Cover plate for display module, display module, display device and method for preparing cover plate

Abstract

A cover plate for a display module, a display module, a display device, and a method for preparing the cover plate, relating to but not limited to the field of display technology, wherein the cover plate comprises a substrate of a transparent material, and a first light-shielding layer, a first semi-permeable ink layer, and a second semi-permeable ink layer disposed on the substrate; the first light-shielding layer is disposed on a first surface of a first region of the substrate, the first light-shielding layer being provided with at least one first hollow region, the first hollow region being shaped like a predetermined character or pattern; the first semi-permeable ink layer is disposed on a surface of the first light-shielding layer facing away from the substrate and on a surface of the substrate exposed by the first hollow region, the first semi-permeable ink layer in the first hollow region forming a predetermined character or pattern; the second semi-permeable ink layer is disposed on a surface of a thinner portion of the first semi-permeable ink layer in the first hollow region facing away from the substrate. When the cover plate of the disclosed embodiment is used in a display module, the uniformity of the brightness of the characters or patterns on the cover plate can be improved.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to, but are not limited to, the field of display technology, and particularly relate to a cover plate for a display module, a display module, a display device, and a method for preparing the cover plate. Background Art

[0002] In the automotive industry, in-car instrument panel buttons fall into two main categories: traditional mechanical buttons, where the characters are printed in white or other colors and do not require backlighting; and touch buttons with backlighting. These buttons are printed with semi-transparent ink and are visible when the backlight is illuminated. The clarity and uniformity of the characters directly impact the appearance of the instrument panel and the user experience. In some current in-car instrument panels, the backlighting of touch buttons emits light that varies in brightness from one position to the next, affecting the user's viewing experience. Summary of the Invention

[0003] The embodiments of the present disclosure provide a cover plate for a display module, a display module, a display device, and a method for manufacturing the cover plate, which can improve the uniformity of brightness of characters or patterns on the cover plate.

[0004] An embodiment of the present disclosure provides a cover plate for a display module, the cover plate comprising a substrate of a transparent material, and a first light-shielding layer, a first semi-permeable ink layer, and a second semi-permeable ink layer arranged on the substrate; the first light-shielding layer is arranged on the first surface of the first area of ​​the substrate, the first light-shielding layer is provided with at least one first hollow area, and the shape of the first hollow area is the shape of a set character or pattern; the first semi-permeable ink layer is arranged on the surface of the first light-shielding layer facing away from the substrate and the surface of the substrate exposed by the first hollow area, the first semi-permeable ink layer in the first hollow area forms a set character or pattern; the first semi-permeable ink layer in at least one of the first hollow areas comprises a first part and a second part, the thickness of the first part of the first semi-permeable ink layer is less than the set thickness value, and the thickness of the second part is greater than the set thickness value; the second semi-permeable ink layer is arranged on the surface of the first part of the first semi-permeable ink layer facing away from the substrate.

[0005] Optionally, the orthographic projection of the first semi-permeable ink layer on the substrate includes the orthographic projection of the first hollow area on the substrate, and the orthographic projection of the second semi-permeable ink layer on the substrate includes the orthographic projection of the first part of the first semi-permeable ink layer on the substrate.

[0006] Optionally, the first semi-permeable ink layer and the second semi-permeable ink layer are both formed by a screen printing process.

[0007] Optionally, the cover plate further includes a second light-shielding layer provided on the side of the first semi-permeable ink layer facing away from the substrate; the second light-shielding layer is provided with the same number of second hollow areas as the first hollow areas, the shape of each second hollow area is the same as the shape of a corresponding first hollow area, the position of the second hollow area corresponds to the position of the first hollow area, and the orthographic projection of the second hollow area on the substrate includes the orthographic projection of the first hollow area on the substrate.

[0008] An embodiment of the present disclosure further provides a display module, comprising the cover plate for the display module described in any embodiment.

[0009] Optionally, the display module further includes a first diffuser, a second diffuser and a light source; the first diffuser is arranged on a side of the cover plate where the first semi-permeable ink layer is provided, and covers the first hollow area; the second diffuser is attached to a side of the first diffuser facing away from the cover plate, the second diffuser covers the first part of the first semi-permeable ink layer and does not cover the second part of the first semi-permeable ink layer; the light source is arranged on a side of the first diffuser and the second diffuser facing away from the cover plate, and the light emitted by the light source can sequentially pass through the second diffuser, the first diffuser, the second semi-permeable ink layer, the first part of the first semi-permeable ink layer and the substrate, and can sequentially pass through the first diffuser, the second part of the first semi-permeable ink layer and the substrate.

[0010] Optionally, the orthographic projection of the first diffuser on the substrate includes the orthographic projection of the first hollow area on the substrate, and the orthographic projection of the second diffuser on the substrate includes the orthographic projection of the first portion of the first semi-permeable ink layer on the substrate.

[0011] Optionally, the first diffusion sheet is bonded to the surface of the cover plate provided with the first semi-permeable ink layer via a first transparent adhesive layer, and the second diffusion sheet is bonded to the surface of the first diffusion sheet facing away from the cover plate via a second transparent adhesive layer.

[0012] Optionally, the light source is a surface light source.

[0013] Optionally, the display module further includes a shell, which is arranged on a side of the cover plate away from the display side and fixed to the cover plate, and the first diffuser, the second diffuser and the light source are located between the cover plate and the shell.

[0014] Optionally, the display module further includes a touch substrate, the touch substrate includes a touch circuit layer provided on a substrate, and the touch substrate is provided between the cover plate and the first diffusion sheet.

[0015] An embodiment of the present disclosure further provides a display device, comprising the cover plate for the display module described in any embodiment.

