JP2009229581A - Light collecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly convenient and versatile light collecting device with a simple configuration can efficiently collect light incident at a wide range of angles (all-round light collection effect) which can be mass-produced inexpensively. <P>SOLUTION: A solar light collection sheet (light collecting device) 620 is constituted of an upper triangle-shaped part 621 having a triangular cross section, a lower plane part 622 of a thick planar shape, and a lower triangle-shaped part 623 identical in shape to the upper triangle-shaped part 621. The triangle-shaped parts 621 and 623 having the identical shape are arranged in a vertically symmetrical fashion, sandwiching the plane part 622. The shape angle of the triangle-shaped parts 621 and 623 is preferably 45° or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light collecting device suitable for collecting sunlight, for example.

  Currently, as a method of photovoltaic power generation (PV), a flat plate method in which a light receiving power generation unit (solar cell) is spread on a light receiving surface is often used. A flat panel solar power generation device (flat PV device) has a function of condensing light in the shape of an installation area, and therefore does not need to track the direction of the sun and is easy to install. However, the flat plate type PV device is expensive because a solar cell is spread over the entire installation area.

  Thus, in recent years, there has been a demand for lower prices of PV devices in order to further spread solar power generation. Therefore, it is required to reduce the number of solar cells that occupy most of the cost.

From such a background, a concentrating PV device that condenses sunlight on a relatively small-diameter solar cell surface by a condensing lens or the like that always faces in the solar direction and performs efficient power generation is becoming widespread. Yes (see, for example, Patent Document 1). Fresnel lenses are often used as condenser lenses. As described above, in the concentrating PV device, the number of solar cells is reduced by forming the light receiving surface with a Fresnel lens and concentrating sunlight several hundred times. Thereby, the condensing type PV apparatus can reduce the use cost of a solar cell to several tenths compared with a flat plate type PV apparatus.
JP 2003-258291 A

  However, in the condensing type PV device, in contrast to the flat plate type PV device that does not need to track the direction of sunlight, when the direction of the condensing lens (Fresnel lens) slightly deviates from the solar direction, The illuminance on the light-receiving surface of the battery is drastically reduced and the amount of power generation is greatly reduced. For this reason, in the concentrating PV device, it is necessary to accurately detect the direction of sunlight and to align the normal surface of the Fresnel lens with that direction. The angle deviation at this time depends on the size of the solar cell and the light collection rate, but is required to be within ± 1 degree, for example. For this reason, an accurate solar light tracking function is essential in the concentrating PV device.

However, in the case of a concentrating PV device of about 3 kW for home use, for example, the solar light tracking device has only about 10 m ^{2 on the} light receiving surface, and is required to be installed outdoors and to withstand strong winds. For this reason, even a concentrating PV device for home use becomes a large-scale device, and if the installation cost is included, the initial cost merit is jeopardized.

  For these reasons, there is a strong demand for the development of a concentrating PV device that does not require solar tracking.

  As a result of diligent efforts, the present inventor can manufacture a large amount at a low cost with a simple configuration, and can efficiently collect light incident at a wide range of angles, and is convenient and versatile. It has been found that a completely new condensing device and method having high performance can be devised, and if this concentrating device and method are used, a concentrating PV device that is light and inexpensive and does not require solar tracking can be realized.

  The present invention has been made in view of such a point, can be manufactured inexpensively in a large amount with a simple configuration, and can efficiently collect light incident at a wide range of angles, Another object of the present invention is to provide a light collecting device and a light collecting method that are highly convenient and versatile.

  The light collecting device of the present invention is a sheet-type light collecting device having a planar structure, in which light irradiated from the outside is incident and guided in the normal direction of the planar structure; and the light collecting portion A light distribution part that makes light from the incident light incident and reflects and refracts the light in a predetermined direction, and a line that makes light from the light distribution part incident and totally reflects the light in a predetermined direction. And a light compression control unit that makes light from the light guide unit incident and compresses and distributes the light in a predetermined target direction.

  The condensing method of the present invention is a condensing method in a sheet-type condensing device having a planar structure, and is a step of introducing light irradiated from the outside into the condensing part and guiding it in the normal direction of the planar structure And the step of causing the light from the light collecting unit to enter the light distribution unit and distributing the light in a predetermined direction while reflecting and refracting the light inside, and the light from the light distribution unit to the linear light guide unit And guiding the light in a predetermined direction while totally reflecting the light inside, and making the light from the light guide unit enter the light compression control unit and compress it to distribute the light in a predetermined target direction. I did it.

  Specifically, in the present invention, for example, light is collected by a sheet-shaped light collecting device (light collecting sheet) fixed on the ground. In the light collecting sheet, sunlight and scattered light irradiated on the surface of the sheet are taken into the sheet from the light collecting unit. The condensing unit has a function and a shape capable of taking incident light in a wide range of angles into the sheet while minimizing reflected light. Incident light taken into the sheet is distributed by the light distribution unit in the direction of the linear light guide on the sheet plane. The light distribution unit has a three-dimensional structure for efficiently distributing incident light taken in by the light collecting unit to the linear light guide and a contact shape with the linear light guide. The linear light guide section preferably has a plurality of linear light guide paths. The optical compression control unit increases the energy density of incident light by combining incident light from a plurality of linear light guides into one. By repeating this optical compression function, the energy density can be further increased.

  Another condensing device of the present invention is a sheet-like condensing device that condenses light emitted from one surface and emits it from the other surface, and is formed on at least the one surface, and the irradiation A surface shape portion having a surface shape that allows not only the incident light to be directly incident on the inside but also the external reflected light caused by the irradiated light to be incident on the inside. A configuration is adopted in which light irradiated at an arbitrary angle from one surface side is incident on the inside by repeating reflection and refraction at the boundary surface.

  Still another light collecting device of the present invention is a sheet-like light collecting device that collects light emitted from one surface and emits the light from the other surface, and is formed on the one surface, and the irradiation Formed on the other surface, the first surface shape portion having a surface shape that allows not only the incident light to be directly incident on the inside but also the external reflected light caused by the irradiated light to be incident on the inside. A second surface shape portion having the same or substantially the same surface shape as the first surface shape portion, and the first surface shape portion and the second surface shape portion are vertically symmetrical. Or the structure arrange | positioned substantially vertically is taken. Preferably, the light collecting device further includes a flat plate portion, and the first surface shape portion and the second surface shape portion are vertically symmetrical or substantially vertically symmetrical with respect to the flat plate portion. Is arranged.

  According to the present invention, it is possible to manufacture a large amount at a low cost with a simple configuration, and it is possible to efficiently collect light incident at a wide range of angles, and realize high convenience and versatility. can do.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the light collecting apparatus according to Embodiment 1 of the present invention.

  A light collecting device 100 shown in FIG. 1 is a sheet-type light collecting device having a planar structure. For example, natural light such as sunlight (including ambient light such as scattered light) on a sheet-shaped flat surface. And has a function of distributing light in a specific direction. The sheet-type concentrating device 100 improves the convenience of using sunlight for various light application systems (for example, concentrating PV, sunlight illumination, backlight, etc.) and provides an inexpensive light application system. It is an object.

  The sheet-type light collecting device (hereinafter also referred to as “this device”) 100 is roughly composed of a normal light collecting unit 110, a normal light distribution unit 120, a linear light guide unit 130, and an optical compression control unit 140. Has been.

  The normal line condensing unit 110 has a function of introducing light (sunlight or other ambient light) irradiated from the outside and guiding it in the normal direction of the apparatus 100. Specifically, the normal light focusing unit 110 captures (condenses) light incident obliquely at an arbitrary angle from the normal direction of the apparatus 100 in the normal direction, and the normal light distribution unit 120 It has a function of entering light at an angle that allows total reflection. In this way, the configuration (shape) of the normal light distribution unit 120 can be facilitated by aligning light incident obliquely in the normal direction as much as possible. As will be described in detail later, the normal light condensing unit 110 has, for example, a configuration in which microlenses are arranged in an array. Incidentally, the more the incident light deviates from the normal direction, the more reflected light. For example, in the case of incidence from the air, the incident angle is 80 ° and the transmittance is about 50%. As an angle, about 80 ° can be assumed (however, it is not completely lost as described above).

  The normal light distribution unit 120 has a function of allowing light from the normal light converging unit 110 to enter and distributing light in a predetermined direction while reflecting and refracting the light. Specifically, the normal light distribution unit 120 receives the light from the normal light condensing unit 110 and reflects and refracts the light inside the light guide unit 130 at an angle that allows total reflection inside the linear light guide unit 130. It has a function to make light incident. As will be described in detail later, the normal light distribution unit 120 includes a plurality of normal light distribution paths. Each normal light distribution path is arranged, for example, at the position of each of the array-shaped microlenses. From the viewpoint of energy efficiency, it is preferable to distribute incident light to the linear light guide unit 130 using only total reflection inside the normal light distribution unit 120. However, as a practical problem, only total reflection is used. Then, it is difficult to distribute a wide range of incident light to the linear light guide unit 130. Therefore, in the present embodiment, while the shape of the normal light distribution unit 120 is made to be totally reflective as much as possible, not only total reflection but also reflection and refraction are used.

  The linear light guide unit 130 has a function of introducing light from the normal light distribution unit 120 and guiding the light in a predetermined direction while totally reflecting the light. Specifically, the linear light guide unit 130 causes the light from the normal light distribution unit 120 to enter and totally reflect the light internally, and compresses and collects the light in a predetermined direction in a linear manner. 140 has a function of entering (transferring) light into the inside. As will be described in detail later, the linear light guide unit 130 has a plurality of linear structure light guides (hereinafter referred to as “linear light guides”) optically separated from each other. For example, the linear light guide is formed by printing on a transparent sheet substrate. In addition, a plurality of normal light distribution paths are connected to the linear light guide path. In this specification, “compression” of light refers to increasing the energy density of light by collecting light or the like.

  The light compression control unit 140 has a function of causing light traveling inside the linear light guide unit 130 to be incident and compressing the light, and distributing the light in a predetermined target direction. Specifically, the light compression control unit 140 collects the light that has entered the linear light guide unit 130 (a plurality of linear light guides) while repeating total reflection, and combined the light into a highly compressed light (highly compressed). Light) and having the light application system unit 200 enter (transfer) light. As will be described in detail later, the optical compression control unit 140, for example, thins the compressed light by the action of a flat lens to further increase the energy density.

  The optical application system unit 200 may be various systems depending on the application. For example, as the optical application system unit 200, as described above, a condensing PV, sunlight illumination, a backlight, or the like can be considered. In any case, the light application system unit 200 has a function of converting light incident from the sheet-type light collecting device 100 (particularly, the optical compression control unit 140) according to the light application system. Specifically, for example, in the case of the condensing type PV, incident light (highly compressed light) from the sheet type condensing device 100 is irradiated to the photovoltaic element (solar cell). Moreover, when using it directly for sunlight illumination, for example, the incident light (high compression light) from the sheet-type light collecting device 100 is directly transferred to the light diffusion sheet. When used as a light source for a backlight, for example, a two-dimensional spectroscopic prism is formed on a flat sheet, and incident light (highly compressed light) from the sheet-type condensing device 100 is formed using the two-dimensional spectroscopic prism. Is split into a predetermined color (RGB) and output.

  Among the components described above, at least a part of the normal light collecting unit 110, the normal light distribution unit 120, and the linear light guide unit 130 are formed on the same substrate. Specifically, for example, a part of the linear light guide 130 (a plurality of linear light guides) is formed on a planar sheet substrate, and this part of the linear light guide 130 (each linear light guide). ) On which a normal light distribution unit 120 (a plurality of normal light distribution paths) is arranged, and a normal light condensing unit 110 (each microlens) is arranged on the normal light distribution unit 120 (each normal light distribution path). Has been. As will be described in detail later, at least the normal light distribution unit 120 and the linear light guide unit 130 are preferably formed on a transparent sheet substrate by screen printing.

