TW201302464A - Light guide plate with protective film - Google Patents

Abstract

The present invention provides the manufacturing method of light guide plate with protective film, which includes the following steps: continuously extruding the resin in a heated and melted state from a mold nozzle to produce the continuous resin sheet as a sheet fabrication step; next, employing the forming roller having its periphery surface formed with transfer mold to transfer the transfer mold onto the surface of the continuous resin sheet, and further fabricating the light guide plate formed with the surfaces of convex portions corresponding to the concave portions formed on the transfer mold as a transfer step; then, laminating the protective film with tensile elastic modulus above 250 N/mm2 onto the surface of the light guide plate formed with the protrusion as a lamination step; and, cutting the light guide plate laminated with the protective film as a cutting step.

Description

Method for manufacturing light guide plate with protective film

The present invention relates to a method of manufacturing a light guide plate with a protective film, a light guide plate with a protective film, and a protective film for the light guide plate.

A light guide plate with a protective film in which a protective film is bonded to the surface of an acrylic resin sheet used as a light guide plate is known (for example, see Patent Document 1). The surface of the acrylic resin sheet is a flat surface.

Patent Document 1: Japanese Patent Laid-Open No. Hei 8-170056

In recent years, a light guide plate (so-called shape light guide plate) having a surface on which a convex portion is formed has been attracting attention. The inventors of the present invention have studied a technique of bonding a protective film to a surface on which a convex portion of a light guide plate is formed. However, it has been clarified that when the protective film is bonded to the light guide plate and is cut to a predetermined size depending on the characteristics of the protective film, the end portion of the protective film may be peeled off from the light guide plate. This problem is not caused when the surface of the light guide plate is flat, but is a problem that occurs when a convex portion is formed on the surface of the light guide plate.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method of manufacturing a light guide plate with a protective film excellent in adhesion characteristics between a surface on which a convex portion of a light guide plate is formed and a protective film, and a guide film with a protective film A light plate and a protective film for the light guide plate.

In order to solve the above problems, a method of manufacturing a light guide plate with a protective film according to a technical aspect of the present invention includes the following steps: a sheet manufacturing step of continuously extruding a resin in a heated molten state from a die. And a continuous resin sheet; a transfer step of transferring the transfer mold onto the surface of the continuous resin sheet by using a shaping roll having a peripheral surface on which the transfer mold is formed, thereby producing and forming a light guide plate on a surface of the convex portion corresponding to the concave portion on the transfer mold; and a bonding step of bonding a protective film having a tensile modulus of 250 N/mm ² or more to the light guide plate to form the convex portion The surface of the portion; and a cutting step of cutting the light guide plate to which the protective film is bonded.

In the case of using a light guide plate having a surface on which a convex portion is formed, for a protective film having a tensile modulus of elasticity of less than 250 N/mm ² , when the light guide plate to which the protective film is attached is cut, there is a protective film The end portion tends to be peeled off from the light guide plate. On the other hand, in the protective film having a tensile modulus of elasticity of less than 250 N/mm ² , even if the light guide plate to which the protective film is bonded is cut, the end portion of the protective film can be prevented from peeling off from the light guide plate. Therefore, it is possible to obtain a light guide plate with a protective film which is excellent in adhesion characteristics between the surface on which the convex portion of the light guide plate is formed and the protective film.

A light guide plate with a protective film according to a technical aspect of the present invention is produced by using the above-described method for producing a light guide plate with a protective film. A light guide plate with a protective film according to another aspect of the present invention includes: a light guide plate having a surface on which a convex portion is formed; and a protective film attached to the surface, wherein the protective film has a tensile elastic modulus of 250 N /mm ² or more.

The protective film in one of the technical contents of the present invention is used in the above-mentioned light guide plate with a protective film.

According to the present invention, it is possible to provide a light guide plate with a protective film which is excellent in adhesion characteristics between a surface on which a convex portion of a light guide plate is formed and a protective film. A method, a light guide plate with a protective film, and a protective film for the light guide plate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent components, and the repeated description is omitted.

(Manufacturing device for light guide plate with protective film)

Fig. 1 is a schematic configuration view showing a manufacturing apparatus of a light guide plate with a protective film according to an embodiment. The apparatus 100 for manufacturing a light guide plate with a protective film shown in FIG. 1 can be used for manufacturing the light guide plate with a protective film of this embodiment. A manufacturing apparatus 100 for a light guide plate with a protective film includes a light guide plate manufacturing apparatus 50, a protective film bonding apparatus 70, and a cutting apparatus 80.

