JP3198519U - Reflective member for surface light source and surface light source using the same - Google Patents

Abstract

A surface light source having a structure capable of easily obtaining a surface light source without wasting a release paper and preparing a light reflection plate in advance while using a light reflection sheet with a light diffuse reflection pattern. And a surface light source using the same. A light emitting region layer containing at least one of a light reflecting powder, a phosphorescent substance, and a fluorescent material is provided on one surface of a base film, and the surface of the light emitting region layer is adhesive and The light reflecting sheet 2 with the light irregular reflection pattern is bonded to the light irregular reflection pattern layer 23 made of translucent ink. The light reflecting film 25 is provided with a release agent layer 25 b on one surface of the reflection sheet 25 a, and the release agent layer side is in close contact with the light irregular reflection pattern layer 23. [Selection] Figure 1

Description

  The present invention relates to a surface light source used for an electric signboard, a backlight of a liquid crystal display device, and the like, and a reflective member for a surface light source used for the surface light source. More specifically, the other surface (back surface) side of the light guide plate emits light from the side surface of the light guide plate (translucent substrate) and emits light having a uniform luminance or a desired luminance distribution from the one surface side. The present invention relates to a surface light source on which a diffused light reflection pattern is formed, and a surface light source reflecting member used therefor.

  A surface light source with a diffused light reflection pattern formed on the back surface is used as a backlight for electric signboards and liquid crystal display devices so that light is incident from the side of the light guide plate and emitted from the front surface with uniform brightness. ing. This surface light source has a structure as shown in FIG. 7, for example (see, for example, Patent Document 1). That is, in FIG. 7, 51 is a light guide plate formed of a translucent substrate made of an acrylic plate or the like, and a light diffuse reflection pattern layer (ink layer) 523 of a light reflection sheet 52 with a light diffuse reflection pattern is attached to the back surface thereof. The light diffusion plate 53 or the light diffusion sheet is provided on the front surface side, and the light reflection plate 56 is provided on the back surface side. As shown in Patent Document 1, the light reflection sheet 52 with a light irregular reflection pattern has a light emitting region layer (light reflective powder layer) 522 formed on the entire surface of a base film 521 and includes an adhesive on the surface thereof. A dot pattern is formed by the ink layer (light diffuse reflection pattern layer) 523. Thereby, the light of the light source 54 provided on the side surface of the light guide plate 51, such as an LED, a fluorescent tube, or a cold cathode tube, is emitted from the surface as light of uniform luminance.

  That is, as shown in FIG. 7B, a top view of the light reflecting sheet 52 with the light irregular reflection pattern is shown in FIG. 7B. It is formed in a large area on the side where the amount of light is weakened. Where the pattern of the ink layer 523 is formed, it is bonded to the light guide plate 51. In this bonded portion, since the difference in refractive index between the light guide plate 51 and the ink layer 523 is small, light tends to enter smoothly. Then, it is irregularly reflected by the light emitting region layer 522, returns to the light guide plate 51 side again, and shines brightly. On the other hand, since the portion without the ink layer 523 has the light emitting region layer 522 through the air layer, the refractive index changes greatly in the air layer, and the total reflection in the light guide plate 51 is easy. Diffuse reflection hardly occurs. As a result, it is easy to radiate light of uniform brightness from the surface of the light guide plate 51 in harmony with the intensity of light from the light source 54 and the area to be diffusely reflected. Therefore, the pattern of the ink layer 523 needs to be formed very finely. In addition, since the light which leaks from the reflection sheet 52 with a light irregular reflection pattern to the opposite side to the light guide plate 51 is wasted, a light reflection plate 56 is provided so as not to let the light escape.

  According to Patent Document 1, the ink layer 523 having a light irregular reflection pattern is not directly formed on the light guide plate 51 but is formed on the base film 521. And by sticking the release paper on the surface to make a plate or roll, cut out according to the length of the light guide plate of the required size, peel off the release paper and stick it on the back of the light guide plate 51 A surface light source can be obtained easily.

JP 2014-209465 A

  As described above, the light emitting region layer 522 and the light diffuse reflection pattern layer are formed on the base film 521, and a release paper is attached to the surface of the base film 521 to form a plate or a roll. Thus, it is possible to easily obtain a surface light source having a desired size by cutting the length to the required size of the light guide plate. However, the light reflecting plate 56 is necessary on the back surface side of the light guide plate, and it is necessary to prepare a light reflecting plate separately. On the other hand, the conventional peeling layer for protecting the ink layer 523 is discarded as it is after being peeled off, and there is a problem that resources are wasted.

  In this case, when a light reflecting sheet having the same configuration is formed using the light reflecting sheet as the base film 521, the release sheet of the light reflecting sheet with the light diffuse reflecting pattern is peeled off without preparing a separate light reflecting plate. A surface light source can be obtained simply by attaching to the light guide plate 51. However, the light reflecting sheet is attached to the light guide plate 51 through the ink layer. Then, since the thermal expansion coefficients of the light guide plate 51 and the light reflection sheet are different, there is a problem that the ink layer 523 is peeled off from the light guide plate 51 or shifted on the light guide plate 51 due to the heat cycle. In addition, when transporting and storing the light irregular reflection sheet 52 with the light irregular reflection pattern in the form of a plate or roll, the release paper is weak with paper, so the edge of the release paper is peeled off or damaged, and the light irregular reflection pattern layer is damaged. There is a fear.