  Preferably, a part of the normal line condensing unit 110, the normal light distribution unit 120, and the linear light guide unit 130 on the sheet substrate is unitized in a predetermined unit. Hereinafter, the unitized unit structure portion is referred to as a “planar light collecting sheet portion”. The planar light collecting sheet unit 150 has a function of condensing external light in a linear specific direction. Further, a unit structure portion that does not have the normal light condensing unit 110 and the normal light distribution unit 120 and is composed only of the linear light guide unit 130 will be referred to as a “linear light guide sheet unit”. The linear light guide sheet section 160 has a function of guiding (transferring) light collected in a specific linear direction in a predetermined direction while further compressing and condensing the light in a linear shape. In this case, the sheet-type condensing device 100 includes at least a planar condensing sheet unit 150 and an optical compression control unit 140, and further includes a linear light guide sheet unit 160 as necessary. Of course, preferably, the optical compression control unit 140 is also formed as a unit on a planar substrate. Hereinafter, this unitized optical compression control unit will be referred to as an “optical compression sheet unit”. Accordingly, by appropriately combining the flat light collecting sheet portion 150, the linear light guide sheet portion 160, and the light compression sheet portion 170 that are unitized in this way, it can be appropriately selected according to the application and environment with a high degree of freedom. It is possible to easily install the sheet-type light collecting device 100 having a proper size and shape. In particular, the flat light collecting sheet portion 150 can be combined not only in the horizontal direction but also in the vertical direction. In other words, a plurality of the planar light collecting sheet portions 150 can be arranged in the horizontal direction on the same plane or can be stacked in the vertical direction.

  As described above, in the linear light guide 130, the incident light propagates while being totally reflected inside. Since light propagating by total reflection does not leak to the outside, the linear light guide 130 appears transparent when viewed from the outside. This is the same for the normal light distribution unit 120 when the normal light distribution unit 120 has a shape of only total reflection. In light transmission, being visible from the outside means loss of light energy.

  Next, a specific configuration example of the sheet type light collecting device 100 will be described in detail with reference to the drawings.

  FIG. 2 is a schematic perspective view of an essential part showing an example of the configuration of the sheet type light collecting device 100. In particular, FIG. 2 shows an example of the configuration of the main part of the flat condensing sheet portion 150.

  A sheet-type condensing device 100a shown in FIG. 2 has a flat condensing sheet portion 150a. As shown in FIG. 2, the flat light collecting sheet portion 150a is configured by forming a normal light collecting portion 110a, a normal light distribution portion 120a, and a linear light guide portion 130a on a sheet substrate 151. .

  For example, the normal light condensing unit 110 a is configured by arranging microlenses 112 in an array on a transparent sheet layer 111.

  In this configuration, since each microlens 112 is circular when viewed from above, a gap is generated between adjacent microlenses 112. Therefore, preferably, the normal line condensing unit 110a is multilayered.

  FIG. 3 is a schematic cross-sectional view showing the configuration of the multilayered normal line condensing unit 110a. In the example shown in FIG. 3, the normal light collector 110a has a two-layer structure, and a first normal light collector layer 113-1 and a second normal light collector layer 113-2 are stacked. Configured. The positional relationship between the upper and lower two layers (normal light condensing part layers 113-1 and 13-2) of the normal light condensing part 110a is as shown in FIG. However, in FIG. 3, for the sake of convenience, the gap between the microlenses 112 in the same normal line condensing portion layer 113 is ignored.

  For example, the normal light concentrating portion layer 113 is configured by arranging the microlenses 112 in an array on the transparent sheet layer 111 as described above. At this time, as will be described later, the microlens 112 of the normal light concentrating portion layer 113 is parallel to the extending direction of each corresponding linear light guide and the linear light guide, as will be described later (for example, see FIG. 11B). Are arranged in a line on a straight line away from (offset). However, since each microlens 112 is circular when viewed from above as described above, a gap is generated between adjacent microlenses 112 in the same normal light condensing portion layer 113. Therefore, in this example, the normal light condensing portion layers 113 having the same structure are arranged above and below to form a two-layer structure. However, at this time, as shown in FIG. 3, the upper and lower normal light condensing portion layers 113-1 and 13-2 are arranged between adjacent microlenses 112 in the microlens rows corresponding to the same linear light guide path. The arrangement of the microlenses 112 is adjusted so that the center of the microlens 112 of the other normal light condensing portion layer 113 is positioned at the center of the gap.

  As described above, the normal light condensing unit 110a has a function of facilitating the configuration of the normal light distributing unit 120 by aligning light incident from an oblique direction in the normal direction as much as possible. Therefore, as shown in this example, the normal light condensing unit 110a is formed into two layers (multilayered), so that the ratio of the incident light from the outside to the microlens 112 is increased, and the realization of this function is further ensured. Can be.

  Furthermore, although not shown, the flat light collecting sheet portion 150a itself has a two-layer structure (multi-layer structure), thereby further condensing rate (ratio at which light from the outside is condensed on the linear light guide portion 130). Can be improved.

  The normal light condensing part 110a (each normal light condensing part layer 113 in the case of having a multilayer structure) is formed by using, for example, a microlens on the transparent sheet layer 111 using an ink jet printing technique using an ultraviolet curable resin as an ink. 112 is printed. The manufacturing method of the microlens 112 is not limited to the ink jet printing technique, and any appropriate manufacturing method can be applied. For example, instead of the ink jet printing technique, a screen printing technique, a plastic molding technique, an optical molding technique, or the like can be applied.

  As described above, the normal light condensing unit 110a has a function of refracting light that is greatly deviated from the normal direction in incident light as close as possible to the normal light distribution unit 120a. In order to realize this function, it is necessary to distribute light in the normal direction while providing an angle to the surface to reduce reflected light. For this reason, the surface of the normal light condensing unit 110a is not a mere plane, but has a circular lens structure as shown in FIGS. 2 and 3, and this lens effectively captures light from an oblique direction. There is a need. Moreover, this lens also has a function of guiding incident light to the normal light distribution unit 120a. However, since the lens is circular, it cannot cover all surfaces. Therefore, in the example shown in FIG. 3, the normal light condensing unit 110a has a two-layer structure. In FIG. 3, a broken line indicates an image in which incident light is collected at one point of the normal light distribution unit 120 a, and an upper solid line arrow indicates an angle of incident light. In this case, incident light is incident at an angle closer to the normal direction of the local surface (lens surface) than when incident on a flat surface. It becomes possible to shine.

  The normal line condensing unit 110 is intended to efficiently capture light incident at a wide range of angles into the apparatus 100a. To achieve this purpose, the normal line condensing unit 110 (in the case of having a multilayer structure) Each normal light condensing portion layer (hereinafter the same) can take various appropriate surface shapes. For example, instead of the microlens array shown in FIGS. 2 and 3, a pyramid shape such as a triangular pyramid or a quadrangular pyramid may be used.

  FIG. 4 is a schematic view showing another configuration (surface shape) of the normal light condensing unit 110. In particular, FIG. 4 (A) is a schematic main part perspective view, and FIG. 4 (B) is a schematic main part. It is sectional drawing.

  In the example illustrated in FIG. 4, the normal light condensing unit 110 b is configured by arranging triangular prisms 114 having a substantially triangular cross section in the longitudinal direction (extending direction of the linear light guide 131) in an array. The normal light condensing unit 110b has a function of guiding incident light in the normal direction by the function of a triangular prism due to the triangular shape of the surface. Also in this case, not only the light incident from the normal direction (solid arrow in FIG. 4A) but also the light incident at an angle deviating from the normal direction (broken arrow in FIG. 4A) The light is condensed in the normal direction by the line condensing unit 110b. For example, light incident at an angle deviating from the normal direction is collected in the normal direction along the path shown in FIG. Specifically, for example, incident light with an incident angle of 80 ° is bent every time it passes through the boundary surface, and the angle changes from 80 ° → 76.35 ° → 53 ° → 47 °.

  Note that the present inventor performed a simulation of the light beam capture efficiency by taking a surface shape (triangular shape) as shown in FIG. 4A as an example. The configuration based on the new knowledge obtained as a result will be described in detail in Embodiment 2.

  FIG. 5 is a schematic perspective view illustrating an example of the configuration of the normal light distribution unit 120a and the linear light guide unit 130a. 6 is a plan view of FIG. 5 as viewed from above, FIG. 7 is a sectional view taken along line VII-VII in FIG. 6, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 9 is a diagram showing details of FIG. 5. In particular, FIG. 9 (A) is a plan view similar to FIG. 6, and FIG. 9 (B) shows the main part of FIG. 9 (A). FIG. 9C is a plan view of the main part of FIG. 9B. 5-8, the direction of the east, west, north, and south is attached | subjected supposing the case where this apparatus 100a is applied to condensing type PV.

  As described above, the normal light distribution unit 120a allows the light from the normal light collection unit 110a to enter and reflect and refract the light inside the linear light guide unit 130a (the linear light guide 131). , And has a function of entering light at an angle that allows total reflection. In the example illustrated in FIGS. 5 to 9, the normal light distribution unit 120 a includes a plurality of normal light distribution paths 121 corresponding to the micro lenses 112 of the normal light condensing unit 110 a. An inlet 122 (light entrance) of the normal light distribution path 121 is connected to the sheet substrate 111 of the normal light collector 110a, and an outlet (light exit) is connected to the linear light guide 130a via the connection 123. It is connected to a corresponding pair of left and right linear light guides 131. That is, the normal light distribution path 121 is disposed on an intermediate position between the corresponding pair of left and right linear light guide paths 131. Further, in this example, the entrance 122 of the normal light distribution path 121 has an elliptical shape, and the main body portion (portion excluding the connection portion 123) of the normal light distribution path 121 has an elliptic frustum shape. That is, the outlet 124 of the main body also has an elliptical shape.

  In particular, preferably, in order to effectively use incident light (sunlight), as shown in FIGS. 5 to 9, the entrance (light entrance) 122 of the adjacent normal light distribution path 121 is a normal light distribution path. In consideration of the height of 121, the shape of the upper surface (inlet), and the area, they are configured to overlap each other. In this example, in order to efficiently collect incident light from the east-west direction regardless of the change in the incident angle (improvement of light collection in the east-west direction), the shape of the inlet 122 of the normal light distribution path 121 is east-west. An elliptical shape that is long in the direction (see FIG. 9 in particular), and the incident light is guided to the pair of left and right linear light guides 131 by the connecting portion 123. That is, in this example, the connection part 123 is provided, and the incident light in the east-west direction of the normal light distribution part 120a is distributed to the pair of left and right linear light guides 131 depending on the direction.

  In this example, in order to minimize the backflow of light from the linear light guide 131 to the normal light distribution path 121, the contact point of the connection portion 123 of the normal light distribution path 121 with the linear light guide 131 is reduced. And it is made to contact in parallel with the linear light guide 131 as much as possible. Thereby, the amount of light traveling backward from the linear light guide path 131 to the normal light distribution path 121 can be reduced.

