JP6878768B2 - Solar cells with illuminance adjustment function and electronic devices with solar cells with illuminance measurement function - Google Patents

Description

The present invention relates to a solar cell capable of adjusting or measuring illuminance.

In recent years, active research and development has been promoted on energy harvesting technology (energy harvesting technology) that converts energy existing in a familiar environment into electric power in various forms such as light, heat, vibration, and radio waves. Energy harvesting technology can be used as a power source that can supply energy for a long period of time without charging, replacing, or refueling, and will be developed as a clean technology for the environment such as energy saving and carbon dioxide reduction. Is expected.

In particular, the power generation technology that uses light energy as an energy source is called photovoltaic power generation, in which light energy from lighting devices such as sunlight, incandescent lamps, fluorescent lamps, and LEDs is collected (harvesting) by solar cells. It is an energy harvesting technology that obtains electricity.

In addition, the development of electronic devices using such energy harvesting technology is also underway. For example, with the development of communication technology in recent years, a service has been provided in which beacon terminal devices having a signal transmission function are placed in various places to provide location information of mobile communication devices and provide peripheral information. .. Beacon terminal devices are required to supply signals throughout the service-providing space in order to provide accurate location information. For this reason, in order to improve the degree of freedom of installation and enable long-term driving, beacon terminal devices with built-in electric power are being widely used.
Here, primary batteries and secondary batteries such as dry batteries and button batteries are used as the power source of the beacon terminal device with built-in electric power. By adopting a solar battery instead of these, the batteries can be replaced. Is no longer required, and it is expected that long-term power supply to beacon terminal devices will be possible.

Further, in Patent Document 1, a main body including an antenna unit including an antenna element for transmitting a radio sign, a sign generation unit for generating a sign signal to be supplied to the antenna element for transmitting the radio sign, and the label generation. A wireless signing device including a connection part for transmitting a sign signal generated by the unit or power supplied from the power source between the main body and the antenna part, and a solar cell sheet connected to the main body via a power cable. It is disclosed. According to Patent Document 1, the illumination light from the luminaire is converted into electric power by the solar cell sheet, and the illumination light is supplied to the sign generation unit of the main body via the power cable.

Utility Model Registration No. 3178013

Solar cells are usually designed for low illuminance (indoors) or high illuminance (outdoors), and an illuminance range (allowable illuminance range) suitable for driving is set.
Further, when using a solar cell, a solar cell having high light receiving sensitivity is selected so that a desired conversion efficiency can be obtained even if the illuminance in the usage environment is low. For example, an amorphous silicone type solar cell is preferably used as an indoor solar cell because it exhibits high light receiving sensitivity with respect to a low illuminance light source such as a fluorescent lamp and has high substation efficiency.

However, the illuminance on the light receiving surface of the solar cell varies in height depending on the distance from the light source and the angle with respect to the light source even in the same closed space such as indoors.
Then, depending on the place of use, the illuminance on the light receiving surface of the solar cell may be too high above the allowable illuminance range. In this case, since the solar cell has high light receiving sensitivity, it deteriorates when it receives high illuminance light, and as a result, the light receiving sensitivity decreases and the desired substation efficiency cannot be obtained, which makes it difficult to generate electricity for a long period of time. Problems such as
On the other hand, assuming that the illuminance on the light receiving surface becomes high, if the light receiving sensitivity of the solar cell is lowered in order to prevent deterioration due to light receiving, the same solar cell is used in another place in the same space. At that time, depending on the location, the illuminance on the light receiving surface is too lower than the allowable illuminance range, and a sufficient amount of light received and the desired substation efficiency cannot be obtained, causing problems such as a decrease in the amount of power generation or no power generation. Such problems can occur outdoors as well as indoors.
As described above, when the same solar cell is used in an environment having different illuminance, it is difficult to obtain a desired conversion efficiency while preventing deterioration of the solar cell due to light reception.

In order to connect an electronic device to a solar cell and drive it, the solar cell needs to supply electric power equal to or higher than a threshold value required for driving the electronic device. However, as described above, if a problem occurs due to the high or low illuminance on the light receiving surface of the solar cell, the necessary power cannot be supplied, and there are problems such as the electronic device not being able to be driven normally or the driving period being shortened. It will occur. Furthermore, the illuminance on the light receiving surface of the solar cell limits the place where the electronic device can be used, and the solar cell is preferably used as a power source for the electronic device such as a beacon terminal device, which requires a degree of freedom in the place of use. Cannot be used.

The present invention has been made in view of the above problems, and an appropriate illuminance for a solar cell with an illuminance adjusting function capable of preventing deterioration of the solar cell and adjusting the illuminance on the light receiving surface, and an electronic device with the solar cell. The main purpose is to provide an electronic device with a solar cell with an illuminance measurement function that can be used below.

In order to achieve the above object, the present invention includes a solar cell and a light-shielding amount adjusting layer arranged on the light-receiving surface side of the solar cell and varying the light-shielding amount. I will provide a.

According to the present invention, the illuminance on the light receiving surface of the solar cell can be adjusted by changing the amount of light shielding by the light shielding amount adjusting layer according to the illuminance in the usage environment. However, the same solar cell can be used under an illuminance suitable for obtaining a desired substation efficiency. Further, by changing the light-shielding amount by the light-shielding amount adjusting layer, deterioration of the solar cell due to receiving high-illuminance light can be prevented, and the life of the solar cell can be extended.

In the above invention, it is preferable that the light-shielding amount adjusting layer is a light-shielding laminate composed of a plurality of light-shielding layers. In the light-shielding laminate having the above structure, since the plurality of light-shielding layers can be attached to and detached from each other, the amount of light-shielding can be adjusted in multiple stages by attaching and detaching the light-shielding layers. This is because the illuminance can be adjusted with higher accuracy, and the amount of light shielding can be changed inexpensively and easily. In addition, the structure of the solar cell can be made smaller and thinner.