  The present invention has been made to solve such a problem. While using a light reflection sheet with a light diffuse reflection pattern, a light reflection plate is prepared in advance without wasting the release paper. Furthermore, it is another object of the present invention to provide a surface light source reflecting member and a surface light source using the surface light source reflecting member that can easily obtain a surface light source that hardly damages the light diffuse reflection pattern layer during transportation and storage.

  A reflective member for a surface light source having a diffused light reflection pattern according to the present invention includes a base film and a light emitting region layer provided on one surface of the base film and including at least one of a light reflective powder, a phosphorescent substance, and a fluorescent substance. And a light reflection sheet with a light irregular reflection pattern provided on the surface of the light emitting region layer and having a light irregular reflection pattern layer made of adhesive and translucent ink, and light reflection with the light irregular reflection pattern A light-reflecting film that is pasted on the light irregular reflection pattern layer of the sheet, the light reflecting film is provided with a release agent layer on one side, and the release agent layer side is affixed on the light irregular reflection pattern layer; ing.

  Here, the base film means a base film such as a substrate. In addition, the light emitting region layer does not mean that it emits light by itself. For example, the light reflecting powder layer causes the incident light to be diffusely reflected and shines as it is. One type of light that is incident on the surface light source so that it can radiate even after the surface light source is turned off, or that that radiates the incident light as another light, such as a fluorescent material Or, it means to include multiple types. In addition, when a light reflective powder layer is used as the light emitting region layer, it may include at least one of titanium oxide, glass beads, silica, and ceramics having an average particle diameter of 1 to 5 μm. In addition, this light emission formation layer may be formed in 0.5-10 micrometers.

  It is preferable that one surface of the light reflecting film is coated with a silicone release agent to form the release agent layer.

  Moreover, it is preferable that the said light reflection film is formed in the thickness of 100-200 micrometers by foaming PET (polyethylene terephthalate).

  Moreover, it is preferable from a viewpoint of protection of the light reflection sheet with a light irregular reflection pattern that the magnitude | size of the said light reflection film is formed larger than the said base film so that it may protrude from the edge part of the said base film.

  The light irregular reflection pattern film for a surface light source of the present invention includes a film sheet, a light irregular reflection pattern layer formed on one surface of the film sheet, made of an adhesive and translucent ink, and a release agent layer on one surface. Provided, and the release agent layer side includes a light reflection film attached on the light diffuse reflection pattern layer.

  A surface light source according to the present invention includes a light-transmitting light guide plate, a light irregular reflection pattern layer provided by adhering to one surface of the light guide plate, light emission including at least one of a light-reflecting powder, a phosphorescent material, and a fluorescent material. A region layer, a light reflecting film provided on the light emitting region layer side or a surface opposite to the surface of the light guide plate to which the light diffuse reflection pattern layer is attached, and a light source provided on a side surface of the light guide plate. The light diffuse reflection pattern layer is the reflection member for the surface light source or the light reflection pattern layer of the light reflection pattern film, and the light reflection film is peeled off from the light guide plate reflection member or the light reflection pattern film. It is formed by using a light reflecting film.

  The light reflecting film is provided so that the light reflecting sheet with the light irregular reflection pattern and the light reflecting film can be displaced so that a difference between expansion and contraction based on a difference in thermal expansion coefficient between them can be absorbed. Is preferred.

  The film on which the light emitting region layer is formed may be removed, and the light reflecting film may be directly laminated on the exposed light emitting region layer.

  According to this invention, it replaces with the release paper which protects the surface of the light irregular reflection pattern layer of the light reflection sheet with a light irregular reflection pattern, and the light reflection film which has a release agent layer on the surface is affixed. Therefore, the light irregular reflection pattern layer containing an adhesive is protected by the light reflection film in the same manner as the conventional release paper. That is, even if the light reflecting film is peeled off, the adhesive light diffuse reflection pattern layer remains without any damage. As a result, it has a light plate shape, and in some cases, it can be wound and conveyed in a roll shape, which makes it very easy to carry and handle. In this case, the light reflecting film is made of PET or the like, and is more rigid than paper, and thus is more preferable for protecting the light irregular reflection pattern layer. In particular, since the light reflecting film is formed so as to protrude beyond the end of the base film, it has a further function of protecting the light irregular reflection pattern layer.

  On the other hand, when forming a surface light source, the light reflecting film can be peeled off and attached as it is. In addition, since it is formed of a light reflecting film, not a simple release paper, the peeled light reflecting film should be used as it is instead of the light reflecting plate provided on the side opposite to the light emitting surface of the light guide plate of the surface light source. Can do. As a result, the reflective member for the surface light source is produced as a long and long strip and wound in a roll shape, so that it is cut according to the size of the light guide plate when necessary, and the light reflecting film is peeled off. A surface light source can be obtained simply by sticking the exposed portion of the light diffuse reflection pattern layer to one surface of the light guide plate. In addition, since the light reflecting film that protects the light diffuse reflection pattern layer of the reflective member for the surface light source with the light diffuse reflection pattern cut according to the size of the light guide plate as the surface light source is used as the light reflective plate as it is, No further cutting or processing of the reflective film is required. As a result, by forming the light guide plate using the reflective member for a surface light source of the present invention, it is possible to use it effectively without wasting the parts of the reflective member for a surface light source with a diffused light reflection pattern, and very easily. A precise surface light source can be obtained.

