JP2014164988A - Light guide plate and surface light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a light guide plate that can reduce adverse effects due to a light scattering part as much as possible while satisfactorily securing characteristic features, such as flexural stiffness and weather resistance, without causing any unnecessary increase in weight; and a surface light-emitting device.SOLUTION: A light guide plate includes: a resin plate 11; glass plates 12 respectively closely secured via an adhesive layer 14 to both surfaces of the resin plate 11; and a light scattering part 13 to guide light propagating inside the resin plate 11 and the glass plate 12 to the exterior. The light scattering part 13 is formed on the surface of one of the resin plate 11 and the glass plate 12, and is covered with the adhesive layer 14.

Description

  The present invention relates to a light guide plate and a surface light emitting device incorporating the same.

  As the surface light emitting device, a device using a light guide plate is widely used, and its structure is as follows. That is, a light source is arranged close to one side or two opposite sides of the light guide plate, light is incident on the inside of the light guide plate from the end surface of the corresponding side, and the light guide part provided in the light guide plate totally reflects inside the light guide plate. However, the light that propagates is scattered and taken out to the outside so that the light guide plate emits light in a planar shape (see, for example, Patent Documents 1 to 3).

  As the light guide plate, a glass plate or a resin plate such as acrylic is often used alone. In general, a light scattering portion is formed on the surface of the light guide plate by a method such as printing a scattering pattern with paint or ink, or engraving with a laser. In addition to the method of providing the light scattering portion on the surface of the light guide plate as described above, for example, as disclosed in Patent Document 3, there is a method of kneading a light scattering material inside the light guide plate. It is difficult to adjust the characteristics, and there are difficulties in practical use.

JP 2007-80531 A WO2010 / 150364 Japanese Patent No. 270312

  By the way, the present condition is that the surface light-emitting device using a light-guide plate is widely used regardless of indoor and outdoor.

  However, when a resin plate is used as the light guide plate, the bending rigidity, chemical resistance, scratch resistance, weather resistance, etc. tend to be insufficient, and the deterioration becomes remarkable particularly when used outdoors.

  On the other hand, when a glass plate is used as the light guide plate, the problem of the resin plate is solved, but there is a drawback that the weight is increased as compared with the resin plate or the glass plate is easily broken by an impact.

  Furthermore, since the light scattering part is provided on the surface of the light guide plate, outside light is scattered by the light scattering part even when the surface light emitting device is turned off. There is a problem that the sex is impaired.

  Further, when the surface light emitting device is turned on, the surface light emitting device is visually recognized as emitting light in the shape of the scattering pattern of the light scattering portion (for example, dot shape), and may deviate from the ideal surface light emission. For this reason, there is a concern that the designability of the surface light emitting device is lowered and the product value is lowered.

  Furthermore, the light scattering portion may be deteriorated by the external environment, which may adversely affect the transparency and light emission state of the light guide plate. In particular, when the scattering pattern of the light scattering part is engraved on the surface of the light guide plate made of a resin plate by a laser, if the light scattering part continues to be exposed to the external environment, the surface of the resin plate damaged by the laser irradiation heat is deteriorated. Easily progresses, and the deterioration of the transparency of the light guide plate becomes remarkable.

  In view of the above circumstances, the present invention is a guide that can reduce the adverse effects of the light scattering portion as much as possible while ensuring good properties such as bending rigidity and weather resistance without causing an unreasonable increase in weight. It is a technical problem to provide an optical plate and a surface light emitting device.

  The light guide plate according to the present invention, created to solve the above problems, propagates through the resin plate, the glass plate tightly fixed to each of both surfaces of the resin plate, and the resin plate and the inside of the glass plate. A light scattering portion for guiding light to the outside, and the light scattering portion is covered with a close contact portion between the resin plate and the glass plate.

