JP2005129364A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of lighting without bias in light quantity, while preventing conversion efficiency as a solar cell from deteriorating. <P>SOLUTION: A surface having a predetermined pattern of an electrode 2b provided on a light receiving surface side of a solar cell 2 is covered with a phosphor 2g. The phosphor 2g absorbs blue or blue ultraviolet light guided by a light guide plate 1 arranged on upper side of the light receiving surface and the phosphor 2g to emit red and yellow light or red and green light. The light emitted from the phosphor 2g and original blue or ultraviolet blue light not absorbed are mixed to allow the entire surface of the solar cell 2 to appear luminous in white. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lighting device in which a solar cell is incorporated. For example, a solar cell installed on a wall surface of a building, a window or a passage, and a light emitting element incorporated in the solar cell are used to illuminate the entire surface of the solar cell. The present invention relates to a lighting device.

  In general, as shown in FIGS. 4 (a) and 4 (b), this type of solar cell 2 is made of silver (Ag) on the surface of a solar cell substrate 2c made of a thinly sliced silicon (Si) crystal. An electrode 2b (hereinafter referred to as Ag electrode 2b) formed by applying (coating) a solder paste is stretched over the entire light receiving surface. Moreover, as shown in FIG.4 (b), the Ag electrode 2e and the Al electrode 2f are alternately provided in the back surface, and the surface sheet 2a and the back surface sheet 2d are provided in the surface side and the back surface side.

  The solar cell 2 configured in this manner has a problem that the conversion efficiency of the entire solar cell is reduced because the area of the electrode that does not contribute to photovoltaic power generation is several percent with respect to the light receiving surface. Further, if the electrode pattern is made thin in order to reduce the area of the electrode, the internal impedance of the solar cell 2 is increased, which also reduces the conversion efficiency.

  As a prior art that uses this solar cell panel as a lighting device, for example, in Patent Document 1, a diffusion panel is arranged on the upper surface side of the light receiving surface of the solar cell, and light from a light emitting diode is incident from the side end surface. An illuminating device is disclosed in which the entire top surface of the device can be used as a light emitting surface by causing the diffusion panel to emit light.

  In Patent Document 2, a diffusion transmission layer is provided on the front side of the solar cell, diffuses light incident from the front side and reflects a part thereof to the front side, and leads the other part to the solar cell. Such a solar cell device is disclosed. This diffuse transmission layer contains a phosphor and absorbs a predetermined wavelength region of light incident from the front side to fluoresce. This fluorescence is diffused in the diffusion equivalent layer, a part is emitted to the front side, and the other part is guided to the solar cell side. Accordingly, a bright appearance can be obtained while hiding the appearance of the solar cell, and sufficient light energy can be supplied to the solar cell.

  Patent Document 3 discloses a solar cell in which a transparent electrode is formed on a glass substrate and an amorphous silicon layer and a back electrode are sequentially formed on the glass substrate in order to increase the utilization efficiency of incident light. The transparent electrode is provided with a transparent thin film on the outer periphery thereof, and light incident on the outer periphery is repeatedly reflected in the transparent thin film and incident on the amorphous silicon layer. As a result, the apparent conversion efficiency can be improved.

Patent Document 4 discloses a solar cell device in which a photocatalyst film that transmits light in a longer wavelength region than ultraviolet light and blocks the ultraviolet wavelength region is formed on the light receiving surface of the solar cell substrate. This photocatalyst film can oxidize and decompose the organic substance to prevent the organic substance from adhering to the light receiving surface, so that a decrease in the amount of received light can be suppressed. Moreover, since the photocatalytic film transmits light in a longer wavelength region than ultraviolet light, the solar cell substrate has high sensitivity and excellent power generation efficiency. Furthermore, since the photocatalytic film blocks the ultraviolet wavelength region, the solar cell substrate can be protected.
JP-A-10-240175 International Publication Number WO 95/17015 JP-A-11-220148 Japanese Patent Laid-Open No. 9-321329

  As in Patent Documents 1 and 2, when a diffusion panel or a diffusion transmission layer is provided on the light-receiving surface side of the solar cell, sunlight is diffused, and the conversion efficiency of the solar cell is significantly reduced. is there. Further, as in Patent Document 1, it is not sufficient in terms of the amount of light to enter light only from one side of the light guide plate, and there is a problem that the light emission intensity distribution on the surface is biased.