  In addition, according to the surface light source of the present invention, a surface light source can be formed simply by affixing the light diffuse reflection pattern layer precisely formed on the base film to the light guide plate. Even a person without knowledge can freely create a surface light source in a desired size. Moreover, since the light reflection film is provided separately from the light diffuse reflection pattern layer attached to the light guide plate, even if there is a difference in thermal expansion coefficient between the light guide plate and the light reflection film, the heat The light irregular reflection pattern layer is not peeled off from the light guide plate by the cycle, and the light irregular reflection pattern is not displaced. Moreover, since the light reflection film uses the light reflection film instead of the release paper that protected the light diffuse reflection pattern of the reflection member for the surface light source, an increase in component cost can be suppressed. In this light reflecting film, for example, a silicone-based release agent layer is formed on one surface of a foamed PET film or the like. However, since this release agent layer itself does not have an adhesive force, the base of the light reflection sheet with the light irregular reflection pattern is used. It does not adhere to one surface of the material film or the light guide plate. Therefore, as long as the peeled light reflecting film is not limited to the reflecting surface of the light reflecting film, there is no problem even if either surface is opposed to the base film or the light guide plate. When only one surface of the light reflecting film has reflection characteristics, a release agent layer is formed on the opposite surface, and the surface on which the release agent layer is not formed is used as the reflection surface. This light reflecting film is held without being bonded if it is held around or has a structure that can be suppressed from the opposite surface.

  If the base film is peeled off after the sheet with diffused light reflection pattern is attached to the light guide plate, the light-emitting area layer such as the light-reflective powder layer under the ink layer adheres to the ink layer due to the penetration of the ink layer. However, since the light emitting area layer such as the light reflective powder layer where the ink layer is not provided is only bonded to the base film, the light emitting area layer such as the light reflective powder layer is also attached together with the base film. Removed. The light-reflecting film is provided on the surface where the light-emitting region layer such as light-reflecting powder is exposed, or another transparent film is provided, and the light-reflecting film is provided through the transparent film. Alternatively, the light reflecting film may be provided on the opposite surface so that light is emitted from the surface of the transparent film. As a result, there is a light emitting region layer such as light-reflecting powder only on the part of the light irregular reflection pattern provided with the ink layer, and the light is not diffusely reflected and shined on the part other than the light irregular reflection pattern. A surface light source with uniform brightness can be obtained. However, even if the light-reflecting powder layer remains on the entire surface without peeling off the base film, a gap is formed between the light guide plate and the portion where the ink layer is not provided as described above. Therefore, it has the same effect as when the base film is peeled off.

  In addition, the laminated structure of the light emitting region layer such as the light reflection powder layer and the ink layer that forms the light irregular reflection pattern is not formed on one base film, but the light irregular reflection pattern is formed on the base film. It may be formed as a light irregular reflection pattern film provided with a light reflection sheet having a release agent layer on the surface. By separately forming the light emitting region forming film, the light reflecting film is peeled off and attached to one surface of the light guide plate, and then the light emitting region layer formed on another film sheet separately formed is used as the light reflecting pattern layer. The light reflecting film that has been pasted and peeled off can be used as a light reflecting plate. If it does in this way, a light diffused reflection pattern is first affixed on a light-guide plate by the user side, the film sheet is peeled, and the film for light emitting area layer formation is left on the other side of the exposed light diffused reflection pattern layer. A surface light source can be obtained by attaching the light emitting region layer. In this case, after the light emitting region layer is pasted, the film sheet on which the light emitting region layer is formed can be peeled off and removed. This is the same as the example of the base film described above. Even when the film sheet is peeled off, the part adhered to the light diffuse reflection pattern is strongly bonded, so when peeling the film sheet, the film sheet is peeled off from the light emitting region layer, and the part where the light diffuse reflection pattern is not formed is Since the light emitting region layer is bonded to the film sheet, the light emitting region layer is transferred where the light diffuse reflection pattern is present, and the part where there is no light diffuse reflection pattern remains on the film sheet. Thereafter, a light reflecting film may be provided directly or through a transparent film.

It is sectional explanatory drawing of one Embodiment of the reflection member for surface light sources of this invention. It is a perspective exploded explanatory drawing of the reflective member for surface light sources of FIG. 1, and a figure which shows an example of the light irregular reflection pattern. It is plane explanatory drawing which shows the other example of a light irregular reflection pattern. It is explanatory drawing which shows embodiment of the surface light source of this invention using the reflection member of FIG. It is explanatory drawing of the light irregular reflection pattern film of the example which formed the light irregular reflection pattern and the light emission area | region layer in a different film sheet, respectively, and a light emission area | region layer film. It is explanatory drawing which forms a surface light source using a light irregular reflection pattern film and a light emission area | region layer film. It is explanatory drawing which shows the structural example of the conventional light-guide plate.

  Next, the surface light source reflecting member of the present invention will be described with reference to the drawings. The surface light source reflecting member 20 of the present invention has at least one of a light reflecting powder, a phosphorescent material, and a fluorescent material on one surface of a base film 21, as shown in FIG. A light emitting region layer 22 including seeds is provided, and a light irregular reflection pattern layer 23 made of adhesive and translucent ink is adhered to the surface of the light emitting region layer 22 to provide light reflection with a light irregular reflection pattern. The sheet 2 is provided, and the light reflection film 25 is attached on the light diffuse reflection pattern layer 23 of the light reflective sheet 2 with the light diffuse reflection pattern. Although the light reflecting film 25 is not shown in FIG. 1A, as shown in FIG. 1B, an exaggerated enlarged view of the light reflecting film 25 is shown, the release agent layer 25b is formed on one surface of the reflecting sheet 25a. Is provided, and the release agent layer 25 b side is in close contact with the light diffuse reflection pattern layer 23. This adhesion is adhered as if attached by the adhesiveness of the light diffuse reflection pattern layer 23, but is easily peeled off by peeling.

