WO2012105518A1 - Method for producing light guide plate, light guide plate, planar light-source device provided with same, and transmissive image-display device - Google Patents

Method for producing light guide plate, light guide plate, planar light-source device provided with same, and transmissive image-display device Download PDF

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Publication number
WO2012105518A1
WO2012105518A1 PCT/JP2012/052033 JP2012052033W WO2012105518A1 WO 2012105518 A1 WO2012105518 A1 WO 2012105518A1 JP 2012052033 W JP2012052033 W JP 2012052033W WO 2012105518 A1 WO2012105518 A1 WO 2012105518A1
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WO
WIPO (PCT)
Prior art keywords
guide plate
light guide
light
light source
resin plate
Prior art date
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PCT/JP2012/052033
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French (fr)
Japanese (ja)
Inventor
健太郎 百田
豊博 濱松
芳永 島田
将典 坪田
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住友化学株式会社
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Application filed by 住友化学株式会社 filed Critical 住友化学株式会社
Publication of WO2012105518A1 publication Critical patent/WO2012105518A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
    • G02B6/004—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles
    • G02B6/0043—Scattering dots or dot-like elements, e.g. microbeads, scattering particles, nanoparticles provided on the surface of the light guide
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0065—Manufacturing aspects; Material aspects
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
    • G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
    • G02B6/0033—Means for improving the coupling-out of light from the light guide
    • G02B6/0058—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide
    • G02B6/0061—Means for improving the coupling-out of light from the light guide varying in density, size, shape or depth along the light guide to provide homogeneous light output intensity