In the case of the above invention, among the light-shielding laminates, the light-shielding layer located on the outermost side opposite to the light-receiving surface side of the solar cell is preferably a complete light-shielding layer. When the solar cell with an illuminance adjusting function of the present invention is provided with, for example, an illuminance meter described later, when measuring the illuminance of the place of use by the illuminance meter, the solar cell receives light having an illuminance equal to or higher than the allowable illuminance. This is because it can be prevented from deteriorating.

In the above invention, it is preferable to include an electronic device connected to the solar cell and driven by the electric power supplied from the solar cell, and in the above case, the electronic device is more preferably a beacon terminal device. This is because the electronic device with a solar cell can be used in various environments with different illuminances, and the electronic device can be driven for a long period of time by using the electric power supplied from the solar cell. Further, by using the beacon terminal device as the electronic device, the degree of freedom in installing the beacon terminal device is improved.

In the above invention, it is preferable to further include an illuminometer. This is because it is possible to measure the illuminance at the place where the solar cell is used in advance and adjust the light-shielding amount appropriately by the light-shielding amount adjusting layer.

Further, the present invention has a solar cell, an electronic device connected to the solar cell and driven by electric power supplied from the solar cell, and an illuminometer arranged inside or outside the solar cell. Provided is an electronic device with a solar cell having an illuminance measurement function.

According to the present invention, the illuminance on the light receiving surface of the solar cell in the usage environment can be confirmed in advance by an illuminance meter arranged inside or outside the solar cell, which is suitable for obtaining a desired substation efficiency. It is possible to select a place where the illuminance is obtained. In addition, it is possible to select the place where the solar cell is used and arrange the electronic device at the same time, improving the workability when installing the electronic device, and using the electric power supplied from the solar cell, the electronic device can be used. It can be driven for a long period of time.

In the above invention, it is more preferable that the electronic device is a beacon terminal device. This is because by using the beacon terminal device as the electronic device, the degree of freedom in installation of the beacon terminal device and the workability at the time of installation are improved.

According to the solar cell with an illuminance adjusting function of the present invention, the illuminance on the light receiving surface of the solar cell can be adjusted, and the same solar cell can be used in various environments with different illuminance while preventing deterioration of the solar cell. It has the effect of being able to be used under various illuminances.
Further, according to the electronic device with a solar cell having an illuminance measurement function of the present invention, the illuminance in the usage environment can be confirmed in advance, and the electronic device with a solar cell can be used under an appropriate illuminance. It plays the effect.

It is the schematic sectional drawing which shows an example of the solar cell with the illuminance adjustment function of this invention. It is schematic cross-sectional view which shows another example of the solar cell with an illuminance adjustment function of this invention. It is schematic cross-sectional view which shows another example of the solar cell with an illuminance adjustment function of this invention. It is schematic cross-sectional view which shows another example of the solar cell with an illuminance adjustment function of this invention. It is a graph showing the correlation between the number of layers of the light-shielding layer constituting the light-shielding laminate, and the illuminance on the light receiving surface of the solar cell via the light-shielding laminate. It is schematic cross-sectional view which shows another example of the solar cell with an illuminance adjustment function of this invention. It is schematic cross-sectional view which shows another example of the electronic device with the solar cell with the illuminance measurement function of this invention.

Hereinafter, the solar cell with an illuminance adjusting function and the electronic device with a solar cell with an illuminance measuring function of the present invention will be described in detail.

A. Solar cell with illuminance adjustment function The solar cell with illuminance adjustment function of the present invention is characterized by having a solar cell and a light-shielding amount adjusting layer arranged on the light-receiving surface side of the solar cell and varying the light-shielding amount.

The solar cell with an illuminance adjusting function of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a solar cell with an illuminance adjusting function of the present invention. The solar cell 1 with an illuminance adjusting function is a solar cell 2 which is a solar cell module to which a plurality of solar cell cells 2a are connected, and a light-shielding amount adjusting layer 3 which is arranged on the light receiving surface side of the solar cell 2 and changes the light-shielding amount. And have.

According to the present invention, the illuminance on the light receiving surface of the solar cell can be adjusted by changing the amount of light shielding by the light shielding amount adjusting layer according to the illuminance in the usage environment. However, the same solar cell can be used under an illuminance suitable for obtaining a desired substation efficiency. Further, by changing the light-shielding amount by the light-shielding amount adjusting layer, deterioration of the solar cell due to receiving high-illuminance light can be prevented, and the life of the solar cell can be extended.

The environment in which the solar cell with the illuminance adjusting function of the present invention is expected to be used may be outdoors or indoors, and is not particularly limited, but indoors is particularly preferable. That is, as the usage environment of the solar cell with the illuminance adjusting function of the present invention, an environment capable of receiving light from a light source installed indoors is generally preferable. Specifically, it is preferably used in an environment where the illuminance on the light receiving surface of the solar cell is in the range of 10 lx to 10000 lx in a state where the light shielding amount adjusting layer is not arranged.
The illuminance on the light receiving surface of the solar cell changes according to the distance from the light source to the place where the solar cell with the illuminance adjusting function of the present invention is used.

Hereinafter, each configuration of the solar cell with an illuminance adjusting function of the present invention will be described.

1. 1. Light-shielding amount adjusting layer The light-shielding amount adjusting layer in the present invention is a layer arranged on the light-receiving surface side of the solar cell and varying the light-shielding amount.
The light-shielding amount adjusting layer is usually arranged so as to cover the entire light receiving surface of the solar cell.