  The surface light source reflecting member 20 is wound in a roll shape with the light reflecting film 25, which is also used as a release paper, formed on the surface, as shown in FIG. 2A, for example. It becomes very easy to store and handle, cut to the required size (length L), peel off the light reflecting film 25, and paste the light diffuse reflection pattern layer 23 on one surface of the light guide plate 1, It is possible to form a surface light source in which luminance adjustment for the light source is performed. However, it may be transported in the form of a plate without being rolled. The peeled light reflecting film 25 is used as a reflecting plate provided on one surface of the light guide plate 1 as it is, as will be described later.

  As the reflection sheet 25a constituting the reflection film, for example, a film obtained by foaming polyethylene terephthalate (PET) or the like, for example, Lumirror (Toray Industries, Inc., registered trademark) which is foamed PET can be used. Other examples include white polyester resin low foam film, white polystyrene resin low foam film, white ABS resin low foam film, white polyester resin with silver vapor deposition, white polycarbonate resin low foam film, etc. A low foamed film made of an acrylic resin, a resin having good optical transparency, or a film obtained by mixing these films or a resin having good optical transparency with titanium oxide, zirconium oxide, barium sulfate, or the like can be used. These materials have a thermal expansion coefficient close to that of the acrylic resin used as the light guide plate 1, and even if provided with a light adhesion on the light guide plate, they do not cause much problems. The thickness of these films is 100 to 200 μm. In addition, the reflective film 25 is formed slightly larger so as to protrude from the end of the base film 21 by about 0.5 to 2 mm. By forming the reflection film 25 slightly larger, the light irregular reflection pattern layer 22 formed on the base film 21 is not damaged even if the end portion collides during transportation and storage.

  Moreover, what formed the reflecting film by Ag vapor deposition etc. on the other sheet | seat with a different thermal expansion coefficient from light guide plates, such as polyester, can also be used. Alternatively, a simple structure formed by mixing a film raw material such as polyester with a micro-reflecting powder such as titanium oxide, alumina or glass powder may be used. In this case, both surfaces can be used as reflecting surfaces. Further, it may be formed by embedding a spherical glass powder in a lens shape. In this case, the reflecting surface is the front side of the lens. In any case, the fine powder is a fine powder having a diameter of about 40 to 90 μm, and the entire thickness is formed to be about 100 to 300 μm, so that the sheet is thin and flexible. If it is thin like this, it can be formed into a roll as described above, which is convenient for transportation and storage, but it may be formed into a thick plate. As described above, a thin film is preferable for forming a roll.

  For the release agent layer 25b provided on one surface of the reflection sheet 25a, for example, a release agent such as silicone-based or non-silicone-based release agent is provided on one surface of the reflection sheet 25a (a surface that is not a reflection surface is preferable when the reflection surface has directivity). It is formed by coating. The release layer attached to the ink layer is preferably a silicone type.

  For the base film 21, for example, a translucent sheet having a thickness of 50 to 100 μm can be used. For example, if an acrylic resin (PMMA) sheet is used as the light-transmitting sheet, the thermal expansion coefficient is substantially equal to that of the light guide plate 1 when PMMA is used as the light guide plate 1, so that light reflection with a light irregular reflection pattern, which will be described later, is performed. Even if the sheet 2 is left attached to the light guide plate 1, the light irregular reflection pattern due to the difference in thermal expansion coefficient does not shift, which is preferable. However, as described later, if the base film 21 is peeled and used, there is no need to worry about the difference in thermal expansion coefficient from the light guide plate 1. Therefore, for example, paper materials such as PET and release paper, various synthetic resin films such as vinyl chloride, OPP (biaxially stretched polypropylene) film, and PE (polyethylene) film or plate-like bodies can be used. When using a translucent film, the light reflection film 25 is provided in the surface opposite to the surface in which the light reflection powder layer 22 of the base film 21 is provided. As will be described later, the light reflecting film 25 may be provided on the opposite surface of the light guide plate. The light reflecting film 25 can prevent light from leaking through the light reflecting powder layer 22. This situation is shown in the partially enlarged explanatory views of FIGS. 4 (a) and 4 (b). That is, the light transmitted through the light reflecting powder layer 22 is transmitted through the base film 21 and reflected by the light reflecting film 25, enters the light reflecting powder layer 22 again, and is diffusely reflected by the light reflecting powder. The light once transmitted through the light-reflecting powder layer 22 can also be used effectively. This is a case where light is extracted from the opposite side of the surface of the light guide plate 1 (see FIG. 4) on which the light reflecting sheet 2 with the light irregular reflection pattern is provided. The light reflecting sheet 2 with the light irregular reflection pattern is provided. Light can also be extracted from the side. In that case, the light reflecting film 25 is provided on the other surface opposite to the surface on which the light reflecting sheet 2 with the light diffuse reflection pattern of the light guide plate 1 is provided.