Definitions

  • the present invention relates to a method of manufacturing a light guide plate, a light guide plate, a surface light source device including the same, and a transmissive image display device.
  • a transmissive image display device such as a liquid crystal display device generally has a surface light source device as a backlight.
  • the edge light type surface light source device includes a light guide plate and a light source that supplies light to an end surface thereof. Light incident from the end surface of the light guide plate is reflected by a reflecting means such as a reflective dot provided on the back side of the light guide plate, and planar light for image display is supplied from the exit surface of the light guide plate.
  • Inkjet printing has been studied as a method for forming reflective dots (light distribution patterns) on a light guide plate (Patent Document 1). According to inkjet printing, it is expected that the reflective dots constituting the designed desired pattern can be easily formed.
  • the present invention has been made to solve such a problem, and in the case of forming a dot-like pattern by inkjet printing, a light guide plate capable of suppressing the uneven formation of the dot-like pattern.
  • An object of the present invention is to provide a method of manufacturing a light guide plate, a light guide plate obtainable by this method, a surface light source device including the same, and a transmissive image display device.
  • the inventors of the present application have found that the uneven printing of the reflective dots is caused by the adhesive residue of the protective film on the resin plate serving as the light guide plate.
  • a protective film having an adhesive layer is bonded to the surface of the resin plate serving as the light guide plate in order to avoid generation of scratches during transportation and the like and adhesion of dust and dirt.
  • a dot-like pattern made of reflective dots is formed.
  • the non-uniform formation of the dot-like pattern resulting from the adhesive residue of the protective film becomes a problem when forming high-definition reflective dots on a light guide plate that becomes a large-screen and high-resolution liquid crystal display in recent years.
  • the method of manufacturing the light guide plate of the present invention includes a peeling process for peeling the protective film from the resin plate having the protective film bonded to the surface, and a water washing treatment for washing the surface of the resin plate from which the protective film has been peeled. And a printing process in which a dot-like pattern is formed by disposing ink on the surface of the washed resin plate.
  • the adhesive film residue of the protective film which is considered to cause the uneven formation of the dot-like pattern, is removed. Removed. As a result, it becomes possible to form a dot-like pattern as designed, and when forming a dot-like pattern by ink jet printing, it is possible to suppress the non-uniform formation of the dot-like pattern.
  • the ink may be an ultraviolet curable ink.
  • the light guide plate according to the present invention can be obtained by a method for producing the light guide plate.
  • This light guide plate suppresses the non-uniform formation of the dot-like pattern when the dot-like pattern is formed by inkjet printing, so that the appearance quality is improved and the surface light with high uniformity is emitted. It is possible to emit.
  • the surface light source device can be configured to include the light guide plate described above and a light source that supplies light to the end face of the light guide plate.
  • pervious image display apparatus which concerns on this invention can be set as the structure provided with the said surface light source device and the transmissive
  • the surface light source device and the transmissive image display device it is possible to emit planar light with high uniformity.
  • FIG. 1 is a cross-sectional view schematically showing a configuration of an embodiment of a transmissive image display device according to the present invention.
  • FIG. 2 is a rear view schematically showing a configuration of an embodiment of the surface light source device according to the present invention.
  • FIG. 3 is a schematic view showing an embodiment of a method for producing a light guide plate.
  • the transmissive image display device 1 includes a transmissive image display unit 10 and a surface light source device 20 disposed on the back side of the transmissive image display unit 10 in FIG.
  • the arrangement direction of the surface light source device 20 and the transmissive image display unit 10 is referred to as a Z direction (plate thickness direction), which is two directions orthogonal to the Z direction and orthogonal to each other. These two directions are referred to as the X direction and the Y direction.
  • the transmissive image display unit 10 examples include, for example, a liquid crystal display panel in which polarizing plates 12 and 12 are disposed on both surfaces of a liquid crystal cell 11.
  • the transmissive image display device 1 is a liquid crystal display device (or a liquid crystal television).
  • the liquid crystal cell 11 and the polarizing plates 12 and 12 those built in the transmissive image display device 1 such as a conventional liquid crystal display device can be used.
  • the liquid crystal cell 11 include known liquid crystal cells such as TFT liquid crystal cells and STN liquid crystal cells.
  • FIG. 2 is a rear view schematically showing a configuration of an embodiment of the surface light source device according to the present invention.
  • the surface light source device 20 includes a light guide plate 30 and an LED light source 22 disposed to face a side surface (end surface) 33 of a light-transmitting resin plate 35 in the light guide plate 30.
  • Edge light type surface light source device the structure by which the various films 41 are arrange
  • the various films 41 include a diffusion film, a prism film, and a brightness enhancement film.
  • the LED light source 22 functions as a point light source of the surface light source device 20, and as shown in FIG. 2, side surfaces 33, 33 extending in the Y-axis direction of the translucent resin plate 35 in the light guide plate 30. Opposed to each other.
  • the plurality of LED light sources 22 are discretely arranged along the longitudinal direction (Y-axis direction) of the side surface 33.
  • the arrangement interval of the LED light sources 22 is usually 5 mm to 20 mm.
  • the point light sources may be arranged so as to face the four sides of the light-transmitting resin plate 35 in the light guide plate 30, respectively, or face the two sides facing the X-axis direction of the light-transmitting resin plate 35.
  • the point light source is not limited to the LED light source, but may be other point light sources.
  • the light source is not limited to a point light source, and may be a configuration in which a linear light source (CCFL: cold cathode tube) is arranged.
  • CCFL cold cathode tube
  • the LED light source 22 may be a white LED, and a plurality of LEDs may be arranged in one place to constitute one light source unit.
  • LEDs of three colors of red, green, and blue may be arranged in close proximity to each other.
  • the light source unit which has several LED is discretely arrange
  • the LED light source 22 preferably has a light intensity distribution in which the luminous intensity in the normal direction of the LED light source is maximum and the half value width of the light intensity distribution is 40 degrees or more and 80 or less.
  • Specific examples of the LED light source type include a Lambertian type, a shell type, and a side emission type.
  • the light guide plate 30 includes a translucent resin plate 35 and a plurality of reflective dots 36 arranged in a predetermined dot-shaped pattern 37 on the back surface 32 of the translucent resin plate 35.
  • the translucent resin plate 35 has a rectangular shape, and the size of the plan view shape is selected so as to match the target screen size of the transmissive image display unit 10.
  • the planar view shape of the translucent resin plate 35 is not limited to a rectangle, and may be a square. In the following description, unless otherwise specified, the plan view shape of the translucent resin plate 35 is described as a rectangle.
  • the translucent resin plate 35 is formed of a translucent resin that transmits light and has a plate shape.
  • the translucent resin polymethyl methacrylate (PMMA), poly (meth) acrylic acid alkyl resin, polystyrene sheet or polycarbonate resin can be used.
  • the translucent resin plate 35 may be a sheet or a film.
  • the thickness T of the translucent resin plate 35 is preferably 1.0 mm or greater and 4.5 mm or less.
  • the translucent resin plate 35 includes a pair of surfaces 31 and 32 facing in the Z-axis direction (thickness direction), a pair of side surfaces 33 and 33 facing in the X-axis direction, and a pair of side surfaces 34 and 34 facing in the Y-axis direction. It has.
  • the surfaces 31 and 32 are formed in a direction intersecting with the side surfaces 33 and 34.
  • One surface 31 of the pair of surfaces opposed to each other in the Z-axis direction functions as an emission surface that can emit planar light.
  • the surface 31 as the emission surface is disposed on the transmissive image display unit 10 side, and the other surface (back surface 32) is disposed on the side opposite to the transmissive image display unit 10.
  • a reflection sheet 42 that reflects the light in the light guide plate 30 toward the front surface 31 as an emission surface is disposed at a position facing the back surface 32.
  • the surface 31 opposite to the surface (back surface 32) on which the reflective dots 36 of the translucent resin plate 35 are formed may be a flat surface as in the present embodiment, or has an uneven shape. Also good.
  • a predetermined dot-shaped pattern 37 made of reflective dots 36 is formed on the back surface 32 of the translucent resin plate 35 as a reflection process for irregularly reflecting light.
  • the dot-shaped pattern 37 is formed by ink jet printing.
  • ink having diffusion particles that diffuse light is used for the formation of the dot-shaped pattern 37.
  • the diameter of each reflective dot 36 constituting the dot-shaped pattern 37 may be formed so as to increase as the distance from the light source side increases.
  • the light is stronger in the region closer to the light source 22, that is, the side surface 33 of the translucent resin plate 35, and the light is weaker in the region farther from the side surface 33. Therefore, the diameter of the reflective dot 36 is increased according to the distance from the side surface 33 so that the luminance of the light emitted from the emission surface 31 of the translucent resin plate 35 becomes substantially uniform.
  • FIG. 3 is a schematic view showing an embodiment of a light guide plate manufacturing apparatus.
  • the light guide plate manufacturing apparatus 100 shown in FIG. 3 includes a conveying means 50, a peeling device 60, a cleaning device 70, an inkjet head 80, a UV lamp 90, and an inspection device 95.
  • the transport means 50, the peeling device (peeling unit) 60, the cleaning device (water washing processing unit) 70, the inkjet head (printing unit) 80, the UV lamp 90, and the inspection device 95 are made of a translucent resin plate ( (Resin plate) are arranged in this order from the upstream side along the moving direction A of the resin plate 35.
  • the conveying means 50 conveys the translucent resin plate 35 that becomes the original plate continuously or intermittently along the direction A.
  • Examples of the conveying means 50 in the present embodiment include a table shuttle, a belt conveyor, a roller, or air floating transfer.
  • the peeling device 60 peels the masking film MF from the translucent resin plate 35 (an example attached to only the lower surface in FIG. 3) in which the masking film (protective film) MF is bonded to one side or both sides. Then, the surface 32 of the translucent resin plate 35 on which the reflective dots 36 are formed is exposed (peeling process).
  • the cleaning device 70 performs a water-washing process on the surface 32 of the light-transmitting resin plate 35 exposed by the peeling device 60 while carrying the light-transmitting resin plate 35 (water-washing process step).
  • the cleaning device 70 includes a first processing unit 71, a second processing unit 72, and a third processing unit 73, and the surface 32 of the translucent resin plate 35 is washed with water in this order. Examples of the conveying speed of the translucent resin plate 35 include 1 to 400 mm / sec.
  • the 1st process part 71 peels the stain
  • the pressure of the pure water shower in the first treatment step are 0.1 to 0.3 MPa, the amount of water is 5.0 to 20 L / min, and the treatment time is 1 to 600 sec.
  • the pressure of the pure water shower can be 0.25 MPa, the amount of water is 20 L / min, and the treatment time can be 15 sec.
  • the second processing unit 72 is applied to the surface 32 of the translucent resin plate 35 by the striking force of two-fluid shower with pure water and CDA (Clean Dry Air). This is the part responsible for the second water washing treatment step for peeling 32 dirt (glue, dust, etc.).
  • the pressure of the two-fluid shower is 0.1 to 0.2 MPa
  • the air amount is 200 to 1000 L / min
  • the water amount is 5.0 to 20 L / min
  • the treatment time is 0.6 to 600 sec.
  • the pressure may be 0.16 MPa
  • the air amount may be 500 L / min
  • the water amount may be 14 L / min
  • the processing time may be 3 sec.
  • the 3rd process part 73 blows the gas flow discharged from a gas ejection port with respect to the surface 32 of the translucent resin board 35 after the process by the 2nd process part 72, and in the 1st and 2nd water washing process process It is a part responsible for the third water washing treatment step for removing moisture (air knife).
  • the air amount of the air knife in the third treatment step are 100 to 1000 L / min.
  • the air amount can be 750 L / min.
  • the inkjet head 80 disposes ink on the surface 32 on the back side of the translucent resin plate 35 conveyed by the conveying means 50 to form a desired dot-shaped pattern 37 (printing process).
  • the inkjet head 80 faces the surface 32 of the translucent resin plate 35 over the entire width direction (direction perpendicular to the transport direction A) of the region where the reflective dots 36 of the translucent resin plate 35 are formed. It has a plurality of nozzles (not shown) arranged. With this configuration, the inkjet head 80 can simultaneously print the reflective dots 36 over the entire width direction of the translucent resin plate 35.
  • the ink used in the ink jet printing for forming the reflective dots 36 includes a diffusing particle for diffusing light and a resin that is cured by a curing process after printing and has adhesion to the translucent resin plate 35. Are preferably used. This ink may not contain diffusing particles and may diffuse light by the prism effect of the cured resin.
  • the diffusing particles include titanium dioxide, calcium carbonate, barium sulfate, and silica, but the diffusing particles are not limited thereto.
  • the diffusing particles are preferably colorless or white so as not to selectively absorb light of a specific wavelength.
  • the resin component various water-soluble resins, solvent-based resins and emulsion-type resins, as well as ultraviolet curable resins can be used.
  • water-soluble resins and ultraviolet curable resins are preferred as resin components from the viewpoint of ease of environmental measures.
  • an ultraviolet curable resin an example in which ultraviolet irradiation by a UV lamp 90 is adopted as a curing means will be described.
  • a water-soluble resin, a solvent-based resin and an emulsion type resin are used as the resin component, drying by heat is adopted as a curing means.
  • Printing by the inkjet head 80 can be performed while moving the translucent resin plate 35 continuously at a constant speed. Printing by the inkjet head 80 may be performed while repeating the printing with the translucent resin plate 35 stopped and the movement of the translucent resin plate 35 to the next printing position and then stopping. it can. The translucent resin plate 35 printed in this way is transported downstream in the transport direction.
  • the UV lamp 90 irradiates the translucent resin plate 35 on which the dot-shaped pattern 37 conveyed from the upstream side by the conveying means 50 is irradiated with ultraviolet rays in the irradiation region 91.
  • the ink on the translucent resin plate 35 is cured by being irradiated with ultraviolet rays from the UV lamp 90. Thereby, the reflective dots 36 made of the cured ink are formed.
  • the inspection device 95 inspects the state of the formed reflective dots 36.
  • the light guide plate 30 is formed through the processes described above.
  • the light guide plate 30 is cut into a desired size as necessary.
  • the light guide plate 30 does not necessarily have to be continuously inspected by the inspection device 95 provided on the downstream side of the inkjet head, and the light guide plate is inspected offline by a separately prepared inspection device. You can also.
  • the masking film MF is bonded to the surface 32 of the translucent resin plate 35, particularly the surface 32 serving as the back surface, thereby generating scratches and dirt on the back surface 32. Is prevented. This is because if the back surface 32 is scratched or has dirt, the ink wets and spreads unevenly, and this may cause the uniformity of the reflective dots 36 to deteriorate. However, when the masking film MF is peeled from the translucent resin plate 35, the paste of the masking film MF may remain slightly on the back surface 32. Due to the remaining glue, when the dot-shaped pattern 37 is formed, a streak-like defect may occur in the dot-shaped pattern 37 or uneven printing (printing unevenness) may occur.
  • the back surface 32 of the light guide plate 30 is washed with water, so that the influence of glue is reduced. For this reason, even if the masking film MF is bonded to the back surface 32, the dot-shaped pattern 37 for forming the reflective dots 36 is printed with high uniformity.
  • the light guide plate 30 manufactured according to this embodiment forms a dot-like pattern by inkjet printing, non-uniform printing is suppressed, and thus it is possible to emit highly uniform planar light. Become.
  • the surface light source device 20 and the transmissive image display device 1 including the light guide plate 30 can emit planar light with high uniformity.
  • Example 1 A PMMA plate (length: 370 mm, width: 320 mm, thickness: 4 mm) having a masking film bonded to both sides was prepared. Next, the masking film bonded to one surface was peeled from the PMMA plate. At this time, it was found by IR analysis (infrared spectroscopy) that the main component composition of the exposed surface of the PMMA plate was EVA (ethylene-vinyl acetate copolymer).
  • EVA ethylene-vinyl acetate copolymer
  • a scanning speed of 200 mm is applied to the surface of the PMMA plate that has been washed with water using an ink-jet head (printing width: 50 mm) and an ultraviolet curable resin ink having a volume of 40 pL and a viscosity of 8.3 mPa ⁇ s. It was printed at a resolution of 150 dpi at / sec.
  • the printed dot-like pattern is reflected by irradiating it with UV light with a UV integrated light quantity of 0.5 J / cm 2. Dots were formed. With the above manufacturing procedure, the light guide plate 30 having the reflective dots 36 was manufactured.
  • Example 2 The light guide plate 30 having the reflective dots 36 is manufactured by the same manufacturing procedure as in Example 1 except that the processes (1) to (3) in the water washing process are the contents of Example 2 shown in Table 1. It was done.
  • Example 3 The light guide plate 30 having the reflective dots 36 is manufactured by the same manufacturing procedure as in Example 1 except that the processes (1) to (3) in the water washing process are the contents of Example 3 shown in Table 1. It was done.
  • Example 4 The reflective dots 36 were formed by the same manufacturing procedure as in Example 1 except that the conveyance speed in the water washing process and the processes (1) to (3) in the water washing process were the same as those in Example 4 shown in Table 1.
  • the light guide plate 30 is manufactured.
  • the light guide plate 30 having the reflective dots 36 is manufactured by the same manufacturing procedure as in Example 1 except that no pretreatment for printing a dot-like pattern is performed on the exposed surface of the PMMA plate. It was.
  • Examples 1 to 4 and Comparative Example 1 were performed by visually observing the surface of the light guide plate on which the reflective dots were formed.
  • the evaluation results are shown in Table 2.
  • Table 2 “ ⁇ ” is shown when non-uniformity of reflection dot printing is not confirmed, and “X” is shown when confirmation is confirmed.
  • the contents of the water washing treatment are as shown in Table 1.
  • SYMBOLS 1 Transmission type image display apparatus, 10 ... Transmission type image display part, 11 ... Liquid crystal cell, 12 ... Polarizing plate, 20 ... Surface light source device, 22 ... Light source, 30 ... Light guide plate, 35 ... Translucent resin plate (resin Plate), 36 ... reflective dots, 37 ... dot-like pattern, 50 ... conveying means, 60 ... peeling device, 70 ... cleaning device, 71 ... first processing unit, 72 ... second processing unit, 73 ... third processing unit , 80 ... inkjet head, 90 ... UV lamp, 91 ... irradiation region, 95 ... inspection device, 100 ... light guide plate manufacturing device.