The light guide plate manufacturing apparatus 50 includes a die 51 that continuously extrudes a resin in a heated molten state to obtain a continuous resin sheet 60, and a continuous resin sheet 60 extruded from the die mouth 51 from both sides in the thickness direction. The first pressing roller 52A and the second pressing roller 52B are pressed. The manufacturing apparatus 50 of the light guide plate may also be provided with a pre-pressing roller 52D in the preceding stage of the first pressing roller 52A as needed. The pre-pressing roller 52D has the same configuration as the first pressing roller 52A. The pre-pressing roller 52D sandwiches the continuous resin sheet 60 between the pre-pressing roller 52D and the first pressing roller 52A and presses it. The light guide plate manufacturing apparatus 50 includes a resin inlet 57 for inserting a resin as a raw material, and an extruder 58 for extruding a resin placed in the resin inlet 57.

The first pressing roller 52A and the second pressing roller 52B are configured to be rotatable about mutually parallel rotation axes. The first pressing roller 52A and the second pressing roller 52B are disposed apart from each other in the thickness direction of the continuous resin sheet 60, and both sides The interval between the circumferential surfaces can be set according to the thickness of the continuous resin sheet 60. As shown in FIG. 3, a transfer mold 53 corresponding to the uneven shape transferred onto the continuous resin sheet 60 is formed on the circumferential surface of the second pressing roll 52B. Details will be described later. The second pressing roller 52B corresponds to a shaping roller. The second pressing roller 52B provided with the transfer mold 53 may also be referred to as a transfer roller. Thereby, the light guide plate 30 can be manufactured.

The protective film bonding apparatus 70 includes a first pressing roller 72A and a second pressing roller 72B for protecting the light guiding plate 30 supplied from the manufacturing apparatus 50 of the light guiding plate and bonding on both sides of the light guiding plate 30. The film 40 and the protective film 42 are pressed from both sides in the thickness direction; and the protective film roll 72C and the protective film roll 72D are wound around the protective film 40 and the protective film 42, respectively. The protective film 40 is supplied from the protective film roll 72C to the first squeeze roll 72A. The protective film 42 is supplied from the protective film roll 72D to the second squeeze roll 72B. The protective film is also referred to as a masking film. The protective film 42 may not be attached to the light guide plate 30. In this case, the protective film roll 72D is not required.

The cutting device 80 cuts the light guide plate 30 to which the protective films 40 and 42 are supplied, which are supplied from the bonding device 70 of the protective film, into a predetermined size. Thereby, the light guide plate 90 with a protective film can be manufactured.

(light guide plate)

Fig. 2 is a perspective view schematically showing the configuration of a light guide plate. FIG. 2 shows a portion of the light guide plate 30. The light guide plate 30 can be used as a light guide plate mounted on a surface light source device (for example, a backlight) of a transmissive image display device (for example, a liquid crystal display). As the surface light source device, a light source such as an LED disposed on the side surface 33 of the light guide plate 30 and a side surface 33 of the self-light guide plate 30 can be cited. The incident light is emitted to the edge-illuminated surface light source device or the like on the front side.

Normally, the back surface 32 of the light guide plate 30 (the surface opposite to the surface 31) is subjected to reflection processing for diffusing and reflecting light incident from the side surface 33. For printing by the reflective processing method, inkjet printing is also included in addition to silk printing. Alternatively, as a method of performing the reflection processing, a method of imparting point-like irregularities by laser irradiation without using printing may be mentioned.

The surface 31 of the light guide plate 30 is formed with a plurality of convex portions 35 extending in the first direction (X-axis direction) and arranged side by side in the second direction (Y-axis direction) orthogonal to the first direction. The uneven shape formed on the surface 31 and having the convex portion 35 is formed by a transfer step which will be described later.

The light guide plate 30 is formed of, for example, a translucent resin. The refractive index of the light transmissive resin is usually from 1.49 to 1.59. A thermoplastic resin which is in a molten state by heating can also be used as the light-transmitting resin used in the light guide plate 30. For example, a methacrylic resin (acrylic resin), a styrene resin, a carbonate resin, a cyclic olefin resin, and an MS resin (copolymer of acrylic acid and styrene) can also be used. The methacrylic resin may, for example, be a copolymer of methyl methacrylate and methyl acrylate.

A thermosetting resin which is cured by heating can also be used as the light-transmitting resin used in the light guide plate 30. An additive such as a light diffusing agent, an ultraviolet absorber, a heat stabilizer, or an antistatic agent may be added to the light transmissive resin used in the light guide plate 30.

