JP2016149193A - Method of manufacturing light guide plate and light guide plate manufactured by same method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a light guide plate in which an uneven state which is uniform on a surface and freely adjustable in size can be formed, and a configuration of the light guide plate based upon the method.SOLUTION: The present invention relates to a light guide plate 1 that is manufactured based upon the formation of a state of an uneven surface 2 on a surface of a transparent plastic resin by etching, accompanied by erosion, with a solution of a pigment 3 employed for printing ink, preferably, any of alcohols, ketone, ethers, aromatic hydrocarbon, esters, and chlorinated hydrocarbon having a transparent pigment uniformly dispersed, the transparent plastic resin forming a single layer or having a three-layer configuration comprising different plastic layers as both outer plastic layers and an inner plastic layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of manufacturing a light guide plate that enables display based on scattered transmitted light by forming an uneven state on the surface, and a configuration of the light guide plate manufactured by the method.

  By forming a concavo-convex state on the longitudinal surface of the transparent plastic resin, reflection on the inner surface of the light beam passing through the inside of the plastic resin along the longitudinal direction and non-specific scattering from the surface having the concavo-convex state A light guide plate that realizes display by transmitted light is widely used in the fields of a sign plate with characters and figures, and further a signal display plate.

  As a method for forming a concavo-convex state on the surface of the light guide plate, a mechanical method such as injection molding or melt extrusion molding using a table having a concavo-convex pattern, a surface etching method using a resist coating film, irradiation with electromagnetic waves such as laser light, etc. The method etc. are adopted.

  The mechanical method is difficult to form a fine uneven state, and the etching method has a drawback that it is difficult to form a uniform coating film. Requires special equipment.

  Incidentally, in Cited Document 1, in order to secure a uniform uneven state, a method of dissolving the surface of the thermoplastic synthetic resin after irradiating active energy rays such as electromagnetic waves is adopted. Irradiation still requires special equipment.

  Thus, in the prior art, a method for manufacturing a light guide plate that is capable of forming a concavo-convex state that is uniform on the surface and can be adjusted in size while being a relatively simple technique is proposed. It has not been.

JP 2002-256091 A

  It is an object of the present invention to provide a method of manufacturing a light guide plate that enables formation of a concavo-convex state that is uniform on the surface and whose size is adjustable, and a configuration of the light guide plate based on the manufacturing method. .

In order to solve the above problems, the basic configuration of the present invention is as follows.
(1) A method of manufacturing a light guide plate by forming a concavo-convex state that enables generation of scattered transmitted light by an erosion action with a solvent in which a pigment of printing ink is uniformly dispersed on the surface of a transparent plastic resin
(2) A light guide plate manufactured by the manufacturing method of (1) above,
Consists of.

  In the basic configuration, the uneven shape on the surface is made uniform by uniformly dispersing the pigment of the same particle size in the solvent, while the uneven shape on the surface is selected by selecting the particle size of the pigment in the solvent. It is possible to realize that the size of the resin is adjustable by a simple technique of etching accompanied by erosion of the solvent on the surface of the plastic resin.

  Since the manufacturing cost of etching is low, the light guide plate manufactured according to the present invention is extremely advantageous in terms of economic cost as compared with the light guide plate manufactured by other methods.

It is sectional drawing which shows the basic principle of this invention. It is sectional drawing which shows the structure of an Example. It is sectional drawing which shows the typical transmission state accompanying the refraction | bending of the light in case an outer plastic resin layer has a larger refractive index especially compared with an inner plastic resin layer among an Example.

As is clear from the basic structure, the surface of the light guide plate 1 of the present invention employs etching that involves erosion of the plastic resin surface with a solvent in which the pigment 3 of printing ink is uniformly dispersed. As shown in FIG. 1, the surface of the uneven surface 2 is formed on the light guide plate.
In FIG. 1, the region on the most surface side of the convex portion has a flat shape, and the cause is that surface finishing is performed at the final stage of etching.

  The basis for uniformly dispersing the pigment 3 is that a uniform uneven state cannot be formed when the dispersed state is inhomogeneous.