  In addition, the said patent documents 1, 2 and 4 are not described about utilizing an electrode part for illumination. Further, in Patent Document 3, since the transparent electrode is on the amorphous silicon layer and a transparent thin film is provided around the transparent electrode in order to improve photoelectric conversion efficiency, an area other than the conversion portion is required.

  This invention solves the said conventional problem, and it aims at providing the illuminating device which can perform illumination efficiently, without reducing the light quantity, without reducing the photoelectric conversion efficiency as a solar cell. .

  The lighting device of the present invention is a lighting device in which a solar cell is incorporated, and an electrode pattern surface provided on a part of the solar cell is covered with a phosphor, and is disposed on a light receiving surface and the phosphor of the solar cell. The phosphor is made to emit light by the light guided by the light guide plate, and the above-mentioned object is achieved.

  The lighting device of the present invention is a lighting device in which a solar cell is incorporated, and a light guide plate in which a phosphor is provided on the surface on the electrode pattern side in the same pattern as the electrode pattern provided on a part of the solar cell. The phosphor is arranged on the light receiving surface so that the patterns of the phosphor and the electrode overlap each other, and the phosphor is made to emit light by the light guided by the light guide plate. Is achieved.

  Preferably, the electrode pattern in the lighting device of the present invention is stretched over the entire surface of the solar cell at a constant rate.

  Further preferably, the phosphor in the illumination device of the present invention absorbs blue or light having a shorter wavelength than the blue, and emits at least one of yellow, green and red.

  Further preferably, the phosphor in the illumination device of the present invention emits two colors of red and yellow or red and green.

  Further preferably, in the illumination device of the present invention, a light emitting element that emits blue light having a wavelength shorter than that of the blue light is provided on a side end surface of the light guide plate.

  Further preferably, the light emitting element in the illumination device of the present invention is provided on two side end surfaces of the light guide plate so that the light incident directions to the light guide plate are orthogonal to each other.

  Further preferably, the light emitting elements in the illumination device of the present invention are provided in two or more rows in the upper and lower directions along the side end face of the light guide plate.

  Further preferably, the row of light emitting elements in the lighting device of the present invention is arranged so as to be able to emit light that is directly incident on the light guide plate and light that is directly irradiated on the light receiving surface of the solar cell. Yes.

  Furthermore, it is preferable that the end surface of the light guide plate of the present invention facing the light incident surface is a reflecting surface.

  Further preferably, in the light guide plate of the lighting device of the present invention, the blue or the most part of the light having a shorter wavelength than the blue is reflected on a surface on which the sunlight on the side opposite to the solar cell is incident. A reflective film is provided.

  Further preferably, the light guide plate in the lighting device of the present invention has a blue or shorter wavelength light than the blue except for a portion overlapping the electrode pattern of the solar cell on the surface of the solar cell. A reflective film that reflects most of the light is provided.

  The operation of the present invention will be described below with the above configuration.

  In the present invention, in order to cause the solar cell to function as a lighting device without reducing the conversion efficiency of the solar cell, the electrode portion of the solar cell that does not originally contribute to photovoltaic power generation is also used.

  For example, the electrode pattern surface provided on a part of the light-receiving surface of the solar cell absorbs light having a wavelength of blue or shorter (hereinafter referred to as blue ultraviolet light), for example, yellow, green and red The electrode portion can be made to emit light by covering with a phosphor that emits at least one of the above. Alternatively, the phosphor may be provided in the same pattern as the electrode pattern on the light guide plate side, and the electrodes and the phosphor may be arranged so as to overlap each other.

  As a result, the light emitted from the phosphor and the original blue or blue ultraviolet light that has not been absorbed by the phosphor are combined, and the entire solar cell appears to shine white.

  Further, since the electrodes of the solar cell are stretched over the entire surface of the solar cell at a constant rate, the entire light can be emitted with a constant light amount without being biased.