(transfer mode)

Figure 3 is a view schematically showing a concave portion formed in a transfer mold and formed on the guide A cross-sectional view of a convex portion of a light panel. FIG. 3 shows a portion of the transfer mold 53 and the light guide plate 30. A plurality of concave portions 53a provided on the surface of the second pressing roller 52B (forming roller) are formed on the transfer mold 53. The plurality of concave portions 53a correspond to the plurality of convex portions 35. For example, the recess 53a is a groove continuously formed in the circumferential direction of the second pressing roller 52B (formed roller). The pitch P between the plurality of concave portions 53a is usually 30 μm or more, and preferably 50 μm or more. The pitch P is, for example, 30 μm to 800 μm. The depth D of the concave portion 53a is, for example, 30 μm to 500 μm. The pitch P refers to the distance between the adjacent concave portions 53a between the centers of the Y-axis directions (bottoms of each other). The depth D of the recess 53a means the distance from the opening surface of the recess 53a to the bottom of the recess 53a.

The cross-sectional shape of the concave portion 53a of the transfer mold 53 can be a semicircular shape, a semi-elliptical shape or the like. The cross-sectional shape of the concave portion 53a may be a V-shaped shape having an acute corner portion corresponding to the 稜鏡 shape.

As a method of producing the transfer mold 53, for example, the following method can be mentioned. First, the surface of a metal roll made of stainless steel, steel, or the like is subjected to a plating treatment such as chrome plating, copper plating, nickel plating, or nickel-phosphorus plating. Then, the shape is processed by performing a removal process, a laser process, or a chemical etching using a diamond turning tool or a metal grinder on the plated surface. However, the method of producing the transfer mold 53 is not particularly limited to the above method.

On the surface of the transfer roller, after the transfer mold 53 is formed, for example, plating such as chrome plating, copper plating, nickel plating, or nickel-phosphorus plating may be performed at a level that does not impair the accuracy of the surface shape.

(Light guide plate with protective film)

Fig. 4 is a cross-sectional view showing a light guide plate with a protective film in the embodiment. Figure 4 shows A part of the light guide plate 90 with the protective film is provided. The light guide plate 90 with a protective film shown in FIG. 4 includes a light guide plate 30 having a surface 31 on which the convex portion 35 is formed, and a protective film 40 bonded to the surface 31 on which the convex portion 35 is formed. In the light guide plate 90 with a protective film, and between the protective film 40 and the light guide plate 30, a gap is formed between the adjacent convex portions 35. The light guide plate 90 with the protective film may also include a protective film 42 attached to the back surface 32 of the light guide plate 30.

The protective film 40 and the protective film 42 include, for example, a base material and an adhesive layer formed on the base material, and the adhesive layer is disposed between the base material and the light guide plate 30. The protective film 40 protects the surface 31 of the light guide plate 30 and is peeled off when the light guide plate 30 is used. The protective film 42 protects the back surface 32 of the light guide plate 30 and is peeled off when the light guide plate 30 is used. The base material of the protective film 40 is made of, for example, a polymer such as polypropylene. The protective film 42 may have the same configuration as the protective film 40, or may have a different configuration.

The peeling strength between the light guide plate 30 and the protective film 40 after the protective film 40 is bonded to the light guide plate 30 heated to 40 ° C may be 0.1 to 0.8 N/25 mm. Similarly, the peeling strength between the light guide plate 30 and the protective film 40 after the protective film 40 is bonded to the light guide plate 30 heated to 70 ° C may be 0.1 to 0.8 N/25 mm.

The peel strength was prepared on the basis of JIS Z0237, and a sample having a width of 25 mm was prepared, and the measured value was peeled off in the 180° direction at a tensile speed of 300 mm/min using an auto graph.

The protective film 40 has a tensile elastic modulus of 250 N/mm ² or more, may be 450 N/mm ² or more, and may be 1000 N/mm ² or less.

The tensile modulus of elasticity is a value measured by a load of 1 kN based on JIS K7161.