  In the case of sunlight, the incident angle varies with the latitude of the place. Therefore, the inclination angles θ and γ (see FIG. 8) of the side surface of the normal light distribution path 121 are optimum values by, for example, actual measurement in consideration of the height of the normal light distribution unit 120a and the latitude and inclination of the installation location. To be determined. Here, for example, the inclination angle θ is set to an angle at which sunlight can be used effectively even when the height of the sun is the lowest (in the northern hemisphere, the winter solstice). In addition, for example, the inclination angle γ is set to an angle at which sunlight can be used effectively even when the height of the sun is the highest (summer solstice in the case of the northern hemisphere). For example, in the example of FIG. 8, as shown in a broken-line circle, the sun summer altitude is set to 80 ° and the winter altitude is set to 30 ° provisionally. Even when it is assumed that the device 100a is arranged on a horizontal plane, there are many variables that can be assumed, such as the height of sunlight is different between summer and winter, and changes depending on the latitude. Therefore, in actual installation, it is preferable to set the inclination angles θ and γ to optimum values by actual measurement as described above in consideration of many variables.

  As described above, the linear light guide unit 130a has a function of causing the light from the normal light distribution unit 120a to enter and guide the light in a predetermined direction while totally reflecting the light internally. The linear light guide part 130a has a plurality of linear structure light guides (linear light guides 131) optically separated from each other. The linear light guide 131 has a function of guiding light incident from the normal light distribution path 121 of the normal light distribution unit 120a in one direction using total reflection. The linear light guide 131 is formed by printing on a transparent sheet substrate 151, for example.

  Since both the normal light distribution path 121 and the linear light guide path 131 preferably transmit light internally by total reflection, it is ideal that the refractive index in visible light is the same. Therefore, basically, the normal light distribution path 121 and the linear light guide path 131 are formed using, for example, the same component resin, preferably, an ultraviolet curable resin. The ultraviolet curable resin is generally constituted by blending a prepolymer, a monomer, a photoinitiator, a sensitizer, a colorant, and various additives. When UV curable resin is irradiated with UV (UV light), the photoinitiator inhales UV to initiate photopolymerization reaction, and converts monomers and prepolymers to polymers to form a network-like cross-linked structure. . When an ultraviolet curable resin is used, the surrounding substance (medium) in contact with the normal light distribution path 121 and the linear light guide path 131 is preferably, for example, air or an inert gas such as nitrogen. However, the type of gas is not limited to this. Basically, any gas can be used since the refractive index of the gas is around 1.0.

  Preferably, the linear light guide 131 is formed by printing on a transparent sheet substrate 151, for example, and the normal light distribution path 121 is formed by printing on the linear light guide 131. The linear light guide path 131 and the normal light distribution path 121 are formed using, for example, a well-known screen printing method. An example of a specific manufacturing method will be described in detail later.

  In the present apparatus 100 a, sunlight 180 is taken (condensed) in the normal direction by the normal light collecting unit 110 a and guided to the normal light distribution path 121. The light 181 incident on the normal light distribution path 121 from the normal light condensing unit 110a propagates through the normal light distribution path 121 by total reflection. Here, total reflection refers to perfect reflection without energy loss at the refractive index interface (reflectance = 100%). For example, when the normal light distribution path 121 is formed of an ultraviolet curable resin and the surrounding medium is air, the critical angle is such that there is no refracted light with respect to incident light (only reflected light), as will be described later. Is about 42 °. Accordingly, the light 181 propagating through the normal light distribution path 121 by total reflection propagates at an inclination angle within about ± 48 ° (= 90 ° -42 °) with respect to the boundary surface (tangential plane). Then, the light 181 propagating through the normal light distribution path 121 enters (distributes) one of the pair of left and right linear light guide paths 131 via the connection portion 123. The light 182 entering the linear light guide 131 from the normal light distribution path 121 propagates in the linear light guide 131 in a predetermined direction by total reflection.

  As described above, since light propagating by total reflection does not leak to the outside, at least the linear light guide 131 looks transparent when viewed from the outside.

  FIG. 10A is a diagram for explaining the principle of total reflection. FIG. 10B is a diagram illustrating an example of specific numerical values.

According to Snell's law (the law of refraction), the incident angle from the medium A to the medium B is θ ₁ , the refraction angle from the medium A to the medium B is θ ₃ , the absolute refractive index of the medium A is n _A , and the medium B When the absolute refractive index of n is n _B , the following relationship holds.
sin θ ₁ / sin θ ₃ = n _B / n _A
Here, the absolute refractive index is a relative refractive index specific to a substance with respect to vacuum in a light wave. At the critical angle (θ ₃ = 90 °), which is the maximum incident angle at which refraction occurs, there is no refracted light and only reflected light. From the above formula, it can be seen that the magnitude of the critical angle is determined by the refractive index of the medium. When n _A > n _B and light enters the medium B from the medium A, the critical angle θ _m (incident angle from the medium A to the medium B) is as follows.
sin θ _m = sin θ _m / sin 90 ° = n _B / n _A
Therefore, for the incident angle θ ₁ from the medium A to the medium B,
θ ₁ > θ _m
Satisfying this relationship is a condition for total reflection. Note that, according to the law of reflection, the incident angle θ ₁ and the reflection angle θ ₂ of the light reflected by the boundary surface (reflecting surface) are equal (θ ₁ = θ ₂ ).

For example, if the medium A is an ultraviolet curable resin and the medium B is air, the absolute refractive index of the ultraviolet curable resin is about 1.5 and the absolute refractive index of air is about 1.0. Therefore, the critical angle θ _m is sin θ _{From m} = 1.0 / 1.5, θ _m = 41.8103 °, which is about 42 °. Accordingly, light incident at a critical angle (about 42 °) or more, that is, light incident at an angle of about 48 ° or less with respect to the boundary surface is all reflected light (total reflection).

  In this embodiment, the principle of such total reflection, specifically, for example, when light is incident on the air from an ultraviolet curable resin, is incident within about ± 48 ° with respect to the boundary surface (tangential plane). The principle that all the light to be reflected is totally reflected at the boundary surface and propagates in the traveling direction is utilized for the propagation of the light through the light guide printed on the plane.

  The normal light distribution unit 120 is intended to efficiently enter the light from the normal light collection unit 110 into the linear light guide unit 130, and in order to achieve this purpose, the normal light collection unit 120 is used. The unit 120 can take various suitable configurations.

  FIG. 11 is a schematic diagram illustrating another configuration of the normal light distribution unit 120. In particular, FIG. 11A is a schematic diagram of a main part, and FIG. 11B is a schematic plan view.

  In the example illustrated in FIG. 11, the normal light distribution path 121 a of the normal light distribution unit 120 b is connected to only one linear light guide path 131. The inlet 122 and the outlet 125 of the normal light distribution path 121a each have an elliptical shape, and the normal light distribution path 121a has an elliptic frustum shape. Unlike the area of the entrance 122, the area of the exit 125 of the normal light distribution path 121a is set as small as possible. Thereby, the amount of light traveling backward from the linear light guide path 131 to the normal light distribution path 121a can be reduced. Further, as shown particularly well in FIG. 11B, on the plane, the center point of the entrance 122 of the normal light distribution path 121a is offset from the center line of the linear light guide path 131 (preferably, the linear light guide path 131 And the normal light distribution path 121a and the light propagation direction in the linear light guide 131 are made to be obtuse, thereby reversing the linear light guide path 131 to the normal light distribution path 121a. The amount of light can be further reduced.

  FIG. 12 is a schematic diagram illustrating still another configuration of the normal light distribution unit 120. In particular, FIG. 12A is a schematic perspective view of a normal light distribution path, and FIG. 12B is a normal distribution. FIG. 12C is a schematic rear view showing a first example of the normal light distribution path, and FIG. 12D is a schematic rear view showing a second example of the normal light distribution path. FIG. FIG. 13 is a schematic perspective view showing a configuration of a normal light distribution unit having the normal light distribution path of FIG.

  In the example shown in FIGS. 12 and 13, the normal light distribution path 121 b of the normal light distribution unit 120 c is connected to only one linear light guide path 131. The entrance and exit of the normal light distribution path 121b each have a quadrangular shape (in this example, a rectangle or a square), and the normal light distribution path 121b has a quadrangular pyramid shape. Also for the normal light distribution path 121b, the exit area is set as small as possible, unlike the entrance area. FIG. 12C shows a case where the center line of the normal light distribution path 121b and the center line of the outlet coincide with each other (first embodiment), and FIG. This is a case where the center line of the outlet is shifted (second embodiment). In order to reduce the amount of light traveling backward from the linear light guide path 131 to the normal light distribution path 121b, the second embodiment shown in FIG. 12 (D) rather than the first embodiment shown in FIG. 12 (C). Is preferred. In FIG. 12, “111” indicates a part of the sheet substrate of the normal light collector 110a where the entrance of the normal light distribution path 121b exists, and “131” indicates the exit of the normal light distribution path 121b. A part of the existing linear light guide is shown.

  FIG. 14 is a schematic view showing an example of the configuration of the linear light guide sheet portion 160a and the light compression sheet portion 170a, and FIG. 15 is an enlarged view of the light high compression function portion shown in FIG.

  As described above, the linear light guide sheet 160a shown in FIG. 14 has a function of guiding (transferring) light condensed in a specific linear direction in a predetermined direction while further compressing and condensing the light in a linear shape. Have As illustrated in FIG. 14, the linear light guide sheet portion 160 a includes a plurality (three in this case) of sets of linear light guide paths 161. In the example illustrated in FIG. 14, the linear light guide path group 161 includes five linear light guide paths 131. In each linear light guide group 161, all the outlets of the five linear light guides 131 are connected to the corresponding primary light compression lens unit 162. The primary light compression lens unit 162 has a function of compressing and condensing light (primary light) propagated in the linear light guide 131 by a lens action. Accordingly, in each linear light guide path group 161, the light (primary light) propagated through the five linear light guide paths 131 is compressed and condensed by the primary light compression lens unit 162, and one beam (primary light). Compressed light) 163 is output. On the other hand, the entrances of the five linear light guide paths 131 are planarly condensed by, for example, the light input joint portion 164 of the linear light guide sheet portion 160a and the light output joint portion (not shown) of the planar light collection sheet portion 150a. Each can be connected to the corresponding linear light guide 131 of the sheet portion 150a.

  As described above, the light compression sheet portion 170a shown in FIG. 14 is a function that collectively converts the light that has entered the plurality of linear light guides 131 into high compression light (highly compressed light) and outputs the light. Have As shown in FIG. 14, the light compression sheet portion 170 a includes a primary compressed light condensing lens portion 171 and a light high compression function portion 172. The primary compressed light condensing lens unit 171 has a function of compressing and condensing a plurality (three in this case) of beams (primary compressed light) 163 output from the linear light guide sheet unit 160a by lens action. Have. The light compressed and condensed by the primary compressed light condensing lens unit 171 enters the light high compression function unit 172 as one beam (secondary compressed light) 173. The light high compression function unit 172 has a function of further compressing the light (secondary compressed light) 173 compressed and condensed by the primary compressed light condensing lens unit 171. The optical high compression function unit 172 includes, for example, a plurality of sets of planar lenses (concave / convex lenses), and is configured to gradually increase the energy density by thinning the secondary compressed light 173 stepwise by the action of the planar lens. ing.

  More specifically, as shown in FIG. 15, the light high compression function unit 172 has a configuration in which concave and convex lenses 175a and 175b are combined in the light guide 174. With this configuration, the secondary compressed light 173 is transmitted. Further, it has a function of increasing the energy density of the secondary compressed light by thinning it and outputting it from the compressed light output unit 176 to the outside. In FIG. 15, for example, the white portion is not filled with resin, so that the refractive index is 1.0. On the other hand, since the portions other than the white portions are filled with resin, the refractive index is about 1.5. Therefore, if the shape of the white portion is a concave lens shape, the portion has the function of a normal convex lens (convex lens 175a). On the contrary, if the shape of the white portion is the shape of a convex lens, the portion has the function of a normal concave lens (concave lens 175b). Therefore, the combination of the two types of lenses 175a and 175b can sequentially turn the light into convergent light.

