Design method of roll mold, method of manufacturing optical sheet, and optical sheet

Abstract

This application relates to the field of optical sheet manufacturing technology, and more particularly to a roller mold design method, an optical sheet manufacturing method, and an optical sheet. In the roller mold design method, the roller mold has a peripheral surface and multiple first microstructures disposed on the peripheral surface, used to press out second microstructures corresponding to the shapes of the first microstructures onto the surface of molten resin, and to manufacture a target optical sheet with multiple target microstructures on its surface. One of the first and second microstructures is a protrusion, and the other is a depression. The target microstructure is defined by the second microstructure. The design method includes: determining the values ​​of k and a based on the material of the target optical sheet, the thickness of the target optical sheet, and the period of the target microstructure; and determining the depth or height X1 of the first microstructure based on the relationship X1=k*Y1+a, where Y1 is the height or depth of the target microstructure.

Description

Technical Field

[0001] This application relates to the field of optical sheet manufacturing technology, and in particular to a method for designing a roller mold, a method for manufacturing an optical sheet, and an optical sheet. Background Technology

[0002] Optical sheets refer to sheet-like materials with excellent optical properties, widely used in various optical devices and electronic products. The main types of materials used to form optical sheets include optical-grade PC (Polycarbonate), optical-grade PMMA (Polymethyl Methacrylate), and MS resin (Styrene-Methyl Methacrylate copolymer) sheets. The structure of optical sheets varies depending on the application. For example, in backlight systems for electronic products, micro- and nano-structures can be fabricated on at least one of the two main surfaces of the optical sheet to create a light guide plate that controls light transmission and alters the light propagation path. To adapt to new optical requirements and improve light utilization, microstructures are often first formed on one surface of the optical sheet during the manufacturing process using a roller-mold transfer method.

[0003] When transferring microstructures onto one side of an optical substrate using a roller mold with microstructures, it is usually not possible to achieve 100% perfect complementarity in shape and size between the microstructures on the optical substrate and the microstructures on the roller mold. The size of the microstructure on the optical substrate will be smaller than that on the roller mold. Therefore, to achieve the required microstructure dimensions (e.g., height or depth) for the optical substrate, the depth or height of the microstructure on the roller mold needs to be appropriately increased. Previously, technicians typically relied entirely on experience to select the initial increase in the depth or height of the microstructure on the roller mold, and then repeatedly decreased or increased the increase based on the resulting dimensions of the microstructure on the manufactured optical substrate. This increased product development costs and placed a high dependence on technical personnel. Summary of the Invention

[0004] In view of this, this application proposes a design method for a roller mold, a manufacturing method for an optical sheet, and an optical sheet.

[0005] In a first aspect, a design method (200) for a roller mold (3) is provided, the roller mold (3) having a peripheral surface (3a) and a plurality of first microstructures (301) disposed on the peripheral surface (3a), for pressing out second microstructures (RE1) corresponding to the shape of the first microstructures (301) onto the surface of molten resin (RE), and manufacturing a target optical plate (1) having a plurality of target microstructures (101) on its surface based thereon, wherein one of the first microstructures (301) and the second microstructures (RE1) is a protrusion and the other is a depression, and the target microstructures (101) are defined by the second microstructures (RE1), the design method (200) comprising:

[0006] The values ​​of k and a are determined based on the material of the target optical plate (1), the thickness (DD) of the target optical plate (1), and the period (Pitch) of the target microstructure (101);

[0007] Based on the relation X1=k*Y1+ a, the depth or height X1 of the first microstructure (301) is determined, where Y1 is the height or depth of the target microstructure (101).

[0008] The determination of the values ​​of k and a based on the material of the target optical plate (1), the thickness (DD) of the target optical plate (1), and the period (DD) of the target microstructure (101) includes:

[0009] A second resin corresponding to the material of the target optical plate (1), a second roller mold having a second peripheral surface and a plurality of third microstructures disposed on the second peripheral surface, and a third roller mold having a third peripheral surface and a plurality of fourth microstructures disposed on the third peripheral surface are provided, wherein the third microstructure, the fourth microstructure and the first microstructure (301) are both protrusions or both are depressions, the period of the third microstructure and the period of the fourth microstructure correspond to the period of the target microstructure (101), the depth or height of the third microstructure is X2, the depth or height of the fourth microstructure is X3, and X2≠X3;

[0010] The second roller mold is used to press out a fifth microstructure corresponding to the shape of the third microstructure on the surface of the molten second resin, and a second optical plate with a plurality of sixth microstructures on the surface is manufactured based on this, wherein the sixth microstructure is defined by the fifth microstructure, and the thickness of the second optical plate is the same as the thickness (DD) of the target optical plate (1).

[0011] The seventh microstructure, corresponding to the shape of the fourth microstructure, is pressed onto the surface of the molten second resin using the third roller mold, and a third optical plate with a plurality of eighth microstructures on its surface is manufactured based on this. The eighth microstructure is defined by the seventh microstructure, and the thickness of the third optical plate is the same as the thickness (DD) of the target optical plate (1).

[0012] The height or depth of the sixth microstructure is measured as Y2, and the height or depth of the eighth microstructure is measured as Y3;

[0013] Based on the relationships X2=k*Y2+a and X3=k*Y3+a, determine the values ​​of k and a.

[0014] In some possible implementations, determining the values ​​of k and a based on the material of the target optical plate (1), the thickness (DD) of the target optical plate (1), and the pitch of the target microstructure (101) includes:

[0015] If the thickness (DD) of the target optical plate (1) is less than 0.7 mm, then the value of a is determined to be 0.