Here, changing the light-shielding amount means that the transmitted light amount (transmittance) of the light-shielding amount adjusting layer can be changed.
The light-shielding amount adjusting layer may be one in which the light-shielding amount can be changed by a binary value by switching between two states, a light-transmitting state having a high light transmittance and a light-shielding state having a low light transmittance. The light-shielding amount may be changed stepwise by changing the transmittance stepwise.
The specific method of varying the light-shielding amount depends on the type of the light-shielding amount adjusting layer used, but for example, a method of increasing or decreasing the number of layers of the light-shielding amount adjusting layer arranged on the light receiving surface of the solar cell, a solar cell. The state in which the light-shielding amount adjusting layer showing the desired light transmittance is arranged on the light-receiving surface of the solar cell is defined as the "ON state of the light-shielding adjustment function", and the unarranged state in which the light-shielding amount adjusting layer is peeled off from the light-receiving surface of the solar cell is defined as "ON state". Examples of the "OFF state of the light-shielding adjustment function" include a method of attaching and detaching the light-shielding amount adjusting layer, a method of aligning the oriented particles contained in the light-shielding amount adjusting layer, and the like.

The light-shielding amount adjusting layer may be composed of a single layer or a plurality of layers as long as the light-shielding amount can be changed by a desired method. Specifically, as such a light-shielding amount adjusting layer, a single-layer light-shielding layer, a light-shielding laminate in which a plurality of light-shielding layers are detachably laminated, a polymer-dispersed liquid crystal, and a polymer network-type liquid crystal are used to apply a voltage. A light control layer having a mold dimming layer and an alignment film, a polarizing plate, and first and second dimming sheets having a transparent support plate are arranged so as to face each other, and both are relatively moved. Examples thereof include a mobile dimming layer that adjusts the amount of transmitted light.

Among them, the light-shielding amount adjusting layer is preferably composed of a plurality of layers and the amount of light-shielding is varied stepwise, and is preferably a light-shielding laminate composed of a plurality of light-shielding layers. It is more preferable that the plurality of light-shielding layers are removable from each other. That is, it is more preferable that the light-shielding amount adjusting layer is a light-shielding laminate in which a plurality of light-shielding layers are detachably laminated. Since the light-shielding laminate having the above structure can adjust the light-shielding amount in multiple stages by attaching and detaching the light-shielding layer, the illuminance on the light-receiving surface can be adjusted with higher accuracy according to the usage environment. This is because the amount of shading can be changed inexpensively and easily. In addition, the structure of the solar cell can be made smaller and thinner.
Hereinafter, the light-shielding laminate will be described.

In the light-shielding laminate, a plurality of light-shielding layers are detachably laminated.
Here, the fact that a plurality of light-shielding layers are detachably laminated means that the number of light-shielding layers laminated can be increased or decreased.

As such a light-shielding laminated body, for example, as shown in FIG. 2, a plurality of light-shielding layers 13A, 13B, 13C are laminated via the sticking layer 14, and the plurality of light-shielding layers 13A, 13B, 13C are respectively. Examples thereof include a configuration in which the sticking layer 14 can be adhered or peeled off.
Further, as another example of the light-shielding laminate, as shown in FIG. 3, a plurality of light-shielding layers 13A, 13B, 13C are independently laminated by the support member 15, and the plurality of light-shielding layers 13A, 13B, 13C are laminated independently. Each can be slidable in the direction parallel to the light receiving surface of the solar cell 2. In the example shown in FIG. 3, a plurality of light-shielding layers 13A, 13B, and 13C are independently laminated in the frame as support members 15.
Above all, in the light-shielding laminate, it is preferable that a plurality of light-shielding layers are detachably laminated via a sticking layer. The adhesive and adhesive used for the sticking layer will be described later.

The light-shielding layer forming the light-shielding laminate can block the transmission of a part of light and can show a desired transmittance, and can be selected according to the light-shielding method. As the light-shielding layer, for example, a light absorption layer, a light reflection layer, a light diffusion layer, or the like can be used.

(1) Light Absorption Layer The light absorption layer may have a function of absorbing light incident on the light-shielding laminate, and for example, a dark resin layer containing dark particles such as black and a resin, a dark inorganic layer, and the like may be used. Can be mentioned.
Examples of dark-colored particles include metal salts such as carbon black, graphite, and black iron oxide, pigments or dyes, and resin particles colored with pigments or dyes.
Examples of the material of the dark inorganic layer include copper nitride, copper oxide, nickel nitride and the like.

(2) Light-reflecting layer The light-reflecting layer may have a function of reflecting light incident on the light-shielding laminate toward the light-shielding laminate, for example, on a metal layer, a particle-containing layer containing particles and a resin, or a surface. Examples thereof include a surface reflective layer having a concavo-convex shape, an internal interfacial reflective layer having an interface whose refractive index changes inside, and the like.

Examples of the metal constituting the metal layer include aluminum, silver and the like.

Examples of the particles contained in the particle-containing layer include metal particles such as aluminum and silver, metal oxide particles such as titanium oxide and aluminum oxide, pigments or dyes, resin particles colored with pigments or dyes, aluminum and silver. Examples thereof include resin particles coated with a metal such as.
Examples of the binder resin contained in the particle-containing layer include polyester resin, polycarbonate resin, polyolefin resin, silicone resin, fluororesin, polyurethane resin, epoxy resin and the like.

The surface reflective layer may have irregularities on the surface, and examples thereof include a layer in which irregularities are formed on the surface by sandblasting or embossing, and a particle-containing layer.
Examples of the material used for the surface reflective layer include resins such as polyester resin, polycarbonate resin, polyolefin resin, silicone resin, fluororesin, polyurethane resin, and epoxy resin.
Further, the particles used in the surface reflective layer can be the same as the particles contained in the above-mentioned particle-containing layer.

The internal interfacial reflection layer may have an interface in which the refractive index changes, and light may be reflected at the interface. For example, a flat layer is formed on the surface of the surface reflection layer having irregularities. Examples thereof include a laminate, a laminate of a high refractive index layer and a low refractive index layer having a refractive index lower than that of the high refractive index layer.
The internal interface reflection layer can adjust the degree of light reflection at the interface by adjusting, for example, the uneven shape of the surface reflection layer, the difference in refractive index between the high refractive index layer and the low refractive index layer, and the like. ..