  According to such a configuration, the resin plate having low bending rigidity is reinforced by the surface glass, and the light guide plate can be thinned. At this time, if the thickness of the glass plate is reduced, there is almost no influence of weight increase. On the other hand, since the glass plate excellent in chemical resistance, scratch resistance, and weather resistance sandwiches the resin plate, the resin plate is protected from the external environment. Therefore, chemical resistance, scratch resistance, and weather resistance can be maintained satisfactorily while ensuring sufficient bending rigidity without causing an undue increase in weight of the light guide plate.

  Moreover, since the light-scattering part is covered with the contact | adherence part of a resin plate and a glass plate and is not exposed to the external environment, deterioration of a light-scattering part can be prevented. At the same time, since the light scattering portion covered by the close contact portion is less scattered by external light, it becomes difficult to be directly recognized from the outside, and the transparency of the light guide plate can be ensured satisfactorily. Furthermore, since a sufficient distance can be formed from the light scattering portion to the surface of the light guide plate, the light scattered by the light scattering portion spreads evenly before reaching the surface of the light guide plate. As a result, the entire surface of the light guide plate corresponding to the light scattering portion tends to be visually recognized as emitting light in a planar shape. Here, the light scattering portion is covered by the contact portion, but since there is a difference in refractive index between the contact portion and the light scattering portion, sufficient scattering occurs at the interface of the light scattering portion, and the light scattering function is maintained. The

  Said structure WHEREIN: It is preferable that the said contact | adherence part is formed with the contact bonding layer which consists of an adhesive agent.

  In this way, the resin plate and the glass plate can be closely adhered and fixed at a low temperature as compared with the case where the surface of the resin plate is melted by heating and directly adhered to the glass plate. Therefore, it is easy to prevent deterioration of the light scattering portion due to heat, and the degree of freedom of the material constituting the light scattering portion is increased. Moreover, since the adhesiveness of a light-scattering part and an adhesion part can be improved easily, it becomes difficult to visually recognize a light-scattering part from the outside, and it can contribute to the further improvement of the design property of a light-guide plate.

  Said structure WHEREIN: It is preferable that the said light-scattering part is formed in the surface of the said resin board.

  That is, since the resin plate is superior to the glass plate in processability, the light scattering portion can be easily formed, and the manufacturing cost can be reduced.

  Said structure WHEREIN: The said light-scattering part may be formed by pattern-printing the coating material or ink containing a light-scattering agent on the surface of any one of the said resin plate and the said glass plate.

  In this way, it is possible to reduce the burden on the surface of the target plate material that forms the light scattering portion as compared with the case where the light scattering portion is engraved on the surface of the resin plate or glass plate with a laser or sandblast.

  Said structure WHEREIN: It is preferable that the plate | board thickness of the said resin plate is larger than the plate | board thickness of the said glass plate.

  If it does in this way, weight reduction of a light-guide plate can be aimed at suitably.

  Said structure WHEREIN: It is preferable that the plate | board thickness of the said glass plate is 0.05 mm-1 mm.

  The surface light-emitting device according to the present invention, which was created to solve the above problems, includes a light guide plate having the above-described configuration as appropriate, and a light source that allows light to enter the light guide plate from at least one end surface of the light guide plate. ing.

  According to such a configuration, it is possible to provide a surface light-emitting device that can exhibit the functions and effects of the light guide plate already described.

  Said structure WHEREIN: It is preferable that the said light source is LED.

  As described above, according to the light guide plate and the surface light emitting device according to the present invention, the light scattering portion is caused while ensuring various properties such as bending rigidity and weather resistance without causing an undue increase in weight. It is possible to eliminate the deterioration of the design property and the light emission failure.

It is a vertical side view which shows the surface emitting device which concerns on 1st Embodiment of this invention. It is a cross-sectional plan view of the surface light-emitting device of FIG. It is a conceptual diagram which shows multichip type LED. It is a conceptual diagram which shows a single chip type LED. It is a graph which shows an example of the transmittance | permeability curve of an adhesive agent. It is a graph which shows an example of the spectrum of multichip type LED. It is a graph which shows an example of the spectrum of a single chip type LED. It is a vertical side view which shows the surface emitting device which concerns on 2nd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment>
As shown in FIG. 1, the surface light emitting device according to the first embodiment includes a light guide plate 1, a light source 2 that guides light from one end face of the light guide plate 1 into the light guide plate 1, and a light source 2 inside. And a housing 3 that is externally fitted to the one side of the light guide plate 1 in the accommodated state.