[0016] The statement that if the thickness of the target optical plate (1) is less than 0.7 mm, then the value of a is determined to be 0 includes:

[0017] In some possible implementations, if the thickness of the target optical plate (1) is less than 0.6 mm, the value of a is determined to be 0.

[0018] In some possible implementations, determining the values ​​of k and a based on the material of the target optical plate (1), the thickness (DD) of the target optical plate (1), and the pitch of the target microstructure (101) includes:

[0019] A third resin corresponding to the material of the target optical plate (1), a fourth roller mold having a fourth peripheral surface and a plurality of ninth microstructures disposed on the fourth peripheral surface, wherein the ninth microstructure and the first microstructure (301) are both the protrusions or the depressions, and the period of the ninth microstructure corresponds to the period (Pitch) of the target microstructure (101), and the depth or height of the ninth microstructure is X4;

[0020] Using the fourth roller mold, a tenth microstructure corresponding to the shape of the ninth microstructure is pressed out on the surface of the molten third resin, and based on this, a fourth optical plate with a plurality of eleventh microstructures on its surface is manufactured, wherein the eleventh microstructure is defined by the tenth microstructure, and the fourth optical plate has the same thickness (DD) as the target optical plate (1).

[0021] The height or depth of the eleventh microstructure was measured to be Y4;

[0022] The value of k is determined based on the relation X4=k*Y4.

[0023] In some possible implementations, the material of the target optical plate (1) is selected from PMMA resin, MS resin or PC resin.

[0024] In some possible implementations, the first microstructure (301) is configured to extend along the circumferential direction (DR3) of the roller die (3), and the plurality of first microstructures (301) are arranged sequentially in the axial direction (DR4) of the roller die (3); or,

[0025] The first microstructure (301) is configured to extend along the axial direction (DR4) of the roller die (3), and the plurality of first microstructures (301) are arranged sequentially in the circumferential direction (DR3) of the roller die (3); or,

[0026] The plurality of first microstructures (301) are configured as island-shaped recesses or island-shaped protrusions spaced apart from each other on the peripheral surface (3a) of the roller mold (3).

[0027] Secondly, a method (300) for manufacturing a target optical plate (1) is proposed, comprising:

[0028] The roller mold (3) is designed according to the design method (200) as described in the first aspect;

[0029] Manufacturing the roller mold (3);

[0030] The target optical plate (1) is manufactured using the roller mold (3).

[0031] In some possible implementations, the manufacture of the target optical plate (1) using the roller mold (3) includes:

[0032] The resin (RE) is brought to a molten state;

[0033] The second microstructure (RE1) is pressed onto the surface (S1) of the molten resin (RE) by using the combination of the roller mold (3) and the pressure rollers (4, 5).

[0034] The resin (RE) to which the second microstructure (RE1) has been extruded is cooled, thereby solidifying the resin (RE);

[0035] A protective film (PF) is attached to the surface (S1) of the resin (RE) in the cured state where the second microstructure (RE1) is pressed.

[0036] The resin (RE) to which the protective film (PF) is attached is cut.

[0037] In some possible implementations, the manufacture of the target optical plate (1) using the roller mold (3) includes:

[0038] The target optical sheet (1) is manufactured using an optical sheet manufacturing apparatus (100) including the roller mold (3), wherein the optical sheet manufacturing apparatus (100) includes:

[0039] The first pressure roller (4) forms a first roller pair (RP1) with the roller mold (3). The first roller pair (RP1) is configured to allow molten resin (RE) to pass through a first space (SP1) between the first pressure roller (4) and the roller mold (3) and to extrude the resin (RE) at the first space (SP1) to press out the second microstructure (RE1) on the surface (S1) of the resin (RE).

[0040] Cooling rollers (6, 7, 8) are disposed on the downstream side of the roller mold (3) and are configured to cool the resin (RE) by contacting another surface (S2) of the resin (RE) to which the second microstructure (RE1) has been pressed out, wherein the other surface (S2) is the surface of the resin (RE) opposite to the second microstructure (RE1).

[0041] In some possible implementations, the optical sheet manufacturing apparatus (100) further includes:

[0042] The second pressure roller (5) is disposed on the side of the roller mold (3) opposite to the first pressure roller (4) and upstream of the cooling rollers (6, 7, 8), and forms a second roller pair (RP2) with the roller mold (3). The second roller pair (RP2) is configured to allow the resin (RE) drawn through the first roller pair (RP1) to pass through a second space (SP2) between the second pressure roller (5) and the roller mold (3), and to support the resin (RE) at the second space (SP2) to optimize the shape of the second microstructure (RE1).

[0043] In a second aspect, a target optical plate (1) is proposed, which is manufactured by the manufacturing method (300) as described in the second aspect.

[0044] In some possible implementations, the target optical plate (1) has a first main surface (1a) and a second main surface (1b) disposed opposite to each other in its thickness direction, and the plurality of target microstructures (101) are formed on the first main surface (1a).

[0045] In some possible implementations, the target microstructure (101) is configured as an elongated shape extending along a first direction (DR1), and the plurality of target microstructures (101) are arranged sequentially in a second direction (DR2) intersecting the first direction (DR1), the first main surface (1a) being defined by the first direction (DR1) and the second direction (DR2); or,

[0046] The plurality of target microstructures (101) are configured as island-shaped protrusions or island-shaped depressions spaced apart from each other on the first main surface (1a).

[0047] According to the roller mold design method provided in this application, the structural parameters of the corresponding roller mold, especially the dimensional parameters of the microstructure on the roller mold, can be quickly and accurately determined based on the material, thickness, microstructure period, and microstructure size of the target optical sheet, thereby helping to reduce the development cost of the optical sheet. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0049] Figure 1 This is a schematic diagram of the structure of the optical substrate manufacturing equipment provided in the embodiments of this application.