When the internal interfacial reflection layer is a laminate in which a flat layer is formed on a surface having irregularities of the surface reflection layer, the flat layer may have a refractive index different from that of the surface reflection layer, and the surface reflection may occur. It may have the same refractive index as the layer. Examples of the flat layer include a low refractive index resin layer such as a fluoropolymer and a high refractive index resin layer such as an ionizing radiation curable resin.

When the internal interface reflective layer is a laminate of a high refractive index layer and a low refractive index layer having a lower refractive index than the high refractive index layer, the high refractive index layer and the low refractive index layer are of light at the laminated interface. Anything having a difference in refractive index to the extent that reflection occurs may be used.
The difference in refractive index between the high refractive index layer and the low refractive index layer can be appropriately set according to the amount of light-shielding property per layer of the light-shielding layer.

Examples of the low refractive index layer include a low refractive index resin layer composed of a low refractive index resin such as a fluorine-containing polymer, a binder resin such as an ionized radiation curable resin, and inorganic or organic porous particles or hollow. Examples thereof include a low refractive index fine particle-containing layer containing low refractive index particles such as particles.
On the other hand, the high refractive index layer includes a high refractive index fine particle-containing layer in which a binder resin such as an ionizing radiation curable resin contains high refractive index fine particles having a higher refractive index than the binder resin such as a metal oxide. Examples thereof include a high refractive index resin layer made of a high refractive index resin such as an ionized radiation curable resin, and an inorganic layer made of a metal compound or a metal inorganic material.
Regarding various types of the low refractive index layer and the high refractive index layer, for example, Japanese Patent Application Laid-Open No. 2015-114531, JP-A-2014-21321, JP-A-2013-142817, JP-A-2012-150226, JP-A-2012-150226 It can be the same as the low refractive index layer and the high refractive index layer disclosed in Japanese Patent Application Laid-Open No. 2011-170208.
The thickness and refractive index of each of the high refractive index layer and the low refractive index layer can be appropriately set.

(3) Light Diffusion Layer The light diffusion layer may have a function of diffusing the light incident on the light-shielding laminate. For example, a layer in which particles are dispersed in a binder resin (hereinafter referred to as a particle diffusion layer) or , A layer having irregularities on the surface (hereinafter referred to as a surface diffusion layer), a layer having an interface whose refractive index changes inside (hereinafter referred to as an internal interfacial diffusion layer), and the like.

Examples of the particles contained in the particle diffusion layer include organic particles such as acrylic, polystyrene, silicone and polyurethane, and inorganic particles such as silica. Examples of the shape of the particles include a spherical shape, a true spherical shape, and a needle shape. The average particle size of the particles is appropriately selected according to the type of the diffusion layer and the like.
Examples of the binder resin contained in the particle diffusion layer include polyester resin, polycarbonate resin, polyolefin resin, silicone resin, fluororesin, polyurethane resin, epoxy resin and the like.

The surface diffusion layer may have irregularities on the surface, and a general diffusion layer can be appropriately selected and used. Examples of the surface diffusion layer include a layer in which irregularities are formed on the surface by sandblasting, embossing, or the like, and a particle-containing layer.
Examples of the material used for the surface diffusion layer include resins such as polyester resin, polycarbonate resin, polyolefin resin, silicone resin, fluororesin, polyurethane resin, and epoxy resin.
Further, the particles used in the surface diffusion layer can be the same as the particles contained in the above-mentioned particle diffusion layer.

The internal interface diffusion layer may have an interface in which the refractive index changes, and light may be diffused at the interface. For example, a flat layer is formed on the uneven surface of the surface diffusion layer. Examples thereof include a laminate, a laminate of a high refractive index layer and a low refractive index layer having a refractive index lower than that of the high refractive index layer. The internal interface diffusion layer can adjust the degree of light diffusion at the interface by adjusting, for example, the uneven shape of the surface diffusion layer and the difference in refractive index between the high refractive index layer and the low refractive index layer. ..

The above-mentioned laminated body that can be used as the internal interfacial diffusion layer can be the same as the internal interfacial reflection layer described in the above-mentioned "(2) Light reflection layer". Omit.
The laminate can also be an internal interface reflective layer that reflects light at the internal interface by adjusting the uneven shape of the surface diffusion layer and the difference in refractive index between the high refractive index layer and the low refractive index layer. It can also be an internal interface diffusion layer that diffuses light at the internal interface.

A commercially available diffusion film can also be used as the light diffusion layer.

The haze of the light diffusing layer is not particularly limited, and can be appropriately set according to the number of layers and the light diffusing function required for each single layer of the light diffusing layer.

(4) Others Various light-shielding layers may contain a wavelength conversion material or the like in addition to the above-mentioned materials. When a wavelength conversion material is included, deterioration can be suppressed while maintaining the amount of power generation by excluding wavelengths that promote deterioration of the solar cell.

The thickness per light-shielding layer is not particularly limited, and can be appropriately set according to the type and transmittance of the light-shielding layer.

The amount of light-shielding per light-shielding layer can be defined by the transmittance of the light-shielding layer. The transmittance per light-shielding layer is preferably 90% or less, and more preferably 70% or less, particularly 50% or less.
Here, the transmittance of the light-shielding layer means the visible light transmittance, and is measured by an ultraviolet-visible near-infrared spectrophotometer (for example, an ultraviolet-visible near-infrared spectrophotometer UV-3100 manufactured by Shimadzu Corporation). , The average transmittance in the visible light region of 380 nm to 780 nm was calculated.

The form of the light-shielding layer can be appropriately selected depending on the mode of attachment / detachment, and examples thereof include a thin film shape, a film shape, and a plate shape. As the plate-shaped light-shielding layer, for example, a metal base material, a colored resin base material, or the like formed of the materials of the various light-shielding layers described above can be used.

