JPH11298026A - Solar cell and electronic device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a pattern of solar cells unseen or the appearance resemble a mirror or white by placing a circularly polarized filter consisting of a non- absorbing reflecting polarizer and phase different plate in front of the solar cell. SOLUTION: A reflecting polarizer 1 and phase different plate 2 are integrated by a transparent adhesive to form a circularly polared filter 3. The optical axis of the phase difference plate 2 is about 45 deg. to the azimuth angle of a linearly polarized light passing through the reflective polarizer 1, a solar cell 4 is disposed behind the phase difference plate 2 via an air layer or transparent adhesive, the reflecting polarizer 1 uses DBEF manufactured by Sumitomo-3M (Ltd.), the phase difference plate 2 uses a broadband wavelength film quarter- wave plate manufactured by Nitto Denko (Ltd.), the solar cell 4 uses a 4-cell series connection type amorphous Si solar cell, and the reflective polarizer may use other polarizer having a cholesteric polymer selective reflecting film combined with a phase difference film than DBEF.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell capable of photoelectrically converting a part of incident light and supplying electric power, and a decorative article, a clock, a calculator, a radio, a small portable device, and a display equipped with the solar cell.

[0002]

2. Description of the Related Art In recent years, the power consumption of an LSI used in a small portable electronic device or the like has been reduced, so that a conventional storage battery has been replaced by a solar battery as a power source. At present, small portable devices such as watches, calculators, radios, etc. incorporating solar cells have been sold in the market.

The configuration of a small portable electronic device incorporating a conventional solar cell will be described below with reference to examples. FIG. 2 shows an external view of a card-type calculator. In the figure, 14 is a reflective LCD,
13 is a solar cell unit, 12 is an input key unit, and 11 is a case.

[0004] A commonly used solar cell is an amorphous silicon solar cell. Its configuration is shown in FIG.
After forming the transparent electrode 16 on the glass substrate 15 as shown in FIG.
P-type 17, i-type 18, and N-type 19 amorphous silicon layers are continuously formed, and finally a metal electrode 20 is formed. Practically, the voltage required for the device is obtained by connecting the cells in series by designing the electrode pattern when forming the cells.

Japanese Patent Laid-Open Publication No. Hei 5-29641 discloses a method for preventing the presence of a solar cell from being seen from the outside, even though the solar cell is disposed on the front of the electronic device. . In this configuration, a coloring layer is provided on the front surface of the solar cell, which transmits at least a part of the wavelength of light contributing to power generation of the solar cell through a region and reflects another wavelength region. As the coloring means layer, a cholesteric liquid crystal microencapsulated material dispersed and applied to a binder or a cholesteric polymer sheet may be used. They selectively scatter light of a specific wavelength in the visible region and transmit the remaining light. When used in a solar cell clock, the dial can see the scattered color of the cholesteric liquid crystal, and the presence of the solar cell hidden behind it cannot be discerned from the outside.

Japanese Patent Application Laid-Open No. 60-147718 discloses an example of an electronic apparatus in which a liquid crystal panel is arranged on the front of a solar cell. In the display layer, necessary segment patterns are formed on a liquid crystal panel using a scattering mode. A selective reflection filter is provided behind the display layer, and a light absorbing layer, for example, black paper, is provided behind the filter. The incident light is transmitted through the display layer in the transparent mode portion A of the display layer, and a color of a specific wavelength, for example, blue is reflected by the filter, but is reflected in an oblique direction, so that the observer looks black. . In the scattering mode portion B of the display layer, the light is scattered and transmitted, blue is reflected by the filter, and scattered again by the display layer. Light transmitted through the filter is absorbed by the light absorbing layer, and the portion B looks blue. The light absorbing layer may be a solar cell, and can provide a bright and easily visible color display.