  The light guide plate 1 is a light that guides the light from the resin plate 11, the glass plate 12 that is tightly fixed to both surfaces of the resin plate 11, and the light source 2 that propagates inside the resin plate 11 and the glass plate 12. The scattering unit 13 is provided.

  By adopting such a composite (laminated) structure of the resin plate 11 and the glass plate 12, the resin plate 11 is reinforced by the glass plate 12, and the resin plate 11 is protected from the external environment by the glass plate 12. Therefore, good properties such as chemical resistance, scratch resistance, and weather resistance derived from the glass plate 12 can be exhibited while improving bending rigidity without causing an unreasonable increase in weight.

  Further, since the resin plate 11 and the glass plate 12 are integrated, it is not necessary to separately assemble the resin plate 11 and the glass plate 12 to the housing 3. Therefore, the work of assembling the light guide plate 1 to the housing 3 becomes extremely simple. In addition, since the assembly | attachment operation | work of such a light-guide plate 1 may be performed in an actual installation site, it can also contribute to shortening of a site construction period.

  Furthermore, since the light guide plate 1 has a structure in which both surfaces of the resin plate 11 are sandwiched between the glass plates 12, the light source plate 1 is deteriorated by heat as compared with the case where the light guide plate 1 is constituted by the resin plate 11 alone. It is thought that it can be suppressed. This is because it can be expected that the glass plate 12 can suppress the deformation of the resin plate 11 due to heat and that the heat radiation can be realized through the glass plate 12 that is more excellent in heat conduction than the resin plate 11.

  The resin plate 11 and the glass plate 12 are firmly fixed via an adhesive layer 14 made of an adhesive. The light scattering portion 13 is covered with the adhesive layer 14 in a state formed on one surface of the resin plate 11. That is, the light scattering portion 13 is covered with the resin plate 11 and the adhesive layer 14 without being exposed to the outside. The contact portion may be formed by melting the surface of the resin plate 11 by heating and directly adhering to the glass plate 12. In this case, the light scattering portion 13 is formed on the surface of the glass plate 12.

  The resin plate 11 is transparent to visible light (for example, the transmittance is 90% or more over the entire wavelength range of 420 nm to 690 nm in the working thickness). Specifically, examples of the resin plate 11 include acrylic, polycarbonate, PET (polyethylene terephthalate), PP (polypropylene), COP (cycloolefin polymer), and urethane.

  As the glass plate 12, one that is transparent to visible light (for example, a transmittance of 90% or more in the entire wavelength range of 420 nm to 690 nm in use thickness) is used. Specifically, examples of the glass plate 12 include soda glass, borosilicate glass, alkali-free glass, quartz glass, lead glass, crystallized glass, and the like. In particular, what is generally called white plate glass is suitable. .

  The plate thickness of the glass plate 12 is smaller than the plate thickness of the resin plate 11. Specifically, the thickness of the glass plate 12 is preferably 0.05 mm to 1 mm, more preferably 0.07 mm to 0.5 mm, and further preferably 0.1 mm to 0.3 mm. preferable. When the plate thickness of the glass plate 12 is 1 mm or less, flexibility appears in the glass plate 12. Therefore, when an impact is applied to the light guide plate 1 from the outside, the glass plate 12 is bent and deformed so as to follow the bending deformation of the resin plate 11 serving as the core material. As a result, even if the glass plate 12 is a thin plate, it is difficult to break. Such an effect is remarkable at 0.5 mm or less, and particularly effective at 0.3 mm or less in combination with lightness. On the other hand, from the viewpoint of improving the rigidity of the light guide plate 1, if the plate thickness of the glass plate 12 is 0.1 mm or more, sufficient rigidity can be secured even in the light guide plate 1 having a large area (for example, 500 mm square or more). .