  The light reflective powder layer 22 is formed on the entire surface of the base film 21. The light reflective powder is, for example, barium sulfate, titanium oxide, silica, glass, white ceramic powder, white plastic powder, or a mixture thereof, which easily reflects visible light, and has a reflectance of 95% or more. White powder can be used. Even if glass powder is mixed, if it is an amorphous powder, it contributes to irregular reflection, and the light transmitted through the glass powder is also irregularly reflected by the next powder, which is effective. From that viewpoint, plastic or plastic beads may be used. The shape is not limited to a spherical shape, and it is possible to use an amorphous powder having various shapes such as a pointed shape, a polygonal shape, and a columnar shape, and a finely divided shape. About 0.1 to 1 μm, preferably about 0.1 to 0.8 μm, and more preferably about 0.1 to 0.6 μm. The light reflective powder layer 22 has a thickness of about 0.5 to 1.5 μm, preferably about 0.5 to 1 μm (distance between the average surface position of the light reflective powder layer and the surface of the base film 21). Formed. On the other hand, when the light reflective powder layer 22 is formed to have a thickness of 1 to 20 μm, the light reflective powder layer 22 does not pass through the light reflective powder layer 22 and is irregularly reflected by some powder. It will be. As a result, there is no need to provide a light reflecting plate or a light reflecting film, which will be described later, which contributes to cost reduction.

  This light-reflecting powder diffuses incident light in all directions, and is preferably a white substance that reflects as easily as possible. Moreover, in order to reflect in all directions, it is preferable that it is the above-mentioned fine amorphous powder. This light-reflective powder layer can be formed, for example, by mixing the light-reflective powder with a light-transmitting ink together with a curing agent, applying the light-reflective powder to the base film 21 by silk printing or gravure printing, and curing. The amount of the curing agent that cures the ink can be adjusted to adjust the transfer adhesive force and the shape maintaining force. To adjust the peeling force, etc., the method is to print on PET that has been subjected to a silicone resin coating treatment. The adhesive strength can be freely adjusted according to the type of silicone resin.

  That is, if it is used as a surface light source with the base film 21 attached, the base film 21 is attached so that the adhesive strength becomes strong, and conversely after the light guide plate 1 and the light reflecting sheet 2 with the light irregular reflection pattern are attached. If it is peeled off, it is sufficient that the light-reflecting powder is adhered to the light guide plate 1 until it is attached to the light guide plate 1. In the case where there is no problem such as separation when it is held by a light reflecting plate or the like during the operation, it can be attached so as to have an intermediate adhesive force.

  The light diffuse reflection pattern layer (ink layer) 23 is, for example, an adhesive-type ink for screen printing (for example, trade name: JELCON RAYTACK-10N (ultraviolet (UV) curable adhesive) manufactured by Jujo Chemical Co., Ltd., or manufactured by ThreeBond Co., Ltd.) A water-based pressure-sensitive adhesive for screen printing (1549B), which is translucent, liquid before UV irradiation, and used as a normal pressure-sensitive adhesive, that is, a conventional white powder is also mixed. It is not an ink made of adhesive, but is a translucent liquid material that does not contain solid matter.Acrylic, rubber, silicone, etc. can be used as the adhesive, and acrylic solvent type For example, acrylic emulsion type pressure-sensitive adhesives (pressure-sensitive adhesives) are transparent (translucent), light resistant, heat resistant, solvent resistant In addition, it is excellent in terms of operability, environmental performance, experimental properties, etc. The same adhesive as that used for normal cellophane tape and gum tape can be used, but it also changes color due to heat. However, a material that can maintain transparency with respect to light is preferable, and an ink that is not deteriorated by light, such as a light-resistant ink, is particularly preferable.

  The ink layer 23 is formed by screen printing or the like from the surface of the light reflective powder layer 22 provided on the base film 21. Similar to the dot pattern formed on the back surface of the conventional light guide plate, the pattern of the ink layer 23 has a dot shape having a small diameter near the light source 4 and a large dot shape far from the light source 4. Is formed. Such an ink layer 23 can be formed by forming a dot pattern on the screen in advance by, for example, screen printing (silk screen printing). In addition, after screen printing, the surface is adhered while being irradiated with ultraviolet rays to make it into a glued state (meaning a state in which it has not been solidified and has been made semi-dry to eliminate shape loss, the same applies hereinafter). You can maintain power.

  For example, the screen printing may be performed by rewinding the roll from the roll by a predetermined pitch and repeating the silk printing while winding the long base film 21 wound in a roll shape. In this case, the long base film 21 in which the light-reflective powder layer 22 is formed in advance on the base film 21 is wound in a roll shape, screen printing is performed while the roll is unwound, and the roll film is wound again. Alternatively, the light-reflecting powder layer 22 may be screen printed while the long base film 21 wound in a roll shape is being unwound, and then the ink layer 23 may be printed. However, it is not limited to the elongate base film 21, The individual base film 21 formed according to the magnitude | size of the light-guide plate 1 of each surface light source may be sufficient.

  When printing on the long base film 21, for example, a printing method using a roller cylinder is used, and a metal cylinder in which a pattern dent corresponding to the dot pattern described above is formed on the outer peripheral surface of the cylindrical cylinder, By synchronizing the rotation of the cylinder and the movement of the base film 21 and printing so that the ink entering the recess of the cylinder is formed on the surface of the light-reflective powder layer 22 by a squeegee, it is easily continuous. Can be printed. By forming the ink layer 23 on the surface of the light reflective powder layer 22, the light irregular reflection pattern 24 is formed on the light reflective powder layer 22 on the surface of the base film 21.

  By printing the ink layer 23 on the surface of the light reflective powder layer 22, part of the ink also flows into the gaps of the light reflective powder layer 22 due to fluidity. Thereafter, the ink layer 23 is glued by a method such as ultraviolet irradiation, so that the ink layer 23 can be changed to an adhesive ink without breaking the pattern. Further, by printing the ink of the ink layer 23, the ink also flows below the ink layer 23, and the light-reflecting powder layer 22 is crushed and fixed between the powders by irradiation of ultraviolet rays.