  The connection between the linear light guide sheet portion 160a and the light compression sheet portion 170a is performed, for example, by joining the light output joint portion 165 of the linear light guide sheet portion 160a and the light input joint portion 177 of the light compression sheet portion 170a at a predetermined position. Is done by doing. Here, “at a predetermined position” means the position of the light guide (primary compressed light output portion) 166 attached to the light output joint portion 165 of the linear light guide sheet portion 160a and the light of the light compression sheet portion 170a. This means that the position of the light guide (primary compressed light input portion) 178 attached to the input joint portion 177 matches.

  Therefore, in the state in which the linear light guide sheet portion 160a and the light compression sheet portion 170a are connected, the light propagated in the linear light guide sheet portion 160a is the primary compressed light output portion 166 and the primary compressed light input portion. 178 is guided into the light compression sheet portion 170a. Specifically, for example, in the example shown in FIG. 14, the light incident on the 15 (= 5 × 3) linear light guides 131 of the linear light guide sheet portion 160 a is within the corresponding linear light guide 131. And is combined into three beams (primary compressed light) 163 by the three primary light compression lens units 162, and a pair of corresponding primary compressed light output units 166 and primary compressed light inputs. The light enters into the light compression sheet portion 170a by the portion 178. Then, the three primary compressed lights 163 incident on the light compression sheet part 170a are collected into one beam (secondary compressed light) 173 by one primary compressed light condensing lens part 171. It is guided to the optical high compression function unit 172. Then, the single secondary compressed light entering the optical high compression function unit 172 is thinned stepwise by the action of the planar lenses (concave / convex lenses 175a and 175b), and the energy density is further increased to increase the high compression. The light is output from the compressed light output unit 176 as light.

  FIG. 16 is a schematic diagram illustrating an example of an overall configuration in which the configurations of FIG. 14 are combined.

  In the example shown in FIG. 16, six linear light guide sheet portions 160a and four light compression sheet portions 170a are combined. Specifically, the system of FIG. 16 divides the six linear light guide sheet portions 160a into two parts, a front stage and a rear stage, respectively, so that the front linear light guide sheet section 160a and the rear linear form are divided. Three light guide sheet portions 160a are connected in parallel, and three rows of linear light guide sheet portions 160a are connected to the three light compression sheet portions 170 on a one-to-one basis. The sheet unit 170 is connected to one light compression sheet unit 170. Further, in this example, the light compressed and collected by each linear light guide sheet group 161 of the linear light guide sheet portion 160a at the front stage is one of the linear light guide path groups 161 of the linear light guide sheet section 160a at the rear stage. Light enters the linear light guide 131. At this time, the light (primary compressed light) 163 output from the primary light compression lens unit 162 corresponding to each linear light guide path group 161 of the subsequent linear light guide sheet unit 160a is the newly incident light. This is the sum of the primary compressed light from the previous stage. By repeating this connection a plurality of times, a larger amount of light can be obtained.

  Next, a method for manufacturing the normal light distribution path 121 and the linear light guide path 131 in the flat light collecting sheet portion 150a will be described with reference to the drawings. Here, as an example, a case where the normal light distribution path 121 and the linear light guide path 131 are manufactured using, for example, screen printing will be described.

  First, the case where the linear light guide 131 is formed (printed) on the transparent sheet substrate 151 by screen printing will be described with reference to FIGS. Here, FIG. 17 is a cross-sectional view for each process showing an example of a method for manufacturing the linear light guide 131. FIG. 18 is a schematic perspective view showing the correspondence between the screen printing original plate shown in FIG. 17 and the screen printing result. FIG. 19 is a schematic diagram for explaining the ultraviolet irradiation process.

  First, as shown in FIG. 17A, a screen printing original plate 300 for forming the pattern of the linear light guide 131 is prepared. The screen printing original plate 300 for the linear light guide pattern is formed by forming a pattern portion (cutout portion) 302 that transmits ultraviolet rays (UV light) on a sheet material 301 such as a stainless steel sheet or an aluminum foil sheet. Specifically, for example, the sheet material 301 is cut out according to the pattern shape of the linear light guide 131 using a YAG laser machine or the like. The screen printing original plate 300 preferably has such a thickness that the thickness can be ignored, for example, about several tens of microns (μm). As an example, the screen printing original plate 300 is, for example, a stainless sheet having a thickness of 10 μm.

  17B, after the screen printing original plate 300 of FIG. 17A is installed on a transparent sheet substrate 151, a liquid ultraviolet curable resin 303 is applied to the cutout portion 302 of the screen printing original plate 300. Fill and apply. The liquid ultraviolet curable resin 303 filled and applied to the cutout portion 302 of the screen printing original plate 300 is not cured and is in an uncured state unless it is irradiated with ultraviolet rays. Since the liquid ultraviolet curable resin 303 uses a resin having a certain degree of viscosity, the liquid ultraviolet curable resin 303 can maintain a filled and applied shape although it is liquid. See also FIG.

  Then, as shown in FIG. 17C, the sheet surface is irradiated with ultraviolet rays (UV light) from the normal direction. As a result, the ultraviolet curable resin 303 in the cutout portion 302 is cured, and the pattern of the linear light guide 131 is formed.

  Specifically, this ultraviolet irradiation step can be performed, for example, by an ultraviolet irradiation method in conventional screen printing. That is, in conventional screen printing, it has not been considered to irradiate ultraviolet rays while shifting the angle from the normal direction of the sheet surface. Rather, in conventional screen printing, it was important to irradiate completely from the normal direction. Therefore, in the conventional ultraviolet irradiation method, ultraviolet rays (UV light) from an ultraviolet light source are converted into parallel light using an optical system such as a Fresnel lens and irradiated from the normal direction of the sheet surface. For example, in the ultraviolet irradiation process of FIG. 17C, as shown in FIG. 19A, the ultraviolet light source 400 is disposed at a position away from the sheet surface, and the ultraviolet light from the ultraviolet light source 400 is, for example, Fresnel. The lens 401 is used to irradiate the ultraviolet curable resin 303 in an uncured state as parallel light from the normal direction of the sheet surface. In order to effectively use the ultraviolet light from the ultraviolet light source 400, a reflector 402 is installed on the back side of the ultraviolet light source 400 (behind the irradiation direction) to reflect the ultraviolet light from the ultraviolet light source 400 in the irradiation direction. I try to turn it.

  Then, as shown in FIG. 17D, the screen printing original plate 300 on the sheet substrate 151 is removed. Thereby, the pattern of the linear light guide 131 is printed on the sheet substrate 151 (see FIG. 19B).

  In the above example, ultraviolet rays are irradiated while the screen printing original plate 300 is installed, but the present invention is not limited to this. For example, the liquid ultraviolet curable resin 303 filled and applied to the cutout portion 302 of the screen printing original plate 300 can retain the filled and applied shape due to the viscosity of the resin as described above. Since there is no possibility that the shape will be lost even if it is removed, it is possible to irradiate with ultraviolet rays after removing the screen printing original plate 300.

  Next, the case where the normal light distribution path 121 is formed (printed) on the linear light guide path 131 by screen printing will be described with reference to FIGS. Here, taking the shape of the normal light distribution path 121 as an example, a manufacturing method corresponding to each shape will be described.

  First, a manufacturing method in the case where the normal light distribution path 121 has a rectangular parallelepiped shape will be described with reference to FIGS. Here, FIG. 20 is a schematic perspective view showing the correspondence between the screen printing original plate and the screen printing result when the normal light distribution path 121 has a rectangular parallelepiped shape. FIG. 21A is a schematic perspective view showing a screen printing original plate when the normal light distribution path 121 has a rectangular parallelepiped shape, and FIG. 21B is a screen printing using the screen printing original plate of FIG. It is a schematic perspective view which shows the result of this.

  In this case, since the normal light distribution path 121c has a rectangular parallelepiped shape, the normal light distribution path 121c can be formed (printed) on the linear light guide 131 using the same manufacturing method as the linear light guide 131. . That is, the screen printing original plate 310 for forming the pattern of the rectangular parallelepiped normal light distribution path 121c is prepared. The screen printing original plate 310 is formed by forming a pattern portion (cutout portion) 312 that transmits ultraviolet rays (UV light) on a sheet material 311 such as a stainless steel sheet or an aluminum foil sheet. Specifically, for example, the sheet material 311 is cut out in accordance with the pattern shape of the normal light distribution path 121c with a YAG laser machine or the like. The screen printing original plate 310 preferably has a thickness with which the thickness can be ignored, for example, a thickness of about several tens of microns (μm). As an example, the screen printing original plate 310 is, for example, a stainless sheet having a thickness of 10 μm. Note that the subsequent steps are the same as those in FIGS. 17B to 17D, and thus description thereof is omitted.

  Next, a manufacturing method when the normal light distribution path 121 has a quadrangular pyramid shape will be described with reference to FIGS. 22 and 23. Here, FIG. 22 is sectional drawing according to process which shows an example of the manufacturing method of the normal light distribution path 121 which has a shape of a square frustum. FIG. 23A is a schematic perspective view showing the screen printing original plate shown in FIG. 22, and FIG. 23B is a schematic perspective view showing a result of screen printing using the screen printing original plate shown in FIG. is there.

  First, as shown in FIG. 22A, a screen printing original plate 320 for forming a pattern of the normal light distribution path 121b of the truncated pyramid is prepared. The screen printing original plate 320 is formed, for example, by forming a pattern portion (cutout portion) 322 that transmits ultraviolet rays (UV light) on a sheet material 321 such as a stainless steel sheet or an aluminum foil sheet. Specifically, for example, the sheet material 321 is cut out in accordance with the pattern shape of the normal light distribution path 121b with a YAG laser machine or the like. The screen printing original plate 320 preferably has such a thickness that the thickness can be ignored, for example, about several tens of microns (μm). As an example, the screen printing original plate 320 is, for example, a stainless sheet having a thickness of 10 μm.

  Then, as shown in FIG. 22B, a liquid ultraviolet curable resin 323 is filled and applied to a predetermined thickness on the sheet substrate 151 on which the pattern of the linear light guide 131 is printed. At this time, the screen printing original plate 320 of FIG. 22A is installed on the liquid ultraviolet curable resin 323. Thereafter, in this state, for example, ultraviolet rays (UV light) are irradiated toward the manufacturing transparent substrate sheet 325 on the back surface of the screen printing original plate 320 from a direction inclined by 60 ° from the normal direction. The ultraviolet rays pass through the cutout portion 322 of the screen printing original plate 320 and reach the liquid ultraviolet curable resin 323. As a result, the liquid ultraviolet curable resin 323 is cured only in the portion 324 irradiated with the ultraviolet rays.

  Then, as shown in FIG. 22C, this time, the ultraviolet ray irradiation angle is changed, for example, from the direction inclined by 45 ° from the normal direction, the transparent substrate sheet 325 for manufacturing the back surface of the screen printing original plate 320 in the same manner. Irradiate with ultraviolet rays (UV light). This ultraviolet ray passes through the cutout portion 322 and reaches the liquid ultraviolet curable resin 323 in another region. As a result, the portion of the ultraviolet curable resin 323 corresponding to the pattern of the normal light distribution path 121b is finally cured to form the pattern of the normal light distribution path 121b.

