Collimated backlight module, its fabrication method and display device

Abstract

A collimated backlight module (100), its fabrication method, and a display device thereof. The fabrication method of the collimated backlight module (100) includes: providing a light guide plate (110); forming a protective layer (410) on the light-emitting side of the light guide plate (110), the protective layer (410) simultaneously covering the light-emitting area (A1) and the non-light-emitting area (A2) on the light-emitting side; forming a hollow area (Q1) on the protective layer (410) to expose the light-emitting area (A1) of the light guide plate (110); and forming a light-collecting grating (310) on the light-emitting area (A1) of the light guide plate (110).

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to collimated backlight modules, their fabrication methods, and display devices. Background Technology

[0002] In collimated light source display technology, the backlight module typically employs a collimated backlight module implementation to emit collimated light. In this collimated backlight module, the light emitted by the light source is coupled into a light guide plate and undergoes total internal reflection within the light guide plate. By setting a light-collecting grating on the surface of the light guide plate, the light transmitted through total internal reflection within the light guide plate is extracted at a collimated angle, thus realizing a collimated light source. Summary of the Invention

[0003] This disclosure provides a method for fabricating a collimated backlight module, including:

[0004] Provide a light guide plate;

[0005] A protective layer is formed on the light-emitting side of the light guide plate, the protective layer covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side, and a hollow area is formed on the protective layer to expose the light-emitting area of ​​the light guide plate.

[0006] A light-collecting grating is formed in the light-emitting area on the light guide plate.

[0007] Optionally, in this embodiment of the present disclosure, after the light-emitting area on the light guide plate forms a light-collecting grating, the method further includes:

[0008] Remove the protective layer from the non-light-emitting area of ​​the light guide plate.

[0009] Optionally, in this embodiment of the present disclosure, forming a protective layer on the light-emitting side of the light guide plate, the protective layer simultaneously covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side, and forming a hollow area on the protective layer to expose the light-emitting area of ​​the light guide plate, includes:

[0010] At least one of a metal protective layer, a metal alloy protective layer, and a metal oxide protective layer is formed on the light guide plate;

[0011] The protective layer is wet-etched to form a hollow area, thereby exposing the light-emitting area of ​​the light guide plate.

[0012] Optionally, in an embodiment of this disclosure, forming a metal oxide protective layer on the light guide plate includes:

[0013] At least one of the following protective layers is formed on the light guide plate: an IGZO protective layer, an ITO protective layer, and an IZO protective layer.

[0014] Optionally, in this embodiment of the present disclosure, before the light-collecting grating is formed in the light-emitting area on the light guide plate, the method further includes:

[0015] The protective layer is annealed at a temperature of 200℃ to 400℃.

[0016] Optionally, in this embodiment of the disclosure, removing the protective layer from the non-light-emitting area of ​​the light guide plate includes:

[0017] The protective layer is removed using an etching solution; wherein the etching solution includes sulfuric acid, nitric acid, additives, and deionized water.

[0018] Optionally, in this embodiment of the disclosure, before removing the protective layer of the non-light-emitting area of ​​the light guide plate, the following steps are further included:

[0019] An anti-etching protective layer is formed on the light guide plate, which only covers the light-collecting grating.

[0020] Optionally, in this embodiment of the disclosure, forming an anti-etching protective layer that only covers the light-collecting grating includes:

[0021] A photoresist layer covering only the light-collecting grating is formed on the light guide plate on which the light-collecting grating is formed.

[0022] Optionally, in this embodiment of the disclosure, the thickness of the formed protective layer is 10 nm to 40 nm.

[0023] Optionally, in this embodiment of the present disclosure, before removing the protective layer of the non-light-emitting area of ​​the light guide plate, the formation of a light-collecting grating in the light-emitting area of ​​the light guide plate includes:

[0024] An insulating layer is formed on the light guide plate to cover the light guide plate, and the refractive index of the insulating layer is greater than the refractive index of the light guide plate;

[0025] A patterning process is used to form a grating structure in each area of ​​the insulating layer on the light guide plate;

[0026] A photoresist layer with multiple opening regions is formed on the grating structure; wherein the opening regions overlap with the non-light-emitting region of the collimating backlight module;

[0027] A dry etching process is used to remove the grating structure in the non-light-emitting area, while retaining the protective layer in the non-light-emitting area.

[0028] The photoresist layer is peeled off to form a light-collecting grating located only within the light-emitting area.