  As the adhesive constituting the adhesive layer 14, since there is a large difference in thermal expansion coefficient between the resin plate 11 and the glass plate 12, an adhesive having a degree of elasticity that can absorb the difference in thermal expansion between the two is preferable.

  As the type of the adhesive, a normal temperature curing type or an energy curing type (for example, an ultraviolet curing type) is used as the liquid adhesive. On the other hand, a thermoplastic type or a thermosetting type is used for a hot melt adhesive sheet. Specifically, examples of the hot-melt adhesive sheet include EVA (ethylene vinyl acetate copolymer) and TPU (thermoplastic polyurethane). An adhesive adhesive such as an optical transparent adhesive sheet can also be used.

  As shown in FIG. 2, the light scattering portion 13 is formed by printing a dot pattern on the surface of the resin plate 11 with a paint or ink containing a light scattering agent made of a transparent or colored pigment, for example. . The dot pattern is configured such that the size of the dot increases as the distance from the light source 2 increases. Thereby, even if light attenuation (decrease in intensity) increases as the distance from the light source 2 increases, light propagating in the light guide plate 1 tends to scatter as the distance from the light source 2 increases. Uniform light emission can be realized in the entire scattering portion 13. The same effect can be obtained even if the number of dots is arranged densely as the distance from the light source 2 increases instead of changing the dot size.

  Since the light scattering portion 13 thus formed on the surface of the resin plate 11 is completely covered with the adhesive layer 14 and is not exposed to the external environment, the light scattering portion 13 can be prevented from deteriorating. it can. Further, since the light scattering portion 13 covered with the adhesive layer 14 is embedded in the adhesive layer 14, scattering due to external light is reduced. As a result, it becomes difficult to visually recognize the light scattering portion 13 from the outside, and the transparency of the light guide plate 1 can be secured satisfactorily. Furthermore, since a sufficient distance is ensured from the light scattering portion 13 to the surface of the light guide plate 1, the light scattered by the light scattering portion 13 spreads evenly before reaching the surface of the light guide plate 1. Therefore, the entire surface of the light guide plate 1 corresponding to the light scattering portion 13 tends to be visually recognized as emitting light in a planar shape instead of a dot shape.

  Here, the light scattering portion 13 may be formed on the surface of the glass plate 12 facing the adhesive layer 14. Further, the light scattering portion 13 is not limited to one side of the resin plate 11 and may be formed on both sides. In this case, the scattering patterns of the light scattering portions 13 on both sides of the resin plate 11 are preferably plane symmetric with each other.

  Instead of printing the dot pattern, the light scattering portion 13 may be configured by, for example, engraving a linear pattern with a laser or engraving an uneven pattern with sand blasting. Even in these cases, it is preferable that the density of the scattering pattern gradually increases as the distance from the light source 2 increases.

  The light scattering portion 13 may be formed on the entire surface of the light guide plate 1 or only on a part thereof. In the former case, since the entire surface of the light guide plate 1 emits light, it is suitable for illumination or the like. In the latter case, for example, if the light scattering portion 13 is formed only in a region corresponding to a character or an illustration, the character or the illustration is lit and displayed, and a light emitting display device (for example, a signboard such as a guide board or a welcome board) Etc.).

  As shown in FIG. 2, a plurality of light sources 2 are arranged along one side of the light guide plate 1. A plurality of light sources 2 may be arranged along each of the two opposing sides of the light guide plate 1.

  In this embodiment, the light source 2 is composed of LEDs from the viewpoint of low power consumption and low heat generation. As the light source 2, in addition to the LED, for example, a fluorescent tube, a cold cathode tube (CCFL), a hot cathode tube (HCFL), an external electrode tube (EEFL), a plasma lamp, or the like can be applied.