[0016] The present disclosure also provides a method for preparing a cover plate for a display module, the method comprising:

[0017] A first light-shielding layer is formed on a first surface of a first region of a transparent substrate, wherein the first light-shielding layer has at least one first hollow region, and the shape of the first hollow region is a predetermined character or pattern;

[0018] forming a first semi-permeable ink layer on a surface of the first light-shielding layer facing away from the substrate and on a surface of the substrate exposed by the first hollow area, wherein the first semi-permeable ink layer in the first hollow area forms a predetermined character or pattern;

[0019] Detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and determining, based on the brightness values ​​of the multiple positions, an area of ​​the characters or patterns in the first hollow area with higher brightness as an area to be compensated;

[0020] A second semi-permeable ink layer is formed on the surface of the first semi-permeable ink layer in the area to be compensated facing away from the substrate.

[0021] Optionally, detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and determining, based on the brightness values ​​at the multiple positions, an area of ​​the characters or patterns in the first hollow area with higher brightness as the area to be compensated includes:

[0022] Detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and obtaining a minimum brightness value a and a maximum brightness value A;

[0023] The uniform brightness value of the characters or patterns in the first hollow area is defined as L, and L=a / A;

[0024] Compare L with the set value M. If L is less than the set value M, the position where the maximum brightness value A of the character or pattern in the first hollow area is located and its adjacent area are determined as the area to be compensated. The area to be compensated does not include the position where the minimum brightness value a of the character or pattern in the first hollow area is located.

[0025] Optionally, the preparation method also includes: forming a second light-shielding layer on the side of the first semi-permeable ink layer facing away from the substrate; wherein, the second light-shielding layer is provided with the same number of second hollow areas as the first hollow areas, the shape of each second hollow area is the same as the shape of a corresponding first hollow area, the position of the second hollow area corresponds to the position of the first hollow area, and the orthographic projection of the second hollow area on the substrate includes the orthographic projection of the first hollow area on the substrate.

[0026] In the cover plate for the display module of the disclosed embodiment, the first semi-permeable ink layer located in the first hollow area of ​​the first light-shielding layer forms a set character or pattern, and a second semi-permeable ink layer is formed on the surface of the first part of the first semi-permeable ink layer in the first hollow area where the thickness is relatively thin, which is away from the substrate. Thus, the second semi-permeable ink layer can compensate for the area of ​​the first semi-permeable ink layer in the first hollow area where the thickness is relatively thin, thereby improving the problem of uneven brightness of the characters or patterns caused by the uneven thickness of the first semi-permeable ink layer in the first hollow area.

[0027] In the display module of the disclosed embodiment, the first diffuser diffuses the light emitted by the light source, thereby improving the overall brightness uniformity of the characters or patterns on the cover plate. A second diffuser is disposed on the side of the first diffuser facing away from the cover plate. The second diffuser covers the first portion of the first semi-permeable ink layer but does not cover the second portion of the first semi-permeable ink layer. This second diffuser compensates for the thinner thickness of the first semi-permeable ink layer in the first hollow area, thereby improving the uneven brightness of the characters or patterns caused by the uneven thickness of the first semi-permeable ink layer in the first hollow area.

[0028] The method for preparing the cover plate of the embodiment of the present disclosure determines that the area with higher brightness of the characters or patterns in the first hollow area is the area to be compensated by detecting the brightness values ​​of the characters or patterns at multiple positions under the illumination of a light source, and forms a second semi-permeable ink layer on the surface of the first semi-permeable ink layer in the area to be compensated that is away from the substrate. In this way, the second semi-permeable ink layer can reduce the brightness of the characters or patterns in the area to be compensated and improve the uniformity of the brightness of the characters or patterns in the first hollow area. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are intended to provide a further understanding of the technical solutions of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solutions of the present disclosure and do not constitute a limitation of the technical solutions of the present disclosure. The shapes and sizes of the components in the accompanying drawings do not reflect the actual scale and are intended only to illustrate the contents of the present disclosure.

[0030] Figure 1 Schematic diagram of a planar structure of a cover plate of a vehicle instrument panel according to some exemplary embodiments;

[0031] Figure 2 After turning on the backlight Figure 1 Schematic diagram of the brightness distribution of the "MENU" character at position A in the middle;

[0032] Figure 3a for Figure 1 Schematic diagram of the local enlarged structure at A in the middle;

[0033] Figure 3b for Figure 3a BB cross-sectional structure diagram in;

[0034] Figure 4 Schematic diagram of the positional relationship between a screen used in forming a second semi-permeable ink layer on the base of the cover plate by a screen printing process in some exemplary embodiments and the base of the cover plate;

[0035] Figure 5a Schematic diagrams of top views of display modules according to some exemplary embodiments;

[0036] Figure 5b In some exemplary embodiments Figure 5a Schematic diagram of CC cross-section structure in;

[0037] Figure 5c In some other exemplary embodiments Figure 5a Schematic diagram of CC cross-section structure in;

[0038] Figure 6 Schematic diagram of the exploded structure of the display module of some exemplary embodiments.

[0039] The accompanying drawings are:

[0040] 10-cover plate, 11-base, 13-first semi-permeable ink layer, 14-second semi-permeable ink layer,

[0041] 111 - first region of the substrate, 112 - second region of the substrate,

[0042] 121-first light-shielding layer, 122-second light-shielding layer, 1211-first hollow area, 1221-second hollow area,

[0043] 21-first diffuser, 22-second diffuser, 23-light source, 24-housing, 25-touch substrate,

[0044] 31-first transparent adhesive layer, 32-second transparent adhesive layer,

[0045] 41-screen, 411-screen ink leakage area,

[0046] 50-Composite diaphragm. DETAILED DESCRIPTION

[0047] Those skilled in the art should understand that the technical solutions of the embodiments of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and all should be included in the scope of the claims of the present disclosure.