  When the particle diameter of the pigment 3 is made uniform, the size of the uneven state can be made uniform as shown in FIG.

  In addition, since the size of the unevenness varies depending on the particle size of the pigment 3 remaining at the bottom of the concave portion, the size of the unevenness can be adjusted by selecting the particle size.

  Although the said particle size is not specifically limited, When 10-500 micrometers is employ | adopted normally, suitable scattered transmitted light can be obtained.

  However, in order to realize an effective display by scattered transmitted light, the non-transparent and colored pigment 3 is not preferable, and the transparent pigment 3 is preferably used.

  The transparent pigment 3 can be used not only in the case of being colorless and transparent but also in the case of colored and transparent.

Typical examples of such a colorless and transparent pigment 3 include calcium oxide (CaCO ₃ ), barium carbonate (BaSO ₄ ), aluminum oxide (Al ₂ O ₃ ), silica (SiO ₂ ), talc (3MgO · SiO _2. H ₂ O), clay _{(Al 2 O 3 · SiO 2} · 2H extender pigments 3 with either 2 O) and pigment 3 were kneaded by fat.

In addition to the typical transparent inorganic pigment 3, for example, titanium oxide (TiO ₂ ) having a particle size of 15 μm or less can also be used.

  In general, organic pigments are markedly colored as compared with inorganic pigments. For example, in the case of anthraquinone, exceptionally high transparency can be ensured.

The colored transparent pigment 3 is in the form of a colored inorganic pigment such as black carbon black (C), red bengara (Fe ₂ O ₃ ), or a blue organic pigment. A certain indigo, indanthrone, or the like may be appropriately mixed with the colorless transparent pigment 3.

  Typical examples of solvents capable of erosion of plastic resin, that is, etching, include alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, dimethyl ether, ethyl ether, and tetrahydrofuran. And ethers such as toluene, xylene and benzene, esters such as ethyl acetate, butyl acetate and isopropyl acetate, and chlorinated hydrocarbons such as chlorinated polyethylene and chlorinated polypropylene.

  However, the solvent is not limited to these, and for example, a strong acid or a strong alkali can be used.

  The plastic resin used in the present invention is not particularly limited, but it is indispensable that it can be eroded by a solvent while being transparent.

  For example, polypropylene (PP), polystyrene (PS), polymethyl methacrylate (PMMA), soluble in any of alcohols, ketones, ethers, aromatic hydrocarbons, esters, chlorinated hydrocarbons, Polyurethane (PU), polysulfone (PSF), and polycarbonate (PC) can be employed as typical examples that satisfy the above requirements.

  Note that the light guide plate 1 is usually formed with a concavo-convex shape on one side surface in the longitudinal direction, but may be exceptionally formed on both sides, and the present invention also has such an exceptional configuration. Inclusive.

  As shown in FIG. 2, the light guide plate 1 according to the embodiment is characterized by a three-layer configuration including an outer plastic resin layer 11 and an inner plastic resin layer 12.

  In the case of such a three-layer configuration, the outer plastic resin layer 11 and the inner plastic resin layer 12 are respectively reflected on the inner wall portion and transmitted from the inner wall portion. Since the direction of the transmitted light from the plastic resin layer 12 and the transmitted light from the outer plastic resin layer 11 are often different, the degree of scattering of the scattered transmitted light on the concavo-convex surface 2 is also larger than that of the single layer configuration. Can be realized.

  For this reason, even if dirt and scratches occur on both the outer surface having the uneven state and the outer surface not having the uneven state, the light guide plate having a three-layer structure is used as compared with the light guide plate 1 having a single-layer structure. In the case of 1, it is possible to obtain an effect that dirt, scratches and the like are not noticeable.

  In FIG. 2, the light entrance stop 110 shown at one end of the outer plastic resin layer 11 is incident only on the inner plastic resin layer 12 of the light guide plate 1. The function of promoting the reflection effect in the boundary region between the plastic resin layer 11 and the inner plastic resin layer 12 is exhibited.