[0007]

The structure of a small portable electronic device incorporating a conventional solar cell has the following disadvantages. For example, in the case of the card-type calculator shown in FIG. 2, if the area of the display unit is increased to make the display easier to read, the area of the solar cell unit becomes smaller, and sufficient power for operating the card-type calculator cannot be obtained. Similarly, if the area of the key input section is increased so that the input operation can be easily performed, the area of the solar cell section decreases, and sufficient power for operating the card-type calculator cannot be obtained.

[0008] Further, since there are large darkened solar cells on the surface panel, the design becomes rugged, the important design is poor, and the commercial value is significantly reduced. Such a problem applies to watches and other portable devices in addition to calculators.

In order to solve the above-mentioned problem, Japanese Patent Application Laid-Open No. 5-2964 is disclosed.
The method disclosed in 1 discloses coloring the surface of a solar cell by selective reflection of a cholesteric polymer so that the presence of the solar cell is not apparent from the outside, even though the solar cell is arranged on the front of the electronic device. Suggest a way.

However, as shown in FIG. 4, in the solar cells connected in series, the reflected light 25 from the transparent electrode and the reflected light 26 from the amorphous silicon have different spectral reflectances. Therefore, a difference occurs in the color tone and the amount of reflected light, so that a pattern of cells connected in series like the solar cell unit 13 in FIG. 2 can be seen. This pattern could not be completely erased even by the method disclosed in JP-A-5-29641. In addition to amorphous Si solar cells, single-crystal Si solar cells, polycrystalline Si solar cells, CdS / Cu ₂ S solar cells,
Similar problems also exist in CdS / CdTe solar cells, GaAs-based solar cells, and the like.

[0011] Another problem, which is a problem of space when a solar cell is arranged in front of an electronic device, is as follows.
There is a method disclosed in JP-A-60-147718.
However, even if the display element and the solar cell are stacked and the solar cell absorbs light and displays black, the problem of the cell pattern appearance cannot be solved. This appearance of the cell pattern reduced the display quality of the liquid crystal display panel.

As described above, in the conventional technology, it is difficult to obscure the cell pattern of the solar cell from the outside, even though the solar cell is disposed on the front of the electronic device. . Even if the LCD panel and solar cell are stacked and placed on the front of the electronic device to make effective use of space, the cell pattern of the solar cell can be seen on the LCD panel display, and display quality and effective use of space It was difficult to achieve both.

[0013]

In order to solve the above-mentioned problems, the present invention provides a function of transmitting a linearly polarized light component in a predetermined direction of incident light and reflecting a linearly polarized light component orthogonal to the predetermined direction. A circularly polarizing filter composed of a reflective polarizer having: and a retardation plate provided on a surface opposite to the surface on which light of the reflective polarizer is incident. The problem of cell pattern appearance was solved by a solar cell with a circular polarization filter installed on the light incident side of the cell.

Further, since a light diffusing layer is arranged on the surface of the reflective polarizer of a solar cell with a circularly polarizing filter comprising the above-mentioned reflective polarizer, retardation plate and solar cell on which light is incident, the surface of the solar cell A solar cell with a white appearance and no cell pattern appearance was realized.

Further, a liquid crystal display panel is laminated on the surface of the reflective polarizer, the retardation plate, and the solar cell with the circularly polarizing filter having the circular polarizer, on which light is incident, on the front side of the electronic device. In this way, the space on the front of the electronic device was effectively utilized, and the electronic device in which the cell pattern of the solar cell could not be seen on the liquid crystal display panel was realized.

Furthermore, a liquid crystal display panel is laminated on a light-incident surface side of the light diffusion layer of a solar cell with a circularly polarizing filter comprising the light diffusion layer, the reflective polarizer, the retardation plate and the solar cell. Therefore, it is possible to generate electricity using a solar cell even when using an STN cell or TN cell using a polarizing plate, or a GH cell using a dichroic dye. By effectively utilizing the technology, we realized an electronic device that does not show the cell pattern of the solar cell on the LCD panel.