  Then, as shown in FIG. 22D, the screen printing original plate 320 is removed, and further, the non-cured resin, that is, the remaining liquid ultraviolet curable resin 323 is washed and removed. Thereby, the pattern of the normal light distribution path 121b of the quadrangular pyramid is printed on the pattern of the linear light guide path 131 (see FIG. 23B).

  In screen printing, a three-dimensional structure can be formed by overcoating many times to increase the thickness. Therefore, in the case of a three-dimensional structure, the thickness of the screen printing original plate and the actually printed thickness are usually different. In addition, when irradiating ultraviolet rays through the screen printing original plate at an angle deviated from the normal direction, the thinner the original plate, the larger the irradiation angle, that is, irradiating at an angle greatly deviated from the normal direction. be able to.

  Next, a manufacturing method in the case where the normal light distribution path 121 has an elliptic frustum shape will be described with reference to FIG. Here, FIG. 24A is a schematic perspective view showing a screen printing original plate when the normal light distribution path 121 has an elliptic frustum shape, and FIG. 24B is a screen printing original plate of FIG. It is a schematic perspective view which shows the result of the screen printing using.

  In this case, since the normal light distribution path 121a has the shape of an elliptic frustum, the normal light distribution path 121a is formed on the linear light guide 131 using the same manufacturing method as the normal light distribution path 121b having a quadrangular pyramid shape. Can be formed (printed). That is, the screen printing original plate 330 for forming the pattern of the normal light distribution path 121a of the elliptical truncated cone is prepared. The screen printing original plate 330 is formed by forming a pattern portion (cutout portion) 332 that transmits ultraviolet rays (UV light) on a sheet material 331 such as a stainless steel sheet or an aluminum foil sheet. Specifically, for example, the sheet material 331 is cut out in accordance with the pattern shape of the normal light distribution path 121a with a YAG laser machine or the like. The screen printing original plate 330 preferably has a thickness such that the thickness can be ignored, for example, a thickness of about several tens of microns (μm). As an example, the screen printing original plate 330 is a stainless sheet having a thickness of 10 μm, for example. Note that the subsequent steps are the same as those in FIGS. 22B to 22D, and thus description thereof is omitted.

  Even when the normal light distribution path 121 has a truncated cone shape, the same manufacturing method as that of the normal light distribution path 121a having an elliptic frustum shape can be used. Therefore, in the following description, for the sake of convenience, the “elliptical frustum” includes a truncated cone.

  As described above, when the shape of the normal light distribution path 121 is an elliptical frustum (normal light distribution path 121a) or a quadrangular frustum (normal light distribution path 121b), the irradiation angle is changed and ultraviolet (UV light) is changed. Irradiation needs to be performed (see particularly FIG. 22B and FIG. 22C). In the conventional screen printing described above, as a method of performing irradiation at an angle shifted from the normal direction, for example, it is conceivable to rotate the entire light source or tilt the Fresnel lens. However, this method has a problem that a difference occurs in the distance from the light source to the sheet surface, and the entire area on the sheet surface cannot be irradiated uniformly. Therefore, there is a need for a method that can vary the irradiation angle and uniformly irradiate the sheet surface. As a result of diligent efforts, the present inventor has found an irradiation method (hereinafter referred to as “variable angle line irradiation method”) that satisfies these two requirements.

  FIG. 25 is a schematic diagram for explaining the concept of the variable angle line irradiation method, and FIG. 26 is a schematic diagram showing an example of specific means for realizing the variable angle line irradiation method of FIG. Here, the case where the normal light distribution path 121a having the shape of an elliptic frustum is manufactured will be described as an example.

  In the variable angle line irradiation method, as shown in FIG. 25, the variable irradiation angle proximity light 340 is irradiated through the screen printing original plate 330 from the opposite side of the normal light distribution path 121a to be printed. Here, the variable irradiation angle proximity light refers to light (proximity irradiation light) irradiated to a nearby irradiation target from an irradiation apparatus that can change the irradiation angle of ultraviolet rays. Specifically, in an irradiation apparatus capable of changing the irradiation angle of ultraviolet rays, a built-in microlens described later is close to the irradiation target (about 1 mm or less), and the focal length of the microlens is about 500 microns (μm). In this case, the spread of the irradiation light can be adjusted by adjusting the distance between the microlens and the irradiation target. Furthermore, for example, the arrangement pattern of the two-layer microlenses can be finely adjusted according to the irradiation target. Irradiation light having such characteristics is variable irradiation angle proximity light. Then, after the portion irradiated with the variable irradiation angle proximity light 340 is cured, the non-cured portion is washed and removed.

  The variable irradiation angle proximity light 340 is emitted from the movable irradiation line unit 500 as shown in FIG. The movable irradiation line unit 500 is, for example, a linear irradiation unit that extends in a direction perpendicular to the extending direction (longitudinal direction) of the linear light guide 131 and is configured to be movable in the extending direction of the linear light guide 131. Has been. The movable irradiation line unit 500 is installed on the opposite side of the normal light distribution path 121a to be printed across the screen printing original plate 330.

  FIG. 27 is a schematic diagram illustrating an example of the configuration of the movable irradiation line unit 500, in particular, FIG. 27A is a cross-sectional view and FIG. 27B is a plan view.

  A movable irradiation line unit 500 shown in FIG. 27 includes a linear ultraviolet light source 501, a linear first reflector 502 that reflects a part of the ultraviolet light (UV light) from the ultraviolet light source 501, and the ultraviolet light source 501. A linear second reflecting plate 503 that reflects the ultraviolet rays and the ultraviolet rays reflected by the first reflecting plate 502 in the exit direction, and a linear irradiation light exit that emits the ultraviolet rays reflected by the second reflecting plate 503 as irradiation light. Part 504. As the linear ultraviolet light source 501, for example, a linear light source such as a high-pressure mercury lamp, a light source in which a plurality of ultraviolet LEDs (Light Emitting Diodes) are arranged in a linear shape, or the like can be used.

  The first reflector 502 preferably has a parabolic shape in a cross section perpendicular to the extending direction (longitudinal direction). In this case, the ultraviolet light source 501 is disposed at the focal point of the parabola (first reflecting plate 502). Thus, as shown particularly well in FIG. 27 (A), when light on the same vertical section from the focal point of the parabola (ultraviolet light source 501) is reflected by the curved surface of the parabola, all the light is parabolic. Reflected in the direction of the central axis. In other words, the ultraviolet rays that are emitted from the ultraviolet light source 501 and reflected by the first reflecting plate 502 become parallel light directed toward the second reflecting plate 503.

  The second reflecting plate 503 is a plate-like reflecting plate whose angle can be varied, and is configured to be rotatable around a rotation shaft 503a. By changing the angle of the second reflecting plate 503, the irradiation angle of the ultraviolet rays to the irradiated sheet 350 can be changed. Here, the irradiated sheet 350 broadly means a sheet to be irradiated with ultraviolet rays, and includes, for example, a sheet at an arbitrary stage including an ultraviolet curable resin to be cured. The irradiation pattern on the irradiated sheet 350 is formed by the screen printing original plate 330 that functions as an irradiation pattern forming sheet. The irradiation pattern forming sheet (screen printing original plate 330) and the irradiated sheet 350 are separated from each other by a minute distance and are not in close contact with each other in order to ensure the flatness of the ultraviolet curing portion on the upper side of the irradiated sheet 350. It is desirable that the irradiation pattern forming sheet (screen printing original plate 330) and the irradiated sheet 350 take a distance of about several tens of microns (μm).

  The irradiation light exit portion 504 includes, for example, two layers of microlens arrays 505 and 506 as shown in FIG. Of these, the near-focus microlens array is closer to the irradiation target. Here, the near-focus microlens array is a microlens array for forming the variable irradiation angle proximity light 340 described above. Specifically, as described above, in the irradiation apparatus capable of changing the irradiation angle of ultraviolet rays, the built-in microlens array 506 is close to the irradiation target (irradiation pattern forming sheet (screen printing original plate 330) and irradiated sheet 350). When the focal length of the microlens array 506 is about 500 microns (μm), the distance between the microlens array 506 and the irradiation target is adjusted, thereby expanding the irradiation light. Can be adjusted. Furthermore, the arrangement pattern of the two-layer microlens arrays 505 and 506 can be finely adjusted according to the irradiation target. A microlens array having such characteristics is a near-focus microlens array. In the two-layer microlens arrays 505 and 506, the size of the microlens of the first-layer microlens array 505 is larger than the size of the microlens of the second-layer microlens array 506. This is because the first-layer microlens array 505 is combined with the action of the first reflecting plate 502 having a paraboloid, and is uniformly ultraviolet (UV) from the normal direction to the second-layer microlens array 506. In order to make the ultraviolet light source 501 flat in the normal direction, and in order to make the irradiation intensity uniform, the microlens array 505 of the first layer is made uniform. This is because the microlens needs to be larger than the microlens 506 of the second-layer microlens array.

  FIG. 28 is a schematic enlarged view of the main part around the irradiation light exit part 504. Here, the radiation pattern of the ultraviolet rays is adjusted by changing the distance d (the distance between the near-focus microlens array and the irradiation target) shown in FIG. Here, the adjustment of the radiation pattern of ultraviolet rays means adjusting the extent of irradiation light by the deviation from the focal length. That is, the distance d between the near-focus microlens array 506 and the irradiation pattern forming sheet (screen printing original plate 330) on the irradiated sheet 350 is changed in accordance with the size of the irradiation point. The array unit (combined with the configuration of the microlens array) attached to the irradiation light exit portion 504 can be exchanged according to the irradiation pattern on the irradiated sheet 350. For example, when creating a sheet of the linear light guide unit 130a, there are a portion that originally needs to be irradiated with UV light and a portion that does not need to be irradiated, so that only the portion that needs to be irradiated can be irradiated with UV light. In addition, the pattern of the microlens array can be optimized. The energy of UV light can be used effectively by unitizing the optimized microlens array portion and exchanging it for each irradiated sheet. In FIG. 28, “351” indicates a non-cured portion (ultraviolet uncured portion) of the irradiated sheet 350 that is not irradiated with ultraviolet rays, and “352” indicates a cured state that is irradiated with ultraviolet rays. The part (ultraviolet curing part) is shown.

  FIG. 29 is a schematic diagram for explaining the action of leveling the light beams in the left and right oblique directions indicated by solid arrows in FIG. 27B in the movable direction. As described above, the first-layer microlens array 505 is uniform from the normal direction to the second-layer microlens array 506 in combination with the action of the first reflector 502 having a paraboloid. In order to make ultraviolet (UV) light incident, it has a function of correcting the spread of the ultraviolet light source 501 in the plane direction in the normal direction. Thereby, the light traveling in the left-right direction can be aligned in the traveling direction.

  FIG. 30 is a schematic diagram for explaining a further usage of the movable irradiation line unit 500. Here, by rotating the movable irradiation line unit 500 with respect to the movable direction, more flexible variable angle irradiation is possible. Specifically, in the above method of using the movable irradiation line unit 500, the angle of the irradiation light can be changed with respect to the movable direction, but the irradiation angle is changed in a direction perpendicular to the movable direction as it is. I can't. Therefore, it is possible to irradiate from a direction perpendicular to the movable direction by tilting the movable irradiation line unit 500 by a certain angle in the movable direction. At that time, it is conceivable to adjust the irradiation angle by rotating the irradiated sheet itself, but the formation accuracy is improved by adjusting the irradiation angle by rotating the movable irradiation line unit 500. This is because in the method of adjusting the irradiation angle by rotating the irradiated sheet itself, the irradiated sheet needs to be rotated and rearranged to a target angle with respect to the movable direction, but the movable irradiation line unit 500 is rotated. In the method of adjusting the irradiation angle, the movable irradiation line unit 500 can be advanced with high accuracy while confirming its position at a pitch of 1 micron (μm), for example, and the positions of both ends of the movable irradiation line unit 500 can be determined. This is because the angle can be adjusted with high accuracy by detecting and controlling.