(Manufacturing method of light guide plate with protective film)

Fig. 5 is a flow chart showing the procedure of a method of manufacturing a light guide plate with a protective film in the embodiment. The method for producing a light guide plate with a protective film according to the present embodiment can be carried out, for example, by using the light guide plate manufacturing apparatus 100 with a protective film shown in Fig. 1 . As shown in FIG. 1 and FIG. 5, the method for producing a light guide plate with a protective film according to the present embodiment includes a sheet manufacturing step (S1) in which a resin in a heated and molten state is continuously extruded from a die 51 to be formed. It is a continuous resin sheet 60; a transfer step (S2) using a second squeeze roll 52B (formed roll) having a peripheral surface on which the transfer mold 53 is formed, and transferring the transfer mold 53 to a continuous resin The surface of the sheet 60, thereby fabricating the light guide plate 30 having the surface 31 on which the convex portion 35 is formed, the convex portion 35 corresponding to the concave portion 53a formed on the transfer mold 53, and the fitting step (S3), which is to pull a protective film 40 having a tensile modulus of 250 N/mm ² or more is attached to the surface 31 of the light guide plate 30 on which the convex portion 35 is formed; and a cutting step (S4) for bonding the protective film 40 The light plate 30 is cut.

(sheet manufacturing step)

In the sheet manufacturing step, the resin is continuously extruded from the die 51 in a heated and molten state, and a continuous resin sheet 60 is produced. The resin is a thermoplastic resin which is in a molten state by heating.

As the die 51 in which the resin is continuously extruded in a heated and molten state, for example, a metal T-die or the like which is the same as the die used in the usual extrusion molding method can be used. In order to extrude the resin from the die 51 in a heated and molten state, the extruder 58 is used in the same manner as the usual extrusion molding. The extruder 58 can be a single shaft extruder or a twin shaft extruder. The resin is heated in the extruder 58 and sent in a molten state. To the nozzle 51 and extruded. The resin extruded from the die 51 is extruded in a continuous sheet form to form a continuous resin sheet 60. The thickness of the continuous resin sheet 60 is, for example, 1.0 mm or more and 4.5 mm or less.

(transfer step)

The transfer step (S2) includes a pressing step of sandwiching the first pressing roller 52A (squeeze roller) and the second pressing roller 52B (forming roller) by the sheet manufacturing step (S1) The continuous resin sheet 60 is produced and extruded; and the conveying step is performed by conveying the continuous resin sheet 60 extruded in the pressing step in a state of being kept in close contact with the circumferential surface of the second pressing roller 52B; The step of peeling off the continuous resin sheet 60 conveyed in the conveying step from the circumferential surface (transfer mold 53) of the second pressing roll 52B.

(extrusion step)

As shown in Fig. 1, the continuous resin sheet 60 obtained in the above-described sheet manufacturing step (S1) is subjected to two steps from the thickness direction of the sheet by the first pressing roll 52A and the second pressing roll 52B by the pressing step. The sides are simultaneously pinched and squeezed.

At this time, the surface temperature of the continuous resin sheet 60 immediately before the contact with the second pressing roll 52B is, for example, a temperature in the range of 180 ° C to 250 ° C. The surface temperature can be adjusted, for example, by a change in the set temperature of the extruder 58 or a change in the set temperature of the nozzle 51. The surface temperature of the continuous resin sheet 60 can be measured, for example, using an infrared thermometer.

In this pressing step, the shape of the transfer mold 53 formed on the surface of the second pressing roller 52B (forming roller) is transferred onto the continuous resin sheet 60. The transfer mold 53 provided on the surface of the transfer roller abuts against the surface of the continuous resin sheet 60. As a result, the reverse mold of the surface shape of the transfer mold 53 is transferred to the continuous tree. Fat sheet 60.

As the first pressing roll 52A and the second pressing roll 52B, a metal roll made of a metal such as stainless steel or steel is usually used, and its diameter is usually 100 mm to 500 mm. When a metal roll is used as the first press roll 52A and the second press roll 52B, the surface may be subjected to a plating treatment such as chrome plating, copper plating, nickel plating, or nickel-phosphorus plating. The surface (peripheral surface) of the first pressing roller 52A may be a mirror surface or a transfer surface to which irregularities such as emboss are applied.

A pre-compression step of pre-extrusion can be carried out before the extrusion step. In the pre-pressing step, the continuous resin sheet 60 manufactured by the sheet manufacturing step (S1) is sandwiched by the pre-pressing roller 52D and the first pressing roller 52A, whereby the continuous resin sheet 60 is pre-extruded. The extruded continuous resin sheet 60 is conveyed while being in close contact with the circumferential surface of the first squeeze roll 52A. Thereafter, the pressing step is performed by the first pressing roller 52A and the second pressing roller 52B.