Further, in an electronic device comprising the above-mentioned liquid crystal display panel and a solar cell with a circular polarization filter,
Since the touch panel is placed on the side of the liquid crystal display panel where light enters, the input key section is eliminated from the front of the electronic device, and the front of the electronic device can be composed of a liquid crystal display panel and a solar cell with a circular polarization filter. And the solar cell area can be expanded.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle of operation of a solar cell with a circularly polarized light filter having the above-described configuration in which a cell pattern does not appear will be described with reference to FIG.

In FIG. 5, the reflection polarizer 1 transmits the non-polarized incident light 5 only in a linear polarization component in a predetermined direction and reflects only a linear polarization component orthogonal to the predetermined direction, and has almost no absorption. Therefore, the incident light 5 is split into two parts, the reflected light 6 from the reflective polarizer and the transmitted light 27 from the reflective polarizer. The transmitted light 27 is incident on the phase difference plate 2 and is transmitted to change the polarization state. Here, if the phase difference amount of the phase difference plate 2 is set to ４λ, circular polarization is obtained. If the retardation plate is designed in consideration of wavelength dispersion, light in the visible light range can be converted into substantially circularly polarized light.

Light 7 incident on the solar cell in a circularly polarized state is absorbed by the solar cell and contributes to power generation. However, due to the difference in the constituent materials of the solar cell shown in FIG.
The light is reflected as reflected light 8 from the solar cell. There is no change in the polarization state due to reflection. The reflected light 8 from the solar cell passes through the retardation plate 2 again. At this time, the polarization state is changed from circularly polarized light to linearly polarized light, and the linearly polarized light 2 transmitted through the retardation plate is converted.
It becomes 8. The azimuth of the linearly polarized light is orthogonal to the azimuth of the linearly polarized light of the transmitted light 27 from the reflective polarizer. Therefore, the linearly polarized light 28 transmitted through the retardation plate is reflected by the reflective polarizer 1 and becomes light 9 reflected by the reflective polarizer. At this time, almost no light 10 passes through the reflective polarizer.

According to the above principle, the solar cell with the circularly polarizing filter allows the reflected light from the solar cell to pass through the reflective polarizer and return, so that the cell pattern appearance of the solar cell can be solved.

The reflected light 6 from the reflective polarizer of the solar cell with the circular polarization filter has a reflectivity of less than 50% and is a mirror surface. Although it is slightly darker than the reflectance of the aluminum mirror of 70 to 80%, it can withstand use as a mirror.

Further, in a solar cell with a circularly polarizing filter, if a light diffusing layer is arranged on the surface of the reflective polarizer on which light is incident, the reflected light 6 from the reflective polarizer is diffused by the light diffusing layer. Looks like. If the degree of diffusion of the diffusion layer is increased, the back scattering from the diffusion layer is increased and the amount of light transmitted through the reflective polarizer contributing to power generation is reduced. Therefore, it is desirable for the diffusion layer to reduce the back scattering.

Further, in a solar cell with a circularly polarizing filter, when a liquid crystal display panel is laminated on the surface of the reflective polarizer on which light enters, the reflective polarizer replaces the reflective plate or the reflective polarizer of the liquid crystal display panel. It functions as a reflective liquid crystal display panel using the reflected light 6. In this case, since the reflective polarizer is a mirror surface, available liquid crystal display modes are a scattering type liquid crystal mode, an STN mode using a forward scattering plate, a TN mode, and a GH mode.