  In the three-layer configuration, when the refractive index of the inner plastic resin layer 12 and the refractive index of the outer plastic resin layer 11 are different, the direction of transmitted light from both plastic resin layers is different. As described above, the degree of scattering of the scattered transmitted light is further promoted.

  In particular, when the refractive index of the outer plastic resin layer 11 is larger than that of the inner plastic resin layer 12, the light beam passing through the inner plastic resin layer 12 is transmitted as shown in FIG. When the light is reflected on the boundary surface, a part of the light rays is refracted into the outer plastic resin layer 11 at an angle smaller than the incident angle, and is easily transmitted from the inner wall of the outer plastic resin layer 11. The display state on the surface forming the state can be displayed with higher luminance.

  For example, when polycarbonate (PC) having a refractive index of 1.548 is adopted as the inner plastic resin layer 12, the outer plastic resin layer 11 having a larger refractive index may have a refractive index of, for example. Polyethylene terephthalate (PET) having a refractive index of 1.65 can be adopted, and as the outer plastic resin layer 11 having a smaller refractive index, for example, polypropylene (PP) having a refractive index of 0.91 or a refractive index of Polymethyl methacrylate (PMMA) which is 1.49 can be employed.

  In the case of polypropylene (PP), aromatic hydrocarbons and chlorinated hydrocarbons are suitable as the solvent. In the case of polymethyl methacrylate (PMMA), ketones, esters, aromatics are preferred as the solvent. Group hydrocarbons and chlorinated hydrocarbons are suitable, and in the case of polyethylene terephthalate (PET), it is necessary to employ a solvent different from typical solvents such as diphenyl ether and diphenylmethane.

  In addition to the optical merit as described above, the inner plastic resin layer 12 is made of a plastic that does not melt by a solvent, such as polyacetal (POM), polyamideimide. It is also possible to employ (PAI), polyvinyl fluoride (PVF), or the like, and on the outside, a plastic resin that can be eroded by the specific solvent as described above.

  As described above, the present invention can ensure a uniform uneven state by adjusting the degree of size by a simple technique of etching with a solvent in which a pigment of printing ink is uniformly dispersed, and is inexpensive. Since the display based on a simple light guide can be realized, its utility value is tremendous.

DESCRIPTION OF SYMBOLS 1 Light guide plate 11 Outer plastic resin layer 110 Light-inhibiting part 12 Inner plastic resin layer 2 Uneven surface 3 Pigment

Claims (9)

  A method of manufacturing a light guide plate by forming a concavo-convex state capable of generating scattered transmitted light on the surface of a transparent plastic resin by an erosion action by a solvent in which a pigment of printing ink is uniformly dispersed.   The method for producing a light guide plate according to claim 1, wherein the particle diameter of the pigment is uniform.   The method for producing a light guide plate according to claim 1, wherein a transparent pigment is employed. As transparent pigments, calcium oxide (CaCO ₃ ), barium carbonate (BaSO ₄ ), aluminum oxide (Al ₂ O ₃ ), silica (SiO ₂ ), talc (3MgO · SiO ₂ · H ₂ O), clay (Al ₂ 4. The method for manufacturing a light guide plate according to claim 3, wherein a pigment obtained by kneading an extender pigment of any one of (O ₃ · SiO ₂ · 2H ₂ O) with fats and oils is employed.   5. The solvent according to claim 1, wherein any one of alcohols, ketones, ethers, aromatic hydrocarbons, esters, and chlorinated hydrocarbons is used as the solvent. Manufacturing method of the light guide plate.   A light guide plate manufactured by the method according to claim 1.   The light guide plate according to claim 5, wherein the light guide plate has a three-layer structure including an outer plastic resin layer and an inner plastic resin layer.   The light guide plate according to claim 6, wherein the refractive index of the inner plastic resin layer is different from the refractive index of the outer plastic resin layer.   2. Polyethylene terephthalate (PET), polypropylene (PP), or polymethyl methacrylate (PMMA) is adopted as the outer plastic resin layer, and polycarbonate (PC) is adopted as the inner plastic resin layer. Item 9. The light guide plate according to Item 8.

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