[0029] Optionally, in this embodiment of the disclosure, the step of using a patterning process to form a grating structure in each region of the insulating layer on the light guide plate includes:

[0030] An embossing or transfer process is used to form a grating structure in each area of ​​the insulating layer on the light guide plate.

[0031] Optionally, in this embodiment of the disclosure, the step of using an imprinting process to form a grating structure in each region of the insulating layer on the light guide plate includes:

[0032] An embossed adhesive covering the insulating layer is formed on the light guide plate;

[0033] The impression template is used to simultaneously imprint each area of ​​the impression adhesive;

[0034] After curing the imprinted adhesive and removing the imprinting template, a dry etching process is used to form the grating structure from the insulating layer.

[0035] Optionally, in an embodiment of this disclosure, forming an insulating layer covering the light guide plate includes:

[0036] A silicon nitride insulating layer is formed on the light guide plate to cover the light guide plate.

[0037] Optionally, in this embodiment of the disclosure, the light guide plate is made of glass.

[0038] Optionally, in this embodiment of the disclosure, after removing the protective layer of the non-light-emitting area of ​​the light guide plate, the method further includes:

[0039] A planarization layer is formed on the light guide plate to cover the light-emitting side of the light guide plate.

[0040] Optionally, in this embodiment of the present disclosure, after forming a planarization layer covering the light-emitting side of the light guide plate, the method further includes:

[0041] A reflective layer is formed on the side opposite to the light-incident side of the light guide plate;

[0042] A light source and a reflector are formed on the light-incident side of the light guide plate.

[0043] This disclosure also provides a collimated backlight module, which is prepared using the above-described preparation method.

[0044] This disclosure also provides a display device, including the above-described collimated backlight module. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of a display device provided in an embodiment of the present disclosure;

[0046] Figure 2A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0047] Figure 3 A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0048] Figure 4a A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0049] Figure 4b A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0050] Figure 4c A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0051] Figure 5 A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0052] Figure 6 A flowchart illustrating a method for fabricating a collimated backlight module provided in one or more embodiments of this disclosure;

[0053] Figures 7a to 7m These are cross-sectional structural diagrams of the backlight module obtained in each manufacturing step of the collimated backlight module manufacturing method provided in the embodiments of this disclosure. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this disclosure clearer, the specific implementation methods of the collimated backlight module, its fabrication method, and the display device provided in the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments described below are for illustration and explanation only and are not intended to limit this disclosure. Furthermore, the embodiments and features in the embodiments of this disclosure can be combined with each other without conflict. It should be noted that the thickness and shape of each thin film layer in the drawings do not reflect actual proportions and are only intended to illustrate the content of this disclosure. And throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions.

[0055] Display devices with collimated light sources, such as Figure 1As shown, the backlight module 100 may include a collimated backlight module 100 and a liquid crystal display (LCD) panel 200 located on the light-emitting side of the collimated backlight module 100. The collimated backlight module 100 may include a light guide plate 110, a light source 120, a light-collecting grating 130, and a planarization layer 140. Specifically, the collimated backlight module 100 has a light-emitting area A1 and a non-light-emitting area A2. Light emitted from the light source 120 is coupled into the light guide plate 110 at a certain central angle and transmitted through total internal reflection within the light guide plate 110. Since the light-collecting grating 130 is provided in the light-emitting area A1 of the light guide plate 110, the light incident on the light-emitting area A1 can be extracted at a collimated angle through the light-collecting grating 130, so that the light is collimated and emitted upwards. The LCD panel 200 may include, sequentially located on the side of the planarization layer 140 opposite to the light guide plate 110, a first alignment layer 210, a liquid crystal layer 220, a second alignment layer 230, a first transparent electrode layer 240, an insulating layer 250, a second transparent electrode layer 260, a color filter layer 270, a light-shielding layer 280, and an upper substrate 290. The LCD panel 200 has multiple pixel units, each pixel unit including multiple sub-pixels (subpx), each sub-pixel (subpx) including a light-shielding region BB and light-transmitting regions AA located on both sides of the light-shielding region BB. The light-shielding layer 280 is disposed corresponding to the light-shielding region BB, and the color filter layer 270 is disposed corresponding to the light-transmitting region AA. When the LCD panel 200 is not loaded with an electrical signal, the light emitted from the light-emitting region A1 is completely absorbed by the light-shielding material in the light-shielding layer 280 of the light-shielding region BB, resulting in a dark state. By applying an electrical signal to the LCD panel 200, the refractive index of the liquid crystal layer 220 can be driven to change periodically to form a liquid crystal grating. This causes light emitted from the light-emitting region A1 to be diffracted by the liquid crystal grating and then emitted from the light-transmitting region AA, resulting in a bright state for display. Furthermore, applying different electrical signals to the liquid crystal layer 220 can achieve different diffraction efficiencies of the liquid crystal grating for incident light, thereby enabling multi-grayscale display.