The number of light-shielding laminates to be laminated is not particularly limited, and can be appropriately designed according to the method for adjusting the amount of light-shielding.
Further, as the light-shielding laminate, a plurality of light-shielding layers having the same transmittance may be laminated, or a plurality of light-shielding layers having different transmittances may be laminated.
Further, the light-shielding layers constituting the light-shielding laminate may be of the same type or may be used in combination of two or more types.

As a method of adjusting the amount of light-shielding by the light-shielding laminate, for example, the light-shielding layer is cut according to the size of the solar cell, and a plurality of cut light-shielding layers are arranged so as to be overlapped on the light-receiving surface of the solar cell. The appropriate number of laminated light-shielding layers is calculated from the relationship between the number of light-shielding layers measured in advance and the transmittance, and the required amount of light-shielding, and the excess number of light-shielding layers is calculated from the light-receiving surface of the solar cell. The amount of light-shielding can be adjusted by peeling off the light-shielding layers so that an appropriate number of light-shielding layers are arranged on the light-receiving surface of the solar cell.

FIG. 4 shows an example in which, as the light-shielding amount adjusting layer 3, a light-shielding laminate in which eight light-shielding layers 13A to 13H showing the following uniform transmittance are laminated is arranged on the light-receiving surface of the solar cell 2. There is. In FIG. 4, the sticking layer passing through each layer of each of the light-shielding layers 13A to 13H is not shown.
Further, FIG. 5 is a graph showing the correlation between the number of layers of the light-shielding layer constituting the light-shielding laminate and the illuminance on the light-receiving surface of the solar cell via the light-shielding laminate. As the light-shielding layer, two translucent light-shielding tapes (Piolan white curing tape manufactured by Diatex) were laminated and used as one layer, and the transmittance per light-shielding layer was 83.5%.
As shown in FIG. 5, in a light-shielding laminate in which a plurality of light-shielding layers exhibiting a uniform transmittance (83.5%) are laminated, the illuminance on the light-receiving surface of the solar cell decreases as the number of layers of the light-shielding layers increases. To do. At this time, the relationship of the following formula (1) is obtained between the number of laminated light-shielding layers (N) and the transmittance (T) of the light-shielding laminated body.
Equation (1): T (%) = 0.835 ^N x 100

That is, in a light-shielding laminate in which a plurality of light-shielding layers exhibiting a uniform transmittance T (s)% are laminated, light is blocked between the number of layers (N) of the light-shielding layers and the transmittance (T) of the light-shielding laminate. It has the relationship of the following formula (2), which is obtained by multiplying the transmittance of the layer by the number of layers.
Equation (2): T (%) = {T (s) / 100} ^N × 100
Further, in the light-shielding laminate in which a plurality of light-shielding layers showing different transmittances T (s ₁ )% are laminated, the number of layers (N) of the light-shielding layers and the transmittance (T) of the light-shielding laminate are different from each other. It has the relationship of the following equation (3) multiplied by the transmittance of the light-shielding layer.
Equation (3): T (%) = {(T (s ₁ ) / 100) × (T (s ₂ ) / 100) ×… × (T (s _n ) / 100)} × 100
(In the above formula (3), T (s ₁ ), T (s ₂ ), and T (s _n ) are the transmittance (%) of the first light-shielding layer and the transmittance of the second light-shielding layer, respectively. (%), The transmittance (%) of the nth light-shielding layer is shown.)
When a light-shielding laminate in which a plurality of light-shielding layers are laminated is used, if the light-shielding amount that provides a suitable illuminance and the transmittance of the light-shielding laminate for achieving the light-shielding amount are specified, the above equations (2) and (3) can be specified. ), The number and combination of light-shielding layers can be obtained and adjusted.

Further, when the set illuminance under the usage environment is high illuminance, the actual illuminance on the light receiving surface of the solar cell is adjusted by adjusting the number of layers of the light shielding layer constituting the light shielding amount adjusting layer. be able to. The set illuminance corresponds to the actual illuminance on the light receiving surface of the solar cell that does not pass through the light shielding amount adjusting layer.
As shown in Table 1 below, when the illuminance on the light receiving surface of the solar cell in the state where the light shielding amount adjusting layer is not arranged is 3000 lx, the light shielding layer constituting the light shielding laminated body having the correlation shown in FIG. By setting the number of layers to 7, the illuminance of the light receiving surface of the solar cell via the light-shielding layer becomes 887 lx. When the illuminance on the light receiving surface of the solar cell is 2000 lx when the light-shielding amount adjusting layer is not arranged, the light-shielding laminate can be formed by setting the number of the light-shielding layers constituting the light-shielding laminate to five. The illuminance on the light receiving surface of the solar cell is 850 lx. Further, when the illuminance on the light receiving surface of the solar cell in the state where the light shielding amount adjusting layer is not arranged is 1500 lx, the number of the light shielding layers constituting the light shielding laminated body is set to three, so that the light shielding stacking is performed. The illuminance of the light receiving surface of the solar cell through the body is 883 lx.

In this way, by attaching and detaching the light-shielding layer constituting the light-shielding laminate and adjusting the number of layers, the illuminance of the light received by the solar cell via the light-shielding laminate can be adjusted.

Of the plurality of light-shielding layers constituting the light-shielding laminate, the light-shielding layer located on the outermost side opposite to the light-receiving surface side of the solar cell may be a complete light-shielding layer.
When the solar cell with an illuminance adjusting function of the present invention is provided with, for example, an illuminance meter described later, when measuring the illuminance of the place of use by the illuminance meter, the solar cell receives light having an illuminance equal to or higher than the allowable illuminance. This is because it can be prevented from deteriorating.
Here, the completely light-shielding layer means a light-shielding layer having a transmittance of 99% or more, and more preferably the transmittance is 99.99% or more. The above-mentioned transmittance means a visible light transmittance, and the measuring method thereof is the same as the above-mentioned method.