[0050] Figure 2 yes Figure 1 Enlarged schematic diagram of the first roller pair.

[0051] Figure 3 yes Figure 1 A side view of the roller mold when viewed from its radial direction.

[0052] Figure 4 yes Figure 1 A partial schematic diagram of the intermediate roller mold.

[0053] Figure 5 This is a partial schematic diagram of the optical plate provided in an embodiment of this application.

[0054] Figure 6 This is a partial schematic diagram of a roller mold provided in another embodiment of this application.

[0055] Figure 7 This is a partial schematic diagram of an optical plate provided in another embodiment of this application.

[0056] Figure 8 This is a partial schematic diagram of a roller mold provided in another embodiment of this application.

[0057] Figure 9 This is a partial schematic diagram of an optical plate provided in another embodiment of this application.

[0058] Figure 10 This is a side view of a roller mold provided in another embodiment of this application when viewed from its radial direction.

[0059] Figure 11 This is a partial schematic diagram of a roller mold provided in another embodiment of this application.

[0060] Figure 12 This is a partial schematic diagram of an optical plate provided in another embodiment of this application.

[0061] Figure 13 This is a partial schematic diagram of a roller mold provided in another embodiment of this application.

[0062] Figure 14 This is a partial schematic diagram of an optical plate provided in another embodiment of this application.

[0063] Figure 15 This is a schematic diagram illustrating the fitting of data from multiple experimental examples provided in an embodiment of this application.

[0064] Figure 16 This is a schematic diagram illustrating the fitting of data from multiple experimental examples provided in an embodiment of this application.

[0065] Figure 17 This is a schematic diagram illustrating the fitting of data from multiple experimental examples provided in an embodiment of this application.

[0066] Figure 18 This is a flowchart of the design method for the roller mold provided in the embodiments of this application.

[0067] Figure 19 This is a flowchart of the design method for the roller mold provided in the embodiments of this application.

[0068] Figure 20 This is a flowchart of the design method for the roller mold provided in the embodiments of this application.

[0069] Figure 21 This is a flowchart of the manufacturing method of the optical substrate provided in the embodiments of this application.

[0070] Figure 22 This is a flowchart of the manufacturing method of the optical substrate provided in the embodiments of this application.

[0071] Explanation of reference numerals in the attached figures:

[0072] 100 - Optical sheet manufacturing equipment;

[0073] 200-Design Methodology;

[0074] 300 - Manufacturing Method;

[0075] DR1 - First direction;

[0076] DR2 - Second Direction;

[0077] DR3 - Circumferential direction;

[0078] DR4 - Axial direction;

[0079] 1-Optical substrate, 101-Microstructure, 1a-First main surface, 1b-Second main surface;

[0080] 2-Extrusion die;

[0081] 3-Roller mold, 301-First microstructure, 3a-Peripheral surface;

[0082] 4-First pressure roller;

[0083] 5 - Second pressure roller;

[0084] 6, 7, 8 - Cooling rollers;

[0085] 9, 10, 11, 12, 13 - Conveyor rollers;

[0086] 14 - Protective film unwinding roller;

[0087] 15, 16 - Film application rollers;

[0088] RE - resin, RE1 - second microstructure, S1 - first surface, S2 - second surface;

[0089] PF - Protective film;

[0090] SP1 - First Space, SP2 - Second Space;

[0091] RP1 - First roller pair, RP2 - Second roller pair. Detailed Implementation

[0092] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It is understood that, without conflict, some technical means of the various embodiments described herein can be substituted for or combined with each other.

[0093] In the description of this application, the terms "first," "second," etc., are used only to distinguish the described objects and have no sequential or technical meaning. Therefore, objects specified with "first," "second," etc., may explicitly or implicitly include one or more of those objects, and, for example, the term "first element" itself does not imply the existence of a "second element," nor does the term "second element" itself imply the existence of a "first element." Furthermore, words such as "a" or "one" do not indicate a quantity limitation, but rather indicate the presence of at least one, while "multiple" indicates not less than two.

[0094] In the description of this application, the terms "comprising" or "having" indicate the presence of the said features, numbers, operations, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, elements, and / or combinations thereof.

[0095] In the description of this application, if there are terms such as “configured as” or “constructed as”, they are generally interchangeable with “having the ability to”, “designed to”, “used for” or “capable”, depending on the context.

[0096] In the description of this application, references to "one embodiment" or "some embodiments" mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0097] Before introducing the design method of the roller mold provided in the embodiments of this application, we will first introduce the optical sheet manufacturing equipment including such roller mold (hereinafter, sometimes simply referred to as equipment 100) and the inventor's related findings.

[0098] Please see Figure 1 , Figure 1A portion of an optical sheet manufacturing apparatus 100 is shown, including an extrusion die 2, a roller die 3, a first pressure roller 4, a second pressure roller 5, multiple cooling rollers 6, 7, 8, an unwinding roller, and two film-applying rollers 15, 16.

[0099] As another part of the optical sheet manufacturing equipment 100 (in Figure 1 (Not shown in the text) may include a screw extruder connected to the extrusion die 2 and a temperature control device coupled to the screw extruder, such as a twin-screw extruder or a single-screw extruder. During operation, granular solid resin RE is supplied to the screw extruder and travels forward under its drive. During this travel, the temperature control device controls the temperature of the resin RE within the screw extruder, thereby bringing the resin RE to a molten state. Since screw extruders and corresponding temperature control devices are well known to those skilled in the art, they will not be described in detail herein. Obviously, other means can also be used to bring the resin RE to a molten state.