[0056] This disclosure provides a method for fabricating a collimated backlight module, such as... Figure 2 As shown, it may include the following steps:

[0057] S01. Provide a light guide plate;

[0058] S02. A protective layer is formed on the light-emitting side of the light guide plate. The protective layer covers both the light-emitting and non-light-emitting areas of the light-emitting side. A cutout area is formed in the protective layer to expose the light-emitting area of ​​the light guide plate. This allows a protective layer with multiple cutout areas to be formed on the light-emitting side of the light guide plate. The cutout areas correspond to the light-emitting areas of the collimating backlight module, thus exposing the light-emitting areas. The protective layer covers the non-light-emitting areas.

[0059] S03. A light-collecting grating is formed in the light-emitting area of ​​the light guide plate.

[0060] The method for fabricating a collimated backlight module provided in this disclosure involves forming a protective layer with multiple hollow areas on a light guide plate before forming the light-collecting grating. This protective layer covers the light guide plate corresponding to the non-light-emitting areas, thus protecting these areas. When forming the light-collecting grating on the light guide plate in the corresponding light-emitting area, the protective layer prevents etching of the light guide plate due to its protection of the non-light-emitting areas. This results in good surface flatness of the non-light-emitting areas of the light guide plate, reducing light leakage. Consequently, when the fabricated collimated backlight module is applied to a display device, the display effect can be improved.

[0061] In specific implementations, the thickness of the protective layer formed in this embodiment can be 10nm to 40nm. For example, the thickness of the protective layer formed can be 10nm, 20nm, 30nm or 40nm, and is not limited thereto.

[0062] To prevent light leakage from the light guide plate caused by the protective layer located in the non-light-emitting area, in specific implementations, as described in this embodiment, Figure 3 As shown, after forming a light-collecting grating in the light-emitting area of ​​the light guide plate in step S03, the process may further include: S04, removing the protective layer of the non-light-emitting area of ​​the light guide plate.

[0063] In specific implementations, in the embodiments of this disclosure, the material of the protective layer can be a film layer that can be etched away by wet etching, and for example, it can include at least one of metal, metal alloy, and metal oxide. In specific implementations, in the embodiments of this disclosure, a protective layer is formed on the light-emitting side of the light guide plate, covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side. A hollow area is formed on the protective layer to expose the light-emitting area of ​​the light guide plate, which can include:

[0064] At least one of a metal protective layer, a metal alloy protective layer, and a metal oxide protective layer is formed on the light guide plate;

[0065] The protective layer is wet-etched to create cutouts, exposing the light-emitting area of ​​the light guide plate. Since wet etching generally does not chemically etch the glass light guide plate, using this process to etch the protective layer further avoids etching the light guide plate itself. This results in a smoother surface in the non-light-emitting areas of the light guide plate, reducing light leakage in these areas.

[0066] Specifically, in specific implementations, in the embodiments of this disclosure, such as Figure 4a As shown, a protective layer is formed on the light-emitting side of the light guide plate, covering both the light-emitting and non-light-emitting areas. A cutout area is formed in the protective layer to expose the light-emitting area of ​​the light guide plate. This process may include the following steps:

[0067] S0111. A metal protective layer is formed on the light-emitting side of the light guide plate, simultaneously covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side; wherein the material of the metal protective layer can be Al, Cu, etc. For example, forming a metal alloy protective layer on the light guide plate may include: forming an Al protective layer that completely covers the light-emitting side of the light guide plate; or forming a Cu protective layer that completely covers the light-emitting side of the light guide plate. Of course, in practical applications, protective layers of other metal materials can also be formed, which are not limited here.

[0068] S0112. Perform wet etching on the formed metal protective layer to create a hollow area on the metal protective layer, so that the light-emitting area of ​​the light guide plate is exposed.

[0069] Specifically, in specific implementations, in the embodiments of this disclosure, such as Figure 4b As shown, a protective layer is formed on the light-emitting side of the light guide plate, covering both the light-emitting and non-light-emitting areas. A cutout area is formed in the protective layer to expose the light-emitting area of ​​the light guide plate. This process may include the following steps:

[0070] S0121. A metal alloy protective layer is formed on the light-emitting side of the light guide plate, simultaneously covering both the light-emitting and non-light-emitting areas of the light-emitting side; wherein the metal alloy can be AlNd, etc. For example, forming a metal alloy protective layer on the light guide plate can include forming an AlNd protective layer that completely covers the light-emitting side of the light guide plate. Of course, in practical applications, protective layers of other metal alloy materials can also be formed, which are not limited here.