Abstract

A method for producing a light guide plate involves a peeling step, a water-rinsing step, and a printing step. In the peeling step, a masking film (MF) bonded to the surface of a light-transmissive resin plate (35) is peeled off therefrom. In the water-rinsing step, the surface (32) of the light-transmissive resin plate (35) from which the masking film (MF) was peeled is rinsed with water. In the printing step, an ink is arranged on the water-rinsed surface (32) of the light-transmissive resin plate (35) to thereby print a pattern (37) consisting of dots.

Description

導光板を製造する方法、導光板、これを備えた面光源装置および透過型画像表示装置Method for manufacturing light guide plate, light guide plate, surface light source device including the same, and transmissive image display device
　本発明は、導光板を製造する方法、導光板、これを備えた面光源装置および透過型画像表示装置に関する。 The present invention relates to a method of manufacturing a light guide plate, a light guide plate, a surface light source device including the same, and a transmissive image display device.
　液晶表示装置などの透過型画像表示装置は、一般に、バックライトとしての面光源装置を有している。エッジライト型面光源装置は、導光板およびその端面に光を供給する光源とから構成される。導光板の端面から入射した光が、導光板の背面側に設けられた反射ドットなどの反射手段によって反射し、導光板の出射面から画像表示用の面状の光が供給される。 2. Description of the Related Art A transmissive image display device such as a liquid crystal display device generally has a surface light source device as a backlight. The edge light type surface light source device includes a light guide plate and a light source that supplies light to an end surface thereof. Light incident from the end surface of the light guide plate is reflected by a reflecting means such as a reflective dot provided on the back side of the light guide plate, and planar light for image display is supplied from the exit surface of the light guide plate.
　導光板の反射ドット（配光パターン）を形成する方法として、インクジェット印刷が検討されている（特許文献１）。インクジェット印刷によれば、設計された所望のパターンを構成する反射ドットを簡易に形成できることが期待される。 Inkjet printing has been studied as a method for forming reflective dots (light distribution patterns) on a light guide plate (Patent Document 1). According to inkjet printing, it is expected that the reflective dots constituting the designed desired pattern can be easily formed.
特開２００４－２４０２９４号公報JP 2004-240294 A
　しかしながら、導光板の樹脂板の表面にインクジェット印刷により反射ドットを形成すると、反射ドットの印刷の均一性が低くなるという問題があった。例えば、反射ドットが所定の位置に印刷されなかったり、反射ドットの形状が円状でなかったり、隣接する反射ドット同士が接触したりするなど、必ずしも設計通りのドット状のパターンで反射ドットが形成されないことがあった。このようなドット状のパターンを有する導光板は、外観品位が低いだけでなく、均一性の高い面状の光を出射することができない。不均一な印刷（印刷ムラ）は、反射ドットの位置が部分的に異なる場合や、反射ドットの形状が部分的に異なる場合に発生する。反射ドット同士が接触する場合には、不均一な印刷は、その接触の程度が部分ごとに差異を有する場合においても発生する。 However, when reflective dots are formed on the surface of the resin plate of the light guide plate by ink jet printing, there is a problem that the uniformity of printing of the reflective dots is lowered. For example, reflective dots are not printed at a predetermined position, reflective dots are not circular, or adjacent reflective dots are in contact with each other. There were times when it was not. The light guide plate having such a dot pattern not only has a low appearance quality but also cannot emit planar light with high uniformity. Non-uniform printing (printing unevenness) occurs when the positions of the reflective dots are partially different or when the shapes of the reflective dots are partially different. When the reflective dots are in contact with each other, non-uniform printing occurs even when the degree of contact has a difference for each part.
　本願発明は、このような問題を解決するためになされたものであり、インクジェット印刷によってドット状のパターンを形成する場合において、ドット状のパターンの不均一な形成を抑制することが可能な導光板を製造する方法、この方法によって得ることができる導光板、これを備えた面光源装置および透過型画像表示装置を提供することを目的とする。 The present invention has been made to solve such a problem, and in the case of forming a dot-like pattern by inkjet printing, a light guide plate capable of suppressing the uneven formation of the dot-like pattern. An object of the present invention is to provide a method of manufacturing a light guide plate, a light guide plate obtainable by this method, a surface light source device including the same, and a transmissive image display device.
　本願発明者らは、鋭意検討を重ねた結果、反射ドットの印刷の不均一は、導光板となる樹脂板における保護フィルムの糊残りが原因であることを見出した。導光板となる樹脂板の表面には、搬送などにおける傷の発生、ほこりや汚れの付着などを回避するために、接着層を有する保護フィルムが貼合されている。導光板を製造する工程では、樹脂板から保護フォルムが剥離された後に、反射ドットからなるドット状のパターンが形成される。このとき、樹脂板の表面には保護フィルムの接着層による糊残りがある。この保護フィルムの糊残りに起因するドット状のパターンの不均一な形成は、近年の大画面かつ高解像度の液晶ディスプレイとなる導光板の高精細な反射ドットを形成する際に問題となる。 As a result of intensive studies, the inventors of the present application have found that the uneven printing of the reflective dots is caused by the adhesive residue of the protective film on the resin plate serving as the light guide plate. A protective film having an adhesive layer is bonded to the surface of the resin plate serving as the light guide plate in order to avoid generation of scratches during transportation and the like and adhesion of dust and dirt. In the process of manufacturing the light guide plate, after the protective form is peeled off from the resin plate, a dot-like pattern made of reflective dots is formed. At this time, there is adhesive residue due to the adhesive layer of the protective film on the surface of the resin plate. The non-uniform formation of the dot-like pattern resulting from the adhesive residue of the protective film becomes a problem when forming high-definition reflective dots on a light guide plate that becomes a large-screen and high-resolution liquid crystal display in recent years.
　そこで、本発明の導光板を製造する方法は、保護フィルムが表面に貼合された樹脂板から当該保護フィルムを剥離する剥離工程と、保護フィルムを剥離した樹脂板の表面を水洗処理する水洗処理工程と、水洗処理された樹脂板の表面にインクを配置することによって、ドット状のパターンが形成される印刷工程と、を備えている。 Then, the method of manufacturing the light guide plate of the present invention includes a peeling process for peeling the protective film from the resin plate having the protective film bonded to the surface, and a water washing treatment for washing the surface of the resin plate from which the protective film has been peeled. And a printing process in which a dot-like pattern is formed by disposing ink on the surface of the washed resin plate.
　この発明によれば、インクジェットによってドット状のパターンが形成される前に、樹脂板の表面が水洗処理されるので、ドット状のパターンの不均一な形成の原因と考えられる保護フィルムの糊残りが除去される。この結果、設計通りのドット状のパターンを形成することが可能となり、インクジェット印刷によってドット状のパターンを形成する場合において、ドット状のパターンの不均一な形成を抑制することが可能となる。 According to the present invention, since the surface of the resin plate is washed with water before the dot-like pattern is formed by inkjet, the adhesive film residue of the protective film, which is considered to cause the uneven formation of the dot-like pattern, is removed. Removed. As a result, it becomes possible to form a dot-like pattern as designed, and when forming a dot-like pattern by ink jet printing, it is possible to suppress the non-uniform formation of the dot-like pattern.
　本発明に係る方法では、インクが紫外線硬化インクであってもよい。 In the method according to the present invention, the ink may be an ultraviolet curable ink.
　本発明に係る導光板は、上記導光板を製造する方法によって得ることができる。この導光板は、ドット状のパターンがインクジェット印刷により形成される場合において、ドット状のパターンの不均一な形成が抑制されるので、外観品位が高くなると共に、均一性の高い面状の光を出射することが可能である。 The light guide plate according to the present invention can be obtained by a method for producing the light guide plate. This light guide plate suppresses the non-uniform formation of the dot-like pattern when the dot-like pattern is formed by inkjet printing, so that the appearance quality is improved and the surface light with high uniformity is emitted. It is possible to emit.
