify the present disclosure, components and settings of specific examples are described above. Of course, they are merely examples and are not intended to limit the present disclosure. In addition, the present disclosure may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0139] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can easily think of various changes or substitutions, and these should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A display device, characterized in that, The display device is in a curved surface shape that curves towards the light-emitting side along a first direction, and the display device includes: A backlight module, which is in a first curved surface shape that curves towards the light-emitting side along the first direction; A display module, located on the light-emitting side of the backlight module. The display module is in a second curved surface shape that matches the shape of the backlight module. The display module includes a display panel, and the display panel includes a first substrate and a second substrate that are oppositely arranged, and liquid crystal located between the first substrate and the second substrate. The first substrate is closer to the backlight module than the second substrate; Wherein, the display module includes a long side, a short side, and corner points, and the corner points are the intersection points of the long side and the short side; the display module further includes a corner region near the corner points. The corner region extends from the corner points along the long side and the short side towards the center of the display panel. When the display device is in a dark state, the light leakage level of the corner region is less than or equal to L3; Wherein, the light leakage region of the corner region is the region enclosed by extending from the brightest position in the corner region towards the surrounding to a preset position. The ratio of the brightness of the brightest position to the brightness of the preset position is k, and the preset position is the position with a preset brightness; For the light leakage level L3, k is in the range of (3, 5]; For the light leakage level L2, k is in the range of (1.3, 3]; For the light leakage level L1, k is less than or equal to 1.3; The light leakage levels L3, L2, and L1 decrease in sequence.

2. The display device according to claim 1, wherein The first substrate includes a first base, the material of the first base includes glass, and the thickness range of the first base is 2.0 mm to 3.0 mm; and / or, The second substrate includes a second base, the material of the second base includes glass, and the thickness range of the first base is 2.0 mm to 3.0 mm.

3. The display device according to claim 1, characterized in that, The corner region includes a sinking region, and the sinking region includes a triangular region defined by the corner point, a third preset edge, and a fourth preset edge. The third preset edge is the edge that extends a third length from the corner point along the long side towards the center, and the fourth preset edge is the edge that extends a fourth length from the corner point along the short side towards the center. The connection line between the end of the third preset edge far from the corner point and the end of the fourth preset edge far from the corner point forms the demarcation line of the sinking region; The sinking region curves towards the backlight module side along the demarcation line.

4. The display device according to claim 3, wherein The third length is less than the length of the corner region along the long side, and the fourth length is less than the length of the corner region along the short side; The third length is the same as the fourth length, and the numerical range of the third length or the fourth length is 80 mm to 120 mm.

5. The display device according to claim 3, wherein The sinking distance of the corner point is 0.6 mm to 3.4 mm.

6. The display device according to claim 5, wherein The sinking distance of the corner point is 1.5 mm to 2.5 mm.

7. The display device according to claim 1, characterized in that, The display module further includes a first polarizer and a second polarizer. The first polarizer is attached to one side of the first substrate facing the backlight module, and the second polarizer is attached to one side of the second substrate facing away from the backlight module. The thickness of the first polarizer is less than the thickness of the second polarizer.

8. The display device according to claim 7, wherein the ratio of the difference between the thickness of the first polarizer and the thickness of the second polarizer to the thickness of the second polarizer is 26.5% - 37.8%; and / or the difference between the thickness of the first polarizer and the thickness of the second polarizer is 45 μm - 65 μm.

9. The display device according to claim 1, wherein The display module further includes a first polarizer and a second polarizer. The first polarizer is attached to one side of the first substrate facing the backlight module. The first polarizer includes a first polarizing film, and the material of the first polarizing film includes polyvinyl alcohol; The second polarizer is attached to one side of the second substrate facing away from the backlight module. The second polarizer includes a second polarizing film, and the material of the second polarizing film includes polyvinyl alcohol; The thickness of the first polarizing film is less than the thickness of the second polarizing film.

10. The display device according to claim 9, wherein the ratio of the difference between the thickness of the first polarizing film and the thickness of the second polarizing film to the thickness of the second polarizing film is 0 - 45%; and / or the difference between the thickness of the first polarizing film and the thickness of the second polarizing film is 0 - 10 μm.

11. A method for preparing a display device, characterized in that, Applied to the display device according to any one of claims 1 - 10, the method includes: placing the flat display module on a jig having a preset radius of curvature; setting the temperature of the jig at a preset temperature, and the display module deforms into a second curved shape at the preset temperature and for a preset time, and the curvature of the second curved shape corresponds to the preset radius of curvature; attaching the display module in the second curved shape to the backlight module. The display module is located on the light - emitting side of the backlight module, and the backlight module is in a first curved shape that bends towards the light - emitting side along a first direction, and the second curved shape matches the first curved shape.

12. The method according to claim 11, wherein The preset radius of curvature is R1000 mm - R1900 mm; and / or The preset temperature is 65°C - 75°C; and / or The preset time is 48 hours - 72 hours.

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