  Thus, in the variable angle line irradiation method, since the distance from the light source 501 to the irradiation point is short and the irradiation pattern is on the line, efficient and powerful ultraviolet rays (UV light) are specified in the irradiated sheet 350. Can be irradiated to any place. Further, the generation of heat from the light source 501 can be greatly reduced. That is, ultraviolet rays that were irradiated on a flat surface at a time in the conventional irradiation method are sequentially irradiated onto the line in this variable angle line irradiation method, and further, only the necessary place is irradiated, so that the loss of ultraviolet rays is reduced. The power consumption can be reduced and the generation of heat can be reduced accordingly.

  As described above, as the linear ultraviolet light source 501, for example, a linear light source such as a high-pressure mercury lamp or a light source in which ultraviolet LEDs are linearly arranged can be used. In the case of using the LED, the luminance of the LED can be dynamically controlled on the order of microseconds (μs), so that a flexible irradiation system can be configured. Further, when the ultraviolet LEDs are arranged in a line, the radiance of a specific place in the irradiated sheet 350 can be changed by finely adjusting the light emission period of each LED element. Therefore, it is possible to freely control the radiance of ultraviolet rays in the sheet surface.

  In addition to the screen printing technique described above, an inkjet printing technique, an offset printing technique, or the like can be used as a printing method using an ultraviolet curable resin. That is, any printing technique may be used as long as it can form a fine three-dimensional structure on the sheet by changing the irradiation angle of the ultraviolet rays a plurality of times and curing it. When printing technology is used, there is an advantage that it can be manufactured in large quantities at a low cost, but in addition to this, for example, by using techniques such as photolithography, sputtering, etching, etc. used for manufacturing LSI etc. There exists an advantage that the light guide part 130a can be manufactured. In particular, for the method of forming the linear light guide 131, a general plastic molding technique can be used in addition to the above printing technique.

  As described above, according to the present embodiment, the normal light collecting unit 110, the normal light distribution unit 120, and the linear light guide unit 130 are provided to collect the light emitted from the outside to obtain a desired value. Since light can be distributed in the direction, light incident at a wide range of angles can be collected efficiently.

  In particular, since the normal light distribution unit 120 and the linear light guide unit 130 can be manufactured by a printing technique using a plurality of layers of ultraviolet curable resin, the LSI element of the optical application system unit 200 (for example, a solar cell of a PV device) Etc.) can be manufactured physically independently. Therefore, it can have lightweight and flexible (foldable) mechanical properties. Furthermore, since it can be manufactured by a general ultraviolet printing technique, it can be manufactured in large quantities at low cost.

  Moreover, since it can be unitized by a predetermined functional unit, high convenience and versatility can be realized.

(Embodiment 2)
The second embodiment is a case where the configuration (particularly the surface shape) of the normal light condensing unit 110 in the first embodiment is optimized. Here, for example, a case where sunlight is collected will be described as an example. Therefore, the normal light collector 110 in this embodiment is referred to as a “sunlight collector sheet”.

  For example, the inventor performed a simulation of the light capture rate by taking a surface shape (triangular shape) as shown in FIG. 4A as an example.

  FIG. 31 is a schematic diagram for explaining the conditions for simulation of the light capture rate in the present embodiment.

In this simulation, as shown in FIG. 31, a solar light collecting sheet 600 having a triangular cross section (specifically, an isosceles triangle) is assumed, and the base angle of the triangle (hereinafter referred to as “shape angle”) is determined. α °, the angle of incident light (hereinafter referred to as “ray angle”) is β °, the pitch of the triangle is P, and the refractive index of the medium (for example, resin) 601 constituting the solar light collecting sheet 600 is n. The ray angle β was defined as the angle of the incident direction of the ray with respect to the horizontal direction. In this simulation, a predetermined number within the range of pitch P (angle: 43 in 4 ° increments in the range of −6 to −174 °, coordinates: 10 in 0.1P increments of −0.05P to −0.95P). A total of 430 rays), with the ray angle changed in 43 steps, the starting point coordinates entered from 10 points at equal intervals, the rays were traced one by one by calculation, and the ray capture rate was calculated did. Here, the light beam capture rate was defined as the ratio (%) of the transmitted light amount to the incident light amount. That is, the light capture rate (%) is expressed by the following equation:
Light capture rate = (transmitted light amount / incident light amount) × 100
It is represented by As is apparent from this equation, the light beam capture rate is synonymous with the light transmittance. The amount of incident light is 430 per pitch P, where the amount of light of one incident light beam is 1. For example, paying attention to one incident light beam, this incident light beam is repeatedly reflected and refracted at the boundary surface of the medium, and finally reflected light upward and transmitted downward with respect to the solar light collecting sheet 600. Divided into light. At this time, except for the case of total reflection, both reflected light and refracted light are attenuated. The amount of incident light and the amount of transmitted light per pitch are the sum of the amounts of final reflected light and transmitted light based on each incident light beam. The ray tracing for each incident ray was performed until the amount of light became 1 / 10,000 or less for all reflected light and refracted light.

  FIG. 32 is a diagram illustrating an example of a simulation result of a light beam capture rate with respect to a light beam angle for each shape angle with respect to the surface shape in FIG. 31. 33 is an enlarged view of a main part of FIG. Here, simulation was performed for 10 cases where the shape angle α is 30 °, 40 °, 45 °, 50 °, 55 °, 60 °, 65 °, 70 °, 75 °, and 80 °. Further, in order to compare with the case of a triangular shape, the same simulation was performed for the case of a flat plate shape. In this simulation, for example, the refractive index n of the medium 601 is set to 1.5.

  As shown in FIGS. 32 and 33, the larger the shape angle α, the higher the light beam capture rate over almost the entire range of the light beam angle β. Moreover, when the shape angle α is 40 ° or more, the light beam capture rate is higher than that in the case of the flat plate shape over almost the entire range of the light beam angle β. However, even when the shape angle α is 30 °, in a region other than the range where the light ray angle β is about −67 ° to −113 ° (that is, within 23 ° from the normal direction), the light ray capture rate is It is higher than the flat plate shape. That is, from FIG. 32 and FIG. 33, generally, when the surface shape is a triangle, the light beam capture rate is higher than when it is a flat plate. In particular, when the surface shape is a triangle, the light beam capture rate increases as the shape angle α increases. Is high. Therefore, when the surface shape is a triangle, the light beam capture rate is the highest over almost the entire range of the light beam angle β when the shape angle α is 80 ° among the above 10 patterns.

  It should be noted that the effect of the surface shape of FIG. 31, that is, the effect that the light ray capture rate is high over almost the entire range of the light ray angle, can obtain a high light collecting effect regardless of the orientation and height of the sun. In a sense, it will be called “omnidirectional light collection effect”. This omnidirectional light condensing effect is a remarkable effect which the surface shape of FIG. 31 has compared with the case where the surface shape is a flat plate.

  This omnidirectional light condensing effect will be described in detail later. This is because the surface shape of FIG. 31 has a shape that allows reflected light to be efficiently used (incident) by repeating reflection and refraction at the boundary surface. In other words, the surface shape of FIG. 31 has both a mechanism for directly incident light and a mechanism for incident reflected light, that is, a mechanism for efficiently receiving not only direct light but also ambient light. Have.

  FIG. 34 is a diagram illustrating an example of a simulation result of a light beam capture rate with respect to a light beam angle, for each refractive index of the medium, with respect to the surface shape of FIG. Here, the simulation was performed for four cases where the refractive index of the medium is 1.3, 1.4, 1.5, and 1.6 for each of the case where the surface shape is a triangle and the case of a flat plate. In this simulation, for example, the shape angle α is set to 80 °.

  As shown in FIG. 34, in both cases where the surface shape is a triangle or a flat plate, the smaller the refractive index of the medium, that is, the smaller the difference in refractive index from air (refractive index is about 1.0), the smaller the light beam. The light capture rate is high over almost the entire range of the angle β. That is, when the surface shape is a triangle, among the above four methods, when the refractive index of the medium is 1.3, the light beam capture rate is the highest over almost the entire range of the light beam angle β. However, the difference in light capture rate due to the difference in refractive index is not so significant.

  In this way, the omnidirectional light condensing effect does not change much with respect to the change in the refractive index. This omnidirectional light condensing effect has the effect of geometric reflection and the law of refraction (Snell's law). ). In this sense, the principle is very simple.

  The above simulation revealed the tendency of the light beam capture rate when the surface shape is a triangle, and the knowledge about the optimum shape was obtained. However, in consideration of actual manufacturing, it is necessary to form a triangular portion on a thick flat plate. Then, this inventor assumed the sunlight condensing sheet | seat 610 which has a structure shown in FIG. 35, and performed the same simulation as the above.

  FIG. 35 is a schematic diagram showing a configuration that is another simulation target of the light beam capture rate in the present embodiment.

  In the example shown in FIG. 35, the solar light collecting sheet 610 to be simulated is composed of an upper triangular portion 611 having a triangular cross section and a lower flat plate portion 612 having a thick flat plate shape. It is configured. The simulation conditions are the same as in the simulation targeting the configuration shown in FIG. However, in this simulation, the triangular portion 611 and the flat plate portion 612 are made of the same material, and the refractive index thereof is set to 1.5, for example. The shape angle α was set to 60 °. In this case, the amount of transmitted light necessary for calculating the light capture rate is the amount of light transmitted downward from the flat plate portion 612.

  FIG. 36 is a diagram illustrating an example of a simulation result of the light beam capture rate with respect to the light beam angle with respect to the sunlight collecting sheet 610 in FIG. 35.

  As shown in FIG. 36, in a region 613 having a large angle from the normal direction (for example, a region having an angle from the normal direction of about 54 ° or more) compared to the case where the surface shape is a flat plate, the surface shape is The light capture rate is higher than in the case of a flat plate, and more light is transmitted. On the other hand, in a region where the angle from the normal direction is small (for example, a region where the angle from the normal direction is about 54 ° or less) 614, the incident angle to the flat plate portion 612 is larger than in the case where the surface shape is a flat plate. For this reason, the light beam capture rate (transmittance) is inferior to that of the flat surface shape. That is, in this case, the light collected by the upper triangular portion 611 does not pass through the lower flat plate portion 612 much. In other words, the omnidirectional light condensing effect of the upper triangular portion 611 is significantly hindered in some angle regions due to the presence of the lower flat plate portion 612.

  37 and 38 are diagrams for explaining the simulation results of FIG. In particular, FIG. 37 is a diagram for explaining the light collection principle (omnidirectional light collection effect) by the upper triangular portion 611, and FIG. 38 shows the lower flat plate portion 612 in addition to the upper triangular portion 611. It is a figure for demonstrating the condensing principle when considering also. Here, of the two opposing surfaces of the triangular portion 611, one surface is referred to as “surface A” and the other surface is referred to as “surface B”.

  First, when only the upper triangular portion 611 is considered, for example, when a light ray enters from the normal direction, this light ray (incident light) is reflected on the boundary surface along a path as shown in FIG. Refraction is repeated, and as a result, about 99.2% or more of light rays can be captured. Specifically, for example, as shown in FIG. 37, about 80% of the light rays incident on the surface B from the normal direction are refracted and totally reflected on the surface A to enter the flat plate portion 612, and the remaining 20 % Is reflected and enters the surface A of the adjacent triangular portion 611 perpendicularly, and almost all (about 19.2%) is refracted and enters the flat plate portion 612. A part of the remaining re-reflected light (about 0.8%) is refracted by the original surface B again, totally reflected by the surface A, and enters the flat plate portion 612. Therefore, in this case, a total of 99.2% or more of light rays are captured by the flat plate portion 612.