In addition to the light-shielding layer described above, the light-shielding laminate may include a design sheet or the like that imparts designability to the surface.

The method for forming the light-shielding laminate is appropriately selected according to the type of the light-shielding layer, its form, and the like. If the light-shielding layer is in the form of a thin film or a film, it can be formed by using, for example, a dry method such as a vacuum deposition method or a sputtering method, or a wet method such as a printing method or a plating method.

When a plurality of light-shielding layers are laminated via the sticking layer, the sticking layer is not particularly limited as long as the light-shielding layers can be bonded and peeled off, and the adhesive used for the sticking layer is specific. Acrylic adhesives or adhesives, silicone adhesives or adhesives, natural rubber adhesives or adhesives, ethylene-vinyl acetate (EVA) adhesives or adhesives, urethane adhesives Alternatively, an adhesive or the like can be mentioned.

Further, when a plurality of light-shielding layers are laminated independently, the support member supporting the plurality of light-shielding layers can be arranged so as to overlap the light-receiving surface of the solar cell in a plan view, and is known. The member is not particularly limited as long as it has the slide mechanism of.

2. Solar cell As the solar cell in the present invention, it suffices as long as it can generate desired power, and a conventionally known solar cell corresponding to the solar cell element can be used.

The solar cell usually has a solar cell element and a transparent front substrate arranged on the light receiving surface side of the solar cell element. More specifically, the solar cell has a structure in which a back surface protective sheet, a filler sheet, a solar cell element, a filler sheet, and a transparent front substrate are laminated in this order.
The light receiving surface of the solar cell usually refers to the surface opposite to the solar cell element of the transparent front substrate arranged on the light receiving surface side of the solar cell element, and the above-mentioned light-shielding layer is formed on the light receiving surface of the solar cell. Be placed.

Examples of the solar cell element include a single crystal silicone type solar cell element, a polycrystalline silicone type solar cell element, an amorphous silicone type solar cell element, a compound semiconductor type solar cell element, a dye sensitized type solar cell element, and a quantum dot type. Examples thereof include a solar cell element and an organic thin film type solar cell element.
Among them, any of indoor solar cell elements having an allowable illuminance range of 10 lx to 10000 lx, specifically, amorphous silicone type solar cell elements, dye-sensitized solar cell elements, and organic thin film type solar cell elements. Is preferable, and an amorphous silicone type solar cell element is particularly preferable. This is because amorphous silicone solar cells are commercially available at low prices with good availability and reliability.
Further, the amorphous silicone type solar cell is characterized in that when it receives strong light, the hydrogen bonds inside the amorphous silicone are broken, and the output tends to decrease due to the increase in the defect density. Therefore, by arranging a light-shielding amount adjusting layer on the light-receiving surface of the amorphous silicone-type solar cell and adjusting the illuminance on the light-receiving surface to an appropriate illuminance, the deterioration of the amorphous silicone-type solar cell is suppressed and a desired transformation is desired. Efficiency can be obtained, and the effects of the present invention can be more easily exhibited.

The connection form of the solar cell element may be a single cell type solar cell element composed of only one solar cell element, or may be a solar cell module or a solar cell array in which a plurality of solar cell elements are connected in parallel or in series. You may.

As the protective sheet, filler sheet, and transparent front substrate constituting the solar cell, members generally used for the solar cell can be used, and for example, the members described in Japanese Patent Application Laid-Open No. 2012-209578 are applied. To.

3. 3. Electronic device In the present invention, it is preferable to include an electronic device connected to the solar cell and driven by electric power supplied from the solar cell. This is because the electronic device with a solar cell can be used in various environments with different illuminances, and the electronic device can be driven for a long period of time by using the electric power supplied from the solar cell.

FIG. 6 is a schematic cross-sectional view showing another example of the solar cell with an illuminance adjusting function of the present invention, which has a light-shielding amount adjusting layer 3 on the light-receiving surface side of the solar cell 2 and is on the light-receiving surface side of the solar cell 2. An electronic device 4 is provided on the opposite surface. The electronic device 4 is connected to the solar cell 2 and is driven by the electric power supplied from the solar cell 2.

The electronic device is not particularly limited as long as it can constantly obtain the threshold power for driving by the electric power supplied from the solar cell, and is, for example, a communication device such as a beacon terminal device or a wireless switch. , Display devices such as electronic paper, and lighting devices such as LEDs.
Among them, a communication device is preferable, and the communication device is preferably a beacon terminal device. Beacon terminal devices need to be used by selecting multiple locations that are less likely to be hindered by signal transmission / reception. By using the above-mentioned solar cells that can be used regardless of the illuminance of the usage environment, the beacon terminal devices can be used together. This is because the degree of freedom in installation and the workability of installation are improved, and the beacon terminal device can be driven for a long period of time by using the electric power supplied from the solar cell.

The beacon terminal device includes, for example, a control unit, a storage unit, and a radio wave transmission unit.
The control unit is a CPU that controls the entire beacon terminal. The control unit executes various functions in cooperation with the above-mentioned hardware by appropriately reading and executing the OS and application programs stored in the storage unit. The storage unit is a storage area such as a semiconductor memory element for storing programs, data, and the like necessary for the control unit to execute various processes. The storage unit stores the beacon ID. The radio wave transmitting unit transmits radio waves including the beacon ID. The radio wave transmitting unit transmits radio waves by repeating strength and weakness at regular intervals (for example, at intervals of 10 seconds) under the control of the control unit.
As the beacon terminal device, a commercially available product can be used.

The location of the electronic device is not particularly limited as long as it is connected to the solar cell and can receive the power supplied from the solar cell. For example, the surface opposite to the light receiving surface side of the solar cell. , The side surface of the solar cell, the surface of the light-shielding amount adjusting layer opposite to the solar cell side, and the like can be arranged. Further, as long as it is connected to the solar cell, it may be arranged at a position close to the solar cell.