[0048] As the times progress, more and more car central control systems use touch screens for interaction, with touch buttons replacing physical buttons. Figure 1 As shown, Figure 1 The following is a schematic planar structural diagram of a cover plate for a vehicle instrument panel according to some exemplary embodiments. The cover plate 10 includes a first area 111 near the circumferential edge of the cover plate 10 and a second area 112 surrounded by the first area 111. The second area 112 of the cover plate 10 may be a transparent area and may be configured to display an image displayed on a display panel on the back side of the second area 112 of the cover plate 10. The first area 111 of the cover plate 10 includes a light-shielding layer provided on a transparent substrate 11. The light-shielding layer is provided with a plurality of hollow areas, each of which is shaped like a set character or pattern. Each hollow area is provided with a semi-permeable ink layer to form the set character or pattern. The set character or pattern of the first area 111 may be a display icon serving as an identifier, or may be a character or pattern of a touch button. Figure 1 In the figure, five patterns are provided on the first side of the second area 112 in the first area 111, namely, a power pattern, a volume increase pattern, a volume decrease pattern, and two horizontal line patterns, and the five patterns correspond to the five hollow areas formed in the light-shielding layer; five patterns are provided on the second side of the second area 112 in the first area 111, namely, the characters "MENU", "MOME", and "APP", and two horizontal line patterns, and the three characters and two patterns correspond to the other five hollow areas formed in the light-shielding layer.

[0049] In order to ensure an excellent user experience, the brightness uniformity of the above characters or patterns is generally controlled. The evaluation index of the brightness uniformity refers to the minimum brightness / maximum brightness of the area where the selected characters or patterns are located. The above characters or patterns can be formed by screen printing technology. The following takes characters as an example. During the process of printing characters, the ink forming the characters is affected by the character structure, screen tension, process fluctuations, etc., and the ink thickness of the actual character area is difficult to achieve uniformity, which leads to large differences in brightness of the character area when the light emitted by the backlight passes through the characters, and the brightness uniformity of the entire character is low. Figure 2 As shown, Figure 2 After turning on the backlight Figure 1 The brightness distribution of the "MENU" character at A in the middle, Figure 2The positions indicated by letters a to h represent eight brightness detection positions. The brightness detection values ​​of the eight brightness detection positions a to h are 16.78, 26.3, 19.09, 28.82, 27.21, 19.08, 26.04, and 16.93, respectively. Among them, the minimum brightness value is 16.78 and the maximum brightness is 28.82. The calculated brightness uniformity value is 58.2%, which is low and will affect the actual viewing effect. In addition, after testing, it is found that the brightness of the two letters "EN" in the middle area of ​​the "MENU" character is higher, while the brightness of the two letters "M" and "U" at the two end areas is lower. The reason for the brightness difference between different areas of the character is that after the shading layer is formed, during the process of screen printing to form the semi-permeable ink layer, there is a height difference of more than 5um in the hollow area of ​​the shading layer. In addition, the structures of different characters are different, resulting in different resistances encountered by the semi-permeable ink during the screen printing process, which in turn affects the flow of the semi-permeable ink and causes the thickness of the semi-permeable ink layer to be uneven. According to the current printing process, it is difficult to obtain a sample with very uniform ink thickness through a single printing, and the printing difficulty will increase as the length of the character increases and the shape and structure of the character become more complex. Therefore, the thickness of the semi-transparent ink in the area where the two letters "EN" of the "MENU" character are located is thinner, and the thickness of the semi-transparent ink in the area where the two letters "M" and "U" are located is thicker. The uneven thickness of the semi-transparent ink layer of the "MENU" character leads to uneven brightness in different positions of the "MENU" character. In addition, other characters on the cover, such as the "HOME" character, have been tested and found that the "HOME" character also has the problem of higher brightness in the area where the middle letter is located and lower brightness in the areas where the letters at both ends are located.

[0050] The present disclosure provides a cover plate for a display module. In some exemplary embodiments, Figure 3a and Figure 3b As shown, Figure 3a for Figure 1 Schematic diagram of the local enlarged structure at A in the middle, Figure 3b for Figure 3aSchematic diagram of the BB cross-section structure. The cover plate includes a substrate 11 made of a transparent material, and a first light-shielding layer 121, a first semi-permeable ink layer 13, and a second semi-permeable ink layer 14 provided on the substrate 11; the first light-shielding layer 121 is provided on the first surface of the first area 111 of the substrate 11, and the first light-shielding layer 121 has at least one first hollow area 1211, and the shape of the first hollow area 1211 is the shape of a set character or pattern; the first semi-permeable ink layer 13 is provided on the surface of the first light-shielding layer 121 facing away from the substrate 11 and the surface of the substrate 11 exposed by the first hollow area 1211, and the first semi-permeable ink layer 13 in the first hollow area 1211 forms a set character or pattern; the first semi-permeable ink layer 13 in at least one first hollow area 1211 includes a first part and a second part, the thickness of the first part of the first semi-permeable ink layer 13 is less than the set thickness value, and the thickness of the second part is greater than the set thickness value; the second semi-permeable ink layer 14 is provided on the surface of the first part of the first semi-permeable ink layer 13 facing away from the substrate 11.