  Furthermore, by providing light emitting elements such as light emitting diodes that emit blue or blue ultraviolet light on the two side end surfaces of the light guide plate so that the light incident directions to the light guide plate are orthogonal to each other, a portion that becomes a shadow of incident light Can be eliminated.

  Furthermore, by providing a reflection film that reflects most of blue or blue ultraviolet light on the surface on the solar cell side or on the back surface on the opposite side, the opposite end surface facing the light incident surface of the light guide plate is provided. It is possible to repeat the multiple reflection inside the light guide plate so that most of the incident light is not emitted to the outside so that the incident light spreads over the entire solar cell.

  Furthermore, the amount of light can be increased by providing the light emitting elements in two or more rows on the side end surface of the light guide plate. In addition, by arranging the light emitting element at a position where the light from the row is divided into light that is directly incident on the light guide plate and light that is directly applied to the light receiving surface of the solar cell, the light scattering property is reduced. Can be increased.

  According to the present invention, it is possible to use a solar cell that cannot perform original photovoltaic power generation in the absence of light, such as at night, with a function different from that of a power generation device called an illumination device.

  In particular, in the present invention, since an electrode portion that does not contribute to photovoltaic power generation is used, it can be used as a lighting device without reducing the photoelectric conversion efficiency of the original solar cell. Further, since the electrodes are stretched over the entire surface of the solar cell, the entire surface of the solar cell can be illuminated.

  Furthermore, by forming a reflective film or phosphor on the light guide plate, there is no need to process the solar cell itself, and it is possible to attach a light guide plate and a light emitting element that match the electrode pattern to conventional products. The lighting device of the invention can be easily manufactured.

  Hereinafter, an embodiment of a lighting device of the present invention will be described with reference to the drawings.

  Fig.1 (a) is a top view which shows the principal part structure in embodiment of the illuminating device of this invention, (b) is the sectional drawing.

  In FIG. 1A and FIG. 1B, the illuminating device 10 includes a light guide plate 1, a solar cell 2 disposed below the light guide plate 1 with a light receiving surface facing upward, and the light guide plate 1. It has a plurality of light emitting diodes 3 as light emitting elements that emit light from two adjacent end faces.

  The light guide plate 1 is disposed on the light receiving surface side of the solar cell 2 and is made of transparent glass, transparent resin, or the like, and also serves as a surface protection function in addition to a light guide function capable of surface light emission. On the upper surface side of the light guide plate 1, a reflective film 1 a that allows red and infrared light to pass and reflects most of blue and blue ultraviolet light is provided by coating. In addition, a reflective film 1b is provided on the side end face of the light guide plate 1 facing the light incident surface (two adjacent side end faces described later), or a mirror (mirror function film) is provided for reflection. It is considered as a surface.

  In the solar cell 2, an Ag electrode 2b formed by applying a solder paste to Ag on the surface side of a silicon (Si) substrate 2c, which is a solar cell substrate made of a thinly sliced silicon (Si) crystal, has an entire light receiving surface. Are stretched at a certain rate. A phosphor 2g that absorbs blue or blue ultraviolet light and emits at least one color of yellow, green, and red is provided by coating, for example, so as to cover the surface of the Ag electrode 2b. On the other hand, Ag electrodes 2e and Al electrodes 2f are alternately provided on the back side of the Si substrate 2c, and a back sheet 2d is provided so as to cover the Ag electrodes 2e and Al electrodes 2f.

  The plurality of light emitting diodes 3 emit blue or blue ultraviolet light and are provided along two adjacent side end surfaces of the light guide plate 1 so that light incident directions on the side end surfaces of the light guide plate 1 are orthogonal to each other. It has been. The light emitting diodes 3 are provided in two upper and lower rows on each side end face of the light guide plate in order to increase the amount of light. The light from the lower light emitting diode 3 is divided into light that directly enters the end face of the light guide plate 1 and light that directly irradiates the light receiving surface of the solar cell 2 in order to increase scattering.