Further, in the case where a liquid crystal display panel is laminated on the light incident surface side of the light diffusion layer of a solar cell with a circularly polarizing filter comprising a light diffusion layer, a reflective polarizer, a retardation plate and a solar cell. The light diffusion layer and the reflective polarizer function as a diffusive reflective polarizer. In this case, an STN cell or TN cell using one polarizing plate on the surface of the liquid crystal display panel on which light is incident, or a GH cell using a dichroic dye that does not require a polarizing plate can be used. By setting the display mode to negative display, more light passes through the reflective polarizer, so that the amount of power generated by the solar cell increases.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (Example 1) FIG. 1 is a sectional view showing a basic structure of a solar cell with a circularly polarizing filter. The reflective polarizer 1 and the retarder 2 are integrated with a transparent adhesive to form a circularly polarizing filter 3. The retardation plate 2 is disposed such that the optical axis thereof is approximately 45 ° with respect to the azimuth of the linearly polarized light transmitted through the reflective polarizer 1. The solar cell 4 was disposed behind the retardation plate 2 via an air layer or a transparent adhesive.

As a reflective polarizer, Sumitomo 3M Limited's DBEF (Dual Brightness E) is used.
nhancement Film). Nitto Denko Corporation's broadband wavelength film 1/4
A λ plate was used. As the solar cell, a 4-cell series-connected amorphous Si solar cell was used. As a reflective polarizer, D
In addition to BEF, a reflective polarizing plate combining a cholesteric polymer selective reflection film and a retardation film may be used. The retardation plate has 波長 λ that compensates for chromatic dispersion.
It is desirable to use a plate. Thereby, reflected light returning from the solar cell can be blocked in the entire visible region. Solar cells are not only amorphous Si solar cells, but also monocrystalline Si solar cells, polycrystalline Si solar cells, CdS / Cu ₂ S solar cells,
A CdS / CdTe solar cell, a GaAs solar cell, or the like may be used.

A solar cell with a circular polarization filter having the structure shown in FIG. 1 was used for a clock. FIG. 7 is an external view of a table clock with a mirror on which a solar cell with a circular polarization filter is mounted. The mirror surface 33 supported by the support base 34 is constituted by a solar cell with a circular polarization filter having the configuration shown in FIG. This mirror surface does not return the reflected light from the solar cell so that the presence of the solar cell behind cannot be confirmed, so that the face and figure can be seen like a normal hand mirror. In addition, the power required to drive the clock display unit 32 can be covered by the power generated by the solar cell in the background.
A secondary battery may be used if necessary. Further, a solar cell using a glass substrate can be used as a mirror without distortion by attaching a circularly polarizing filter to the glass substrate.

A solar cell with a circularly polarizing filter having the structure shown in FIG. 1 was used for a clock face. FIG. 6 is an external view of a timepiece on which a solar cell with a circular polarization filter is mounted. When a light diffusing layer is arranged on the surface of the reflective polarizer of a solar cell with a circularly polarizing filter that has been perforated to pass a shaft for driving the timepiece 31 through the timepiece case 30,
Because it is diffused by the diffusion layer, it looks white. This white dial completely obscures the presence of the solar cell behind, enabling a design similar to a watch without a solar cell. IDS-21 of Dai Nippon Printing Co., Ltd. is attached as the light diffusion layer. Coloring and printing are also possible as needed.

Embodiment 2 In this embodiment, an electronic device in which a solar cell with a circularly polarizing filter and a scattering type liquid crystal panel are laminated will be described with reference to FIG. A scattering type liquid crystal panel 35 is laminated on a solar cell with a circular polarization filter and used as a reflection type liquid crystal display device. A solar cell with a circularly polarizing filter was manufactured with the same configuration as in Example 1.

The scattering type liquid crystal panel is formed by forming an ITO film on two glass substrates and then patterning to form an alignment film.
The two substrates were bonded via an 8-micron spacer. A polymer network liquid crystal “PNM-156” manufactured by Roddick Co., Ltd. as a liquid crystal material was vacuum-injected into the empty panel while maintaining the empty cell at a temperature of 30 ° C. While maintaining this at a temperature of 25.5 ° C., a scattering type liquid crystal panel was produced by irradiating a metal halide lamp with ultraviolet rays of 75 mW / cm 2 for 20 seconds.