　本発明に係る面光源装置は、上記の導光板と、この導光板の端面に光を供給する光源と、備える構成とすることができる。また、本発明に係る透過型画像表示装置は、上記面光源装置と、面光源装置の導光板と対向して配置された透過型画像表示部と、備えた構成とすることができる。 The surface light source device according to the present invention can be configured to include the light guide plate described above and a light source that supplies light to the end face of the light guide plate. Moreover, the transmissive | pervious image display apparatus which concerns on this invention can be set as the structure provided with the said surface light source device and the transmissive | pervious image display part arrange | positioned facing the light-guide plate of a surface light source device.
　この面光源装置および透過型画像表示装置によれば、均一性の高い面状の光を出射することが可能となる。 According to the surface light source device and the transmissive image display device, it is possible to emit planar light with high uniformity.
　本発明によれば、インクジェット印刷によってドット状のパターンが形成される場合において、ドット状のパターンの不均一な形成を抑制することが可能となる。 According to the present invention, when a dot-like pattern is formed by ink jet printing, it is possible to suppress the non-uniform formation of the dot-like pattern.
図１は、本発明に係る透過型画像表示装置の一実施形態の構成を模式的に示す断面図である。FIG. 1 is a cross-sectional view schematically showing a configuration of an embodiment of a transmissive image display device according to the present invention. 図２は、本発明に係る面光源装置の一実施形態の構成を模式的に示す背面図である。FIG. 2 is a rear view schematically showing a configuration of an embodiment of the surface light source device according to the present invention. 図３は、導光板を製造する方法の一実施形態を示す模式図である。FIG. 3 is a schematic view showing an embodiment of a method for producing a light guide plate.
　以下、本発明の実施形態が、図面を参照しながら説明される。同一または相当要素には同一符号が付され、重複する説明が省略される。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.
　（透過型画像表示装置）
　透過型画像表示装置１は、透過型画像表示部１０と、図１において透過型画像表示部１０の背面側に配置された面光源装置２０とを備えている。以下の説明では、図１に示すように、面光源装置２０と透過型画像表示部１０の配列方向をＺ方向（板厚方向）と称され、Ｚ方向に直交する２方向であって互いに直交する２方向をＸ方向およびＹ方向と称される。 (Transparent image display device)
The transmissive image display device 1 includes a transmissive image display unit 10 and a surface light source device 20 disposed on the back side of the transmissive image display unit 10 in FIG. In the following description, as shown in FIG. 1, the arrangement direction of the surface light source device 20 and the transmissive image display unit 10 is referred to as a Z direction (plate thickness direction), which is two directions orthogonal to the Z direction and orthogonal to each other. These two directions are referred to as the X direction and the Y direction.
　透過型画像表示部１０の例には、例えば液晶セル１１の両面に偏光板１２，１２が配置された液晶表示パネルが含まれる。この場合、透過型画像表示装置１は液晶表示装置（又は液晶テレビ）である。液晶セル１１，偏光板１２，１２は、従来の液晶表示装置などの透過型画像表示装置１に内蔵されているものを用いることができる。液晶セル１１としてはＴＦＴ型の液晶セル、ＳＴＮ型の液晶セルなど、公知の液晶セルが例示される。 Examples of the transmissive image display unit 10 include, for example, a liquid crystal display panel in which polarizing plates 12 and 12 are disposed on both surfaces of a liquid crystal cell 11. In this case, the transmissive image display device 1 is a liquid crystal display device (or a liquid crystal television). As the liquid crystal cell 11 and the polarizing plates 12 and 12, those built in the transmissive image display device 1 such as a conventional liquid crystal display device can be used. Examples of the liquid crystal cell 11 include known liquid crystal cells such as TFT liquid crystal cells and STN liquid crystal cells.
　（面光源装置）
　図２は、本発明に係る面光源装置の一実施形態の構成を模式的に示す背面図である。面光源装置２０は、図１および図２に示すように、導光板３０と、導光板３０における透光性樹脂板３５の側面（端面）３３と対向して配置されたＬＥＤ光源２２とを備えたエッジライト型面光源装置である。なお、導光板３０における透光性樹脂板３５の正面側において、導光板３０と透過型画像表示部１０との間に、各種フィルム４１が配置されている構成でもよい。各種フィルム４１としては、拡散フィルム、プリズムフィルム、輝度向上フィルムなどが挙げられる。 (Surface light source device)
FIG. 2 is a rear view schematically showing a configuration of an embodiment of the surface light source device according to the present invention. As shown in FIGS. 1 and 2, the surface light source device 20 includes a light guide plate 30 and an LED light source 22 disposed to face a side surface (end surface) 33 of a light-transmitting resin plate 35 in the light guide plate 30. Edge light type surface light source device. In addition, the structure by which the various films 41 are arrange | positioned between the light guide plate 30 and the transmissive image display part 10 in the front side of the translucent resin board 35 in the light guide plate 30 may be sufficient. Examples of the various films 41 include a diffusion film, a prism film, and a brightness enhancement film.
　（光源）
　ＬＥＤ光源２２は、面光源装置２０の点状光源として機能するものであり、図２に示すように、導光板３０における透光性樹脂板３５のＹ軸方向に延在する側面３３，３３と対向して配置されている。複数のＬＥＤ光源２２は、側面３３の長手方向（Ｙ軸方向）に沿って、離散的に配置されている。ＬＥＤ光源２２の配置間隔は、通常５ｍｍ～２０ｍｍである。点状光源は、導光板３０における透光性樹脂板３５の４辺とそれぞれ対向するように配置されてもよいし、透光性樹脂板３５のＸ軸方向に対向する２辺にそれぞれ対向するように配置されてもよいし、透光性樹脂板３５のＹ軸方向に対向する２辺にそれぞれ対向するように配置されてもよいし、透光性樹脂板３５の１辺のみに対向するように配置されてもよい。また、点状光源は、ＬＥＤ光源に限らずその他の点状光源でもよい。さらに、光源は、点状光源に限定されず、線状光源（ＣＣＦＬ：冷陰極管）が配置されている構成でもよい。 (light source)
The LED light source 22 functions as a point light source of the surface light source device 20, and as shown in FIG. 2, side surfaces 33, 33 extending in the Y-axis direction of the translucent resin plate 35 in the light guide plate 30. Opposed to each other. The plurality of LED light sources 22 are discretely arranged along the longitudinal direction (Y-axis direction) of the side surface 33. The arrangement interval of the LED light sources 22 is usually 5 mm to 20 mm. The point light sources may be arranged so as to face the four sides of the light-transmitting resin plate 35 in the light guide plate 30, respectively, or face the two sides facing the X-axis direction of the light-transmitting resin plate 35. May be arranged so as to be opposed to two sides of the translucent resin plate 35 facing each other in the Y-axis direction, or opposed to only one side of the translucent resin plate 35. May be arranged as follows. Further, the point light source is not limited to the LED light source, but may be other point light sources. Furthermore, the light source is not limited to a point light source, and may be a configuration in which a linear light source (CCFL: cold cathode tube) is arranged.
　ＬＥＤ光源２２は、白色ＬＥＤでもよく、一つの箇所に複数のＬＥＤを配置して一つの光源単位を構成してもよい。例えば、一つの光源単位として、赤色、緑色、青色の異なる三色のＬＥＤが、近接されて並べられて配置されていてもよい。そして、複数のＬＥＤを有する光源単位が、上述した配置方向に従い離散的に配置される。このような場合には、異なるＬＥＤ同士は可能な限り近づけられて配置されていることが好ましい。 The LED light source 22 may be a white LED, and a plurality of LEDs may be arranged in one place to constitute one light source unit. For example, as one light source unit, LEDs of three colors of red, green, and blue may be arranged in close proximity to each other. And the light source unit which has several LED is discretely arrange | positioned according to the arrangement | positioning direction mentioned above. In such a case, it is preferable that different LEDs are arranged as close as possible.
　ＬＥＤ光源２２は、様々な出光分布を有するものが使用可能である。ＬＥＤ光源２２としては、ＬＥＤ光源の法線方向の光度が最大であり、光度分布の半値幅が４０度以上８０以下である出光分布を有するものが、好適である。また、ＬＥＤ光源のタイプとしては、具体的に、ランバーシアン型、砲弾型、サイドエミッション型などが挙げられる。 LED light sources 22 having various light output distributions can be used. The LED light source 22 preferably has a light intensity distribution in which the luminous intensity in the normal direction of the LED light source is maximum and the half value width of the light intensity distribution is 40 degrees or more and 80 or less. Specific examples of the LED light source type include a Lambertian type, a shell type, and a side emission type.
　（導光板）
　導光板３０は、透光性樹脂板３５と、透光性樹脂板３５の背面３２に所定のドット状のパターン３７に配置される複数の反射ドット３６とを有する。図２に示すように、透光性樹脂板３５は、長方形を成し、平面視形状のサイズは目的とする透過型画像表示部１０の画面サイズに適合するように選択される。透光性樹脂板３５の平面視形状は、長方形に限らず、正方形とされてもよい。以下の説明では、特に断らない限り、透光性樹脂板３５の平面視形状は、長方形として説明される。 (Light guide plate)