[0100] The extrusion die 2 receives molten resin RE and supplies the molten resin RE to the roller die 3.

[0101] The roller mold 3 has a circumferential surface and a plurality of first microstructures 301 disposed on the circumferential surface 3a. The first microstructures 301 can be recesses into the circumferential surface or protrusions from the circumferential surface. In practice, the device 100 can use the roller mold 3 to press out second microstructures RE1 corresponding to the shape of the first microstructures 301 onto the surface of molten resin RE, and thereby manufacture an optical plate 1 with a surface having a plurality of microstructures 101, wherein the microstructures 101 of the optical plate 1 are defined by the second microstructures RE1. Figure 4 and Figure 5 As shown, when the first microstructure 301 is a depression, the second microstructure RE1 and the microstructure 101 of the optical substrate 1 are protrusions corresponding to the shape of the depression; as Figure 8 and Figure 9 As shown, when the first microstructure 301 is a protrusion, the second microstructure RE1 and the microstructure 101 of the optical plate 1 are depressions corresponding to the shape of the protrusion.

[0102] exist Figures 1 to 7 In the embodiments shown, the first microstructure 301 of the roller die 3 is configured as a recess extending along the circumferential direction DR3 of the roller die 3, and these first microstructures 301 are arranged sequentially parallel to each other in the axial direction DR4 of the roller die 3. More specifically, the first microstructure 301 is a recess extending in annular shape along the entire circumference of the roller die 3, and the cross-section of the recess can be arched or polygonal, for example, triangular or trapezoidal. Furthermore, in Figure 6In the illustrated embodiment, the individual first microstructures 301 are spaced apart on the axial direction DR4 of the roller die 3 for use in manufacturing, respectively. Figure 7 The optical plate 1 shown is... Figure 4 In the illustrated embodiment, each of the first microstructures 301 is continuously arranged in the axial direction DR4 of the roller die 3 for manufacturing such as Figure 5 The optical plate shown is 1.

[0103] exist Figure 8 In another embodiment shown, the first microstructures 301 of the roller die 3 are configured as protrusions extending in the circumferential direction DR3 of the roller die 3, and these first microstructures 301 are arranged parallel to each other in the axial direction DR4 of the roller die 3, which can be used to manufacture such as Figure 9 The optical plate 1 shown. More specifically, the first microstructure 301 is a protrusion extending in annular shape around the entire circumference of the roller mold 3. The cross-section of the protrusion can be arched or polygonal, for example, triangular or trapezoidal.

[0104] In other embodiments, such as Figure 10 As shown, the first microstructure 301 of the roller die 3 is constructed as an elongated recess extending along the axial direction DR4 of the roller die 3, and these first microstructures 301 are arranged continuously and parallel to each other in the circumferential direction DR3 of the roller die 3. Such a roller die 3 can also be used to manufacture, for example, Figure 5 The optical plate 1 shown. More specifically, in Figure 10 In this process, the first microstructure 301 extends along the entire length of the roller mold 3, from one end face to the other end face. Furthermore, it is consistent with... Figure 4 and Figure 6 The implementation examples are similar, Figure 10 The cross-section of the first microstructure 301 can be polygonal or arched.

[0105] also, Figure 10 The first microstructures 301 on the intermediate roller die 3 can also be arranged parallel to each other in the circumferential direction DR3 of the roller die 3 for manufacturing such as Figure 7 The optical plate shown is 1.

[0106] In some other embodiments, such as Figure 11 As shown, each of the first microstructures 301 of the roller die 3 is configured as an island-shaped recess spaced apart from each other on the peripheral surface 3a of the roller die 3. Such a roller die 3 can be used to manufacture, for example, Figure 12 The optical plate 1 shown. The island-shaped recess can be constructed into a pyramidal, prismal, truncated spherical, truncated conical, or other shapes. Furthermore, as... Figure 13As shown, each of the first microstructures 301 of the roller die 3 can also be constructed as island-shaped protrusions spaced apart from each other on the peripheral surface 3a of the roller die 3, in order to manufacture as... Figure 14 The optical plate 1 shown. The island-shaped protrusion can be constructed into a pyramidal, prismal, truncated spherical, truncated conical, or other shapes.

[0107] The first pressure roller 4 and the roller mold 3 form a first roller pair RP1. The first roller pair RP1 is configured to allow molten resin RE to pass through a first space SP1 between the first pressure roller 4 and the roller mold 3, and to extrude the resin RE at the first space SP1 to press out a second microstructure RE1 on one side surface of the resin RE, namely the first surface S1.

[0108] The second pressure roller 5 is disposed on the side of the roller mold 3 opposite to the first pressure roller 4, and the second pressure roller 5 and the roller mold 3 form a second roller pair RP2. This second roller pair RP2 is configured to allow the resin RE drawn through the first pressure roller pair 4 to pass through a second space SP2 between the second pressure roller 5 and the roller mold 3, and to support the resin RE at the second space SP2, thereby prolonging the contact time between the resin RE and the roller mold 3, thus optimizing the shape of the second microstructure RE1, thereby aiming to obtain a microstructure 101 of an ideal shape on the optical substrate 1. In other embodiments, the second pressure roller 5 may be omitted, or a third pressure roller with the same function as the second pressure roller 5 may be added.