The scattering mode liquid crystal used is a cholesteric-nematic phase transition type liquid crystal mode, a ferroelectric liquid crystal scattering mode, a polymer dispersed liquid crystal mode, a dynamic scattering liquid crystal mode (DSM), a thermal writing mode, in addition to the polymer network liquid crystal. May be used. Further, in combination with an active element such as MIM or TFT, a polymer dispersed liquid crystal mode, a dynamic scattering liquid crystal mode (DSM), a thermal writing mode, or the like may be used.

Next, the back surface of the scattering type liquid crystal panel 35 and the surface on the reflective polarizer side of the circularly polarizing filter were brought into close contact with each other via a transparent adhesive. On the other hand, the solar cell 4 was disposed on the back surface of the retardation plate 2 of the circularly polarizing filter via an air layer. An amorphous Si solar cell was used as the solar cell. The solar cell was operated under a fluorescent lamp of 200 lx under an operating voltage of 1.5 V.
And an output of 3 μA / cm ² is obtained. Amorphous Si
In addition to solar cells, single-crystal Si solar cells, polycrystalline Si solar cells, CdS / Cu ₂ S solar cells, CdS / CdTe
A solar cell, a GaAs-based solar cell, or the like may be used.

In a state where the solar cell with the circularly polarizing filter manufactured in this way and the scattering type liquid crystal panel are laminated, 20
Observation was performed under illumination conditions of 0 lx fluorescent light. Then, in a region where the drive voltage was not sufficiently applied, the incident white light was scattered and observed as bright white. In the region where the drive voltage was sufficiently applied, the incident white light was absorbed by the solar cell and appeared black. Also, the solar cell pattern was not seen at all.

The power generation capacity of the solar cell was verified under the same conditions. 1.1μ at operating voltage 1.5V when OFF
An output of A / cm ² was obtained. At the time of ON, an output of 1.2 μA / cm ² was obtained at an operating voltage of 1.5 V.

Next, as an electronic device, a solar cell with a circularly polarizing filter of the present invention and a scattering type liquid crystal panel were mounted on a digital timepiece in a laminated state. The area of the display section has been increased, and the display has become easier to see. In addition, the lack of darkened solar cells from the front panel eliminated the clunkiness in design. The truly paper-white, bright white background and the black display gave the digital watch an elegance, with no visible solar cell pattern.

(Embodiment 3) In this embodiment, an electronic apparatus in which a solar cell with a circularly polarizing filter and an STN type liquid crystal panel are stacked will be described with reference to FIG. A light diffusion layer 29 is disposed on a solar cell with a circular polarization filter, and an STN cell 38 is further disposed thereon, and a retardation film 37 is further disposed thereon.
Is further laminated thereon with an upper polarizing plate 36 to be used as a reflection type liquid crystal display device. A solar cell with a circularly polarizing filter was manufactured with the same configuration as in Example 1.

The STN type cell is composed of two glass substrates with an IT
After forming an O film, patterning was performed by patterning to form an alignment film. After the alignment treatment, the two substrates were bonded together with a 6.2-micron spacer. An STN liquid crystal material was vacuum-injected into this empty cell.

As a liquid crystal mode to be used, a TN liquid crystal mode or a ferroelectric liquid crystal mode may be used in addition to the STN liquid crystal. Further, it may be used in combination with an active element such as MIM or TFT.

Next, the upper polarizing plate 36, the retardation film 3
7. The STN cell 38 and the reflective polarizer of the circularly polarizing filter were adhered via a transparent adhesive. However, the angles were adjusted so that the display became normally black, and they were brought into close contact with each other.
In the light diffusion layer 29, diffusion particles are mixed in a transparent adhesive material to reduce backscatter as much as possible. The solar cell 4 was arranged on the back surface of the retardation plate 2 of the circularly polarizing filter via an air layer. An amorphous Si solar cell was used as the solar cell. This solar cell is under 200lx fluorescent lighting,
An output of 3 μA / cm ² is obtained at an operating voltage of 1.5 V.
In addition to amorphous Si solar cells, single-crystal Si solar cells, polycrystalline Si solar cells, CdS / Cu ₂ S solar cells,
A CdS / CdTe solar cell, a GaAs solar cell, or the like may be used.