[0071] S0122. Wet etching is performed on the formed metal alloy protective layer to form a hollow area on the metal alloy protective layer, so that the light-emitting area of ​​the light guide plate is exposed.

[0072] Specifically, in specific implementations, in the embodiments of this disclosure, such as Figure 4c As shown, a protective layer is formed on the light-emitting side of the light guide plate, covering both the light-emitting and non-light-emitting areas. A cutout area is formed in the protective layer to expose the light-emitting area of ​​the light guide plate. This process may include the following steps:

[0073] S0131. A metal oxide protective layer is formed on the light-emitting side of the light guide plate, simultaneously covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side. The metal oxide can be indium tin oxide (ITO), indium gallium zinc oxide (IGZO), indium zinc oxide (IZO), etc. For example, forming a metal oxide protective layer that completely covers the light-emitting side of the light guide plate can include forming at least one of an IGZO (indium gallium zinc oxide) protective layer, an ITO (indium tin oxide) protective layer, and an IZO (indium zinc oxide) protective layer on the light guide plate. Of course, in practical applications, protective layers made of other metal oxide materials can also be formed, and this is not limited here.

[0074] S0132. Wet etching is performed on the formed metal oxide protective layer to form a hollow area on the metal oxide protective layer, so that the light-emitting area of ​​the light guide plate is exposed.

[0075] Of course, in specific implementations, two of the following protective layers can be formed on the light-emitting side of the light guide plate: a metal protective layer, a metal alloy protective layer, and a metal oxide protective layer, which simultaneously cover both the light-emitting and non-light-emitting areas. Furthermore, a metal protective layer, a metal alloy protective layer, and a metal oxide protective layer can also be formed on the light-emitting side of the light guide plate, simultaneously covering both the light-emitting and non-light-emitting areas. Naturally, the specific implementation method of the protective layer can be designed and determined according to the actual application environment, and is not limited here.

[0076] In practical implementation, after using a metal oxide film, a deposition method, such as plasma-enhanced chemical vapor deposition (PECVD), is required to form an insulating layer with a refractive index higher than that of the light guide plate. This insulating layer is then used to fabricate the light-collecting grating on the light guide plate. During the deposition of this insulating layer, there is a possibility of metal precipitation from the metal oxide. Therefore, the metal oxide protective layer can be annealed first. For example, the material of the protective layer can be set as IGZO. To avoid In precipitation in the protective layer during the formation of the light-collecting grating, in this embodiment, before forming the light-collecting grating in the light-emitting area of ​​the light guide plate in step S03, such as... Figure 3 As shown, it may also include: S05, annealing the protective layer at a temperature of 200℃ to 400℃. This prevents In precipitation from the protective layer during the formation of the light-collecting grating. The temperature can be set to 200℃, 380℃, or 400℃. Of course, the specific value of this temperature can be designed and determined according to the actual application environment, and is not limited here.

[0077] In specific implementations, in this embodiment, removing the protective layer of the non-light-emitting area of ​​the light guide plate can include: removing the protective layer using an etching solution, wherein the etching solution can include sulfuric acid, nitric acid, additives, and deionized water. This allows for the use of a wet etching process to remove the protective layer. Since wet etching generally does not produce a chemical etching effect on glass light guide plates, using a wet etching process to remove the protective layer can further avoid etching the light guide plate, thereby further improving the surface flatness of the non-light-emitting area of ​​the light guide plate and reducing light leakage in the non-light-emitting area.

[0078] Optionally, in specific implementations, the mass ratio of sulfuric acid, nitric acid, additives, and deionized water in the etching solution can be selected based on the material of the protective layer in the actual application. For example, if the material of the protective layer is IGZO, the mass ratio of sulfuric acid, nitric acid, additives, and deionized water in the etching solution can optionally be 8:4.5:2:76. Of course, in practical applications, when the material of the protective layer is IGZO, other values ​​that achieve the functions of this disclosure can be selected for the mass ratio of sulfuric acid, nitric acid, additives, and deionized water in the etching solution, and no limitation is made here.

