Indication device

Abstract

The present invention provides a display device that is aesthetically pleasing, easy to carry, does not reduce the power generation efficiency of solar panels, and can prevent premature battery depletion. [Solution] A display device 1 according to one embodiment comprises a solar cell SC having a light-receiving surface SC1 that receives sunlight L1, a printed material 2 disposed on the light-receiving surface SC1 side of the solar cell SC and having a light-transmitting substrate and a pattern printing layer that transmits light, a display unit 50 that displays information by irradiating the printed material 2 with light L2 from the opposite direction to sunlight L1, and a housing B that holds the solar cell SC, the printed material 2 and the display unit 50.

Description

Technical Field

[0001] This disclosure relates to a display device.

Background Art

[0002] Patent Document 1 describes a signboard device using a solar panel as a power supply source. The signboard device includes a solar panel, a signboard main body, a frame member, and a storage battery. The signboard main body has a space for an arbitrary advertisement and digital signage. The frame member is box-shaped, and a charge / discharge control device is housed in the frame member.

[0003] Patent Document 2 describes an artificial tree equipped with an information device using solar power generation. This artificial tree includes a plurality of solar cells arranged on the trunk and branches of the artificial tree, a lighting fixture arranged on the trunk of the artificial tree, and a transmission device and a storage battery arranged below the lighting fixture. The transmission device transmits and displays information. The electric power obtained by the solar cells through power generation is supplied to the transmission device during the day and stored in the storage battery. At night, the electric power stored in the storage battery is supplied to the transmission device and the lighting device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in a display device that stores electricity generated by solar power in a battery and uses the stored electricity to display information, the exposed solar power generation panel presents design problems. Also, improving the visibility of the display consumes a lot of power, which can lead to the battery running out quickly. In the signage devices and artificial trees described in Patent Documents 1 and 2, the solar panel or solar cell is provided separately from the display device, which makes them difficult to carry. Furthermore, when used in small display devices such as information terminals or process control terminals, the limited area of ​​the solar panel leads to the problem of the battery running out quickly. Increasing the area of ​​the solar panel would solve the problem, but this would make them difficult to carry.

[0006] The purpose of this disclosure is to provide a display device that is aesthetically pleasing, easy to carry, does not reduce the power generation efficiency of solar panels, and can suppress the premature depletion of the battery. [Means for solving the problem]

[0007] (1) The display device according to this disclosure comprises a solar cell having a light-receiving surface that receives sunlight, a printed material disposed on the light-receiving surface side of the solar cell and having a light-transmitting substrate and a pattern printing layer that transmits light, a display unit that displays information by irradiating the printed material with light from the opposite direction to sunlight, and a housing that holds the solar cell, the printed material and the display unit.

[0008] This display device comprises a printed material having a translucent substrate and a patterned printing layer, with the printed material positioned on the light-receiving side of the solar cell. Because the printed material transmits light, the solar cell can receive the light that has passed through the printed material. Therefore, by generating electricity when the solar cell receives sunlight, sufficient power can be stored in the battery, thus preventing premature battery depletion. Furthermore, because the printed material has a patterned printing layer, the pattern on the printed layer is visible, resulting in a good aesthetic appearance. The solar cell, printed material, and display unit are held within a housing. Therefore, by integrating the solar cell, printed material, and display unit into the housing, the display device can have a good appearance and be easily portable.