  Further, like the middle ray in FIG. 38, the ray inclined by 60 ° from the normal direction is incident perpendicularly to the triangular slope (surface A) (96% light is incident at this time) and is incident. The refracted light is totally reflected at the next slope (surface B). As a result, since the light other than the reflected light from the first slope (surface A) is captured in the triangular portion 611, the external light capturing rate is 96%.

  Therefore, in this case, incident light within 60 ° from the normal direction is mostly collected (99% or more) by this principle (see FIGS. 32 and 33).

  However, when the lower flat plate portion 612 is considered in addition to the upper triangular portion 611, the result shown in FIG. 36 is obtained by the following principle.

  First, in the case where the angle from the normal direction is large, as in the example of the middle ray in FIG. 38, among the incident light from the surface A, there is a lot of light reflected by the surface B, of which the surface B The light that is totally reflected at 1 is largely reflected in the normal direction, so that the incident angle to the flat plate portion 612 is close to the normal direction, and the amount of light transmitted through the flat plate portion 612 increases. As a result, the transmittance at both ends (region 613) in FIG. 36 is relatively good.

  However, as in the example of the light beam on the left side of FIG. 38, when the incident light is originally very close to the normal direction, most of the light beam incident on the surface A directly reflects to the lower flat plate portion 612 without being reflected by the surface B. Incident. During this time, when the light incident on the surface A is refracted on the surface A, the light is deviated from the normal direction, and the incident angle to the flat plate portion 612 is deviated from the normal direction. Become. This is a decrease in the transmittance of incident light particularly in a region 614a that is very close to the normal direction (for example, a region having an angle of about 24 ° or less from the normal direction) among the regions 614 that have a small angle from the normal direction. It is the cause.

  Further, as in the example of the right ray in FIG. 38, when the incident light is relatively close to the normal direction, that is, when the angle from the normal direction is about 24 to 54 °, the ray incident on the surface A Most of the light directly enters the lower flat plate portion 612 without being reflected by the surface B. During this time, the light incident on the surface A is more deviated from the normal direction during refraction at the surface A, and the incident angle to the flat plate portion 612 is further deviated from the normal direction. Becomes larger and the transmittance is greatly reduced. In addition, light having a certain incident angle with respect to the flat plate portion 612 is totally reflected by the flat plate portion 612 and cannot pass through the flat plate portion 612 at all. This is a large transmission of incident light in the region 614 having a small angle from the normal direction, particularly in a region 614b that is relatively close to the normal direction (for example, a region having an angle from the normal direction of about 24 to 54 °). It is the cause of the rate drop.

  In short, in the region 614 where the angle from the normal direction is small, the light collected by the upper triangular portion 611 is reflected by the lower flat plate portion 612, so that the light transmittance (light ray capture rate) is lowered. ing.

  Based on the above consideration, the present inventor has devised a configuration that does not cause a decrease in transmittance as shown in FIG.

  FIG. 39 is a schematic diagram showing a configuration to be subjected to another simulation of the light beam capture rate in the present embodiment, and shows an example of the two-dimensional shape of the solar light collecting sheet according to the present embodiment. FIG.

  In the example shown in FIG. 39, the solar light collecting sheet 620 to be simulated is an upper triangular portion 621 having a triangular cross section, and a lower flat plate portion 622 having a thick flat plate shape, The upper triangular portion 621 and the lower triangular portion 623 having the same shape are configured. In other words, the sunlight condensing sheet 620 is configured such that the triangular portion 621 and the triangular portion 623 having the same shape are aligned in the middle with the flat plate portion 622 interposed therebetween, that is, arranged vertically symmetrically with the flat plate portion 622 interposed therebetween. Have Thus, the sunlight condensing sheet 620 has a shape in which the flat plate portion 622 is sandwiched between the triangular portions 621 and 623 having the same shape in a vertically symmetrical manner from above and below. The conditions for the simulation are the same as those for the simulation targeting the configuration shown in FIGS. However, in this simulation, the triangular portions 621 and 623 and the flat plate portion 622 are made of the same material, and the refractive index thereof is set to 1.5, for example. The shape angle α was set to 60 °. In this case, the amount of transmitted light necessary for calculating the light capture rate is the amount of light transmitted downward from the lower triangular portion 623.

  FIG. 40 is a diagram illustrating an example of a simulation result of the light beam capture rate with respect to the light beam angle with respect to the sunlight collecting sheet 620 in FIG. 39.

  As shown in FIG. 40, in this sunlight condensing sheet 620, in comparison with the simulation result of FIG. 36, the decrease in the light beam capture rate in the region 614 of FIG. 36 is eliminated. That is, in this case, the light beam capture rate is higher than that of the flat plate shape over the entire range of the light beam angle β. Moreover, the light beam capture rate is 90% or more over the entire range of the light beam angle β.

  This principle can be considered as follows. In FIG. 39, the surface corresponding to the surface A of the upper triangular portion 621 corresponding to the upper surface of the lower triangular portion 623 is referred to as “surface A ′” and the surface of the triangular portion 621. The surface corresponding to B will be referred to as “surface B ′”.

  First, when the angle from the normal direction is large (see the region 613 in FIG. 36) as in the example of the middle ray in FIG. 39, the incident light from the surface A finally becomes the triangular portion 623 in the lower part. Is incident on the surface A ′ substantially perpendicularly (see the light ray 624), the amount of light transmitted through the triangular portion 623 increases. As a result, the transmittance of this region is still relatively good.

  Further, as in the example of the light beam on the left side of FIG. 39, when the incident light is originally very close to the normal direction (see the region 614a in FIG. 36), the refracted light incident from the surface A is the lower triangular portion 623. The light is emitted from the surface B ′ at the same angle as the incident angle to the surface A (see the light ray 625), that is, is transmitted. Further, since the reflected light on the surface A and the surface B ′ is incident on the surface B and the surface A ′ at an angle close to the vertical, the light finally passes through the triangular portion 623 and is captured. As a result, the transmittance of this region is significantly improved.

  Similarly, when the incident light is relatively close to the normal direction (see the region 614b in FIG. 36), as in the example of the right ray in FIG. 39, the refracted light incident from the surface A is The light is emitted from the surface B ′ of the lower triangular portion 623 at the same angle as the incident angle to the surface A (see the light beam 626), that is, is transmitted. Further, since the reflected light on the surface A and the surface B ′ is incident on the surface B and the surface A ′ at an angle close to the vertical, the light finally passes through the triangular portion 623 and is captured. As a result, the transmittance in this region is also significantly improved.

  As described above, in the solar light collecting sheet 620 according to the present embodiment, the triangular portion 623 having the same shape as the upper triangular portion 621 formed on the surface of the flat plate portion 622 is formed on the back surface of the flat plate portion 622. By forming it symmetrically in the vertical direction, the light transmittance (light capture rate) is greatly improved.

  FIG. 41 is a diagram illustrating an example of a simulation result of a light beam capture rate with respect to a light beam angle for each shape angle with respect to the sunlight collecting sheet 620 in FIG. 39. FIG. 42 is an enlarged view of a main part of FIG. Here, simulation was performed for seven cases of the shape angle α of 40 °, 45 °, 50 °, 60 °, 70 °, 75 °, and 80 °. Further, in order to compare with the case of a triangular shape, the same simulation was performed for the case of a flat plate shape. In this simulation, for example, the refractive index n of the medium (the triangular portions 621 and 623 and the flat plate portion 622) constituting the solar light collecting sheet 620 is set to 1.5.

  As shown in FIGS. 41 and 42, basically, the larger the shape angle α, the higher the light beam capture rate over almost the entire range of the light beam angle β. Moreover, when the shape angle α is 45 ° or more, the light beam capture rate is higher than that of the flat plate shape over almost the entire range of the light beam angle β. However, even when the shape angle α is 40 °, in a region other than the range where the light ray angle β is approximately −60 ° to −120 ° (that is, within 30 ° from the normal direction), the light capture rate is It is higher than the flat plate shape. In particular, among the above seven patterns, when the shape angle β is 75 °, the light beam capture rate is 94.5% or more over the entire range of the light beam angle β.

  Therefore, the sunlight condensing sheet 620 in FIG. 39 has a higher light beam capture rate over almost the entire range of the light beam angle β than the case where the surface shape is a flat plate, and efficiently captures the light beams in the entire surrounding angle range. It has a function that can be. This is because the sunlight condensing sheet 620 in FIG. 39 has a shape that allows the reflected light to be efficiently used (incident) by repeating reflection and refraction at the boundary surface as described above. That is, the sunlight condensing sheet 620 in FIG. 39 has a function of entering the other triangular portion without emitting the reflected light.

  In addition to the method of forming the triangular portions 621 and 623 in separate steps above and below one flat plate portion 622, the solar light collecting sheet 620 in FIG. A method of forming two sheets 610 together so as to have a vertically symmetrical shape is conceivable.

  In the example shown in FIG. 39, the upper and lower triangular portions 621 and 623 are disposed completely symmetrically with respect to the flat plate portion 622, but the present invention is not limited to this. Even if the upper and lower triangular portions 621 and 623 are not completely symmetrically arranged, the effect is hardly changed. For example, the shape angle α may be changed or the position may be shifted between the upper and lower triangular portions 621 and 623.

  In addition, in the example shown in FIG. 39, the shape is two-dimensional. However, as the three-dimensional shape, in addition to the shape in the longitudinal direction as shown in FIG. It may be a pyramid shape. In any shape, it is necessary to have a function of entering the other shape portion without emitting the reflected light. However, compared to the case of the shape in the longitudinal direction as shown in FIG. 4A, the shape of the pyramid has less change in the three-dimensional ray angle due to the orientation, and a higher effect can be obtained. For example, FIG. 43 is a plan view of a sunlight collecting sheet having a quadrangular pyramid surface shape. The solar light collecting sheet 650 in FIG. 43 includes a quadrangular pyramid portion 651 having a two-dimensional cross section in FIG.

  In the case of a three-dimensional shape, in order to eliminate the blind spot of the omnidirectional light collecting effect at a three-dimensional ray angle, as shown in FIG. 43, an arrangement shifted by a half pitch for each column is preferable. Among the pyramid shapes, a three-dimensional shape that can form a planar filling structure (see FIG. 43) such as a triangular pyramid, a quadrangular pyramid, and a hexagonal pyramid is particularly preferable.

  Thus, according to the present embodiment, the two-dimensional cross-sectional shape has a configuration in which the reflected light is incident on another shape portion without emitting the light, specifically, for example, the same shape with the flat plate portion interposed therebetween. Because it has a configuration in which the triangular parts are arranged vertically symmetrically, the reflected light can be used (incident) efficiently regardless of the incident angle of the light beam, and a very wide range of incident light can be captured (condensed) very efficiently. )can do. Therefore, when applied to the normal light condensing unit 110 in the first embodiment, the configuration can be optimized.

  In the present embodiment, the optimization of the normal light focusing unit 110 in the first embodiment has been described as an example, but the application is not limited to this. That is, the solar light collecting sheet according to the present embodiment can be used not only as one element of the light collecting device according to the first embodiment but also as an independent light collecting device.