[0079] To avoid adverse effects on the light-collecting grating when removing the protective layer using an etching solution, in specific implementations, as described in the embodiments of this disclosure... Figure 3 As shown, before removing the protective layer of the non-light-emitting area of ​​the light guide plate in step S04, the process may further include: S06, forming an anti-etching protective layer on the light guide plate that only covers the light-collecting grating. This protects the light-collecting grating with the anti-etching protective layer, thus preventing the etching solution from adversely affecting the light-collecting grating when the protective layer is removed.

[0080] Optionally, to reduce production costs, the anti-etching protective layer can be made of photoresist. This allows the anti-etching protective layer to be directly applied to the light-collecting grating using photolithography, eliminating the need for an additional film layer and reducing process complexity. In specific implementations, in the embodiments of this disclosure, forming an anti-etching protective layer that only covers the light-collecting grating may include: forming a photoresist layer that only covers the light-collecting grating on the light guide plate where the light-collecting grating is formed.

[0081] In specific implementation, in this embodiment of the disclosure, before removing the protective layer of the non-light-emitting area of ​​the light guide plate, a light-collecting grating is formed in the light-emitting area of ​​the light guide plate, such as... Figure 5 As shown, the specific steps may include the following:

[0082] S021. An insulating layer is formed on the light guide plate, covering the light-emitting area and the non-light-emitting area of ​​the light guide plate. The refractive index of the insulating layer is greater than the refractive index of the light guide plate, so as to ensure that the light from the light guide plate is totally reflected in the non-light-emitting area.

[0083] S022. A patterning process is used to form a grating structure in each area of ​​the insulating layer on the light guide plate;

[0084] S023. A photoresist layer with multiple opening regions is formed on the grating structure; wherein the opening regions overlap with the non-light-emitting regions of the collimating backlight module.

[0085] S024. Use dry etching process to remove the grating structure in the corresponding non-light-emitting area, and retain the protective layer of the non-light-emitting area.

[0086] S025. Strip the photoresist layer to form a light-collecting grating located only in the light-emitting area.

[0087] In specific implementation, in the embodiments of this disclosure, the patterning process is used to form grating structures in various areas of the light guide plate by the insulating layer. This may include: using an imprinting process or a transfer process to form grating structures in various areas of the light guide plate by the insulating layer.

[0088] For example, in a specific implementation, in the embodiments of this disclosure, the patterning process used to form grating structures in various regions of the light guide plate by the insulating layer may include: using a soft film transfer process to form grating structures in various regions of the light guide plate by the insulating layer.

[0089] In specific implementation, in the embodiments of this disclosure, the patterning process is used to form grating structures in various regions of the light guide plate by the insulating layer, which may include: using an imprinting process to form grating structures in various regions of the light guide plate by the insulating layer.

[0090] For example, in a specific implementation, in the embodiments of this disclosure, an imprinting process is used to form a grating structure in each area of ​​the insulating layer on the light guide plate, such as... Figure 6 As shown, the specific steps may include the following:

[0091] S0221. An imprinted adhesive covering the above-mentioned insulating layer is formed on the light guide plate;

[0092] S0222, Simultaneously imprint each area of ​​the imprinting adhesive using an imprinting template.

[0093] S0223. After curing the imprinting adhesive and removing the imprinting template, a dry etching process is used to form a grating structure from the insulating layer. This allows for a finer grating structure.

[0094] In specific implementations, the material of the light guide plate may include glass. For example, the light guide plate may be made of glass. The material of the light-collecting grating may be a material with a refractive index greater than that of glass. Since the refractive index of glass is generally around 1.4, the light-collecting grating may have a refractive index greater than 1.4; optionally, it may use a material with a refractive index of 1.9. For example, in this embodiment, the material of the light-collecting grating may include silicon nitride, i.e., SiNx. For example, forming an insulating layer covering the light guide plate may include forming a silicon nitride insulating layer covering the light guide plate. Of course, in practical applications, other materials capable of achieving the functions of this disclosure may be selected as the material of the light-collecting grating, and this is not limited here.

[0095] In specific implementation, as described in the embodiments of this disclosure, such as Figure 3 As shown, after step S04, removing the protective layer of the non-light-emitting area of ​​the light guide plate, the process may further include: S07, forming a planarization layer on the light guide plate that covers the light-emitting side of the light guide plate.

[0096] In specific implementation, in the embodiments of this disclosure, after forming a planarization layer covering the light-emitting side of the light guide plate, as follows: Figure 3 As shown, it may also include:

[0097] S08. A reflective layer is formed on the side opposite to the light-incident side of the light guide plate;

[0098] S09. A light source and a reflector are formed on the light-incident side of the light guide plate.