(transport step)

The conveying step is a step of conveying the continuous resin sheet 60 in accordance with the rotation of the second pressing roller 52B in a state where the continuous resin sheet 60 is in close contact with the circumferential surface of the second pressing roller 52B.

(peeling step)

The peeling step is a step of peeling off the continuous resin sheet 60 from the peripheral surface of the second pressing roll 52B.

Through the above steps, the light guide plate 30 can be manufactured. The temperature of the light guide plate 30 immediately after the peeling step is performed is, for example, 90 ° C or higher.

(Fitting step)

As shown in FIG. 1, in the bonding step (S3), the protective films 40 and 42 are bonded to the light guide plate 30 by the bonding apparatus 70 using a protective film. The light guide plate 30 and the protective films 40 and 42 are simultaneously sandwiched and pressed by the first pressing roller 72A and the second pressing roller 72B from both sides in the thickness direction of the light guiding plate 30. The first squeezing roller 72A and the second squeezing roller 72B are rotated to bond the protective film 40 to the surface 31 of the light guide plate 30, and the protective film 42 is attached to the back surface 32 of the light guide plate 30. The protective film 40 is supplied to the first pressing roller 72A by the rotation of the protective film roll 72C, and is bonded to the light guide plate 30 in a state of being in close contact with the circumferential surface of the first pressing roller 72A. The protective film 42 is supplied to the second pressing roller 72B by the rotation of the protective film roll 72D, and is bonded to the light guide plate 30 in a state of being in close contact with the circumferential surface of the second pressing roller 72B.

The temperature of the light guide plate 30 at the time of bonding can be controlled by adjusting the temperature of the light guide plate 30 immediately after the peeling step, and may be 40 to 70 ° C or 50 to 60 ° C. For example, the temperature of the light guide plate 30 at the time of bonding can be adjusted by the distance between the manufacturing apparatus 50 of the light guide plate and the bonding apparatus 70 of the protective film.

(cutting step)

As shown in FIG. 1, in the cutting step (S4), the light guide plate 30 to which the protective films 40 and 42 are bonded is cut into a predetermined size by using the cutting device 80. Thereby, the light guide plate 90 with a protective film as shown in FIG. 4 can be obtained.

In the case of using a light guide plate having a surface on which a convex portion is formed, in a protective film having a tensile modulus of elasticity of less than 250 N/mm ² , there is a protective film when the light guide plate to which the protective film is attached is cut. The end portion tends to be peeled off from the light guide plate. The reason for this is that the protective film stretches when it is attached, and shrinks after the bonding. On the other hand, in the protective film 40 having a tensile modulus of elasticity of less than 250 N/mm ² , even if the light guide plate 30 to which the protective film 40 is bonded is cut, the end portion of the protective film 40 can be suppressed from the light guide plate 30 . Stripped. Therefore, in the method of manufacturing a light guide plate with a protective film according to the present embodiment, it is possible to obtain a protective film having excellent adhesion characteristics between the surface 31 on which the convex portion 35 of the light guide plate 30 is formed and the protective film 40. Light guide plate 90.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above.

(Example)

Hereinafter, the present invention will be more specifically described based on examples, reference examples and comparative examples, but the present invention is not limited to the following examples.

(Example 1)

The protective film was bonded to a light guide plate preheated to 40 ° C using the manufacturing apparatus of the light guide plate with a protective film shown in FIG. As the light guide plate, a shaped light guide plate having a surface on which a convex portion is formed is used. The protective film is bonded to the surface on which the convex portion is formed. A polypropylene film (trade name: L7330, manufactured by Hitachi Chemical Co., Ltd.) was used as a protective film. Based on JIS K7161, the tensile modulus of the protective film was measured in accordance with a load of 1 kN. The results are shown in Table 1. Thereafter, the protective film and the light guide plate were cut into a width of 25 mm × a length of 300 mm to prepare a light guide plate with a protective film.

For the light guide plate which is not preheated to 40 ° C but preheated to 70 ° C, the protective film is bonded to the light guide plate, and the protective film and the light guide plate are cut into a width of 25 mm × a length of 300 mm to prepare A light guide plate with a protective film attached.

For the two kinds of light guide plates with protective film obtained, based on JISZ0237 The peeling strength (N/25 mm) was measured by peeling the protective film in the 180° direction in the longitudinal direction by an automatic stretching machine at a stretching speed of 300 mm/min. The results are shown in Table 1.