  The pattern of the ink layer 23 is formed so that the luminance on the surface of the surface light source has a desired luminance distribution in the surface of the display surface. That is, since the refractive index of the light guide plate 1 and the ink layer 23 is close to the portion where the ink layer 23 is formed, the light proceeds to the ink layer 23 without being totally reflected at the contact surface between the light guide plate 1 and the ink layer 23. Further, light also travels into the light reflective powder layer 22. As a result, the incident light is diffusely reflected in the light reflective powder layer 22 and appears to shine from the outside. The shining light is diffused by the light guide plate 1 and the light diffusion plate 3 provided on the light guide plate 1 and becomes bright in a wide range. For this reason, the pattern of the ink layer 23 is formed so that this bright portion becomes a desired luminance distribution within the surface of the light guide plate 1, for example, uniformly bright within the surface. For example, in order to make the in-plane luminance uniform, the cross-sectional area of the ink layer 23 is reduced near the light source 4 and the amount of light is large, and the amount of light decreases at a position far from the light source 4. Therefore, the ink layer 23 is formed so that the cross-sectional area of the ink layer 23 is increased so that light can be captured as easily as possible.

  Therefore, the light diffuse reflection pattern 24 is closely related to the position of the light source 4. For example, the light source 4 is arranged on two opposite side surfaces of the light guide plate 1 and light is incident from both side surfaces thereof. In this case, for example, as shown in FIG. 3A, the cross-sectional area of the ink layer 23 on both ends of the width W is reduced, and the cross-sectional area is increased on the central side in the width W direction. It is formed. In the case of producing a surface light source having such a constant width W and different only in the length direction, the light guide plate 1 is formed from the sheet 2 with a long light irregular reflection pattern as shown in FIG. A surface light source can be produced by cutting to the required length L according to the size and attaching to the light guide plate 1. Although not shown, light can be incident from four sides of the light guide plate 1. In this case, the light guide plate 1 is formed into a large pattern at the center and a small pattern at each of the four sides.

  On the other hand, even with a surface light source, there is a case where luminance uniformity is not so required. In such a case, with the light diffuse reflection pattern in which the ink layer 23 having the same cross-sectional area is formed, for example, as shown in FIG. 3B, without changing the cross-sectional area of the ink layer 23 to a pattern. The light reflecting sheet 2 can also be used.

  Furthermore, even a surface light source that partially increases the brightness of a partial area of the surface light source and partially darkens the brightness of another partial area can be freely controlled only by forming this ink layer pattern. Can do. In other words, the ink layer 23 can be freely set only by forming a pattern at the time of manufacturing by printing or the like, and the manufacturing process can be made in exactly the same process.

  The light reflecting film 25 (see FIG. 2) is brought into close contact with the surface of the light diffuse reflection pattern 24, so that the light reflective sheet 2 with the light diffuse reflection pattern can be wound in a roll shape and stored or transported. That is, when wound and stored in a roll shape, as shown in FIG. 2A, the light guide plate 1 is cut in accordance with the size (length L) of the light guide plate 1 and the release paper 25 is peeled off. It can form by sticking to. Without damaging the light diffuse reflection pattern 22, the light reflective sheet 2 with the light diffuse reflection pattern can be wound and transported and stored. The width W of the light reflecting sheet 2 (base film 21) with the light irregular reflection pattern is formed in a width that matches the width W of the light guide plate 1. For a surface light source used for an electric signboard or the like, it is usually formed with a predetermined dimension (fixed length) such as 500 mm, 900 mm, or 1200 mm, and a desired length of about 300 to 3000 mm according to the length L of the light guide plate 1. Can be cut into lengths and used. In addition, a surface light source as a backlight of a liquid crystal panel or the like can be freely formed in accordance with a use from a portable type to a large TV.

  In addition, the surface light source 10 using the surface light source reflecting member 20 has a light irregular reflection pattern layer on one surface of the light-transmissive light guide plate 1 as shown in a cross-sectional explanatory view of one embodiment in FIG. A light emitting region layer 22 containing at least one of a light reflective powder, a phosphorescent material, and a fluorescent material is adhered to the light diffuse reflection pattern layer 23. And the light reflection film 25 is provided in the light emission area | region layer 22 side or the surface opposite to the surface of the light-guide plate 1 on which the light irregular reflection pattern layer 23 was affixed, and the light source 4 is provided in the side surface of the light-guide plate 1. FIG. The light irregular reflection pattern layer 23 and the light reflection film 25 are formed by using the light reflection pattern layer 23 and the light reflection film 25 of the reflection member for a surface light source described above.

  In the structure shown in FIG. 4B, the base film 21 is peeled off after the light reflecting sheet 2 with the light irregular reflection pattern is attached to the light guide plate 1, and the light reflecting film 25 is provided on the peeled surface. Structure. When the base film 21 is peeled off, the portion of the light emitting area layer 22 formed on the entire surface of the base film 21 where the light reflection pattern layer 23 is not formed is not adhered. Has been removed. Even in such a structure, as described above, a gap is formed between the portion where the light diffuse reflection pattern layer 23 is not formed and the light guide plate 1, and the light in the light guide plate 1 is easily totally reflected. There is no problem since almost no light leaks. Other configurations are the same as the structure shown in FIG.