  As the LEDs constituting the light source 2, for example, as shown in FIG. 3, a multi-chip LED on which LEDs 21, 22, and 23 corresponding to RGB are respectively mounted, or a single-color LED 24 is 1 as shown in FIG. 4. Two single-chip LEDs with a phosphor 25 on the light emitting surface side can be applied. In the case of a single-chip type white LED, for example, a blue phosphor is covered with a yellow phosphor to reproduce a white emission color, and in the case of a multi-chip type white LED, for example, an RGB LED is turned on simultaneously to produce a white emission color. Reproduce.

  When the light source 2 includes blue light emission, the light source 2 preferably has a blue center wavelength in a wavelength range of 460 nm or more and 490 nm or less.

  That is, in the configuration of the light guide plate 1, in particular, the adhesive forming the adhesive layer 14 absorbs from the ultraviolet region to the visible light short wavelength region (about 450 nm or less) as shown in the transmittance curve of FIG. There are many things. And although the case where the thickness of the contact bonding layer 14 is 0.4 mm, 0.8 mm, and 1.6 mm is illustrated in the same figure, respectively, there exists a tendency for absorption to become large as the thickness becomes large. Since the adhesive layer 14 of the light guide plate 1 spreads in a planar shape, the apparent thickness of the adhesive layer 14 is large for light propagating in the light guide plate 1 along the plane direction, and the influence of absorption is necessarily large. Become. Therefore, when a large amount of blue component of the light source 2 is included in the absorption region, it is difficult to propagate light into the light guide plate 1 while maintaining the blue emission color emitted from the light source 2 as it is. Thus, the emission color may be greatly different between the light emitted from the light guide plate 1 and the light from the light source 2. In other words, for example, when white light is propagated from the light source 2 into the light guide plate 1, the blue component is absorbed, and the light guide plate 1 emits yellow as a whole (combination of R and G) as the light guide proceeds. The color reproducibility of the light from the light source 2 is deteriorated.

  Therefore, as described above, it is preferable that the blue center wavelength of the light source 2 is set to a wavelength range of 460 nm or more and 490 nm or less so as to be shifted to a longer wavelength side than the wavelength range where absorption by the adhesive occurs. In this way, absorption by the adhesive layer 14 is suppressed, and the difference between the light emission color of the light guide plate 1 and the light emission color of the light source 2 can be reduced. Therefore, even if a versatile and inexpensive adhesive is used, the light emission color of the light source 2 can be reproduced by the light guide plate 1 without any problem.

  Here, as shown in FIG. 6, the above-described multi-chip LEDs are mainly those having a blue center wavelength of about 460 nm to 470 nm, so that the above condition is easily satisfied. In the figure, R represents the spectrum of the red LED, G represents the spectrum of the green LED, and B represents the spectrum of the blue LED.

  On the other hand, the blue LED used for the above-mentioned single-chip LED has a blue center wavelength of about 440 nm or more and less than 460 nm (see FIG. 7), but the blue center wavelength is 460 nm or more and 490 nm or less. If this is used, the above conditions can be satisfied as in the case of a multichip LED.

  Moreover, when the light source 2 contains blue light emission, it is also preferable that it has a blue center wavelength in the wavelength range of 440 nm or more and less than 460 nm, and the color temperature is 4000K or less.

  According to this, even when the blue center wavelength of the light source 2 is included in a wavelength range where absorption by the adhesive layer 14 is likely to occur, the color temperature is 4000 K or less (for example, warm white or light bulb color). Since the blue component itself contained in the light source 2 is small, the influence of light absorption by the adhesive layer 14 is small. That is, even if light of the blue component of the light source 2 is absorbed, it is difficult for the human eye to perceive the decrease of the blue component, and there is a large difference between the light emission color of the light source 2 and the light emission color of the light guide plate 1. There is no.