[0099] The following examples illustrate methods for fabricating collimated backlight modules, but readers should understand that the specific process is not limited to these examples. The methods for fabricating collimated backlight modules provided in this disclosure may include the following steps:

[0100] (1) A light guide plate 110 with a glass substrate is provided. An IGZO protective layer is formed on the light guide plate 110, which simultaneously covers the light-emitting area A1 and the non-light-emitting area A2 on the light-emitting side of the light guide plate 110. A hollow area Q1 is formed on the protective layer, so that the light-emitting area A1 of the light guide plate 110 is exposed, thereby forming an IGZO protective layer 410 with multiple hollow areas Q1 on the light guide plate 110. Wherein, as Figure 7a As shown, the hollow area Q1 overlaps with the light-emitting area A1 of the collimated backlight module, and the orthographic projection of the IGZO protective layer 410 onto the light guide plate 110 overlaps with the non-light-emitting area A2 of the collimated backlight module, thus covering the non-light-emitting area A2 of the light guide plate 110. The thickness of the IGZO protective layer 410 can be 20 nm in the direction perpendicular to the light guide plate 110.

[0101] Specifically, a single-layer IGZO protective layer is formed on the light guide plate 110. Then, photolithography and wet etching are sequentially used to remove the IGZO protective layer in the area corresponding to the light-emitting region A1, while retaining the IGZO protective layer in the area corresponding to the non-light-emitting region A2, so that the retained IGZO protective layer forms the IGZO protective layer 410. This avoids interface loss in the light-emitting region A1 caused by the IGZO protective layer 410.

[0102] (2) The IGZO protective layer 410 was annealed at a temperature of 380℃.

[0103] (3) A silicon nitride insulating layer 420 is formed on the light guide plate 110, simultaneously covering the light-emitting area A1 and the non-light-emitting area A2 of the light guide plate 110; wherein, as Figure 7b As shown.

[0104] Specifically, a silicon nitride insulating layer 420 is deposited on the light guide plate 110 using plasma enhanced chemical vapor deposition (PECVD) to cover the light guide plate 110.

[0105] (4) An imprinting adhesive 430 covering a silicon nitride insulating layer 420 is formed on the light guide plate 110; wherein, as shown in the figure Figure 7c As shown.

[0106] (5) The impression template 500 is used to simultaneously imprint each area of ​​the impression adhesive 430; among which, such as Figure 7d As shown.

[0107] (6) After curing the imprinting adhesive and removing the imprinting template, a dry etching process is used to form the grating structure 310 of the insulating layer. For example, Figure 7e As shown, there is a gap between two adjacent grating structures 310, and the width of the gap between each adjacent grating structure 310 is the same. The thickness d of the formed grating structure 310 can be 320 nm, and the period Z of the grating structure 310 can be 377 nm. It should be noted that the thickness d is the distance between the upper surface of the grating structure 310 and the upper surface of the light guide plate. The period Z is the sum of the width z2 of one grating structure 310 and the width z1 of an adjacent gap, i.e., Z = z1 + z2. Of course, in practical applications, since different application environments have different display effects on the display device, the thickness and period of the grating structure 310 can be designed and determined according to the actual application environment, and are not limited here.

[0108] (7) A pattern of photoresist layer 440 with multiple opening regions is formed on the grating structure 310; wherein, the opening regions overlap with the non-light-emitting region A2 of the collimated backlight module, and the photoresist layer 440 only covers the grating structure 310 in the light-emitting region A1, such as... Figure 7f As shown.

[0109] (8) Using a dry etching process, the grating structure 310 in the corresponding non-light-emitting region A2 is removed, while the protective layer 410 in the non-light-emitting region A2 and the photoresist layer 440 in the corresponding light-emitting region A1 are retained, so as to retain the grating structure 310 in the corresponding light-emitting region A1. Figure 7g As shown. The etching rate of the grating structure 310 and the etching rate of the IGZO protective layer 410 can be set to a ratio of 50:1. Of course, in practical applications, the ratio between the etching rate of the grating structure 310 and the etching rate of the IGZO protective layer 410 can be designed and determined according to the actual application environment, and is not limited here.

[0110] (9) The photoresist layer is peeled off to form a grating structure 310 located only within the light-emitting region A1, so that the grating structure 310 located in the same light-emitting region A1 forms a light-collecting grating located in that light-emitting region A1, wherein, as Figure 7h As shown.