[0109] Multiple cooling rollers 6, 7, and 8 are disposed downstream of the second roller pair RP2 and are configured to cool the resin RE to cure it by contacting the other side surface of the resin RE to which the second microstructure RE1 has been pressed out, namely the second surface S2. The second surface S2 is the surface of the resin RE opposite to the second microstructure RE1. It is understood that, compared to a scheme where the cooling rollers 6, 7, and 8 cool the resin RE by contacting the first surface S1 of the resin RE, cooling the resin RE by contacting the second surface S2 of the resin RE can prevent damage to the second microstructure RE1.

[0110] A protective film PF is wound on the protective film unwinding roller 14. During operation, the protective film PF is unwound so that it is supplied between the two laminating rollers 15 and 16. Furthermore, the resin RE cooled by the cooling rollers 6, 7, and 8 is also supplied between the two laminating rollers 15 and 16. Specifically, the protective film PF is supplied between the upper laminating roller 15 and the first surface S1 of the resin RE where the second microstructure RE1 is pressed. Based on this, the protective film PF is adhered to the first surface S1 of the resin RE where the second microstructure RE1 is pressed, thereby protecting the first surface S1, particularly the second microstructure RE1 on the first surface S1.

[0111] The inventor used Figure 1 The device 100 shown and its connection to Figure 1 When similar optical sheet manufacturing equipment is used to manufacture optical sheet 1, it was found that, with the material, thickness DD, and microstructure periodic pitch of optical sheet 1 remaining constant, there is a mathematical relationship between the height or depth Y of microstructure 101 on optical sheet 1 and the depth or height X of the first microstructure 301: X = k * Y + a. That is, the values ​​of k and a in the relationship X = k * Y + a are determined by the material, thickness DD, and periodic pitch of microstructure 101 on optical sheet 1. With the material, thickness DD, and microstructure periodic pitch of optical sheet 1 remaining constant, if the depth or height X of the first microstructure 301 is changed, the height or depth Y of the microstructure 101 on the resulting optical sheet 1 will change accordingly according to the mathematical relationship X = k * Y + a.

[0112] Next, the inventors will use several experimental examples to illustrate the above findings.

[0113] First, the inventor selected products with... Figure 4 The four roller molds 3, with different depths of the first microstructure 301 (which is recessed) shown in the diagram, produced four optical substrates 1. All four optical substrates 1 were made of PMMA, had a thickness of 2.0 mm, and had a periodic pitch of 200 μm for the microstructure 101 on each of the four optical substrates 1. Since the techniques for controlling the thickness and periodic pitch of the fabricated optical substrates 1 are well known, they will not be described in detail here.

[0114] The inventors obtained the following Table 1 by testing the height Y (average value) of the microstructure 101 (protrusion) on the four optical plates 1.

[0115] Table 1:

[0116]

[0117] Perform a linear fit on the data in Table 1, such as... Figure 15 As shown. From this Figure 15 We can obtain X = 2.72 * Y - 24, that is, k = 2.72, a = -24. That is, for the optical plate 1 made of PMMA, with a thickness of 2.0 mm and a microstructure period pitch of 200 μm, there is a mathematical relationship between the height Y (average value) of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3, which is X = 2.72 * Y - 24.

[0118] Furthermore, the inventors also selected products with... Figure 4The four roller molds 3 shown in the diagram, but with different depths of the first microstructure 301 (which is recessed), produced four other optical substrates 1. All four optical substrates 1 were made of MS resin, with a thickness of 1.5 mm, and the periodic pitch of the microstructure 101 on each of the four optical substrates 1 was 155 μm. The inventors obtained the following Table 2 by testing the height Y of the microstructure 101 (which is raised) on these four optical substrates 1.

[0119] Table 2:

[0120]

[0121] Perform a linear fit on the data in Table 2, such as... Figure 16 As shown. From this Figure 16 We can obtain X = 2.29 * Y + 33, that is, k = 2.29, a = 33. That is, for the optical plate 1 made of PMMA, with a thickness of 1.5 mm and a microstructure period pitch of 155 μm, there is a mathematical relationship between the height Y (average value) of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3, which is X = 2.29 * Y + 33.

[0122] In addition, the inventors also selected products with... Figure 4 The three roller dies shown, with different depths of the first microstructure 301 (which is recessed), produced three other optical substrates 1. All three optical substrates 1 were made of PMMA, with a thickness of 0.7 mm, and the pitch of the microstructure 101 on each of the three optical substrates 1 was 30 μm. The inventors obtained the following Table 3 by testing the height Y of the microstructure 101 (which is raised) on these four optical substrates 1.

[0123] Table 3:

[0124]

[0125] Perform a linear fit on the data in Table 3, such as... Figure 17 As shown. From this Figure 17 We can obtain X = 2.24 * Y - 6.5, that is, k = 2.24, a = -6.5. That is, for the optical plate 1 made of PMMA, with a thickness of 0.7 mm and a microstructure period pitch of 30 μm, there is a mathematical relationship between the height Y (average value) of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3, which is X = 2.24 * Y - 6.5.

[0126] In addition, the inventors also selected products with... Figure 4The configuration shown, but with different depths of the first microstructure 301 (recessed), was used to manufacture twelve other optical substrates 1. These twelve optical substrates 1 can be divided into four groups of three. Furthermore, the three optical substrates 1 in each group use the same material and have the same thickness and the same microstructure period pitch (see table below). The inventors obtained the following Table 4 by testing the height Y of the microstructure 101 on these four groups of twelve optical substrates 1.