The light guide plate 30 includes a translucent resin plate 35 and a plurality of reflective dots 36 arranged in a predetermined dot-shaped pattern 37 on the back surface 32 of the translucent resin plate 35. As shown in FIG. 2, the translucent resin plate 35 has a rectangular shape, and the size of the plan view shape is selected so as to match the target screen size of the transmissive image display unit 10. The planar view shape of the translucent resin plate 35 is not limited to a rectangle, and may be a square. In the following description, unless otherwise specified, the plan view shape of the translucent resin plate 35 is described as a rectangle.
　透光性樹脂板３５は、光を透過させる透光性樹脂から形成され板状を成している。透光性樹脂としては、ポリメチルメタクリレート（ＰＭＭＡ）、ポリ（メタ）アクリル酸アルキル樹脂、ポリスチレンシート又はポリカーボネート系樹脂を用いることができる。透光性樹脂板３５は、シート状でもよく、フィルム状でもよい。透光性樹脂板３５の厚みＴは、１．０ｍｍ以上４．５ｍｍ以下であることが好ましい。 The translucent resin plate 35 is formed of a translucent resin that transmits light and has a plate shape. As the translucent resin, polymethyl methacrylate (PMMA), poly (meth) acrylic acid alkyl resin, polystyrene sheet or polycarbonate resin can be used. The translucent resin plate 35 may be a sheet or a film. The thickness T of the translucent resin plate 35 is preferably 1.0 mm or greater and 4.5 mm or less.
　透光性樹脂板３５は、Ｚ軸方向（厚み方向）に対向する一対の表面３１，３２、Ｘ軸方向に対向する一対の側面３３，３３およびＹ軸方向に対向する一対の側面３４，３４を備えている。表面３１，３２は、側面３３，３４と交差する方向に形成されている。 The translucent resin plate 35 includes a pair of surfaces 31 and 32 facing in the Z-axis direction (thickness direction), a pair of side surfaces 33 and 33 facing in the X-axis direction, and a pair of side surfaces 34 and 34 facing in the Y-axis direction. It has. The surfaces 31 and 32 are formed in a direction intersecting with the side surfaces 33 and 34.
　Ｚ軸方向に対向する一対の表面のうち一方の表面３１は、面状の光を出射可能な出射面として機能する。出射面としての表面３１は、透過型画像表示部１０側に配置され、他方の表面（背面３２）は、透過型画像表示部１０とは反対側に配置される。また、背面３２と対向する位置には、導光板３０内の光を出射面としての表面３１側へ反射させる反射シート４２が配置されている。透光性樹脂板３５の反射ドット３６が形成される表面（背面３２）とは反対側の表面３１は、本実施形態のように平坦面であってもよいし、凹凸形状を有していてもよい。 One surface 31 of the pair of surfaces opposed to each other in the Z-axis direction functions as an emission surface that can emit planar light. The surface 31 as the emission surface is disposed on the transmissive image display unit 10 side, and the other surface (back surface 32) is disposed on the side opposite to the transmissive image display unit 10. In addition, a reflection sheet 42 that reflects the light in the light guide plate 30 toward the front surface 31 as an emission surface is disposed at a position facing the back surface 32. The surface 31 opposite to the surface (back surface 32) on which the reflective dots 36 of the translucent resin plate 35 are formed may be a flat surface as in the present embodiment, or has an uneven shape. Also good.
　（反射加工）
　図２および図３に示すように、透光性樹脂板３５の背面３２には、光を乱反射させる反射加工として反射ドット３６からなる所定のドット状のパターン３７が形成されている。本実施形態の導光板３０では、インクジェット印刷によって当該ドット状のパターン３７が形成されている。ドット状のパターン３７の形成には、光を拡散させる拡散粒子を有するインクが使用されている。ドット状のパターン３７を構成する各反射ドット３６の径は、図２に示すように、光源側から離間するにつれて大きくなるように形成されていてもよい。
　本実施形態のように、エッジライト型の面光源装置では、光源２２、すなわち透光性樹脂板３５の側面３３に近い領域ほど光が強く、側面３３から遠ざかる領域ほど光が弱くなる。そのため、透光性樹脂板３５の出射面３１から出射される光の輝度が略均一になるように、側面３３からの距離に応じて、反射ドット３６の径が大きくされる。 (Reflection processing)
As shown in FIGS. 2 and 3, a predetermined dot-shaped pattern 37 made of reflective dots 36 is formed on the back surface 32 of the translucent resin plate 35 as a reflection process for irregularly reflecting light. In the light guide plate 30 of the present embodiment, the dot-shaped pattern 37 is formed by ink jet printing. For the formation of the dot-shaped pattern 37, ink having diffusion particles that diffuse light is used. As shown in FIG. 2, the diameter of each reflective dot 36 constituting the dot-shaped pattern 37 may be formed so as to increase as the distance from the light source side increases.
As in the present embodiment, in the edge light type surface light source device, the light is stronger in the region closer to the light source 22, that is, the side surface 33 of the translucent resin plate 35, and the light is weaker in the region farther from the side surface 33. Therefore, the diameter of the reflective dot 36 is increased according to the distance from the side surface 33 so that the luminance of the light emitted from the emission surface 31 of the translucent resin plate 35 becomes substantially uniform.
　（導光板の製造装置）
　次に、上記面光源装置２０および透過型画像表示装置１に含まれている導光板３０を製造する方法が説明される。図３は、導光板の製造装置の一実施形態を示す模式図である。図３に示す導光板の製造装置１００は、搬送手段５０と、剥離装置６０と、洗浄装置７０と、インクジェットヘッド８０と、ＵＶランプ９０と、検査装置９５とを備えている。搬送手段５０と、剥離装置（剥離部）６０と、洗浄装置（水洗処理部）７０と、インクジェットヘッド（印刷部）８０と、ＵＶランプ９０と、検査装置９５とは、透光性樹脂板（樹脂板）３５の移動方向Ａに沿って上流側からこの順に配置される。 (Light guide plate manufacturing equipment)
Next, a method for manufacturing the light guide plate 30 included in the surface light source device 20 and the transmissive image display device 1 will be described. FIG. 3 is a schematic view showing an embodiment of a light guide plate manufacturing apparatus. The light guide plate manufacturing apparatus 100 shown in FIG. 3 includes a conveying means 50, a peeling device 60, a cleaning device 70, an inkjet head 80, a UV lamp 90, and an inspection device 95. The transport means 50, the peeling device (peeling unit) 60, the cleaning device (water washing processing unit) 70, the inkjet head (printing unit) 80, the UV lamp 90, and the inspection device 95 are made of a translucent resin plate ( (Resin plate) are arranged in this order from the upstream side along the moving direction A of the resin plate 35.
　搬送手段５０は、方向Ａに沿って連続的又は間欠的に原板となる透光性樹脂板３５を搬送する。本実施形態における搬送手段５０の例には、テーブルシャトル、ベルトコンベア、コロ、又はエア浮上移送などが含まれる。 The conveying means 50 conveys the translucent resin plate 35 that becomes the original plate continuously or intermittently along the direction A. Examples of the conveying means 50 in the present embodiment include a table shuttle, a belt conveyor, a roller, or air floating transfer.
　剥離装置６０は、片面又は両面にマスキングフィルム（保護フィルム）ＭＦが貼合された透光性樹脂板３５（図３では下面のみに貼付された例を図示している）からマスキングフィルムＭＦを剥離して、反射ドット３６が形成される透光性樹脂板３５の表面３２を露出させる（剥離工程）。 The peeling device 60 peels the masking film MF from the translucent resin plate 35 (an example attached to only the lower surface in FIG. 3) in which the masking film (protective film) MF is bonded to one side or both sides. Then, the surface 32 of the translucent resin plate 35 on which the reflective dots 36 are formed is exposed (peeling process).
　洗浄装置７０は、透光性樹脂板３５を搬送しながら、剥離装置６０によって露出された透光性樹脂板３５の表面３２を水洗処理する（水洗処理工程）。洗浄装置７０は、第１処理部７１と、第２処理部７２と、第３処理部７３とを有しており、この順番で、透光性樹脂板３５の表面３２を水洗処理する。透光性樹脂板３５の搬送速度として、１～４００ｍｍ／ｓｅｃが例示される。 The cleaning device 70 performs a water-washing process on the surface 32 of the light-transmitting resin plate 35 exposed by the peeling device 60 while carrying the light-transmitting resin plate 35 (water-washing process step). The cleaning device 70 includes a first processing unit 71, a second processing unit 72, and a third processing unit 73, and the surface 32 of the translucent resin plate 35 is washed with water in this order. Examples of the conveying speed of the translucent resin plate 35 include 1 to 400 mm / sec.