[0009] (2) In (1) above, the pattern printing layer described above may have a first-color pattern layer composed of a plurality of first-color dots and a second-color pattern layer provided on the first-color pattern layer and composed of a plurality of second-color dots. Each of the plurality of first-color dots may include a first-color binder and a plurality of first-color pigment chips dispersed inside the first-color binder. Each of the plurality of second-color dots may include a second-color binder and a plurality of second-color pigment chips dispersed inside the second-color binder. One of the plurality of first-color pigment chips and the plurality of second-color pigment chips may be a plurality of first interference pigments of different colors that each generate different first interference light. The other of the plurality of first-color pigment chips and the plurality of second-color pigment chips may be a second interference pigment that generates a single-color second interference light different from the color mixing shown by the plurality of first interference pigments. The plurality of first interference light and the second interference light may be additively mixed. In this case, since either the first-color pattern layer or the second-color pattern layer contains multiple interference pigments that generate different interference light from each other, a three-dimensional effect can be achieved even with a small number of printing layers. Furthermore, in this printed material, since only one of the first-color pattern layer or the second-color pattern layer needs to contain the interference pigments that generate multiple interference light, the color matching and registration work during printing can be simplified. Therefore, this printed material can express a three-dimensional effect even with a small number of printing layers, and the color matching and registration work during printing can be simplified. In addition, while obtaining these effects, the printed material has transmittance to sunlight into the solar cells, thus suppressing a decrease in the power generation efficiency of the solar cell module.

[0010] (3) In (2) above, the pattern printing layer may further include a white pattern layer provided on the second color pattern layer and composed of a plurality of silver dots. Each of the plurality of silver dots may contain a silver binder and a plurality of silver pigment chips dispersed inside the silver binder. In this case, the color development of the first color pattern layer and the second color pattern layer is excellent, and the pattern printing layer can have a pattern that gives a whitish impression.

[0011] (4) In any of (1) to (3) above, the printed material may further include a transparent smoke printing layer provided on the outermost surface opposite to the translucent substrate relative to the pattern printing layer. In this case, the color development of the first color pattern layer and the second color pattern layer is improved. Furthermore, because the transparent smoke printing layer is transparent, the decrease in the power generation efficiency of the solar cell module is well suppressed.

[0012] (5) In any of (2) to (4) above, the first interference pigment and the second interference pigment may each contain titanium dioxide-coated mica having a particle size of 25 μm or more and 60 μm or less. When titanium dioxide-coated mica with a particle size of 25 μm or more is included, the transparency and color development of the print layer can be improved. When titanium dioxide-coated mica with a particle size of 60 μm or less is included, a decrease in the resolution and gradation of the print layer can be suppressed.

[0013] (6) In any of (2) to (5) above, the content of the multiple first-color pigment chips may be within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the first-color binder is 100 parts by weight. The content of the multiple second-color pigment chips may be within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the second-color binder is 100 parts by weight. When the content of the multiple first-color pigment chips is within the range of 0.5 parts by weight or more, the pattern of the first-color pattern layer is well expressed. When the content of the multiple first-color pigment chips is within the range of 20 parts by weight or less, a decrease in the film-forming properties and transparency of the first-color pattern layer can be suppressed. Similarly, when the content of the multiple second-color pigment chips is within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the second-color binder is 100 parts by weight, the pattern of the second-color pattern layer can be well expressed while a decrease in the film-forming properties and transparency of the second-color pattern layer can be suppressed.

[0014] (7) In any of (1) to (6) above, the display unit may have a display pixel unit and a backlight located on the opposite side from the printed material when viewed from the display pixel unit. At least one of the display pixel unit and the backlight may have a function to reflect sunlight, and the display pixel unit may have a function to transmit light from the backlight. In this case, it is not necessary to increase the brightness of the display unit when using the display device outdoors, and power consumption can be reduced. Furthermore, since the image of the printed material can be seen by sunlight, outdoor visibility can be improved.

[0015] (8) In the above (7), the display pixel portion may have a transmissive portion that transmits sunlight and a reflective portion which is a reflective metal layer that reflects sunlight.

[0016] (9) In (7) or (8) above, the display pixel portion may have a reflective polarizing plate located in the portion facing the backlight, and a diffusion layer located on the opposite side from the backlight when viewed from the reflective polarizing plate. The backlight may have a white LED in which a blue LED is combined with green and red phosphors.