In a state where the solar cell with the circularly polarizing filter manufactured as described above and the STN type liquid crystal panel are laminated,
Observation was performed under the conditions of 200 lx fluorescent lamp illumination. Then, in the region where the selection voltage was applied, the incident white light was scattered and observed white. In the region where the non-selection voltage was applied, the incident white light was absorbed by the solar cell and appeared black. Also, the solar cell pattern was not seen at all.

Under the same conditions, the power generation capacity of the solar cell was verified. 0.8μ at operating voltage 1.5V when OFF
An output of A / cm ² was obtained. No output was obtained when the entire surface was ON. However, in normal display,
The entire power is not turned on, and the power generation amount fluctuates depending on the area ratio of the ON display.

Next, as an electronic device, a solar cell with a circularly polarizing filter of the present invention and an STN type liquid crystal panel were mounted on a digital timepiece in a laminated state. Since the area of the display section is large, the display is easy to see. In addition, the lack of darkened solar cells from the front panel eliminated the clunkiness in design. The white display on a black background without any visible solar cell pattern gave the digital watch an elegance.

(Embodiment 4) In this embodiment, an electronic apparatus in which a solar cell with a circularly polarizing filter and a GH type liquid crystal panel are stacked will be described with reference to FIG. A light diffusion layer 29 is disposed on a solar cell with a circularly polarizing filter, and a GH type liquid crystal panel 38 is further laminated thereon to be used as a reflection type liquid crystal display device. A solar cell with a circularly polarizing filter was manufactured with the same configuration as in Example 1.

The GH type liquid crystal panel is formed by forming an ITO film on two glass substrates, forming an alignment film by anti-para alignment treatment, and then bonding the two substrates together with a 6.2-micron spacer. Matched. In this empty cell, low-viscosity EN-31G (Chisso Corporation) was used as a host liquid crystal, and S-manufactured by Mitsui Toatsu Dye Co., Ltd. was used as a guest dye.
-344 (black) was mixed and vacuum injected. The guest may be mixed with the N-type liquid crystal.

The guest-host mode liquid crystal used is HM
In addition to the type guest host liquid crystal, a ferroelectric liquid crystal guest host mode, a polymer dispersed liquid crystal guest host mode, and a phase transition guest host mode may be used. Also, MIM and TF
It can be combined with an active element such as T.

Next, the GH type liquid crystal panel 39 and the reflective polarizer of the circularly polarizing filter were adhered through a transparent adhesive. However, the angles were adjusted so that the orientation direction of the GH-type liquid crystal panel 39 and the transmission linear polarization direction of the reflective polarizer were orthogonal to each other, and were adhered. In the light diffusion layer 29, diffusion particles are mixed in a transparent adhesive material to reduce backscatter as much as possible. Solar cell 4
Was disposed on the back surface of the retardation plate 2 of the circularly polarizing filter via an air layer. An amorphous Si solar cell was used as the solar cell. This solar cell can obtain an output of 3 μA / cm ² at an operating voltage of 1.5 V under illumination of a fluorescent lamp of 200 lx. In addition to amorphous Si solar cells, single crystal S
i solar cells, polycrystalline Si solar cells, CdS / Cu ₂ S solar cells, CdS / CdTe solar cells, GaAs solar cells, and the like may be used.

In the state where the solar cell with the circularly polarizing filter and the GH type liquid crystal panel manufactured in this manner are laminated, 2
The observation was performed under the condition of 00lx fluorescent lamp illumination. Then, in the region where the non-selection voltage was applied, a part of the incident white light was absorbed by the dye and the rest was absorbed by the solar cell and observed in black. In the area where the selection voltage is applied, about half of the incident white light is reflected and looks white. The other half is absorbed by solar cells and contributes to power generation. Also, the solar cell pattern was not seen at all.