　第１処理部７１は、マスキングフィルムＭＦが貼合されていた透光性樹脂板３５の表面３２に対して、純水シャワーの打撃力により、表面３２の汚れ(糊、塵埃など)を剥離させる第１水洗処理工程を担う部分である。第１処理工程における純水シャワーの圧力として０．１～０．３ＭＰａ、水量として５．０～２０Ｌ／ｍｉｎ、処理時間として１～６００ｓｅｃが例示される。例えば、純水シャワーの圧力が０．２５ＭＰａ、水量が２０Ｌ／ｍｉｎ、処理時間が１５ｓｅｃとされ得る。 The 1st process part 71 peels the stain | pollution | contamination (glue, dust, etc.) of the surface 32 with the striking force of a pure water shower with respect to the surface 32 of the translucent resin board 35 with which the masking film MF was bonded. It is a part which bears a 1st water-washing process process. Examples of the pressure of the pure water shower in the first treatment step are 0.1 to 0.3 MPa, the amount of water is 5.0 to 20 L / min, and the treatment time is 1 to 600 sec. For example, the pressure of the pure water shower can be 0.25 MPa, the amount of water is 20 L / min, and the treatment time can be 15 sec.
　第２処理部７２は、第１処理部７１による処理の後、透光性樹脂板３５の表面３２に対して、純水とＣＤＡ（Clean Dry Air）とによる２流体シャワーの打撃力により、表面３２の汚れ(糊、塵埃など)を剥離させる第２水洗処理工程を担う部分である。第２処理工程における２流体シャワーの圧力として０．１～０．２ＭＰａ、エアー量として２００～１０００Ｌ／ｍｉｎ、水量として５．０～２０Ｌ／ｍｉｎ、処理時間として０．６～６００ｓｅｃが例示される。例えば、圧力が０．１６ＭＰａ、エアー量が５００Ｌ／ｍｉｎ、水量が１４Ｌ／ｍｉｎ、処理時間が３ｓｅｃとされ得る。 After the processing by the first processing unit 71, the second processing unit 72 is applied to the surface 32 of the translucent resin plate 35 by the striking force of two-fluid shower with pure water and CDA (Clean Dry Air). This is the part responsible for the second water washing treatment step for peeling 32 dirt (glue, dust, etc.). In the second treatment step, the pressure of the two-fluid shower is 0.1 to 0.2 MPa, the air amount is 200 to 1000 L / min, the water amount is 5.0 to 20 L / min, and the treatment time is 0.6 to 600 sec. . For example, the pressure may be 0.16 MPa, the air amount may be 500 L / min, the water amount may be 14 L / min, and the processing time may be 3 sec.
　第３処理部７３は、第２処理部７２による処理の後、透光性樹脂板３５の表面３２に対してガス噴出口から吐き出される気体流を吹きつけ、第１および第２水洗処理工程における水分を除去する（エアーナイフ）第３水洗処理工程を担う部分である。第３処理工程におけるエアーナイフのエアー量として１００～１０００Ｌ／ｍｉｎが例示される。例えば、エアー量が７５０Ｌ／ｍｉｎとされ得る。 The 3rd process part 73 blows the gas flow discharged from a gas ejection port with respect to the surface 32 of the translucent resin board 35 after the process by the 2nd process part 72, and in the 1st and 2nd water washing process process It is a part responsible for the third water washing treatment step for removing moisture (air knife). Examples of the air amount of the air knife in the third treatment step are 100 to 1000 L / min. For example, the air amount can be 750 L / min.
　インクジェットヘッド８０は、搬送手段５０により搬送される透光性樹脂板３５の背面側である表面３２にインクを配置して所望のドット状のパターン３７を形成する（印刷工程）。インクジェットヘッド８０は、透光性樹脂板３５の反射ドット３６が形成される領域の幅方向（搬送方向Ａに対して垂直な方向）全体にわたって、透光性樹脂板３５の表面３２に対向して配置された複数のノズル（図示せず）を有している。インクジェットヘッド８０は、この構成により、透光性樹脂板３５の幅方向全体にわたり同時に反射ドット３６を印刷することができる。 The inkjet head 80 disposes ink on the surface 32 on the back side of the translucent resin plate 35 conveyed by the conveying means 50 to form a desired dot-shaped pattern 37 (printing process). The inkjet head 80 faces the surface 32 of the translucent resin plate 35 over the entire width direction (direction perpendicular to the transport direction A) of the region where the reflective dots 36 of the translucent resin plate 35 are formed. It has a plurality of nozzles (not shown) arranged. With this configuration, the inkjet head 80 can simultaneously print the reflective dots 36 over the entire width direction of the translucent resin plate 35.
　反射ドット３６を形成するためのインクジェット印刷において用いられるインクとしては、光を拡散させるための拡散粒子と、印刷後の硬化処理にて硬化し透光性樹脂板３５に対して密着性を有する樹脂とを含有するインクが好適に用いられる。このインクは、拡散粒子を含まず、硬化後の樹脂によるプリズム効果によって光を拡散させるものであってもよい。 The ink used in the ink jet printing for forming the reflective dots 36 includes a diffusing particle for diffusing light and a resin that is cured by a curing process after printing and has adhesion to the translucent resin plate 35. Are preferably used. This ink may not contain diffusing particles and may diffuse light by the prism effect of the cured resin.
　拡散粒子としては、二酸化チタン、炭酸カルシウム、硫酸バリウム、シリカなどが例示されるが、拡散粒子はこれに限定されるものではない。拡散粒子は、特定の波長の光を選択的に吸収することのないよう、無色あるいは白色であることが好ましい。 Examples of the diffusing particles include titanium dioxide, calcium carbonate, barium sulfate, and silica, but the diffusing particles are not limited thereto. The diffusing particles are preferably colorless or white so as not to selectively absorb light of a specific wavelength.
　樹脂成分としては、各種の水溶性樹脂、溶剤系樹脂およびエマルジョン型の樹脂の他、紫外線硬化樹脂などを用いることができる。これらの中でも、環境対策の容易さなどの観点から、水溶性樹脂および紫外線硬化樹脂が樹脂成分として好ましい。ここでは、紫外線硬化樹脂を用いた場合について、硬化手段としてＵＶランプ９０による紫外線照射が採用された例が説明される。樹脂成分として水溶性樹脂、溶剤系樹脂およびエマルジョン型樹脂を用いた場合においては、硬化手段として熱による乾燥が採用される。 As the resin component, various water-soluble resins, solvent-based resins and emulsion-type resins, as well as ultraviolet curable resins can be used. Among these, water-soluble resins and ultraviolet curable resins are preferred as resin components from the viewpoint of ease of environmental measures. Here, in the case of using an ultraviolet curable resin, an example in which ultraviolet irradiation by a UV lamp 90 is adopted as a curing means will be described. In the case where a water-soluble resin, a solvent-based resin and an emulsion type resin are used as the resin component, drying by heat is adopted as a curing means.
　インクジェットヘッド８０による印刷は、透光性樹脂板３５を一定の速度で連続的に移動させながら行うことができる。インクジェットヘッド８０による印刷は、透光性樹脂板３５を停止させた状態で印刷すること、および透光性樹脂板３５を次の印刷位置まで移動させてから停止することを繰り返しながら印刷することもできる。このようにして印刷された透光性樹脂板３５は、搬送方向下流側に搬送される。 Printing by the inkjet head 80 can be performed while moving the translucent resin plate 35 continuously at a constant speed. Printing by the inkjet head 80 may be performed while repeating the printing with the translucent resin plate 35 stopped and the movement of the translucent resin plate 35 to the next printing position and then stopping. it can. The translucent resin plate 35 printed in this way is transported downstream in the transport direction.
　ＵＶランプ９０は、搬送手段５０により上流側から搬送されてくるドット状のパターン３７が形成された透光性樹脂板３５に対して照射領域９１において紫外線を照射する。透光性樹脂板３５上のインクは、ＵＶランプ９０により紫外線が照射されることによって硬化する。これにより、硬化したインクからなる反射ドット３６が形成される。 The UV lamp 90 irradiates the translucent resin plate 35 on which the dot-shaped pattern 37 conveyed from the upstream side by the conveying means 50 is irradiated with ultraviolet rays in the irradiation region 91. The ink on the translucent resin plate 35 is cured by being irradiated with ultraviolet rays from the UV lamp 90. Thereby, the reflective dots 36 made of the cured ink are formed.
　検査装置９５は、形成された反射ドット３６の状態を検査する。導光板３０は、以上のような工程を経て形成される。導光板３０は、必要により所望のサイズに裁断される。本実施形態のように、インクジェットヘッドの下流側に設けられた検査装置９５により導光板３０が連続的に検査される必要は必ずしもなく、別途準備された検査装置によりオフラインで導光板を検査することもできる。 The inspection device 95 inspects the state of the formed reflective dots 36. The light guide plate 30 is formed through the processes described above. The light guide plate 30 is cut into a desired size as necessary. As in the present embodiment, the light guide plate 30 does not necessarily have to be continuously inspected by the inspection device 95 provided on the downstream side of the inkjet head, and the light guide plate is inspected offline by a separately prepared inspection device. You can also.