  Here, blue LEDs used for single-chip LEDs have a blue center wavelength of 440 nm or more and less than 460 nm, but the peak size of the blue center wavelength varies depending on the color temperature. As shown in FIG. 7, in the case of a single-chip blue LED having a blue center wavelength of about 450 nm, the peak of the blue component is the green component in the visible light wavelength range when the color temperature is about 6000 K. And larger than the peak of the red component. On the other hand, when the color temperature is about 4000K, the peak of the blue component is significantly reduced. Therefore, if it has a blue center wavelength in the wavelength range of 440 nm or more and less than 460 nm (preferably 445 nm or more and 455 nm or less) and the color temperature is 4000 K or less (preferably 3000 K or less corresponding to the light bulb color), absorption by the adhesive occurs. The blue component contained in the wavelength range is suppressed in advance. Therefore, if it is single chip type LED, the light source 2 which satisfies the said conditions can be prepared easily.

  In this case, it is preferable that there is a peak larger than the peak of the blue component on the longer wavelength side than 460 nm. That is, the peak of the blue component is preferably smaller than the peaks of the green component and the red component. In FIG. 7, it has a maximum peak near 620 nm.

  Of course, the above conditions may be satisfied by a multichip LED.

  Instead of adjusting the light source 2 as described above, the light absorption characteristics of the adhesive may be improved to achieve high transmittance in the entire visible light range. That is, an adhesive that is transparent to visible light is selected as in the case of the resin plate 11 and the glass plate 12. Specifically, the spectral transmittance of the adhesive is 90% or more in the wavelength range of at least 430 nm to 680 nm (preferably 420 nm to 690 nm, more preferably 410 nm to 700 nm) in the thickness of the adhesive layer 14. The difference between the maximum value and the minimum value of the transmittance is preferably within 1%. In this way, the adhesive layer 14 transmits almost no light in the wavelength range of 410 nm to 430 nm which is the lower limit of the wavelength range of substantial visible light of human beings and 680 nm to 700 nm which is the upper limit thereof. The light emission color of 2 and the light emission color of the light guide plate 1 can be substantially matched.

Second Embodiment
As shown in FIG. 8, the surface light emitting device according to the second embodiment is different from the surface light emitting device according to the first embodiment in that a functional coat 15 is formed on the surface of the glass plate 12.

  Examples of the functional coat 15 include a total reflection film (mirror) made of a metal film or a dielectric film. In this way, the scattered light in the light guide plate 1 is reflected on the functional coat 15 side and is not emitted to the outside. Therefore, only one side opposite to the functional coat 15 emits light, which is suitable for illumination and the like. is there. Here, the total reflection film may be white. In this case, the light guide plate 1 becomes a white plate when the light is extinguished.

  The functional coat 15 may be composed of a half mirror. By adjusting the transmittance with the half mirror, the ratio of the amount of light emitted to both surfaces of the light guide plate 1 can be changed, so that various effects can be produced and the design is improved. For example, when a planar light emitting device configured using a light guide plate 1 on which a half mirror with relatively low transmittance is formed is used as a wall material, the opposite side of the wall can be visually recognized because it is a half mirror when turned off. However, when it is lit, light is emitted in one direction and the opposite side of the wall cannot be seen. That is, the presence / absence of visibility on the opposite side of the wall can be appropriately switched. When this surface light emitting device is used as epi-illumination for attaching to the ceiling, the interior of the room is directly illuminated from the lower surface side of the light guide plate 1 by the incident light, and at the same time the ceiling located on the upper surface side of the light guide plate 1 by the half mirror. Can also illuminate, resulting in highly designed lighting. A white reflective film can be applied as the half mirror.

  The functional coat 15 may include a total transmission part (no mirror), a total reflection part (total reflection mirror), and a partial transmission part (half mirror). In this way, the light emission characteristics can be adjusted at various locations on the light emitting surface, and various effects including the display of characters and illustrations can be achieved.

  The functional coat 15 may be a transmissive film having wavelength selectivity. Thereby, when a surface light-emitting device is used as illumination, harmful light and unnecessary light can be blocked by the wavelength selective transparency. For example, when used as illumination for a plant factory, light having a green wavelength range that is harmful to plants is cut by the functional coat 15 and irradiated.