(Adhesive property evaluation)

For the light guide plate which is not preheated to 40 ° C but preheated to 50 to 60 ° C, the protective film is bonded to the light guide plate, and the protective film and the light guide plate are cut into A4 size to prepare a protective film. Light guide plate. With respect to the obtained light guide plate with a protective film, it was evaluated whether the protective film had a peeling length of 5 mm or more from the end portion. The case where the protective film was peeled off from the end portion by 5 mm or more was regarded as peeling. On the other hand, the case where the protective film was peeled off from the end portion by less than 5 mm was regarded as no peeling. The results are shown in Table 1.

(Example 2)

A light guide plate with a protective film was produced and evaluated in the same manner as in Example 1 except that a polypropylene film (trade name: FM-470, manufactured by Daewoo Paper Co., Ltd.) was used as the protective film. The results are shown in Table 1.

(Example 3)

A light guide plate with a protective film was produced and evaluated in the same manner as in Example 1 except that a polypropylene film (trade name: FM-382, manufactured by Daewoo Paper Co., Ltd.) was used as the protective film. The results are shown in Table 1.

(Comparative Example 1)

A light guide plate with a protective film was produced and evaluated in the same manner as in Example 1 except that a polyethylene film (trade name: #6318B-60, manufactured by Sekisui Chemical Co., Ltd.) was used as the protective film. The results are shown in Table 1.

(Reference example 1)

A light guide plate (planar light guide plate) having a flat surface is used instead of a shaped light guide plate having a surface on which a convex portion is formed, and a polyethylene film (trade name: ML2020, manufactured by Hitachi Chemical Co., Ltd.) is used as a protective film. In the same manner as in Example 1, a light guide plate with a protective film was produced and evaluated. The results are shown in Table 1.

As shown in Table 1, in Examples 1 to 3, a light guide plate with a protective film excellent in adhesion characteristics was obtained. On the other hand, good results were not obtained in Comparative Example 1. Therefore, in the shaped light guide plate, since the tensile elastic modulus of the protective film is set to a specific range, a light guide plate with a protective film excellent in adhesion characteristics can be obtained.

30‧‧‧Light guide

31‧‧‧ surface

32‧‧‧Back

35‧‧‧ convex

40, 42‧‧‧ protective film

51‧‧‧ mould mouth

52A‧‧‧First squeeze roller

52B‧‧‧Second Squeeze Roller (Forming Roller)

52D‧‧‧Preloading roller

53‧‧‧Transfer mode

53a‧‧‧ recess

57‧‧‧Resin entrance

58‧‧‧Extrusion machine

60‧‧‧Continuous resin sheet

70‧‧‧Fitting device

72A‧‧‧First squeeze roller

72B‧‧‧Second squeeze roller

72C‧‧‧Protective film roll

72D‧‧‧Protective film roll

90‧‧‧Light guide plate with protective film

Fig. 1 is a schematic configuration view showing a manufacturing apparatus of a light guide plate with a protective film in the embodiment.

Fig. 2 is a perspective view schematically showing the configuration of a light guide plate.

Fig. 3 is a cross-sectional view schematically showing a concave portion formed in a transfer mold and a convex portion formed on the light guide plate.

Fig. 4 is a cross-sectional view showing a light guide plate with a protective film in the embodiment.

Fig. 5 is a flow chart showing the procedure of a method of manufacturing a light guide plate with a protective film in the embodiment.

30‧‧‧Light guide

31‧‧‧ surface

32‧‧‧Back

35‧‧‧ convex

40‧‧‧Protective film

42‧‧‧Protective film

90‧‧‧Light guide plate with protective film

Claims (4)

A method for producing a light guide plate with a protective film, comprising the steps of: a sheet manufacturing step of continuously extruding a resin in a heated molten state from a die to produce a continuous resin sheet; and a transfer step The transfer mold is transferred onto the surface of the continuous resin sheet by using a shaping roller having a peripheral surface on which the transfer mold is formed, thereby producing a projection having a concave portion formed on the transfer mold. a light guide plate on a surface of the portion; a bonding step of bonding a protective film having a tensile modulus of 250 N/mm ² or more to the surface of the light guide plate on which the convex portion is formed; and a cutting step This is to cut the above-mentioned light guide plate to which the above protective film is bonded. A light guide plate with a protective film, comprising: a light guide plate having a surface on which a convex portion is formed; and a protective film attached to the surface; and the tensile modulus of the protective film is 250 N/ Mm ² or more. A light guide plate with a protective film, which is manufactured by using the method of manufacturing a light guide plate with a protective film according to claim 1. A protective film which is used in a light guide plate of a protective film as claimed in claim 2 or 3.