  The light guide plate 1 is a translucent substrate that transmits light without being attenuated. For example, the light guide plate 1 is a parallel acrylic plate (PMMA), polycarbonate (PC) plate, PET plate, glass plate or the like having a thickness of about 3 to 10 mm. A plate or a plate having a tapered cross section with one surface inclined can be used. Although not shown, it is preferable that a light reflecting film is formed on the side surface other than the side surface where light from the light source 4 is introduced and the portion where the light guide plate 1 is connected. The size can be formed in various sizes depending on the application, and even when used as an electric signboard, it is made according to the size of the signboard. For example, as shown in an exploded perspective view in FIG. W × length L can be formed in a size of about (500 to 1200) mm × (80 to 3000) mm. In addition, the liquid crystal display device can be formed in various sizes depending on the application, and can be formed in a size from a mobile phone to a large TV display. Although the thickness of the light guide plate 1 can be variously formed according to the size thereof, for example, a thickness of about 3 mm to 10 mm can be used as described above. Further, this thickness can be formed on a parallel plate having a substantially constant thickness over the entire surface, but as described above, for example, it is tapered so as to become farther away from the light source 4 and thicker toward the light source 4. It can also be formed. Moreover, the back surface (surface opposite to the display surface) of the light guide plate 1 can be formed into a curved shape. According to the manufacturing method of the present invention, even when the back surface of the light guide plate 1 is not flat, the ink layer 23 of the light irregular reflection pattern 24 described later can be formed very easily.

  The light diffusing plate 3 is, for example, about 1 to 5 mm thick, and is made of a plate-shaped body such as milky white acrylic resin (PMMA), polyethylene terephthalate (PET), polycarbonate, glass, etc. The diffusely reflected light is not particularly noticeable, and the light is uniformly emitted from the entire surface. The light diffusing plate 3 is preferably thicker because it can be light having no directivity even in the oblique direction coming from the lower surface, but the light from the translucent substrate 1 on the lower surface is relatively uniform. If so, a light diffusion sheet or milky white sheet having a thickness of about 0.1 to 0.2 mm such as a thin vinyl sheet (FF sheet) may be used.

  As the light source 4 provided on the side surface of the light guide plate 1, a cold cathode tube, a fluorescent tube, or the like can be used, or LEDs can be arranged side by side and used as a linear light source. In the case of a light source that emits light in all directions, such as a fluorescent tube, the opposite side to the light guide plate is covered with a light reflecting sheet, and the light reflecting member is covered so that the light from the light source is not wasted as much as possible. preferable.

  According to the present invention, by preparing the reflection sheet 2 with the light irregular reflection pattern in advance, it is possible to produce a desired surface light source simply by preparing and attaching a light guide plate having a length that matches the width. it can. Moreover, since the light reflection film can be used as it is as the protective film of the reflection sheet 2 with the light irregular reflection pattern, it is not necessary to prepare a light reflection plate separately, and it is very simple and inexpensive to manufacture. can do.

  The above example is an example of the light reflection sheet 2 with the light irregular reflection pattern in which the light irregular reflection pattern layer (ink layer) 23 and the light emitting region layer 22 such as the light irregular reflection powder layer are integrally formed on the base film 21. However, the user's convenience is further improved by forming the light irregular reflection pattern layer (ink layer) 23 and the light emitting region layer 22 by separate films. The example will be described with reference to FIGS.

  First, FIG. 5A shows a light irregular reflection pattern forming film 2a, and FIG. 5B shows a light emitting region layer 22 forming film 2b. The light irregular reflection pattern forming film 2a is formed, for example, on the surface of a light-transmitting thin film sheet 28 using the same material as the above-described light irregular reflection pattern layer 23 and similarly by silk printing or the like. As described above, the ink layer 23 is made of light-transmitting ink and is firmly fixed to the film sheet 28. However, the ink layer 23 is easily separated from the film sheet 28. It is preferable to apply a silicone resin or the like in advance to the surface of the film sheet 28 because it is easy to peel off. And since the surface of this light irregular reflection pattern 23 is very adhesive, it is protected by the light reflection film 25 on which the aforementioned release agent layer is formed.

  FIG. 5B shows a light emitting region layer forming film 2b. For example, light emission such as a light reflecting powder, a phosphorescent material, and a fluorescent material is provided on one surface of a thin light transmissive film sheet 29. The region layer 22 is formed by a method such as full surface printing. The light emitting region layer 22 is the same as the above-described light reflective powder layer and the like, and is fixed to an organic solvent to have the same thickness. Therefore, the fixing strength is not so high and, as will be described later, it is fixed and fixed to a portion having a strong adhesive force, but the other portion is easily peeled off and separated. The light emitting region layer 22 is not formed in a pattern but is formed as a solid surface. Also in this case, it is possible to facilitate separation from the film sheet 29 by applying a silicone resin or the like to the surface of the film sheet 29. However, the film sheet 29 can be left as it is without being peeled off.

  In order to form a surface light source using these, first, as shown in FIG. 6A, the light reflection film 25 of the light irregular reflection pattern forming film 2 a is peeled off and attached to one surface of the light guide plate 1. . This affixing procedure is the same as that when the light reflection sheet 2 is affixed. Thereafter, the film sheet 28 is peeled off. The adhesive strength between the film sheet 28 and the light irregular reflection pattern layer 23 can be made weaker than the adhesive strength between the light guide plate 1 and the light irregular reflection pattern layer 23 by applying a silicone resin or the like to the interface. Therefore, only the film sheet 28 is easily peeled off, and the light irregular reflection pattern layer 23 is formed on one surface of the light guide plate 1.