[0127] Table 4:

[0128]

[0129] As can be seen from Table 4, when the thickness DD of the optical substrate 1 is less than 0.7 mm, especially not greater than 0.6 mm, under the condition that the material, thickness DD, and microstructure periodic pitch of the optical substrate 1 remain unchanged, a=0 in the aforementioned relationship, and the height Y of the microstructure 101 on the optical substrate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the mathematical relationship X=k*Y. Specifically:

[0130] For the optical plate 1 made of PMMA, with a thickness DD of 0.4 mm and a microstructure period pitch of 30 μm, the height Y of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the relationship X=0.87*Y.

[0131] For the optical plate 1 made of PMMA, with a thickness DD of 0.5 mm and a microstructure period pitch of 30 μm, the height Y of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the relationship X=0.83*Y.

[0132] For the optical plate 1 made of PMMA, with a thickness DD of 0.55 mm and a microstructure period pitch of 30 μm, the height Y of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the relationship X=0.82*Y.

[0133] For the optical plate 1 made of PMMA, with a thickness DD of 0.6 mm and a microstructure period pitch of 30 μm, the height Y of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the relationship X=0.79*Y.

[0134] As can be clearly seen from Tables 1 to 4 above, when using Figure 4 and Figure 6When the roller mold 3 of this configuration is used to manufacture the optical plate 1, the height Y of the microstructure 101 on the optical plate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the mathematical relationship X=k*Y+a. Furthermore, given that the material, thickness DD, and periodic pitch of the microstructure 101 on the optical plate 1 are constant, the values ​​of k and a in the aforementioned relationship are constant. Therefore, when it is desired to manufacture an optical plate 1 with a microstructure 101 of a target height, the target height Y of the microstructure 101 can be substituted into the relationship X=k*Y+a to determine the target depth X of the first microstructure 301 on the matching roller mold 3. Then, the roller mold 3 can be designed and manufactured according to the determined target depth X, and the manufactured roller mold 3 can easily be used to manufacture the optical plate 1 with the microstructure 101 of the aforementioned target height.

[0135] It is also necessary to point out that although the data in Tables 1 to 4 above are all directly from... Figure 4 and Figure 6 This type of roller mold 3, however, the inventors discovered that when using... Figure 8 , Figures 10 to 11 When the roller mold 3 shown is used to manufacture the optical substrate 1, the depth or height X of the first microstructure 301 on the roller mold 3 and the height or depth Y of the microstructure 101 on the manufactured optical substrate 1 also satisfy the relationship X=k*Y+a, and when the thickness of the optical substrate 1 is less than 0.7mm, especially not greater than 0.6mm, a=0. In addition, when the manufactured optical substrate 1 is not PMMA resin RE or MS resin RE but other materials, such as PC resin RE, the relationship X=k*Y+a is also satisfied.

[0136] Based on the above explanation and Figures 1 to 14 This application proposes a design method 200 for a roller mold 3. The roller mold 3 to be designed has a peripheral surface 3a and a plurality of first microstructures 301 disposed on the peripheral surface 3a. These are used to press out second microstructures RE1 corresponding to the shape of the first microstructures 301 onto the surface of molten resin RE. Based on this, a target optical plate 1 with a plurality of target microstructures 101 on its surface is manufactured. One of the first microstructures 301 and the second microstructure RE1 is a protrusion, and the other is a depression. The target microstructures 101 are defined by the second microstructures RE1. This design method 200 utilizes the inventor's above-mentioned discovery. Figure 18 As shown, the design method 200 includes:

[0137] S181, Determine the values ​​of k and a based on the material of the target optical plate 1, the thickness of the target optical plate 1, and the period of the target microstructure 101;

[0138] S182, based on the relation X1=k*Y1+a, determine the depth or height X1 of the first microstructure 301, where Y1 is the height or depth of the target microstructure 101.

[0139] In some embodiments, such as Figure 19 As shown, the aforementioned step S182 may specifically include:

[0140] S191, a second resin corresponding to the material of the target optical plate 1 is provided, a second roller mold having a second peripheral surface and a plurality of third microstructures disposed on the second peripheral surface, and a third roller mold having a third peripheral surface and a plurality of fourth microstructures disposed on the third peripheral surface, wherein the third microstructure, the fourth microstructure and the first microstructure 301 are all protrusions or all are recesses, the period of the third microstructure and the period of the fourth microstructure correspond to the period pitch of the target microstructure 101, the depth or height of the third microstructure is X2, the depth or height of the fourth microstructure is X3, and X2≠X3;

[0141] S192, using a second roller mold to press out a fifth microstructure corresponding to the shape of the third microstructure on the surface of the molten second resin, and based on this, a second optical plate with a plurality of sixth microstructures on its surface is manufactured, wherein the sixth microstructure is defined by the fifth microstructure, and the thickness DD of the second optical plate is the same as that of the target optical plate 1.

[0142] S193, using a third roller mold to press out a seventh microstructure corresponding to the shape of the fourth microstructure on the surface of the molten second resin, and based on this, a third optical plate with multiple eighth microstructures on its surface is manufactured, wherein the eighth microstructure is defined by the seventh microstructure, and the thickness DD of the third optical plate is the same as that of the target optical plate 1.

[0143] S194, the height or depth of the seventh microstructure is measured as Y2, and the height or depth of the eighth microstructure is measured as Y3;

[0144] S195. Based on the relationships X2=k*Y2+a and X3=k*Y3+a, determine the values ​​of k and a.