[0111] (10) A photoresist is used to form an anti-etching protective layer 450 on the light guide plate 110 on which the light-collecting gratings are formed, which only covers each light-emitting area A1; wherein, for example Figure 7i As shown. Specifically, an anti-etching protective layer 450 is formed using a photolithography process.

[0112] (11) The IGZO protective layer is removed using an etching solution; wherein, the grating structure 310 is formed in the light-emitting area A1 of the light guide plate 110, so that the grating structure 310 in the same light-emitting area A1 forms a light-collecting grating 600, such as Figure 7j As shown. The etching solution may include sulfuric acid, nitric acid, additives, and deionized water. For example, the mass ratio of sulfuric acid, nitric acid, additives, and deionized water can be 8:4.5:2:76.

[0113] (12) A planarization layer 140 covering the light guide plate 110 is formed on the light guide plate 110, such as Figure 7k As shown.

[0114] (13) A reflective layer 150 is formed on the side opposite to the light-incident side of the light guide plate 110, such as Figure 7l As shown.

[0115] (14) A light source 120 and a reflector 160 are formed on the light-incident side of the light guide plate 110, such as Figure 7m As shown.

[0116] Based on the same inventive concept, this disclosure also provides a collimated backlight module prepared using the above-described preparation method. The principle by which this collimated backlight module solves the problem is similar to the aforementioned preparation method; therefore, the implementation of this collimated backlight module can refer to the implementation of the above-described preparation method, and the repetitions will not be repeated here.

[0117] Specifically, such as Figure 7m As shown, the collimated backlight module may include: a light guide plate 110, and a light-collecting grating 600 located on one side of the light guide plate 110; wherein the orthographic projection of the light-collecting grating 600 onto the light guide plate 110 is located within the light-emitting area A1 of the collimated backlight module. Alternatively, in this embodiment, the collimated backlight module may include: a light guide plate, a protective layer located on one side of the light guide plate, and a light-collecting grating located on one side of the light guide plate; wherein the orthographic projection of the protective layer onto the light guide plate does not overlap with the light-emitting area of ​​the collimated backlight module, and the orthographic projection of the light-collecting grating onto the light guide plate is located within the light-emitting area of ​​the collimated backlight module.

[0118] In specific implementation, as described in the embodiments of this disclosure, such as Figure 7m As shown, the collimated backlight module may further include a planarization layer 140 located on the side of the light-collecting grating 600 facing away from the light guide plate 110. The refractive index of the material of the planarization layer 140 may be less than the refractive index of the light guide plate. For example, the refractive index of the material of the planarization layer 140 may be less than 1.4.

[0119] In specific implementation, as described in the embodiments of this disclosure, such as Figure 7m As shown, the collimated backlight module may further include: a light source 120 and a reflector 160 formed on the light-incident side of the light guide plate 110, and a reflective layer 150 formed on the side opposite to the light-incident side of the light guide plate 110.

[0120] Based on the same inventive concept, embodiments of this disclosure also provide a display device, such as... Figure 1 As shown, the display device may include the collimated backlight module 100 provided in the embodiments of this disclosure. Further, the display device also includes a liquid crystal display panel 200 located on the light-emitting side of the collimated backlight module 100. The specific structure of the display device can be found in the above description and will not be repeated here. Furthermore, the principle by which this display device solves the problem is similar to that of the aforementioned collimated backlight module; therefore, the implementation of this display device can refer to the implementation of the aforementioned collimated backlight module, and the repetitions will not be repeated here.

[0121] In specific implementations, the display device provided in the embodiments of this disclosure can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator. Other essential components of this display device are those that should be understood by those skilled in the art, and will not be described in detail here, nor should they be construed as limiting this disclosure.

[0122] The collimated backlight module and its manufacturing method and display device provided in this disclosure, by forming a protective layer with multiple hollow areas on a light guide plate before forming the light-collecting grating, can cover the light guide plate corresponding to the non-light-emitting area, thereby protecting the non-light-emitting area of ​​the light guide plate. When forming the light-collecting grating on the light guide plate in the area corresponding to the light-emitting area, the protective layer's protection of the non-light-emitting area of ​​the light guide plate prevents etching of the light guide plate. This results in good surface flatness of the non-light-emitting area of ​​the light guide plate, reducing light leakage in the non-light-emitting area. Furthermore, when the collimated backlight module prepared above is applied to a display device, the display effect can be improved.

[0123] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of the embodiments of this disclosure. Therefore, if these modifications and variations to the embodiments of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include these modifications and variations.