[0051] In the cover plate for the display module of the disclosed embodiment, the first semi-permeable ink layer 13 located in the first hollow area 1211 of the first light-shielding layer 121 forms a set character or pattern, and a second semi-permeable ink layer 14 is formed on the surface of the first part of the first semi-permeable ink layer 13 in the first hollow area 1211 where the thickness is relatively thin and faces away from the substrate 11. Thus, the second semi-permeable ink layer 14 can compensate for the area where the thickness of the first semi-permeable ink layer 13 in the first hollow area 1211 is relatively thin, thereby improving the problem of uneven brightness of the characters or patterns caused by the uneven thickness of the first semi-permeable ink layer 13 in the first hollow area 1211.

[0052] In some exemplary embodiments, Figure 3a As shown, the orthographic projection of the first semi-permeable ink layer 13 on the substrate 11 includes the orthographic projection of the first hollow area 1211 on the substrate 11, and the orthographic projection of the second semi-permeable ink layer 14 on the substrate 11 includes the orthographic projection of the first part of the first semi-permeable ink layer 13 on the substrate 11.

[0053] In an example of this embodiment, Figure 3a As shown, take the character "MENU" as an example. Figure 3a In the figure, the area where the character "MENU" is located is a first hollow area 1211, and the orthographic projection of the first semi-permeable ink layer 13 on the substrate 11 includes the orthographic projection of the first hollow area 1211 on the substrate 11. Figure 2From the analysis, it can be seen that in the character "MENU", the thickness of the first semi-permeable ink layer 13 (i.e., the first part of the first semi-permeable ink layer 13) in the area where the middle letter "EN" is located is thinner, and the thickness of the first semi-permeable ink layer 13 (i.e., the second part of the first semi-permeable ink layer 13) in the area where the two letters "M" and "U" are located is thicker. Therefore, a second semi-permeable ink layer 14 is formed on the surface of the first semi-permeable ink layer 13 away from the substrate 11, and the orthographic projection of the second semi-permeable ink layer 14 on the substrate 11 includes the orthographic projection of the first semi-permeable ink layer 13 in the area where the middle letter "EN" is located on the substrate 11. Therefore, the second semi-permeable ink layer 14 can compensate for the thickness of the first semi-permeable ink layer 13 in the area where the middle letter "EN" is located, reduce the brightness of the area where the middle letter "EN" is located, and improve the problem of uneven brightness of the character "MENU" caused by the uneven thickness of the first semi-permeable ink layer 13 in the area where the character "MENU" is located. Similarly, the second semi-permeable ink layer 14 can compensate for the thinner areas of the first semi-permeable ink layer 13 of other characters on the cover plate 10 , thereby improving the brightness uniformity of other characters.

[0054] In an example of this embodiment, Figure 4 As shown, Figure 4 This figure illustrates the positional relationship between the screen plate and the cover substrate used in forming a second semi-permeable ink layer on the cover substrate using a screen printing process in some exemplary embodiments. During the screen printing process, the substrate 11, having formed the first semi-permeable ink layer, is placed on a workbench. The screen plate 41 is positioned above the substrate 11. The ink leakage area 411 of the screen plate 41 can be rectangular and can cover the area where the letters "EN" are located. The resulting second semi-permeable ink layer can cover the letters "EN." The thickness of the second semi-permeable ink layer can be adjusted to an appropriate level by adjusting parameters such as the mesh size of the screen plate 41.

[0055] Some technologies only adjust printing parameters (such as printing direction, printing speed, and screen mesh count) during the semi-transparent ink printing process, performing a single print. This solution, however, adds a second reprint (forming a second semi-transparent ink layer) to the adjusted printing parameters, and this can be performed on the finished cover sheet. Measurements before and after the reprint show that the brightness uniformity of the characters or patterns can be improved by nearly 10%, resulting in a significant improvement in overall performance.

[0056] In some exemplary embodiments, Figure 3bAs shown, the cover plate may further include a second light-shielding layer 122 provided on the side of the first semi-permeable ink layer 13 facing away from the substrate 11; the second light-shielding layer 122 is provided with the same number of second hollow areas 1221 as the first hollow areas 1211, the shape of each second hollow area 1221 is the same as the shape of a corresponding first hollow area 1211, the position of the second hollow area 1221 corresponds to the position of the first hollow area 1211, and the orthographic projection of the second hollow area 1221 on the substrate 11 includes the orthographic projection of the first hollow area 1211 on the substrate 11.

[0057] In this embodiment, the first light-shielding layer 121 and the second light-shielding layer 122 can both be formed using a screen printing process. Providing two light-shielding layers can ensure a light-shielding effect. The orthographic projection of the second hollowed-out area 1221 of the second light-shielding layer 122 on the substrate 11 includes the orthographic projection of the first hollowed-out area 1211 of the first light-shielding layer 121 on the substrate 11. This ensures that, during the formation of the second light-shielding layer 122, the second light-shielding layer 122 is unlikely to be formed on the characters or patterns in the first hollowed-out area 1211.

[0058] In some exemplary embodiments, the first semi-permeable ink layer 13 and the second semi-permeable ink layer 14 may be formed by screen printing. The first semi-permeable ink layer 13 and the second semi-permeable ink layer 14 may be made of white semi-permeable ink or semi-permeable ink of other colors.

[0059] An embodiment of the present disclosure further provides a display module, comprising the cover plate for the display module described in any embodiment.

[0060] In some exemplary embodiments, the display module includes the cover plate, a light source, and a housing. The housing is disposed on a side of the cover plate facing away from the display side and is fixed to the cover plate. The light source is located between the cover plate and the housing and can be fixed to the housing. Light emitted by the light source can pass through characters or patterns on the cover plate and then be emitted from the display side of the cover plate, thereby displaying the characters or patterns on the cover plate with good brightness uniformity.