  In addition, since the light guide plate 1 exhibits excellent chemical resistance, scratch resistance, and weather resistance because the glass plate 12 is located on the outer surface, the functional coat 15 is provided on the adhesive layer 14 side of the glass plate 12. It is preferable to form on the surface. However, when the functional coat 15 is an antifouling coat or the like, it is preferably formed on the outer surface side of the glass plate 12 and positioned on the outermost surface of the light guide plate 1.

  The functional coat 15 is preferably formed on the smooth surface of the glass plate 12 from the viewpoint of film forming accuracy, but may be formed on the surface of the resin plate 11.

  Here, the function of the functional coat 15 described above may be imparted to the adhesive layer 14. In this way, it is not necessary to separately form the functional coat 15.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, although the planar light guide plate 1 has been described in the above embodiment, the light guide plate 1 may be curved. In the production of the curved light guide plate 1, a curved glass plate may be bonded to the curved resin plate, or the curved resin plate may be attached to the surface thereof. The flat glass plate may be bonded together while being deformed.

  Moreover, although the light guide plate 1 demonstrated the case where the light emission function was a main function in the said embodiment, you may add a touchscreen function to the light guide plate 1. FIG. In this case, a touch sensor function may be imparted to the resin plate 11 used for the light guide plate 1, and a sheet having the touch sensor function is additionally inserted into the adhesive layer between the resin plate 11 and the glass plate 12. Alternatively, the surface glass may be directly provided with a touch sensor function. As a touch panel detection method, a resistance film method or a capacitance method is adopted.

<Example 1>
(1) Size and shape: 400 mm × 400 mm flat plate (2) Resin plate: 5 mm thick acrylic plate (3) Glass plate: 0.2 mm thick alkali-free glass (4) Adhesive layer: 0.4 mm thick EVA
(5) Light source: Single-chip white LED (blue center wavelength 450 nm, color temperature 6500 K)
(6) Light scattering portion: Screen printing of dot pattern on one entire surface of resin plate (7) Functional coating: None By the above (1) to (7), a double-sided light emission type window was produced. Its feature is that it functions as a transparent window when turned off, and becomes a wall that emits white light when turned on.

<Example 2>
(1) Size and shape: 800 mm x 800 mm flat plate (2) Resin plate: 5 mm thick acrylic plate (3) Glass plate: 0.2 mm thick non-alkali glass (4) Adhesive layer: 0.4 mm thick TPU
(5) Light source: Single chip type white LED (blue center wavelength 450 nm, color temperature 3000 K)
(6) Light scattering portion: Screen printing of dot pattern on one whole surface of resin plate (7) Functional coating: Total reflection mirror is formed at the central portion on the bonding surface side of one glass plate, A half mirror having a transmittance of 50% was formed in the range of the width of the contour portion of 100 mm. The epi-illumination was produced as described above in (1) to (7). The feature is that the lower side is illuminated by the total reflection mirror on the back side, and at the same time, light is transmitted to the back side by the half mirror formed around it, and the ceiling is illuminated like a frame.

<Example 3>
(1) Size and shape: 300 mm × 600 mm flat plate (2) Resin plate: 5 mm thick acrylic plate (3) Glass plate: 0.3 mm thick non-alkali glass (4) Adhesive layer: 0.3 mm thick optically transparent Adhesive sheet (5) Light source: Multi-chip type (RGB type) white LED (blue center wavelength 468 nm, color temperature 6500 K)
(6) Light scattering portion: Screen printing of dot pattern on one whole surface of resin plate (7) Functional coating: None By the above (1) to (7), a Wolcombe board on which characters were described was produced. The feature is that the character color can be changed by switching the emission color of the light source to white, blue, green, red or the like.