  Thereafter, as shown in FIG. 6B, the light emitting region layer forming film 2b is attached to the surface of the light guide plate 1 on which the light irregular reflection pattern layer 23 is formed. Since the light diffuse reflection pattern layer 23 has adhesiveness, the light diffuse reflection pattern layer 23 is in close contact with a part of the light diffuse reflection pattern layer 23. When the film sheet 29 is peeled in this state, the light emitting region layer 22 that is not bonded to the light diffuse reflection pattern layer 23 is adhered to the film sheet 29 and removed. Alternatively, the film sheet 29 may not be removed and may remain adhered.

  Next, as shown in FIG. 6C, the light reflecting film 25 peeled from the light irregular reflection pattern forming film 2 a is overlaid on the exposed surface side of the light emitting region layer 22. As a result, a surface light source similar to that shown in FIG. 4B is obtained. When the film sheet 29 is not removed in FIG. 4B, the surface similar to the structure shown in FIG. 4A is provided by providing the light reflecting film 25 on the opposite surface of the film sheet 29. A light source is obtained. In any case, the light reflecting film 25 used in place of the release paper is effectively used as the light reflecting plate of the light guide plate.

  As described above, since the light diffuse reflection pattern 23 is independent, the light diffuse reflection pattern forming film can be cut into a shape to be emitted and affixed to the light guide plate. Can be formed.

DESCRIPTION OF SYMBOLS 1 Light guide plate 2 Light reflection sheet with a light irregular reflection pattern 3 Light diffusing plate 4 Light source 21 Base film 22 Light emitting area layer (light reflective powder layer)
23 Light diffuse reflection pattern layer (ink layer)
24 Light reflection pattern 25 Light reflection film

The surface light source of the present invention is provided with a light-transmitting light guide plate, a light irregular reflection pattern layer provided on one surface of the light guide plate, and a light reflective powder, a phosphorescent material provided on the light irregular reflection pattern layer. A light-emitting region layer comprising at least one of a substance and a fluorescent material, and a light-reflecting film provided on the light-emitting region layer side or the surface opposite to the surface of the light guide plate on which the light irregular reflection pattern layer is attached, comprising a light source provided on a side surface of the light guide plate, the light irregularly reflected pattern layer optical turbulent reflection pattern layer of the reflecting member or the optical turbulent reflection pattern film for the surface light source is used, the light reflective film is the surface light source It is formed by peeling light reflective film use reflecting member or the optical turbulent reflection pattern film is used.

It is preferable that the light reflecting film is provided so that the light guide plate and the light reflecting film can be displaced so that a difference between expansion and contraction based on a difference in thermal expansion coefficient between them can be absorbed.

The light-emitting region layer is a light emitting region layer of the reflection member for the surface light source, the substrate film to which the light-emitting region layer is formed is removed, even if the light reflection film directly on the light emitting region layer exposed are stacked Good.

Claims (8)

A base film, provided on one side of the base film, a light emitting region layer containing at least one of a light reflective powder, a phosphorescent material, and a fluorescent material, and provided adhered to the surface of the light emitting region layer; A light reflecting sheet with a light irregular reflection pattern having a light irregular reflection pattern layer made of an adhesive and translucent ink, and a light reflection applied to the light irregular reflection pattern layer of the light reflecting sheet with the light irregular reflection pattern A reflective member for a surface light source having a light diffuse reflection pattern, comprising a film, wherein the light reflective film is provided with a release agent layer on one surface, and the release agent layer side is attached on the light diffuse reflection pattern layer. The reflective member for a surface light source with a light irregular reflection pattern according to claim 1, wherein a silicone release agent is coated on one surface of the light reflection film, and the release agent layer is formed. The reflective member for a surface light source with a light irregular reflection pattern according to claim 1 or 2, wherein the light reflecting film is formed with foamed PET to a thickness of 100 to 200 µm. The surface with the light irregular reflection pattern according to any one of claims 1 to 3, wherein the light reflecting film is formed larger than the base film so that a size of the light reflecting film protrudes from an end of the base film. Reflective member for light source. A film sheet, a light irregular reflection pattern layer formed on one surface of the film sheet and made of an adhesive and translucent ink, and a release agent layer provided on one surface, the release agent layer side being the light irregular reflection pattern layer A light irregular reflection pattern film for a surface light source, comprising: a light reflection film affixed on the surface. A light-transmitting light guide plate, a diffused light reflection pattern layer provided on one surface of the light guide plate, a light-emitting region layer including at least one of light-reflecting powder, a phosphorescent material, and a fluorescent material; and the light-emitting region A light reflecting film provided on the side opposite to the surface of the light guide plate to which the light diffuse reflection pattern layer is attached or a light source provided on a side surface of the light guide plate, the light diffuse reflection pattern layer comprising: The reflective member for a surface light source according to claim 1 or the light reflective pattern layer of the light reflective pattern film according to claim 5 is used, and the light reflective film is a reflection for the light guide plate according to claim 1 or 5. A surface light source formed by using the light reflecting film from which a member or the light reflecting pattern film is peeled off. The light reflecting film is provided so that the light reflecting sheet with the light irregular reflection pattern and the light reflecting film can be displaced so that a difference between expansion and contraction based on a difference in thermal expansion coefficient between them can be absorbed. The surface light source according to claim 6. The surface light source according to claim 6 or 7, wherein the film on which the light emitting region layer is formed is removed, and the light reflecting film is directly laminated on the exposed light emitting region layer.

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