[0061] In some exemplary embodiments, Figure 5a and Figure 5b As shown, Figure 5a Schematic diagrams of top views of display modules of some exemplary embodiments are shown. Figure 5b In some exemplary embodiments Figure 5aThe CC cross-sectional structural diagram in FIG. The display module includes the cover plate 10, the first diffuser 21, the second diffuser 22, and the light source 23. The first diffuser 21 is arranged on the side of the cover plate 10 where the first semi-permeable ink layer 13 is provided, and covers the first hollow area 1211; the second diffuser 22 is attached to the side of the first diffuser 21 away from the cover plate 10, and the second diffuser 22 covers the first part of the first semi-permeable ink layer 13 but does not cover the second part of the first semi-permeable ink layer 13. The light source 23 is arranged on the side of the first diffuser 21 and the second diffuser 22 away from the cover plate 10. The light emitted by the light source 23 can sequentially pass through the second diffuser 22, the first diffuser 21, the second semi-permeable ink layer 14, the first part of the first semi-permeable ink layer 13, and the substrate 11, and can sequentially pass through the first diffuser 21, the second part of the first semi-permeable ink layer 13, and the substrate 11.

[0062] In the display module of this embodiment, the first diffuser 21 diffuses the light emitted by the light source 23, thereby improving the overall brightness uniformity of the characters or patterns on the cover plate 10. The second diffuser 22 is disposed on the side of the first diffuser 21 facing away from the cover plate 10. The second diffuser 22 covers the first portion of the first semi-permeable ink layer 13 but does not cover the second portion of the first semi-permeable ink layer 13. In this way, the second diffuser 22 compensates for the thinner thickness of the first semi-permeable ink layer 13 in the first hollow area 1211, thereby improving the uneven brightness of the characters or patterns caused by the uneven thickness of the first semi-permeable ink layer 13 in the first hollow area 1211.

[0063] In an example of this embodiment, Figure 5a As shown, the orthographic projection of the first diffuser 21 on the substrate 11 includes the orthographic projection of the first hollow area 1211 on the substrate 11, and the orthographic projection of the second diffuser 22 on the substrate 11 includes the orthographic projection of the first part of the first semi-permeable ink layer 13 on the substrate 11.

[0064] like Figure 5aAs shown, this embodiment takes the character "MENU" on the cover plate 10 as an example. The orthographic projection of the first diffuser 21 on the substrate 11 includes the orthographic projection of the character "MENU" on the substrate 11. As mentioned above, in the character "MENU", the thickness of the first semi-permeable ink layer (i.e., the first part of the first semi-permeable ink layer) in the area where the middle letter "EN" is located is thinner, and the thickness of the first semi-permeable ink layer (i.e., the second part of the first semi-permeable ink layer) in the area where the two letters "M" and "U" are located is thicker. Therefore, a second diffuser 22 is provided on the side of the first diffuser 21 away from the cover plate 10. The orthographic projection of the second diffuser 22 on the substrate 11 includes the orthographic projection of the first semi-permeable ink layer in the area where the middle letter "EN" is located on the substrate 11, and may not include the orthographic projection of the first semi-permeable ink layer in the area where the two letters "M" and "U" are located on the substrate 11. As a result, the second diffuser 22 can reduce the brightness of the middle letter "EN" and improve the brightness uniformity of the character "MENU". The width of the second diffuser 22 ( Figure 5a The width in the left and right directions can be around 0.5mm. Figure 5a In the example shown, two diffusers are provided at the center of the letters "EN". In other examples, more than two diffusers may be provided as needed. In this example, the second diffuser 22 may be a different model based on the brightness distribution of the characters or patterns on the cover plate 10. The haze of the second diffuser 22 may be higher than that of the first diffuser 21.

[0065] In an example of this embodiment, Figure 5b As shown, the first diffuser 21 can be bonded to the surface of the cover plate 10 provided with the first semi-permeable ink layer 13 via a first transparent adhesive layer 31, and the second diffuser 22 can be bonded to the surface of the first diffuser 21 facing away from the cover plate 10 via a second transparent adhesive layer 32. For example, the first transparent adhesive layer 31 and the second transparent adhesive layer 32 can both be optically clear adhesive (OCA).

[0066] In an example of this embodiment, Figure 5b As shown, the display module also includes a shell 24, which is arranged on the side of the cover plate 10 away from the display side and fixed to the cover plate 10, and the first diffuser 21, the second diffuser 22 and the light source 23 are located between the cover plate 10 and the shell 24. The light source 23 can be fixed on the shell 24, and the surface of the second diffuser 22 away from the cover plate 10 can have a certain gap with the light emitting surface of the light source 23. The light source 23 can be a surface light source 23, which can correspond to multiple characters or pattern positions on the cover plate 10 to provide uniform light. In one example of this example, as Figure 6 As shown, Figure 6The following is an exploded structural diagram of a display module according to some exemplary embodiments. Five characters and / or patterns are provided near both sides of the cover plate 10. The display module includes two light sources 23 and two composite films 50 provided on the side of the cover plate 10 facing away from the display side. Each composite film 50 includes a first transparent adhesive layer 31, a first diffuser 21, a second transparent adhesive layer 32, and a second diffuser 22 stacked in sequence. One composite film 50 is attached to the surface of the cover plate 10 facing away from the display side and corresponds to the five pattern positions near one side of the cover plate 10. The other composite film 50 is attached to the surface of the cover plate 10 facing away from the display side and corresponds to the five pattern positions near the other side of the cover plate 10. The two light sources 23 are fixed to the housing 24 and correspond to the positions of the two composite films 50, respectively. The light emitted by each light source 23 can pass through a corresponding composite film 50 and five patterns near one side of the cover plate 10 and then be emitted from the display side of the cover plate 10, thereby displaying the characters or patterns at the corresponding position on the cover plate 10.