<Example 4>
(1) Size and shape: 600 mm × 600 mm flat plate (2) Resin plate: 5 mm thick acrylic plate (3) Glass plate: 0.1 mm thick non-alkali glass (4) Adhesive layer: 0.3 mm thick optically transparent Adhesive sheet (5) Light source: Multi-chip type (RGB type) white LED (blue center wavelength 468 nm, color temperature 6500 K)
(6) Light scattering portion: Screen printing of dot pattern on one entire surface of resin plate (7) Functional coating: Total reflection mirror is formed on the bonding surface side of one glass plate, and the bonding surface of the other glass plate The wavelength selective transmission film which cuts the green wavelength is formed on the side. By the above (1) to (7), epi-illumination for a plant factory was produced. The feature is that light is emitted only to the plant side by the total reflection mirror on the back side, and light in a wavelength range (green) harmful to plants is cut by the wavelength selective transmission film on the front side.

<Example 5>
(1) Size and shape: 300 mm × 100 mm flat plate (2) Resin plate: 1 mm thick polycarbonate plate (3) Glass plate: 0.1 mm thick borosilicate glass (4) Adhesive layer: 0.1 mm thick optically transparent Adhesive sheet (5) Light source: Single-chip white LED (blue center wavelength 460 nm, color temperature 5000K)
(6) Light scattering part: A linear pattern is engraved on the entire surface of one side of the resin plate with a laser. (7) Functional coating: The adhesion surface side of one glass plate is coated in white. (1) to (7) Thus, a stand lamp for a desk was produced. Its feature is that it is thin and lightweight and has excellent design.

<Example 6>
(1) Size and shape: 800 mm × 1000 mm flat plate (2) Resin plate: 8 mm thick acrylic plate (3) Glass plate: 0.3 mm thick non-alkali glass (4) Adhesive layer: 0.6 mm thick TPU
(5) Light source: Multi-chip type (RGB type) white LED (blue center wavelength 468 nm, color temperature 6500K)
(6) Light scattering portion: Screen printing of dot pattern on one entire surface of resin plate (7) Functional coating: None Large-sized wall by connecting a plurality of planar light emitting devices comprising (1) to (7) above Was made. Its feature is that it is transparent when it is turned off, and the color and the atmosphere of the wall can be changed by switching on and off the RGB.

<Example 7>
(1) Size and shape: 600 mm × 900 mm, semi-cylindrical plate having a curvature of 2000 mm (2) Resin plate: 5 mm thick acrylic plate (3) Glass plate: 0.2 mm thick alkali-free glass (4) Adhesive layer: thickness 0.4mm TPU
(5) Light source: Single-chip white LED (blue center wavelength 455 nm, color temperature 6500K)
(6) Light scattering portion: Screen printing of dot pattern on one whole surface of resin plate (7) Functional coating: None The surface light emitting device comprising the above (1) to (7) is formed in a box shape made of a transparent resin plate It was installed on the ceiling of the space and used as lighting. Its feature is that it is a space having a transparent wall including the illumination part when it is turned off, but the illumination part emits light when illuminated to illuminate the interior of the space.

DESCRIPTION OF SYMBOLS 1 Light guide plate 2 Light source 3 Housing 11 Resin plate 12 Glass plate 13 Light scattering part 14 Adhesive layer 15 Functional coating

Claims (8)

A resin plate, a glass plate tightly fixed to each of both surfaces of the resin plate, and a light scattering portion for guiding light propagating through the resin plate and the glass plate to the outside,
The light guide plate, wherein the light scattering portion is covered with a close contact portion between the resin plate and the glass plate.   The light guide plate according to claim 1, wherein the contact portion is formed of an adhesive layer made of an adhesive.   The light guide plate according to claim 1, wherein the light scattering portion is formed on a surface of the resin plate.   The said light-scattering part is formed by pattern-printing the coating material or ink containing a light-scattering agent on the surface of any one of the said resin plate and the said glass plate. The light guide plate according to any one of the above.   The light guide plate according to claim 1, wherein a thickness of the resin plate is larger than a thickness of the glass plate.   The light guide plate according to claim 1, wherein the glass plate has a thickness of 0.05 mm to 1 mm.   A surface light-emitting device comprising: the light guide plate according to claim 1; and a light source that allows light to enter the light guide plate from at least one end surface of the light guide plate.   The surface light-emitting device according to claim 7, wherein the light source is an LED.

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