[0145] As mentioned above, the inventors discovered that when using the roller mold 3 to manufacture the optical substrate 1, the height Y of the microstructure 101 on the resulting optical substrate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the mathematical relationship X=k*Y+a. Furthermore, given a fixed material, thickness, and periodic pitch of the microstructure 101 on the optical substrate 1, the values ​​of k and a in this relationship are constant. Therefore, if the values ​​of k and a in the relationship are known, the depth or height X1 of the first microstructure 301 on the roller mold 3 used to manufacture the target optical substrate 1 can be determined according to the relationship X1=k*Y1+a, based on the height or depth Y1 of the target microstructure 101 on the target optical substrate 1 (which is a known quantity). Based on this idea, this application embodiment provides a second roller mold and a third roller mold corresponding to the period pitch of the target microstructure on the target optical plate 1 using known techniques (e.g., designing the period of the third microstructure on the second roller mold to correspond to the period of the target microstructure 101 on the target optical plate 1, and also designing the period of the fourth microstructure on the third roller mold to correspond to the period of the target microstructure 101 on the target optical plate 1). It also provides a second resin corresponding to the material of the target optical plate. Furthermore, the third microstructure on the second roller mold and the fourth microstructure on the third roller mold are designed to be different in terms of depth or height. Then, using known techniques (e.g., by adjusting...),... The gap between the roller mold and the first pressure roller 4 and the second pressure roller 5 is used to manufacture the second and third optical plates with the same thickness (and the same microstructure period pitch) as the target optical plate 1. Then, the height or depth of the sixth microstructure on the second optical plate is measured as Y2 and the height or depth of the eighth microstructure on the third optical plate is measured as Y3. Then, combined with the known depth or height of the third microstructure on the second roller mold as X2 and the known depth or height of the fourth microstructure on the third roller mold as X3, the values ​​of k and a can be calculated according to the system of equations consisting of the relationship X2=k*Y2+a and X3=k*Y3+a.

[0146] As mentioned above, when the thickness of the optical substrate 1 is less than 0.7 mm, especially not greater than 0.6 mm, the value of 'a' in the formula X=k*Y+a is 0. That is, the height Y of the microstructure 101 on the optical substrate 1 and the depth X of the first microstructure 301 on the roller mold 3 satisfy the mathematical relationship X=k*Y. Therefore, in this design method 200, if the thickness of the target optical substrate 1 is less than 0.7 mm, especially not greater than 0.6 mm, the value of 'a' in X1=k*Y1+a can be directly determined to be 0, and the value of 'k' in X1=k*Y1 can be further determined through relevant means. Specifically, as... Figure 20 As shown, the aforementioned step S182 may include the following design:

[0147] S201, if the thickness of the target optical plate 1 is less than 0.7mm, especially not greater than 0.6mm, then the value of a in X1=k*Y1+a is determined to be 0;

[0148] S202, a third resin corresponding to the material of the target optical plate 1, a fourth roller mold having a fourth peripheral surface and a plurality of ninth microstructures disposed on the fourth peripheral surface are provided, wherein the ninth microstructure and the first microstructure 301 are both protrusions or both are recesses, the period of the ninth microstructure corresponds to the period of the target microstructure 101, and the depth or height of the ninth microstructure is X4.

[0149] S203, using the fourth roller mold to press out the tenth microstructure corresponding to the shape of the ninth microstructure on the surface of the molten third resin, and based on this, a fourth optical plate with multiple eleventh microstructures on the surface is manufactured, wherein the eleventh microstructure is defined by the tenth microstructure, and the thickness DD of the fourth optical plate corresponds to that of the target optical plate 1.

[0150] S204, the height or depth of the eleventh microstructure is measured as Y4;

[0151] S205, based on the relation X4=k*Y4, determine the value of k.

[0152] Thus, we know the values ​​of a and k in X1=k*Y1+a.

[0153] Please see Figure 21 This application embodiment also provides a method 300 for manufacturing an optical substrate 1, the method 300 including:

[0154] S211, Design the roller mold 3 according to the aforementioned design method 200;

[0155] S212, Manufacturing the designed roller mold 3;

[0156] S213, use the roller mold 3 manufactured in step S212 to manufacture the optical plate 1 (target optical plate).

[0157] Based on the preceding text Figure 1 The description, in some embodiments, such as Figure 22 As shown, step S213 can utilize Figure 1 This optical substrate manufacturing equipment 100 is used, and specifically may include:

[0158] S221, which makes the resin RE molten;

[0159] S222, by using the cooperation of roller mold 3 with first pressure roller 4 and second pressure roller 5, the second microstructure RE1 is pressed out on the first surface S1 of the molten resin RE;

[0160] S223, the resin RE that has been pressed out with the second microstructure RE1 is cooled, thereby making the resin RE into a solidified state;

[0161] S224, A protective film PF is attached to the first surface S1 of the cured resin RE that corresponds to the second microstructure RE1.

[0162] S225, the resin RE with the protective film PF attached is cut to obtain multiple optical plates 1.

[0163] Based on the above introduction and review Figure 5 , Figure 7 , Figure 8 , Figure 12 and Figure 14 This application embodiment also provides an optical substrate 1, which is manufactured by the manufacturing method 300 described above. The optical substrate 1 has a first main surface 1a and a second main surface 1b disposed opposite to each other in its thickness direction, and a plurality of microstructures 101 formed by a roller mold 3 are formed on the first main surface 1a.

[0164] exist Figure 5 , Figure 7 and Figure 8 In this optical substrate 1, the microstructures 101 are elongated strips extending along a first direction DR1, and multiple microstructures 101 are arranged sequentially along a second direction DR2 perpendicular to the first direction DR1. The first main surface 1a is defined by the first direction DR1 and the second direction DR2, that is, the first main surface 1a extends along the mutually perpendicular first direction DR1 and second direction DR2. This optical substrate 1 can be made, for example, into a light guide plate or a light diffuser plate.