[0067] In an example of this embodiment, the brightness measurement data of the characters or patterns on the cover plate 10 when different numbers of diffusion sheets are used are compared, as shown in the following Table 1:

[0068] Table 1

[0069] Average brightness Minimum brightness Maximum brightness Brightness uniformity No diffuser 66.91 47.68 79.19 60.21％ Single-layer diffuser 48.57 36.32 57.38 63.30％ Double-layer diffuser 46.73 37.29 54.19 68.81％

[0070] In the table, brightness uniformity data refers to the ratio of the minimum brightness to the maximum brightness within a character. It can be seen that the solution with a double-layer diffuser (i.e., the first diffuser 21 and the second diffuser 22 in this example) can improve brightness uniformity by approximately 14% ((68.81% - 60.21%) / 60.21% ≈ 14%) compared to the solution without a diffuser. The solution with a double-layer diffuser also improves brightness uniformity compared to the solution with a single-layer diffuser (the first diffuser 21).

[0071] In some exemplary embodiments, Figure 5c As shown, Figure 5c In some other exemplary embodiments Figure 5a Schematic diagram of the CC cross-sectional structure in . In this embodiment, the display module may further include a touch substrate 25, and the touch substrate 25 includes a touch circuit layer provided on a substrate for performing touch operations on the screen. The touch substrate 25 is provided between the cover plate 10 and the first diffuser 21. The cover plate 10 can be attached to the touch substrate 25, and the first diffuser 21 can be attached to the substrate of the touch substrate 25. The base 11 of the cover plate 10 and the substrate of the touch substrate 25 can both be made of glass material. In this example, the characters or patterns on the cover plate 10 can be characters or patterns of touch buttons.

[0072] The present disclosure also provides a method for preparing a cover plate for a display module, the method comprising:

[0073] A first light-shielding layer is formed on a first surface of a first region of a transparent substrate, wherein the first light-shielding layer has at least one first hollow region, and the shape of the first hollow region is a predetermined character or pattern;

[0074] forming a first semi-permeable ink layer on a surface of the first light-shielding layer facing away from the substrate and on a surface of the substrate exposed by the first hollow area, wherein the first semi-permeable ink layer in the first hollow area forms a predetermined character or pattern;

[0075] Detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and determining, based on the brightness values ​​of the multiple positions, an area of ​​the characters or patterns in the first hollow area with higher brightness as an area to be compensated;

[0076] A second semi-permeable ink layer is formed on the surface of the first semi-permeable ink layer in the area to be compensated facing away from the substrate.

[0077] The method for preparing the cover plate of the embodiment of the present disclosure determines that the area with higher brightness of the characters or patterns in the first hollow area is the area to be compensated by detecting the brightness values ​​of the characters or patterns at multiple positions under the illumination of a light source, and forms a second semi-permeable ink layer on the surface of the first semi-permeable ink layer in the area to be compensated that is away from the substrate. In this way, the second semi-permeable ink layer can reduce the brightness of the characters or patterns in the area to be compensated and improve the uniformity of the brightness of the characters or patterns in the first hollow area.

[0078] In some exemplary embodiments, detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and determining, based on the brightness values ​​at the multiple positions, an area of ​​the characters or patterns in the first hollow area with higher brightness as an area to be compensated includes:

[0079] Detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and obtaining a minimum brightness value a and a maximum brightness value A;

[0080] The uniform brightness value of the characters or patterns in the first hollow area is defined as L, and L=a / A;

[0081] Compare L with the set value M. If L is less than the set value M, the position where the maximum brightness value A of the character or pattern in the first hollow area is located and its adjacent area are determined as the area to be compensated. The area to be compensated does not include the position where the minimum brightness value a of the character or pattern in the first hollow area is located.

[0082] In some exemplary embodiments, the preparation method further includes: forming a second light-shielding layer on the side of the first semi-permeable ink layer facing away from the substrate; wherein the second light-shielding layer is provided with the same number of second hollow areas as the first hollow areas, the shape of each second hollow area is the same as the shape of a corresponding first hollow area, the position of the second hollow area corresponds to the position of the first hollow area, and the orthographic projection of the second hollow area on the substrate includes the orthographic projection of the first hollow area on the substrate.

[0083] The following is combined with the previous Figure 1 、 Figure 2 、 Figure 3a and Figure 3b The structure of the cover plate is exemplified to illustrate the method for preparing the cover plate according to the embodiment of the present disclosure. The method for preparing the cover plate may include:

[0084] 1) forming a first light shielding layer 121 on a first surface of a first region 111 of a transparent substrate 11, wherein the first light shielding layer 121 has at least one first hollow area 1211, and the shape of the first hollow area 1211 is a predetermined character or pattern, such as Figure 3b As shown. For example, Figure 1 In the illustrated cover plate 10, five characters or / and patterns are provided near the two side edges of the first area 111 of the cover plate 10. In this step, the corresponding positions of the first light shielding layer 121 are provided with the above ten hollow areas.

[0085] 2) forming a first semi-permeable ink layer 13 on the surface of the first light-shielding layer 121 facing away from the substrate 11 and on the surface of the substrate 11 exposed by the first hollow area 1211, wherein the first semi-permeable ink layer 13 covers the first hollow area 1211, and the first semi-permeable ink layer 13 in the first hollow area 1211 forms a predetermined character or pattern, such as Figure 3a and Figure 3b As shown, Figure 3a In the figure, the area where the character “MENU” is located is a first hollow area 1211 .