The power generation capacity of the solar cell was verified under the same conditions. 0.9μ at 1.5V operating voltage when OFF
An output of A / cm ² was obtained. Further, when the entire surface was turned on, an output of 1.1 μA / cm ² was obtained at an operating voltage of 1.5 V. This is because the orientation direction of the GH type liquid crystal panel 39 and the transmission linear polarization direction of the reflective polarizer are arranged to be orthogonal.

Next, an electronic device was mounted on a digital watch in a state in which the solar cell with the circularly polarizing filter of the present invention and a GH type liquid crystal panel were laminated. The area of the display section has been increased, and the display has become easier to see. In addition, the lack of darkened solar cells from the front panel eliminated the clunkiness in design. There is no visible solar cell pattern.

(Embodiment 5) In this embodiment, an electronic device in which a solar cell with a circularly polarizing filter, an STN type liquid crystal panel, and a touch panel are further laminated thereon will be described with reference to FIG. Example 3 A reflective liquid crystal display device in which a solar cell with a circularly polarizing filter and an STN type liquid crystal panel were stacked was described in Example 3.
It was produced in the same way as. Further, a touch panel was superimposed on the touch panel, and the touch panel 40 was mounted so as to be in front of the mobile phone.

As a touch panel, a switch is displayed on an STN-type liquid crystal panel as shown in FIG. 11 using a resistive film system, and the switch and the display are integrated by changing the switch layout of the touch panel accordingly. did. As a result, a normal push-button switch can be removed from the front of the mobile phone, and a reflection type liquid crystal display device in which a solar cell with a circular polarization filter and an STN type liquid crystal panel are stacked on the entire front surface can be arranged.

As a result, it is possible to arrange a large and easy-to-see display section and a large-area solar cell on the front of a limited portable telephone. Further, as the touch panel, other than the resistive film type, other types may be used as long as transparency can be ensured.
Further, the liquid crystal panel may use a scattering type liquid crystal or a GH type liquid crystal.

[0054]

As described above, according to the present invention, a circularly polarizing filter composed of a reflective polarizer having no absorption and a retardation plate is arranged on the front surface of a solar cell, and thus a solar cell which could not be solved conventionally. I did not mind the appearance of the pattern at all. In addition, the appearance becomes white when it functions as a mirror or when a diffusion layer is provided on the front surface of the reflective polarizer, and it is possible to provide a highly designed solar cell that renews the appearance of a conventional solar cell. .

Further, according to the present invention, a liquid crystal display panel is arranged on a front surface of a solar cell with a circularly polarizing filter composed of a reflective polarizer having no absorption and a retardation plate, and the power generation efficiency is maintained at a practical level. We solved the appearance of the pattern of the solar cell in the appearance of the liquid crystal display panel. Furthermore, since a reflective polarizer having no absorption is used, integration by lamination of an LCD and a solar cell, which cannot be realized by a method using a TN or STN mode polarizing plate, is realized.

As described above, the solar cell with the circularly polarizing filter of the present invention maintains a high photovoltaic power which could not be realized by the conventional method, has no visible solar cell pattern, and has a mirror surface excellent in aesthetic potential. And has white display ability. Therefore, when used as a watch, a display for other portable electronic devices, or a decorative article, it is effective in differentiating the design, the operability, and the display ability of the front of the electronic device, which have not existed before.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a basic configuration of the present invention.

FIG. 2 is an external view of an example of a card-type calculator incorporating a conventional solar cell.

FIG. 3 is a schematic diagram of a configuration of a conventional solar cell.

FIG. 4 is a structural sectional view of a conventional solar cell connected in series.

FIG. 5 is a diagram illustrating the principle of the present invention.