[0165] exist Figure 12 In the optical plate 1, the microstructure 101 is constructed as island-shaped protrusions spaced apart from each other on the first main surface 1a.

[0166] exist Figure 14 In the optical plate 1, the microstructure 101 is constructed as island-shaped recesses spaced apart from each other on the first main surface 1a.

Claims

1. A method for designing a roller mold, the roller mold having a peripheral surface and a plurality of first microstructures disposed on the peripheral surface, for pressing out second microstructures corresponding to the shapes of the first microstructures onto the surface of molten resin, and for manufacturing a target optical plate having a plurality of target microstructures on its surface based thereon, wherein, One of the first microstructure and the second microstructure is a protrusion, and the other is a depression, wherein the target microstructure is defined by the second microstructure, characterized in that the design method includes: The values ​​of k and a are determined based on the material of the target optical plate, the thickness of the target optical plate, and the period of the target microstructure. Based on the relation X1=k*Y1+ a, the depth or height X1 of the first microstructure is determined, where Y1 is the height or depth of the target microstructure. The determination of the values ​​of k and a based on the material of the target optical plate, the thickness of the target optical plate, and the period of the target microstructure includes: A second resin corresponding to the material of the target optical plate is provided, a second roller mold having a second peripheral surface and a plurality of third microstructures disposed on the second peripheral surface, and a third roller mold having a third peripheral surface and a plurality of fourth microstructures disposed on the third peripheral surface, wherein the third microstructure, the fourth microstructure and the first microstructure are all protrusions or all are recesses, and the period of the third microstructure and the period of the fourth microstructure correspond to the period of the target microstructure, respectively. The depth or height of the third microstructure is X2, the depth or height of the fourth microstructure is X3, and X2 ≠ X3. Using the second roller mold, a fifth microstructure corresponding to the shape of the third microstructure is pressed onto the surface of the molten second resin, and based on this, a second optical plate with a plurality of sixth microstructures on its surface is manufactured, wherein the sixth microstructure is defined by the fifth microstructure, and the second optical plate has the same thickness as the target optical plate; Using the third roller mold, a seventh microstructure corresponding to the shape of the fourth microstructure is pressed onto the surface of the molten second resin, and based on this, a third optical plate with a plurality of eighth microstructures on its surface is manufactured, wherein the eighth microstructure is defined by the seventh microstructure, and the third optical plate has the same thickness as the target optical plate; The height or depth of the sixth microstructure is measured as Y2, and the height or depth of the eighth microstructure is measured as Y3; Based on the relationships X2=k*Y2+a and X3=k*Y3+a, determine the values ​​of k and a.

2. The design method according to claim 1, characterized in that, The material of the target optical plate is selected from PMMA resin, MS resin or PC resin.

3. The design method according to claim 1, characterized in that, The first microstructure is configured to extend along the circumferential direction of the roller die, and the plurality of first microstructures are arranged sequentially in the axial direction of the roller die; or, The first microstructure is configured to extend along the axial direction of the roller die, and the plurality of first microstructures are arranged sequentially in the circumferential direction of the roller die; or, The plurality of first microstructures are configured as island-shaped recesses or island-shaped protrusions spaced apart from each other on the circumferential surface of the roller die.

4. A method for manufacturing a target optical plate, characterized in that, include: Design the roller mold according to the design method as described in any one of claims 1 to 3; Manufacturing the roller mold; The target optical plate is manufactured using the roller mold.

5. The manufacturing method according to claim 4, characterized in that, The process of manufacturing the target optical plate using the roller mold includes: Make the resin into a molten state; The second microstructure is pressed onto the surface of the molten resin by using the combination of the roller mold and the pressure roller; The resin that has been extruded into the second microstructure is cooled to solidify the resin. A protective film is attached to the surface of the resin in the cured state where the second microstructure is pressed; The resin to which the protective film is attached is cut.

6. The manufacturing method according to claim 4 or 5, characterized in that, The process of manufacturing the target optical plate using the roller mold includes: The target optical substrate is manufactured using an optical substrate manufacturing apparatus including the roller mold, wherein the optical substrate manufacturing apparatus includes: A first pressure roller forms a first roller pair with the roller mold. The first roller pair is configured to allow molten resin to pass through a first space between the first pressure roller and the roller mold, and to extrude the resin at the first space to press out the second microstructure on the surface of the resin. A cooling roller, disposed on the downstream side of the roller die, is configured to cool the resin by contacting another surface of the resin from which the second microstructure has been pressed out, wherein the other surface is the surface of the resin opposite to the second microstructure.

7. The manufacturing method according to claim 6, characterized in that, The optical substrate manufacturing equipment also includes: The second pressure roller is disposed on the side of the roller die opposite to the first pressure roller and upstream of the cooling roller, and forms a second roller pair with the roller die. The second roller pair is configured to allow the resin drawn through the first pressure roller pair to pass through a second space between the second pressure roller and the roller die, and to support the resin in the second space to optimize the shape of the second microstructure.

8. A target optical plate, characterized in that, The target optical plate is manufactured by the manufacturing method as described in any one of claims 4 to 7.

9. The target optical substrate according to claim 8, characterized in that, The target optical plate has a first main surface and a second main surface disposed opposite to each other in its thickness direction, and the plurality of target microstructures are formed on the first main surface.

10. The target optical plate according to claim 9, characterized in that, The target microstructure is constructed as an elongated shape extending along a first direction, and the plurality of target microstructures are arranged sequentially in a second direction intersecting the first direction, the first main surface being defined by the first direction and the second direction; or, The plurality of target microstructures are configured as island-shaped protrusions or island-shaped depressions spaced apart from each other on the first main surface.

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