　本実施形態に係る導光板を製造する方法では、透光性樹脂板３５の表面３２、特に背面となる表面３２にマスキングフィルムＭＦが貼合されていることにより、背面３２における傷および汚れの発生が防止される。背面３２に傷があったり、汚れが付着していたりすると、インクの濡れ拡がり方が不均一となり、このことが反射ドット３６の均一性が低下する原因となり得るからである。ただし、マスキングフィルムＭＦを透光性樹脂板３５から剥離した際に、マスキングフィルムＭＦの糊が背面３２上にわずかに残る場合がある。残った糊に起因して、ドット状のパターン３７が形成された際に当該ドット状のパターン３７にスジ状の欠陥が生じたり、不均一な印刷（印刷ムラ）が生じたりすることがある。本実施形態の方法では、導光板３０の背面３２を水洗処理するので、糊の影響が低減される。このため、背面３２にマスキングフィルムＭＦが貼合されていた場合であっても、反射ドット３６形成用のドット状のパターン３７が、高い均一性で印刷される。 In the method of manufacturing the light guide plate according to the present embodiment, the masking film MF is bonded to the surface 32 of the translucent resin plate 35, particularly the surface 32 serving as the back surface, thereby generating scratches and dirt on the back surface 32. Is prevented. This is because if the back surface 32 is scratched or has dirt, the ink wets and spreads unevenly, and this may cause the uniformity of the reflective dots 36 to deteriorate. However, when the masking film MF is peeled from the translucent resin plate 35, the paste of the masking film MF may remain slightly on the back surface 32. Due to the remaining glue, when the dot-shaped pattern 37 is formed, a streak-like defect may occur in the dot-shaped pattern 37 or uneven printing (printing unevenness) may occur. In the method of this embodiment, the back surface 32 of the light guide plate 30 is washed with water, so that the influence of glue is reduced. For this reason, even if the masking film MF is bonded to the back surface 32, the dot-shaped pattern 37 for forming the reflective dots 36 is printed with high uniformity.
　この実施形態により製造された導光板３０は、インクジェット印刷によってドット状のパターンを形成する場合に、不均一な印刷が抑制されるので、均一性の高い面状の光を出射することが可能となる。この導光板３０を備える面光源装置２０、透過型画像表示装置１は、均一性の高い面状の光を出射することが可能となる。 Since the light guide plate 30 manufactured according to this embodiment forms a dot-like pattern by inkjet printing, non-uniform printing is suppressed, and thus it is possible to emit highly uniform planar light. Become. The surface light source device 20 and the transmissive image display device 1 including the light guide plate 30 can emit planar light with high uniformity.
　以下、本発明が、実施例に基づいてさらに具体的に説明される。ただし、本発明は、これらの実施例に限定されるものではない。 Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples.
（実施例１）
　マスキングフィルムが両面に貼合されたＰＭＭＡ板（長さ３７０ｍｍ、幅３２０ｍｍ、厚み４ｍｍ）が準備された。次に、片方の面に貼合されたマスキングフィルムがＰＭＭＡ板から剥離された。このとき、露出されたＰＭＭＡ板の表面の主成分組成がＥＶＡ（エチレン・酢酸ビニル共重合体）であることが、ＩＲ分析（赤外分光分析）により分かった。 Example 1
A PMMA plate (length: 370 mm, width: 320 mm, thickness: 4 mm) having a masking film bonded to both sides was prepared. Next, the masking film bonded to one surface was peeled from the PMMA plate. At this time, it was found by IR analysis (infrared spectroscopy) that the main component composition of the exposed surface of the PMMA plate was EVA (ethylene-vinyl acetate copolymer).
　次に、ドット状のパターンを印刷する前処理として、露出したＰＭＭＡ板の表面に対して、以下の表１に示す条件で水洗処理（１）～（３）が、この順番に行われた。
Figure JPOXMLDOC01-appb-T000001
 Next, as a pretreatment for printing a dot-shaped pattern, water washing treatments (1) to (3) were performed in this order on the exposed surface of the PMMA plate under the conditions shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
　次に、水洗処理が成されたＰＭＭＡ板の表面に対して、インクジェットヘッド（印字幅５０ｍｍ）を用いて、体積が４０ｐＬ、粘度が８．３ｍＰａ・ｓの紫外線硬化樹脂のインクによって、走査速度２００ｍｍ／ｓｅｃで１５０ｄｐｉの解像度で印刷された。 Next, a scanning speed of 200 mm is applied to the surface of the PMMA plate that has been washed with water using an ink-jet head (printing width: 50 mm) and an ultraviolet curable resin ink having a volume of 40 pL and a viscosity of 8.3 mPa · s. It was printed at a resolution of 150 dpi at / sec.
　次に、印刷されたドット状のパターンに対して、ＰＭＭＡ板の表面にインクが着弾してから２秒後に、ＵＶランプを用いてＵＶ積算光量０．５Ｊ／ｃｍ２の紫外線を照射して反射ドットを形成させた。以上の製造手順により、反射ドット３６を有する導光板３０が製造された。 Next, 2 seconds after the ink lands on the surface of the PMMA plate, the printed dot-like pattern is reflected by irradiating it with UV light with a UV integrated light quantity of 0.5 J / cm 2. Dots were formed. With the above manufacturing procedure, the light guide plate 30 having the reflective dots 36 was manufactured.
（実施例２）
　水洗処理における（１）～（３）の各処理を表１に示す実施例２の内容としたこと以外は、上記実施例１と同様の製造手順により、反射ドット３６を有する導光板３０が製造された。
（実施例３）
　水洗処理における（１）～（３）の各処理を表１に示す実施例３の内容としたこと以外は、上記実施例１と同様の製造手順により、反射ドット３６を有する導光板３０が製造された。
（実施例４）
　水洗処理における搬送速度および水洗処理における（１）～（３）の各処理を表１に示す実施例４の内容としたこと以外は、上記実施例１と同様の製造手順により、反射ドット３６を有する導光板３０が製造された。 (Example 2)
The light guide plate 30 having the reflective dots 36 is manufactured by the same manufacturing procedure as in Example 1 except that the processes (1) to (3) in the water washing process are the contents of Example 2 shown in Table 1. It was done.
(Example 3)
The light guide plate 30 having the reflective dots 36 is manufactured by the same manufacturing procedure as in Example 1 except that the processes (1) to (3) in the water washing process are the contents of Example 3 shown in Table 1. It was done.
Example 4
The reflective dots 36 were formed by the same manufacturing procedure as in Example 1 except that the conveyance speed in the water washing process and the processes (1) to (3) in the water washing process were the same as those in Example 4 shown in Table 1. The light guide plate 30 is manufactured.
（比較例１）
　露出したＰＭＭＡ板の表面に対して、ドット状のパターンを印刷する前処理を何もしなかったこと以外は、上記実施例１と同様の製造手順により、反射ドット３６を有する導光板３０が製造された。 (Comparative Example 1)
The light guide plate 30 having the reflective dots 36 is manufactured by the same manufacturing procedure as in Example 1 except that no pretreatment for printing a dot-like pattern is performed on the exposed surface of the PMMA plate. It was.
　本評価では、上記実施例１～４、比較例１について、反射ドットが形成された導光板の表面を目視にて観察することで行った。その評価結果が、表２に示される。表２では、反射ドットの印刷の不均一が確認されなかった場合に「○」が示され、確認された場合に「×」が示されている。なお、水洗処理の内容については、表１に示すとおりである。 In this evaluation, Examples 1 to 4 and Comparative Example 1 were performed by visually observing the surface of the light guide plate on which the reflective dots were formed. The evaluation results are shown in Table 2. In Table 2, “◯” is shown when non-uniformity of reflection dot printing is not confirmed, and “X” is shown when confirmation is confirmed. The contents of the water washing treatment are as shown in Table 1.
　この評価結果によれば、ドット状のパターンを印刷する前処理として、ＰＭＭＡ板における保護フィルムを剥離した印刷面を所定の条件で水洗処理することによって、ドット状のパターンの印刷の不均一を抑制できることが確認された。
Figure JPOXMLDOC01-appb-T000002
 According to this evaluation result, as a pretreatment for printing a dot pattern, the printing surface of the PMMA plate from which the protective film has been peeled is washed with water under predetermined conditions, thereby suppressing uneven printing of the dot pattern. It was confirmed that it was possible.
Figure JPOXMLDOC01-appb-T000002
　以上、本発明に係る実施形態および実施例について説明されたが、本発明は、これらに限定されるものではなく、発明の趣旨を逸脱しない範囲で種々の変更が可能である。 As mentioned above, although embodiment and the Example which concern on this invention were described, this invention is not limited to these, A various change is possible in the range which does not deviate from the meaning of invention.
　上記実施形態においては、剥離工程と水洗処理工程と印刷工程とが一連のラインで製造される導光板の製造装置の例が挙げられて説明された。本発明はこれに限定されるものではなく、それぞれの工程は、それぞれ別に用意された装置で行われてもよい。 In the above embodiment, an example of a light guide plate manufacturing apparatus in which the peeling process, the water washing process, and the printing process are manufactured in a series of lines has been described. The present invention is not limited to this, and each step may be performed by a separately prepared apparatus.
　１…透過型画像表示装置、１０…透過型画像表示部、１１…液晶セル、１２…偏光板、２０…面光源装置、２２…光源、３０…導光板、３５…透光性樹脂板（樹脂板）、３６…反射ドット、３７…ドット状のパターン、５０…搬送手段、６０…剥離装置、７０…洗浄装置、７１…第１処理部、７２…第２処理部、７３…第３処理部、８０…インクジェットヘッド、９０…ＵＶランプ、９１…照射領域、９５…検査装置、１００…導光板の製造装置。 DESCRIPTION OF SYMBOLS 1 ... Transmission type image display apparatus, 10 ... Transmission type image display part, 11 ... Liquid crystal cell, 12 ... Polarizing plate, 20 ... Surface light source device, 22 ... Light source, 30 ... Light guide plate, 35 ... Translucent resin plate (resin Plate), 36 ... reflective dots, 37 ... dot-like pattern, 50 ... conveying means, 60 ... peeling device, 70 ... cleaning device, 71 ... first processing unit, 72 ... second processing unit, 73 ... third processing unit , 80 ... inkjet head, 90 ... UV lamp, 91 ... irradiation region, 95 ... inspection device, 100 ... light guide plate manufacturing device.