FIG. 6 is an external view of a timepiece on which a solar cell with a circular polarization filter of the present invention is mounted.

FIG. 7 is an external view of a table clock with a mirror on which the solar cell with a circularly polarizing filter of the present invention is mounted.

FIG. 8 is a configuration diagram of an electronic device in which a solar cell with a circular polarization filter of the present invention and a scattering type liquid crystal panel are stacked.

FIG. 9 shows a solar cell with a circularly polarizing filter of the present invention and ST.
It is a block diagram of the electronic device laminated N liquid crystal panels.

FIG. 10 shows a solar cell with a circularly polarizing filter of the present invention and G
It is a block diagram of the electronic device by which the H-type liquid crystal panel was laminated.

FIG. 11 is an external view of a mobile phone as an example of an electronic device in which a solar cell with a circularly polarizing filter, a liquid crystal display panel, and a touch panel are stacked.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 reflective polarizer 2 retarder 3 circular polarization filter 4 solar cell 5 incident light 6 reflected light from reflective polarizer 7 incident light to solar cell 8 reflected light from solar cell 9 reflected light from solar cell is reflected polarized light Light reflected by the element 10 Light transmitted from the solar cell through the reflective polarizer 11 Case 12 Input key section 13 Solar cell section 14 Reflective LCD 15 Glass substrate 27 Linear polarized light transmitted through the reflective polarizer 28 Phase difference Linear polarized light passing through the plate 29 Light diffusion layer 30 Watch case 31 Hand 35 Scattering type liquid crystal panel

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shigeru Senbonmatsu 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba Inside Seiko Instruments Inc. (72) Inventor Shunichi Monobukuro 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba Inside Seiko Instruments Inc. (72) Inventor Takakazu Fukuchi 1-8-1, Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside Seiko Instruments Inc. (72) Hiroshi Sakuma 1-8-1, Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside Iko Instruments Co., Ltd. (72) Inventor Osamu Yamazaki 1-8-1, Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside 72 Co., Ltd. Masafumi Hoshino 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Prefecture Seiko Instruments Inc. (72) Inventor Naoto 1-8-8 Nakase, Mihama-ku, Chiba-shi, Seiko Instruments Inc. (72) Inventor Shuhei Yamamoto 1-8-8 Nakase, Mihama-ku, Chiba-shi, Chiba SII IRD Center (72) Invention Person Masanori Fujita 1-1-1 Akanehama, Narashino-shi, Chiba Seiko Precision Co., Ltd.

Claims (5)

[Claims] 1. A reflection polarizer having a function of transmitting a linear polarization component in a predetermined direction of incident light and reflecting a linear polarization component orthogonal to the predetermined direction, and light from the reflection polarizer is incident. With a circularly polarizing filter composed of a retardation plate provided on the surface opposite to the surface,
A solar cell, wherein the phase difference plate side of the circularly polarizing filter is set to be on the light incident surface side of the solar cell. 2. The solar cell according to claim 1, wherein a light diffusion layer is disposed on a surface of the reflection polarizer where light is incident. 3. A reflective polarizer having a function of transmitting a linearly polarized light component in a predetermined direction of incident light and reflecting a linearly polarized light component orthogonal to the predetermined direction, and light from the reflective polarizer is incident. With a circularly polarizing filter composed of a retardation plate provided on the surface opposite to the surface,
A solar cell installed such that the phase difference plate side of the circularly polarizing filter is on the light incident surface side of the solar cell, and a display element arranged on the surface of the reflective polarizer where light is incident. Electronic equipment characterized. 4. The solar cell has a light diffusion layer on a surface of the reflective polarizer on which light enters, and the display element is disposed on a surface of the light diffusion layer on which light enters. The electronic device according to claim 3, wherein 5. The touch panel according to claim 3, wherein a touch panel is arranged on a surface of the display element on which light is incident.
An electronic device according to claim 1.