[0086] 3) forming a second light-shielding layer 122 on a side of the first semi-permeable ink layer 13 facing away from the substrate 11; wherein the second light-shielding layer 122 has the same number of second hollow areas 1221 as the first hollow areas 1211, the shape of each second hollow area 1221 is the same as the shape of a corresponding first hollow area 1211, the position of the second hollow area 1221 corresponds to the position of the first hollow area 1211, and the orthographic projection of the second hollow area 1221 on the substrate 11 includes the orthographic projection of the first hollow area 1211 on the substrate 11, as shown in FIG. Figure 3b shown.

[0087] 4) Detecting the brightness values ​​of the characters or patterns in the first hollow area 1211 at multiple positions under the illumination of the light source 23, and determining, based on the brightness values ​​of the multiple positions, the area of ​​the characters or patterns in the first hollow area 1211 with higher brightness as the area to be compensated. In some exemplary embodiments, this step includes:

[0088] ① Detect the brightness values ​​of the characters or patterns in the first hollow area 1211 at multiple positions under the illumination of the light source 23, and obtain the minimum brightness value a and the maximum brightness value A. Figure 2 As shown, take the "MENU" character as an example. Figure 2 The positions indicated by letters a to h represent 8 brightness detection positions (including the minimum brightness position and maximum brightness position of each letter in the "MENU" character). The brightness detection values ​​of the 8 brightness detection positions a to h are 16.78, 26.3, 19.09, 28.82, 27.21, 19.08, 26.04, and 16.93, respectively. Among them, the minimum brightness value a is 16.78 and the maximum brightness value A is 28.82. The position with the minimum brightness value a is the position of the end letter M of the "MENU" character, and the position with the maximum brightness value A is the position of the middle letter E of the "MENU" character.

[0089] ② The uniform brightness value of the characters or patterns in the first hollow area is defined as L, and L = a / A. In this example, L = 16.78 / 28.82 = 58.2%.

[0090] ③ Compare L with the set value M. If L is smaller than the set value M, the position where the maximum brightness value A of the character or pattern in the first hollow area is located and its adjacent area are determined as the area to be compensated. The area to be compensated does not include the position where the minimum brightness value a of the character or pattern in the first hollow area is located.

[0091] In this example, the position of the maximum brightness value A is the position of the middle letter E of the character "MENU", and the overall brightness of the letter N adjacent to the middle letter E is higher than the brightness of the letter M. Therefore, the area where the two letters "EN" in the character "MENU" are located is determined as the area to be compensated.

[0092] 5) forming a second semi-permeable ink layer 14 on the surface of the second light-shielding layer 122 facing away from the substrate 11 and on the surface of the first semi-permeable ink layer 13 in the area to be compensated facing away from the substrate 11, wherein the second semi-permeable ink layer 14 covers the area where the two letters "EN" in the character "MENU" are located, i.e., covers the area to be compensated. Figure 3a and Figure 3b shown.

[0093] In other embodiments, step 3) above may be performed after step 5). Alternatively, the step of forming the second light-shielding layer 122 may be performed before the step of forming the first semi-permeable ink layer 13. In the method for preparing the cover plate 10 of this embodiment, the step of forming the first semi-permeable ink layer 13 is performed before the step of forming the second light-shielding layer 122. Compared to the method of forming the first semi-permeable ink layer 13 after the step of forming the second light-shielding layer 122, the height difference of the light-shielding layer in the hollow area can be reduced, which is conducive to controlling the thickness of the first semi-permeable ink layer 13.

[0094] The present disclosure also provides a display device comprising the cover plate for the display module described in any of the above embodiments. The display device can be any product or component with a display function, such as a vehicle dashboard, a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, or a navigation system.

[0095] In the drawings, the sizes of components, layer thicknesses, or regions are sometimes exaggerated for clarity. Therefore, the embodiments of the present disclosure are not necessarily limited to these dimensions, and the shapes and sizes of each component in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate some examples, and the embodiments of the present disclosure are not limited to the shapes or values ​​shown in the drawings.

[0096] In this description, "parallel" refers to a state where the angle formed by two straight lines is greater than -10° and less than 10°, and thus includes a state where the angle is greater than -5° and less than 5°. Furthermore, "perpendicular" refers to a state where the angle formed by two straight lines is greater than 80° and less than 100°, and thus includes a state where the angle is greater than 85° and less than 95°.

[0097] In the description herein, the terms "upper", "lower", "left", "right", "top", "inner", "outer", "axial", "four corners", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing the embodiments of the present disclosure, and do not indicate or imply that the structure referred to has a specific orientation, is constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present disclosure.

[0098] In the description herein, unless otherwise expressly specified or limited, the terms "connect," "fixed connection," "installation," and "assembly" should be understood in a broad sense, for example, to mean a fixed connection, a detachable connection, or an integral connection; the terms "installation," "connection," and "fixed connection" can mean a direct connection, an indirect connection through an intermediate medium, or internal communication between two components. A person of ordinary skill in the art can understand the meaning of the above terms in the embodiments of the present disclosure according to the circumstances.

Claims

1. A cover plate for a display module, characterized in that: The cover plate includes a transparent substrate, and a first light-shielding layer, a first semi-transparent ink layer, and a second semi-transparent ink layer provided on the substrate; The first light-shielding layer is provided on the first surface of the first region of the substrate, and the first light-shielding layer is provided with at least one first hollow area, and the shape of the first hollow area is the shape of a predetermined character or pattern; The first semi-permeable ink layer is provided on a surface of the first light-shielding layer facing away from the substrate and on a surface of the substrate exposed by the first hollow area, and the first semi-permeable ink layer in the first hollow area forms a predetermined character or pattern; The first semi-permeable ink layer of at least one of the first hollow areas includes a first portion and a second portion, the thickness of the first portion of the first semi-permeable ink layer is less than a set thickness value, and the thickness of the second portion is greater than the set thickness value; The second semi-permeable ink layer is disposed on a surface of the first portion of the first semi-permeable ink layer facing away from the substrate to compensate for the thinner area of ​​the first semi-permeable ink layer in the first hollow region.