  For example, the sunlight collecting sheet 620 (see FIG. 39) according to the present embodiment can be applied to a flat plate PV device. In this case, as described above, the sunlight condensing sheet 620 shown in FIG. 39 has an extremely wide range of incident light as compared with the conventional flat surface (the light capture rate is 81% on average, see FIG. 32). Because it can be captured efficiently (for example, when the shape angle is 60 °, the light beam capture rate is 94.5% or more over the entire range of the light beam angle), it is placed on the surface of the photovoltaic power generation LSI element (solar cell). By doing so, not only direct sunlight but also ambient light can be used efficiently, and the power generation efficiency can be greatly improved. In addition, since the surface shape only needs to be the surface shape shown in FIG. 39, it can be manufactured at low cost.

  In addition, when considering that the LSI elements for photovoltaic power generation do not generate power in the entire area but use the light that reaches the partial area, the light is concentrated in the partial area. The power generation efficiency can be further improved by optimizing the shape of the triangular portion 623 below the 39 solar light collecting sheet 620.

  Further, as other uses, for example, application to buildings such as buildings (widely buildings) is also conceivable. That is, as described above, the sunlight condensing sheet 620 in FIG. 39 is equal to or greater than the maximum value of the flat plate-shaped light capture rate (condensing rate) in the entire range of the light beam angle as compared with the conventional flat plate-type surface. Therefore, a large effect can be expected particularly in the time zone (morning and evening) where the efficiency is low, or when it is cloudy. Due to such characteristics, the solar light collecting sheet 620 is not necessarily installed in the direction of sunlight. For example, even if this sunlight condensing sheet 620 is installed on the wall surface of a building, a large amount of light can be captured. Therefore, according to the sunlight condensing sheet according to the present embodiment, it is possible to construct a highly flexible condensing system to be applied to a field that could not be used conventionally. Furthermore, in combination with the sheet-type condensing device (condensing sheet) according to the first embodiment, the light collected earlier is further condensed and used for various applications such as illumination and condensing PV devices. be able to.

  As an example, for example, in an area with many buildings as shown in FIG. 44, the solar light collecting sheet 670 according to the present embodiment (for example, the solar light collecting sheet 620 in FIG. 39 is provided on the side of each building. The following remarkable effects can be expected.

  First, since ambient light including sunlight is collected and used, the energy does not enter the inside of the building, and a large heat insulating effect is obtained. In particular, since heat energy is not reflected, the reflection is eliminated and a great effect can be expected in summer.

  Secondly, it does not reflect the heat energy of sunlight unlike the conventional heat insulating material, and can realize a good environment coexisting with other buildings.

Third, the energy of sunlight is about 1 kW / m ^2, and a large building has a surface area of about tens of thousands m ² . Therefore, when energy of ambient light is absorbed and converted into electric energy, electric energy of about several thousand kW can be expected depending on conditions. Thereby, the electric energy used in the daytime which a normal building uses can be reduced significantly.

  Fourth, by using only the solar condensing sheet 670 according to the present embodiment on the wall surface of the building by the concentrating power generation system and the illumination light distribution system, a large cost merit for expensive solar power generation equipment Can be realized.

  The light condensing device and the light condensing method according to the present invention can be manufactured with a simple configuration and in a large amount at low cost, and can efficiently collect light incident at a wide range of angles, and is convenient. It is useful as a light collecting device and a light collecting method that are highly versatile and versatile.

The block diagram which shows the structure of the condensing apparatus which concerns on one embodiment of this invention 1 is a schematic perspective view showing an example of the configuration of the sheet-type light collecting device in FIG. Schematic cross-sectional view showing the configuration of the multilayered normal line condensing unit It is the schematic which shows the other structure (surface shape) of a normal light collection part, (A) is a schematic principal part perspective view, (B) is a schematic principal part sectional drawing. The schematic perspective view which shows an example of a structure of a normal light distribution part and a linear light guide part Top view of FIG. 5 viewed from above Sectional drawing which follows the VII-VII line of FIG. Sectional drawing which follows the VIII-VIII line of FIG. 5A is a plan view similar to FIG. 6, FIG. 5B is a plan view showing the main part of FIG. 9A, and FIG. 9C is a plan view showing the details of FIG. ) Enlarged view of the main part (A) is a figure for demonstrating the principle of total reflection, (B) is a figure which shows an example of a specific numerical value. It is the schematic which shows the other structure of a normal light distribution part, (A) is a principal part schematic, (B) is a schematic plan view It is the schematic which shows the further another structure of a normal light distribution part, (A) is a schematic perspective view of a normal light distribution path, (B) is a schematic side view of a normal light distribution path, (C) is Schematic rear view showing a first embodiment of the normal light distribution path, (D) is a schematic rear view showing a second embodiment of the normal light distribution path The schematic perspective view which shows the structure of the normal light distribution part which has the normal light distribution path of FIG. Schematic which shows an example of a structure of a linear light guide sheet part and a light compression sheet part Enlarged view of the optical high compression function section shown in FIG. Schematic showing an example of the overall configuration combining the configurations of FIG. Sectional drawing according to process which shows an example of the manufacturing method of a linear light guide FIG. 17 is a schematic perspective view showing the correspondence between the screen printing original plate shown in FIG. 17 and the screen printing result. Schematic for explaining the ultraviolet irradiation process Schematic perspective view showing a correspondence relationship between a screen printing original plate and a result of the screen printing when the normal light distribution path has a rectangular parallelepiped shape (A) is a schematic perspective view showing a screen printing original plate when the normal light distribution path has a rectangular parallelepiped shape, and (B) shows a result of screen printing using the screen printing original plate of FIG. Schematic perspective view Sectional drawing according to process which shows an example of the manufacturing method of the normal light distribution path which has the shape of a square frustum (A) is a schematic perspective view which shows the screen printing original plate shown in FIG. 22, (B) is a schematic perspective view which shows the result of screen printing using the screen printing original plate of FIG. 23 (A). (A) is a schematic perspective view showing a screen printing original plate when the normal light distribution path has a shape of an elliptic frustum, and (B) is a result of screen printing using the screen printing original plate of FIG. 24 (A). Schematic perspective view showing Schematic for explaining the concept of variable angle line irradiation method Schematic which shows an example of the concrete means which implement | achieves the variable angle line irradiation method of FIG. It is the schematic which shows an example of a structure of a movable irradiation line part, (A) is sectional drawing, (B) is a top view Overview FIG. 27B is a schematic diagram for explaining the action of leveling the light beam traveling in the oblique direction indicated by the solid line arrow in the movable direction. Schematic for explaining further usage of movable irradiation line section Schematic for explaining the conditions of the light capture rate simulation in the present embodiment The figure which shows an example of the simulation result of the light ray capture rate with respect to the light ray angle according to shape angle with respect to the surface shape of FIG. 32 is an enlarged view of the main part of FIG. The figure which shows an example of the simulation result of the light ray capture rate with respect to the light ray angle according to the refractive index of the medium with respect to the surface shape of FIG. Schematic showing the configuration that is the subject of another simulation of the light capture rate in the present embodiment The figure which shows an example of the simulation result of the light ray capture rate with respect to a light ray angle with respect to the sunlight condensing sheet | seat of FIG. It is a figure for demonstrating the simulation result of FIG. 36, and especially the figure for demonstrating the condensing principle (omnidirectional condensing effect) by an upper triangular part. It is a figure for demonstrating the simulation result of FIG. 36, Comprising: The figure for demonstrating the condensing principle especially when the lower flat plate part is also considered in addition to the upper triangular part. It is the schematic which shows the structure used as the object of the further another simulation of the light beam capture rate in this Embodiment, Comprising: The schematic which shows an example of the two-dimensional shape of the sunlight condensing sheet which concerns on this Embodiment The figure which shows an example of the simulation result of the light ray capture rate with respect to the light ray angle with respect to the sunlight condensing sheet | seat of FIG. The figure which shows an example of the simulation result of the light ray capture rate with respect to the light ray angle according to shape angle with respect to the sunlight condensing sheet | seat of FIG. 41 is an enlarged view of the main part of FIG. The top view which shows the sunlight condensing sheet which has the surface shape of a quadrangular pyramid as a three-dimensional shape which implement | achieves the sunlight condensing sheet of FIG. The figure for demonstrating the other application example of the sunlight condensing sheet | seat of FIG.

Explanation of symbols

100, 100a Sheet type condensing device 110, 110a, 110b Normal condensing part 111 Sheet layer 112 Micro lens 113 Normal condensing part layer 120, 120a, 120b, 120c Normal light distributing part 121, 121a, 121b, 121c Normal light distribution path 123 Connection section 130, 130a Linear light guide section 131 Linear light guide path 140 Optical compression controller 150, 150a Planar light collection sheet section 151 Sheet substrate 160, 160a Linear light guide sheet section 161 Linear light guide path Group 162 Primary light compression lens portion 163 Primary compression light 164 Light input joint portion 165 Light output joint portion 166 Primary compression light output portion 170, 170a Light compression sheet portion 171 Primary compression light condensing lens portion 172 Light high compression Functional part 173 Secondary compressed light 174 Light guide 175a Convex lens 175b Concave lens 176 Compressed light Output unit 177 Optical input joint 178 Primary compressed light input unit 200 Optical application system unit 300, 310, 320, 330 Screen printing original plate 301, 311, 321, 331 Sheet material 302, 312, 322, 332 Cutout unit 303 UV curing Resin 325 Manufacturing transparent substrate sheet 340 Variable irradiation angle proximity light 350 Irradiated sheet 400 Ultraviolet light source 401 Fresnel lens 402 Reflecting plate 500 Movable irradiation line section 501 Linear ultraviolet light source 502 First reflecting plate 503 Second reflecting plate 504 Irradiation light Outlet portion 505, 506 Micro lens array 600, 610, 620, 650, 670 Sunlight collecting sheet 611, 621, 623, 651 Triangular portion 612, 622 Flat plate portion

Claims (11)

A sheet-like condensing device that condenses light emitted from one surface and emits it from the other surface,
A surface shape portion that is formed on at least one of the surfaces and has a surface shape that not only allows the irradiated light to directly enter the inside, but also allows external reflected light to be incident on the inside due to the irradiated light; Comprising
The surface shape portion is
The light irradiated at an arbitrary angle from the one surface side is incident on the inside by repeating reflection and refraction at the boundary surface,
Concentrator. The surface shape is a triangular shape in cross section,
The light collecting device according to claim 1. The surface shape is a shape of an isosceles triangle in cross section and the base angle is 45 degrees or more.
The light collecting device according to claim 2. The surface shape is a pyramid shape with a cross section of an isosceles triangle,
The light collecting device according to claim 3. The shape of the pyramid is arranged shifted by a half pitch for each row,
The light collecting device according to claim 4. The shape of the pyramid is a shape that can be filled on a plane.
The light collecting device according to claim 5. A sheet-like condensing device that condenses light emitted from one surface and emits it from the other surface,
A first surface shape that is formed on the one surface and has a surface shape that not only directly causes the irradiated light to enter the inside but also causes external reflected light to be incident on the inside due to the irradiated light. And
A second surface shape portion formed on the other surface and having the same or substantially the same surface shape as the first surface shape portion,
The first surface shape portion and the second surface shape portion are arranged vertically symmetrically or substantially symmetrically vertically.
Concentrator. The first surface shape portion and the second surface shape portion are formed of the same material,
The light collecting device according to claim 7. Further comprising a flat plate portion,
The first surface shape portion and the second surface shape portion are arranged vertically symmetrically or substantially vertically symmetrically across the flat plate portion,
The light collecting device according to claim 7. The first surface shape portion, the second surface shape portion, and the planar portion are formed of the same material.
The light collecting device according to claim 9. The light is sunlight;
The condensing device according to any one of claims 1 to 10.

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