  With the above configuration, a part of the light emitted from the light emitting diode 3 is emitted to the outside of the light guide plate 1, but most of the light is repeatedly reflected inside the light guide plate 1 by the reflective film 1a and the reflective film 1b. Then, after being spread on the front surface of the light guide plate 1, the solar cell 2 and its Ag electrode 2b are irradiated. The light applied to the Ag electrode 2b is absorbed by the phosphor 2g provided on the surface thereof, and green, yellow, or red light is emitted from the phosphor 2g depending on the type of the phosphor 2g. The emitted light and the original blue or blue ultraviolet light are combined and emitted as white light from the front surface (wide surface) of the light guide plate 1 so that the entire lower surface of the light guide plate 1 appears to shine white. .

  Further, by setting the light incident directions from the plurality of light emitting diodes 3 to two directions orthogonal to each other, the phosphor 2g is applied to the plurality of Ag electrodes 2b formed to be orthogonal to the surface of the Si substrate 2c. The irradiation efficiency to the phosphor 2g can be further increased by preventing the shadow portion from being generated by the irradiation.

  As described above, according to the present invention, the surface of the electrode 2b having a predetermined pattern provided on the light receiving surface side of the solar cell 2 is covered with the phosphor 2g, and the light guide plate 1 disposed above the light receiving surface and the phosphor 2g. For example, the phosphor 2g emits red and yellow or red and green light by absorbing the blue or blue-ultraviolet light guided by. The light emitted from the phosphor 2g and the original blue or blue ultraviolet light that has not been absorbed by the phosphor 2g are combined, and the entire surface of the solar cell 2 appears to shine white. As a result, as the illumination device 10, the phosphor 2g is provided on the electrode pattern portion that does not originally contribute to the photovoltaic power generation of the solar cell 2 to emit light, and diffusion is performed as in the prior art in Patent Document 1 and Patent Document 2. Since no plate or diffusion layer is provided, the photoelectric conversion efficiency of the solar cell 2 is not lowered, and the electrode 2b is stretched over the entire surface, so that the amount of light is not biased, and the walls, windows, or passages of the building The entire surface of the solar cell 3 can be illuminated by using the solar cell 2 installed in the above and the light emitting diode 3 incorporated therein.

  In the above embodiment, red or infrared light is passed through the upper surface (front wide surface) of the light guide plate 1 on which sunlight on the side opposite to the solar cell 2 is incident, and has a wavelength shorter than blue or blue. Although the reflective film 1a that reflects most of the blue-ultraviolet light is provided, the present invention is not limited to this, and as shown in the illumination device 10A of FIG. 2, the lower surface (rear wide surface) of the light guide plate 1A on the solar cell 2 side is also provided. By providing the reflective film 1c similar to the reflective film 1a, blue or blue ultraviolet light absorbed by the solar cell 2 can be reduced. In this case, by forming the reflective film 1c except for the pattern portion that overlaps the electrode pattern of the electrode 2b of the solar cell 2, light is emitted only under the light guide plate 1A from the electrode pattern portion where the reflective film 1c is not formed. The phosphor 2g on the surface of the Ag electrode 2b that is emitted and provided in the vicinity thereof can be efficiently irradiated with blue light or blue ultraviolet light. In addition, by providing the reflection film 1c on the lower surface of the light guide plate 1A as described above, there is an effect that the multiple reflections are repeated inside the light guide plate 1A to spread the incident light over the entire surface.

  As described above, the configuration in which the reflective film 1c is provided on the surface of the light guide plate 1A on the solar cell 2 side (the lower surface in FIG. 2) forms the phosphor 2g on the surface of the light guide plate 1A with the same pattern as the electrode pattern of the Ag electrode 2b. This is even more effective. In this case, the phosphor 2g is provided on the light guide plate side. Thus, it is not necessary to process the solar cell 2 by processing the light guide plate side.

  Further, the arrangement (electrode pattern) of the Ag electrode 2b is not limited to the arrangement shown in FIG. 1, and may be arranged at a certain ratio on the entire light receiving surface, for example, as shown in the illumination device 10B of FIG. It may be an arrangement (electrode pattern) of the Ag electrode 2b of the solar cell 2B.

  Furthermore, in the above-described embodiment, the phosphor 2g emits red and yellow, or red and green, for example, thereby combining the original blue or blue ultraviolet light that is not absorbed by the phosphor 2g as white light. However, phosphors of two or more colors are alternately arranged for each adjacent electrode 2b, or phosphors 2g that emit two or more different colors are provided on one electrode 2b. Also good.