4. Illuminance meter In the present invention, an illuminometer may be further provided. This is because it is possible to measure the illuminance at the place where the solar cell is used in advance and adjust the light-shielding amount appropriately by the light-shielding amount adjusting layer.
Further, when the solar cell with the illuminance adjusting function of the present invention is provided with an electronic device, it is possible to confirm the illuminance suitable for obtaining the desired substation efficiency, so that the workability when installing the solar cell and the electronic device is improved. Because it improves.

The illuminometer is, for example, a light receiving unit that receives light from the outside, a measuring unit that measures the illuminance from the light receiving unit, a display unit that displays the illuminance value measured by the measuring unit, or a notification unit that notifies the determination of the illuminance. Can be configured to have at least.
The method of displaying the illuminance by the illuminometer or the method of notifying the determination result of the illuminance is not particularly limited, but for example, a method of displaying a numerical value on a liquid crystal screen as a display unit, an excess or deficiency of a threshold value due to lighting of an LED lamp. Various methods such as a method of visually determining the illuminance and a method of notifying the non-suitability by a buzzer can be used.

The illuminometer may be arranged at a position on the light receiving surface of the solar cell where the illuminance can be measured, and the arrangement position is not particularly limited. Above all, it is preferable that the solar cells are arranged in the same plane as the light receiving surface of the solar cell or in the vicinity of the light receiving surface. This is because the illuminance on the light receiving surface of the solar cell can be measured more accurately. Further, the illuminometer may be arranged in the same plane as the surface opposite to the light receiving surface of the solar cell, or close to the surface on the opposite side. This is because the illuminance on the back surface of the solar cell can be measured and the illuminance on the front surface can be estimated with low accuracy from the measured value.
Specific examples of the arrangement position of the illuminometer include a light-receiving surface of the solar cell, a surface opposite to the light-receiving surface, a light-shielding amount adjusting layer, and the like. That is, the solar cell with the illuminance adjusting function of the present invention may be arranged in the order of, for example, the light-shielding amount adjusting layer, the illuminance meter, and the solar cell from the light source side, and the illuminance meter, the light-shielding amount adjusting layer, and the sun. The batteries may be arranged in this order, or the light-shielding amount adjusting layer, the solar cell, and the illuminometer may be arranged in this order.
When the solar cell with an illuminance adjusting function of the present invention is provided with an electronic device, for example, an illuminometer may be arranged on the surface of the solar cell of the electronic device on the side where light is incident, and the illuminance meter may be appropriately set. Can be done.

Further, the illuminometer may be arranged outside the solar cell and separately from the solar cell, or may be arranged inside the solar cell and integrated with the solar cell.
The fact that the solar cell is arranged inside the solar cell and is integrated with the solar cell means that the solar cell also functions as an illuminometer. In the above case, the illuminance on the light receiving surface can be measured by converting the output value of the solar cell.
When the solar cell with an illuminance adjusting function of the present invention has an electronic device, the illuminometer may be arranged inside the electronic device and integrated with the electronic device.
When the illuminometer is separate from the solar cell or the electronic device, a commercially available illuminometer may be used.

5. In addition to the above configuration, the solar cell with an illuminance adjusting function of the present invention may include a control unit or the like that automatically adjusts the illuminance to an appropriate transmission amount according to the illuminance measured by the illuminometer.

Since the solar cell with an illuminance adjusting function of the present invention can be used regardless of the high or low illuminance of the place, it can be suitably used for applications in which the solar cell is used indoors or outdoors. Above all, it can be suitably used as a solar cell for indoor use.
Further, the solar cell with an illuminance adjusting function of the present invention can be suitably used as a power source for a device that requires electric power, such as an electronic device.

B. Electronic device with solar cell with illuminance measurement function The electronic device with solar cell with illuminance measurement function of the present invention includes a solar cell, an electronic device connected to the solar cell and driven by electric power supplied from the solar cell, and the above. It is characterized by having a luminometer arranged inside or outside the solar cell.

The electronic device with a solar cell with an illuminance measurement function of the present invention will be described with reference to the drawings. FIG. 7 is a schematic cross-sectional view showing an example of an electronic device with a solar cell having an illuminance measurement function of the present invention. The electronic device 11 with a solar cell having an illuminance measurement function is connected to a solar cell 2 which is a solar cell module to which a plurality of solar cell cells 2a are connected, and is driven by electric power supplied from the solar cell 2 and connected to the solar cell 2. It has an electronic device 4 and a luminometer 5 arranged inside or outside the solar cell 2. In FIG. 7, the electronic device 4 is arranged on the surface of the solar cell 2 opposite to the light receiving surface side.

When an electronic device is driven by supplying electrodes from a solar cell using energy harvesting technology, the solar cell is required to supply electric power equal to or higher than the threshold value required for driving the electronic device.
As already described, the illuminance on the light receiving surface of the solar cell varies in height depending on the distance from the light source and the angle with respect to the light source even in the same closed space such as indoors. Then, depending on the place of use, the illuminance on the light receiving surface of the solar cell may be too high or too low than the allowable illuminance range. Therefore, in a space where the illuminance from the light source varies, the illuminance of the place of use is confirmed in advance, it is judged whether or not it is appropriate as the place of use of the solar cell, and the place is determined. Equipment needs to be connected.
However, in order to confirm the illuminance, an illuminance measuring device must be used separately, and there is a problem that the selection of the place where the solar cell is used and the arrangement of the electronic device cannot be performed at the same time.
The above-mentioned problems can occur not only indoors but also outdoors.