Claims (5)

  1. 　保護フィルムが表面に貼合された樹脂板から当該保護フィルムを剥離する剥離工程と、
    　前記保護フィルムを剥離した樹脂板の表面を水洗処理する水洗処理工程と、
    　前記水洗処理された樹脂板の表面にインクを配置することによって、ドット状のパターンを形成する印刷工程と、
    を備える、導光板を製造する方法。     A peeling step for peeling the protective film from the resin plate having the protective film bonded to the surface;
    A water washing treatment step of washing the surface of the resin plate from which the protective film has been peeled off,
    A printing step of forming a dot-like pattern by disposing ink on the surface of the water-washed resin plate;
    A method of manufacturing a light guide plate.
  2. 　前記インクが紫外線硬化インクである、請求項１に記載の方法。 The method according to claim 1, wherein the ink is an ultraviolet curable ink.
  3. 　請求項１又は２に記載の導光板を製造する方法によって得ることのできる導光板。 A light guide plate obtainable by the method for producing the light guide plate according to claim 1.
  4. 　請求項３に記載の導光板と、
    　前記導光板の端面に光を供給する光源と、
    を備える、面光源装置。     The light guide plate according to claim 3,
    A light source for supplying light to an end face of the light guide plate;
    A surface light source device.
  5. 　請求項４に記載の面光源装置と、
    　前記面光源装置の導光板と対向して配置された透過型画像表示部と、
    を備える、透過型画像表示装置。     A surface light source device according to claim 4,
    A transmissive image display unit disposed opposite to the light guide plate of the surface light source device;
    A transmissive image display device.
PCT/JP2012/052033 2011-02-01 2012-01-30 Method for producing light guide plate, light guide plate, planar light-source device provided with same, and transmissive image-display device WO2012105518A1 (en)

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Citations (3)

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JP2002277642A (en) * 2001-03-16 2002-09-25 Sanyo Electric Co Ltd Method for manufacturing light guide body, light guide body manufactured by the method, face illumination device, and display device
JP2005131783A (en) * 2003-10-07 2005-05-26 Sumitomo Chemical Co Ltd Method of manufacturing transparent resin light conductive plate
JP2005249882A (en) * 2004-03-01 2005-09-15 Miyakawa:Kk Liquid crystal display device

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JP2004240294A (en) * 2003-02-07 2004-08-26 Seiko Epson Corp Method of manufacturing electro-optic panel and electro-optic panel, and electro-optic device and electronic device equipped with the electr-optic panel

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
JP2002277642A (en) * 2001-03-16 2002-09-25 Sanyo Electric Co Ltd Method for manufacturing light guide body, light guide body manufactured by the method, face illumination device, and display device
JP2005131783A (en) * 2003-10-07 2005-05-26 Sumitomo Chemical Co Ltd Method of manufacturing transparent resin light conductive plate
JP2005249882A (en) * 2004-03-01 2005-09-15 Miyakawa:Kk Liquid crystal display device

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