  As mentioned above, although this invention has been illustrated using preferable embodiment of this invention, this invention should not be limited and limited to this embodiment. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention. Patents, patent applications, and documents cited herein should be incorporated by reference in their entirety, as if the contents themselves were specifically described herein. Understood.

  In the field of lighting devices incorporating solar cells, the present invention provides a solar cell panel that cannot perform original photovoltaic power generation in the absence of light, such as at night, with another function called a lighting device. It can be used as a lighting device by being installed on a wall surface, a window, a passage or the like.

  In particular, in the present invention, an electrode pattern portion that does not contribute to photovoltaic power generation can be used as a lighting device without lowering the photoelectric conversion efficiency as the original solar cell, and on the entire surface of the solar cell. Since the electrode pattern is stretched, the entire surface of the solar cell can be illuminated. Furthermore, by disposing a reflective film or phosphor on the light guide plate, there is no need to process the solar cell itself, and even for conventional products, by attaching a light guide plate and LEDs that match the electrode pattern, The lighting device of the invention can be manufactured.

(A) is a top view which shows the principal part structure in embodiment of the illuminating device of this invention, (b) is the sectional drawing. It is sectional drawing which shows the principal part structure in other embodiment of the illuminating device of this invention. The top view which shows the other example of arrangement | positioning of the electrode pattern in embodiment of the illuminating device of this invention, (b) is the sectional drawing. (A) is a top view for demonstrating schematic structure of the conventional illuminating device, (b) is the sectional drawing.

Explanation of symbols

1, 1A Light guide plate 1a, 1b, 1c Reflective film 2, 2B Solar cell 2b, 2f Ag electrode (solder plating)
2c Si substrate 2d Back sheet 2e Al electrode 2g Phosphor 3 Light emitting diode (LED)
10, 10A, 10B Lighting device

Claims (12)

  In an illuminating device incorporating a solar cell, the electrode pattern surface provided on a part of the solar cell is covered with a phosphor, and is guided by a light receiving surface of the solar cell and a light guide plate disposed on the phosphor. An illuminating device configured to illuminate the phosphor by emitting light.   In a lighting device incorporating a solar cell, a light guide plate in which a phosphor is provided on the surface on the electrode pattern side in the same pattern as an electrode pattern provided on a part of the solar cell, the phosphor and the electrode An illumination device that is arranged on the light receiving surface so as to overlap each other and configured to emit light by the light guided by the light guide plate.   The lighting device according to claim 1, wherein the electrode pattern is stretched around the entire surface of the solar cell at a constant rate.   The lighting device according to claim 1, wherein the phosphor absorbs blue or light having a shorter wavelength than the blue and emits at least one of yellow, green, and red.   The lighting device according to claim 4, wherein the phosphor emits two colors of red and yellow or red and green.   The illuminating device according to claim 4, wherein a light emitting element that emits the blue light or light having a shorter wavelength than the blue light is provided on a side end surface of the light guide plate.   The lighting device according to claim 6, wherein the light emitting element is provided on two side end surfaces of the light guide plate so that light incident directions on the light guide plate are orthogonal to each other.   The illuminating device according to claim 6 or 7, wherein the light emitting elements are provided in two or more upper and lower rows along a side end surface of the light guide plate.   The lighting device according to claim 8, wherein the row of the light emitting elements is arranged so as to emit light that is directly incident on the light guide plate and light that is directly irradiated on the light receiving surface of the solar cell.   The lighting device according to claim 6 or 7, wherein an end surface of the light guide plate facing the light incident surface is a reflecting surface.   The surface of the light guide plate on which the sunlight opposite to the solar cell is incident is provided with a reflective film that reflects most of the blue light or light having a shorter wavelength than the blue light. The illumination device according to 4 or 9. The light guide plate is provided on the surface on the solar cell side with a reflective film that reflects most of the blue light or light having a shorter wavelength than the blue color except for a portion overlapping the electrode pattern of the solar cell. The lighting device according to claim 4 or 9.

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