In response to the above problems, the electronic device with a solar cell having an illuminance measurement function of the present invention includes a solar cell, an electronic device connected to the solar cell and driven by electric power supplied from the solar cell, and further, the solar cell. A luminometer is placed inside or outside the. As a result, the illuminance on the light receiving surface of the solar cell in the usage environment can be confirmed in advance, and it is possible to select a place where the illuminance is suitable for obtaining the desired substation efficiency. In addition, it is possible to select the place where the solar cell is used and arrange the electronic device at the same time, improving the workability when installing the electronic device, and using the electric power supplied from the solar cell, the electronic device can be used. It can be driven for a long period of time.

Furthermore, for electronic devices such as beacon terminal devices, it is necessary to select and use a plurality of locations that are less likely to be hindered by signal transmission / reception. Even if a suitable place for using a solar cell is selected, the above place may not be suitable for using an electronic device.
On the other hand, since the electronic device with a solar cell with an illuminance measurement function of the present invention has the above-mentioned structure, a place suitable for use of the electronic device is selected, and at the same time, on the light receiving surface of the solar cell at the above place. You can check the illuminance of.
That is, according to the present invention, it is possible to easily select a location suitable for both the use of solar cells and the use of electronic devices.

Since the solar cell constituting the electronic device with the solar cell with the illuminance measurement function of the present invention has been described in the above-mentioned section "A. Solar cell with the illuminance adjustment function", the description thereof is omitted here.
The solar cell preferably has a completely light-shielding layer on the light receiving surface of the solar cell. When measuring the illuminance of the place of use with an illuminometer, the light emitted to the light receiving surface of the solar cell is blocked by the completely light-shielding layer, so that the solar cell deteriorates by receiving light with an illuminance higher than the allowable illuminance. This is because it can be prevented.
Since the completely light-shielding layer has been described in the above section "A. Solar cell with illuminance adjustment function", the description thereof is omitted here.

Since the illuminometer constituting the electronic device with the solar cell with the illuminance measurement function of the present invention has been described in the above section "A. Solar cell with the illuminance adjustment function", the description thereof is omitted here.

Since the electronic device constituting the electronic device with the solar cell with the illuminance measurement function of the present invention has been described in the above-mentioned section "A. Solar cell with the illuminance adjustment function", the description thereof is omitted here.
Above all, the electronic device is preferably a beacon terminal device. This is because by using the beacon terminal device as the electronic device, the degree of freedom in installation of the beacon terminal device and the workability at the time of installation are improved.

As described above, the electronic device with a solar cell with an illuminance measurement function of the present invention can easily select the place of use by measuring the illuminance with an illuminance meter, but instead of selecting the place, measurement is performed. By taking measures such as devising the installation method and providing an optional member to the solar cell based on the value, it becomes possible to preferably use the electronic device with the solar cell with the illuminance measurement function at the selected place.

Specifically, the electronic device with a solar cell with an illuminance measurement function of the present invention can measure the illuminance at a desired position with an illuminance meter when deciding the position to be used, but the measured illuminance is the sun. If it is higher than the permissible illuminance range of the battery, it is determined that the above position is an environment in which a problem is likely to occur in the solar cell and is not appropriate as the arrangement position of the solar cell.
At this time, the user changes the arrangement position of the electronic device with a solar cell with an illuminance measurement function, changes the installation angle, lowers the illuminance of the light source, and puts a light-shielding layer on the light receiving surface of the solar cell according to the measured value. By taking measures such as arranging, the above position can be made an environment suitable for use of an electronic device with a solar cell with an illuminance measurement function.

On the other hand, if the measured illuminance is lower than the permissible illuminance range of the solar cell, it is determined that the above position is a place where it is difficult to obtain the threshold power of the electronic device, and it is necessary to increase the sensitivity of the solar cell. ..
At this time, the user takes measures such as changing the arrangement position of the electronic device with a solar cell with an illuminance measurement function, changing the installation angle, and increasing the illuminance of the light source according to the measured value. Can be set up in an environment suitable for use in an electronic device with a solar cell with an illuminance measurement function.

The application of the electronic device with a solar cell with an illuminance measurement function of the present invention depends on the type of the electronic device, but can be used for, for example, a beacon terminal device, a wireless switch, an electronic poster, or the like.

The present invention is not limited to the above embodiment. The above embodiment is an example, and any one having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. It is included in the technical scope of the invention.

1 ... Solar cell with illuminance adjustment function 2 ... Solar cell 2a ... Solar cell element 3 ... Light-shielding amount adjustment layer 4 ... Electronic device 5 ... Illuminance meter 11 ... Electronic device with solar cell with illuminance measurement function 13A, 13B, 13C ... Light-shielding layer

Claims (7)

It has a solar cell and a light-shielding amount adjusting layer arranged on the light-receiving surface side of the solar cell and varying the light-shielding amount.
The light-shielding amount adjusting layer is a light-shielding laminate composed of a plurality of light-shielding layers having the same transmittance, and the plurality of light-shielding layers are detachably laminated via a sticking layer. Solar cell with illuminance adjustment function. The sun with an illuminance adjusting function according to claim 1, wherein the light-shielding layer located on the outermost side of the solar cell opposite to the light-receiving surface side is a completely light-shielding layer. battery. The solar cell with an illuminance adjusting function according to claim 1 or 2 , further comprising an electronic device connected to the solar cell and driven by electric power supplied from the solar cell. The solar cell with an illuminance adjusting function according to claim 3 , wherein the electronic device is a beacon terminal device. The solar cell with an illuminance adjusting function according to any one of claims 1 to 4, further comprising an illuminance meter. The solar cell with an illuminance adjusting function according to any one of claims 1 to 5 is connected to the solar cell with an illuminance adjusting function and is driven by electric power supplied from the solar cell having an illuminance adjusting function. An electronic device with a solar cell having an illuminance measurement function, which comprises an electronic device for the illuminance and an illuminance meter arranged inside or outside the solar cell with an illuminance adjusting function. The electronic device with a solar cell having an illuminance measurement function according to claim 6 , wherein the electronic device is a beacon terminal device.

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