2. The cover plate for a display module according to claim 1, wherein: The orthographic projection of the first semi-permeable ink layer on the substrate includes the orthographic projection of the first hollow area on the substrate, and the orthographic projection of the second semi-permeable ink layer on the substrate includes the orthographic projection of the first portion of the first semi-permeable ink layer on the substrate.

3. The cover plate for a display module according to claim 1, wherein: The first semi-permeable ink layer and the second semi-permeable ink layer are both formed by a screen printing process.

4. The cover plate for a display module according to claim 1, wherein: The cover plate further includes a second light shielding layer provided on a side of the first semi-permeable ink layer facing away from the substrate; The second light-shielding layer is provided with second hollow areas with the same number as the first hollow areas, the shape of each second hollow area is the same as the shape of a corresponding first hollow area, the position of the second hollow area corresponds to the position of the first hollow area, and the orthographic projection of the second hollow area on the substrate includes the orthographic projection of the first hollow area on the substrate.

5. A display module, characterized in that: The cover plate for display module comprises the cover plate for display module according to any one of claims 1 to 4.

6. The display module according to claim 5, wherein: The display module further includes a first diffuser, a second diffuser and a light source; The first diffuser is disposed on a side of the cover plate where the first semi-permeable ink layer is disposed, and covers the first hollow area; the second diffuser is attached to a side of the first diffuser facing away from the cover plate, and covers a first portion of the first semi-permeable ink layer but does not cover a second portion of the first semi-permeable ink layer; The light source is arranged on the side of the first diffuser and the second diffuser facing away from the cover plate, and the light emitted by the light source can sequentially pass through the second diffuser, the first diffuser, the second semi-permeable ink layer, the first part of the first semi-permeable ink layer and the substrate, and can sequentially pass through the first diffuser, the second part of the first semi-permeable ink layer and the substrate.

7. The display module according to claim 6, wherein: The orthographic projection of the first diffuser on the substrate includes the orthographic projection of the first hollow area on the substrate, and the orthographic projection of the second diffuser on the substrate includes the orthographic projection of the first portion of the first semi-permeable ink layer on the substrate.

8. The display module according to claim 6, wherein: The first diffusion sheet is bonded to the surface of the cover plate provided with the first semi-permeable ink layer through a first transparent adhesive layer, and the second diffusion sheet is bonded to the surface of the first diffusion sheet facing away from the cover plate through a second transparent adhesive layer.

9. The display module according to claim 6, wherein: The light source is a surface light source.

10. The display module according to claim 6, wherein: The display module further includes a housing, which is disposed on a side of the cover plate away from the display side and is fixed to the cover plate. The first diffuser, the second diffuser and the light source are located between the cover plate and the housing.

11. The display module according to claim 6, wherein: The display module further includes a touch substrate, which includes a touch circuit layer provided on a substrate. The touch substrate is provided between the cover plate and the first diffusion sheet.

12. A display device, characterized in that: The cover plate for display module comprises the cover plate for display module according to any one of claims 1 to 4.

13. A method for preparing a cover plate for a display module, characterized in that: The preparation method comprises: A first light-shielding layer is formed on a first surface of a first region of a transparent substrate, wherein the first light-shielding layer has at least one first hollow region, and the shape of the first hollow region is a predetermined character or pattern; forming a first semi-permeable ink layer on a surface of the first light-shielding layer facing away from the substrate and on a surface of the substrate exposed by the first hollow area, wherein the first semi-permeable ink layer in the first hollow area forms a predetermined character or pattern; Detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and determining, based on the brightness values ​​of the multiple positions, an area of ​​the characters or patterns in the first hollow area with higher brightness as an area to be compensated; A second semi-permeable ink layer is formed on a surface of the first semi-permeable ink layer in the area to be compensated facing away from the substrate, so as to compensate for the area with higher brightness of the first semi-permeable ink layer in the first hollow area.

14. The method for preparing a cover plate for a display module according to claim 13, wherein: The detecting of brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and determining, based on the brightness values ​​of the multiple positions, an area of ​​the characters or patterns in the first hollow area with higher brightness as an area to be compensated, includes: Detecting brightness values ​​of the characters or patterns in the first hollow area at multiple positions under illumination by a light source, and obtaining a minimum brightness value a and a maximum brightness value A; The uniform brightness value of the characters or patterns in the first hollow area is defined as L, and L=a / A; Compare L with the set value M. If L is less than the set value M, the position where the maximum brightness value A of the character or pattern in the first hollow area is located and its adjacent area are determined as the area to be compensated. The adjacent area is the character or pattern adjacent to the position where the maximum brightness value A of the character or pattern in the first hollow area is located and whose brightness is greater than the minimum brightness value a. The area to be compensated does not include the position where the minimum brightness value a of the character or pattern in the first hollow area is located.

15. The method for preparing a cover plate for a display module according to claim 13, wherein: The preparation method further comprises: A second light-shielding layer is formed on the side of the first semi-permeable ink layer facing away from the substrate; wherein the second light-shielding layer is provided with the same number of second hollow areas as the first hollow areas, the shape of each second hollow area is the same as the shape of a corresponding first hollow area, the position of the second hollow area corresponds to the position of the first hollow area, and the orthographic projection of the second hollow area on the substrate includes the orthographic projection of the first hollow area on the substrate.

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