Claims

1. A method for fabricating a collimated backlight module, wherein, include: Provide a light guide plate; A protective layer is formed on the light-emitting side of the light guide plate, the protective layer covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side, and a hollow area is formed on the protective layer to expose the light-emitting area of ​​the light guide plate. A light-collecting grating is formed in the light-emitting area on the light guide plate; Remove the protective layer from the non-light-emitting area of ​​the light guide plate; The formation of a light-collecting grating in the light-emitting area on the light guide plate includes: An insulating layer is formed on the light guide plate to cover the light guide plate, and the refractive index of the insulating layer is greater than the refractive index of the light guide plate; A patterning process is used to form a grating structure in each area of ​​the insulating layer on the light guide plate; A photoresist layer with multiple opening regions is formed on the grating structure; wherein the opening regions overlap with the non-light-emitting region of the collimating backlight module; A dry etching process is used to remove the grating structure in the non-light-emitting area, while retaining the protective layer in the non-light-emitting area. The photoresist layer is peeled off to form a light-collecting grating located only within the light-emitting area; The process of using a patterning technique to form a grating structure in each region of the insulating layer on the light guide plate includes: An embossing or transfer process is used to form a grating structure in each area of ​​the insulating layer on the light guide plate.

2. The method for fabricating the collimated backlight module as described in claim 1, wherein, The method of forming a protective layer on the light-emitting side of the light guide plate, the protective layer simultaneously covering both the light-emitting area and the non-light-emitting area of ​​the light-emitting side, and forming a hollow area in the protective layer to expose the light-emitting area of ​​the light guide plate, includes: At least one of a metal protective layer, a metal alloy protective layer, and a metal oxide protective layer is formed on the light guide plate; The protective layer is wet-etched to form a hollow area, thereby exposing the light-emitting area of ​​the light guide plate.

3. The method for preparing the collimated backlight module as described in claim 2, wherein, The formation of a metal oxide protective layer on the light guide plate includes: At least one of the following protective layers is formed on the light guide plate: an IGZO protective layer, an ITO protective layer, and an IZO protective layer.

4. The method for fabricating the collimated backlight module as described in claim 3, wherein, Before the light-collecting grating is formed in the light-emitting area on the light guide plate, the following is also included: The protective layer is annealed at a temperature of 200℃ to 400℃.

5. The method for fabricating the collimated backlight module according to any one of claims 1-4, wherein, The removal of the protective layer from the non-light-emitting area of ​​the light guide plate includes: The protective layer is removed using an etching solution; wherein the etching solution includes sulfuric acid, nitric acid, additives, and deionized water.

6. The method for fabricating the collimated backlight module as described in claim 5, wherein, Before removing the protective layer of the non-light-emitting area of ​​the light guide plate, the following steps are also included: An anti-etching protective layer is formed on the light guide plate, which only covers the light-collecting grating.

7. The method for fabricating the collimated backlight module as described in claim 6, wherein, The formation of the anti-etching protective layer that covers only the light-collecting grating includes: A photoresist layer covering only the light-collecting grating is formed on the light guide plate on which the light-collecting grating is formed.

8. The method for fabricating the collimated backlight module according to any one of claims 1-4, wherein, The thickness of the formed protective layer is 10nm~40nm.

9. The method for fabricating the collimated backlight module as described in claim 1, wherein, The process of using an imprinting process to form a grating structure in each region of the insulating layer on the light guide plate includes: An embossed adhesive covering the insulating layer is formed on the light guide plate; The impression template is used to simultaneously imprint each area of ​​the impression adhesive; After curing the imprinted adhesive and removing the imprinting template, a dry etching process is used to form the grating structure from the insulating layer.

10. The method for fabricating the collimated backlight module as described in claim 1, wherein, The process of forming an insulating layer covering the light guide plate includes: A silicon nitride insulating layer is formed on the light guide plate to cover the light guide plate.

11. The method for fabricating a collimated backlight module according to any one of claims 1-4, wherein, The light guide plate is made of glass.

12. The method for fabricating a collimated backlight module according to any one of claims 1-4, wherein, After removing the protective layer from the non-light-emitting area of ​​the light guide plate, it further includes: A planarization layer is formed on the light guide plate to cover the light-emitting side of the light guide plate.

13. The method for fabricating the collimated backlight module as described in claim 12, wherein, After forming a planarization layer covering the light-emitting side of the light guide plate on the light guide plate, the method further includes: A reflective layer is formed on the side opposite to the light-incident side of the light guide plate; A light source and a reflector are formed on the light-incident side of the light guide plate.

Images