[0017] (10) In any of (7) to (9) above, the display pixel may have the following color filter: The color characteristics of the light transmitted through the color filter may be such that the average Y value of white of RGB is 33 or more, and the Y values ​​of each RGB satisfy RY value ≥ 21, GY value ≥ 58, and BY value ≥ 15, and the x of whiteness(x,y) is 0.290 to 0.320, and the y of whiteness(x,y) is x - 0.010 ≤ y ≤ x + 0.030. In this case, the transmittance and reflectance of light in the display pixel can be increased, power consumption can be further reduced, and visibility outdoors can be improved. [Effects of the Invention]

[0018] According to this disclosure, it is possible to improve the design, make it easy to carry, and prevent the solar panel from reducing its power generation efficiency while suppressing the occurrence of premature battery depletion. [Brief explanation of the drawing]

[0019] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a part of a display device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a printed matter of the display device of FIG. 1. [Figure 3] FIG. 3 is a cross-sectional view schematically showing a pattern printing layer of the printed matter of FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view schematically showing a printed matter of a display device according to a first modification. [Figure 5] FIG. 5 is a cross-sectional view schematically showing a white pattern layer of the printed matter of FIG. 4. [Figure 6] FIG. 6 is a cross-sectional view schematically showing a printed matter of a display device according to a second modification. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a printed matter of a display device according to a third modification. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a display portion of a display device according to an embodiment. [Figure 9] FIG. 9 is a cross-sectional view schematically showing a display portion different from that of FIG. 8. [Figure 10] FIG. 10 is a graph showing the relationship between the wavelength of light and the relative spectral luminance in a backlight. [Figure 11] FIG. 11 is a graph showing the relationship between the wavelength of light and the relative spectral luminance in a color filter. [Figure 12] FIG. 12 is a chart showing the color characteristics of a color filter. [Figure 13] (a) of FIG. 13 is a diagram schematically showing a display device according to an embodiment. (b) of FIG. 13 is a diagram schematically showing the positional relationship among the printed matter, the display portion, and the solar cell of the display device according to the embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0020] Specific examples of the display device according to the embodiment will be described below with reference to the drawings. However, the present invention is not limited to these examples, and is intended to include all modifications within the meaning and scope of the claims, as indicated by the claims. In the description of the drawings, identical or corresponding elements are denoted by the same reference numerals, and redundant descriptions are omitted. For the sake of clarity, some parts of the drawings may be simplified or exaggerated, and dimensional ratios, etc., are not limited to those shown in the drawings.

[0021] Figures 13(a) and 13(b) are schematic diagrams showing a display device 1 according to an embodiment. As shown in Figure 13, the display device 1 includes a printed material 2, a solar cell SC, a display unit 50, and a housing B. The solar cell SC has a light-receiving surface SC1 that receives sunlight. The printed material 2 is placed on the side of the light-receiving surface SC1 of the solar cell SC.

[0022] The housing B holds the solar cell SC, the printed material 2, and the display unit 50. The display unit 50 displays information by irradiating the printed material 2 with light L2 from the opposite direction to sunlight L1. The display unit 50 is, for example, a display. The printed material 2 covers at least a portion of the solar cell SC and the display unit 50. For example, the printed material 2 covers the solar cell SC and the display unit 50. However, the printed material 2 may cover only a portion of the solar cell SC and the display unit 50, and the extent to which the printed material 2 covers the solar cell SC and the display unit 50 can be changed as appropriate. The display device 1 includes, for example, a battery R. The battery R is housed inside the housing B. The battery R stores the electricity generated by the solar cell SC. The display unit 50 operates using the electricity stored in the battery R.

[0023] Figure 1 is a schematic diagram showing a cross-section of a part of the display device 1. As shown in Figure 1, a thin plate-shaped solar cell SC may be placed on the back material 100 with its light-receiving surface SC1 facing upward and embedded in the sealing material layer 111. A surface plate 112 may be laminated on the light-receiving surface SC1 side of the solar cell SC for the purpose of protecting the solar cell SC. A printed material 2 may be laminated on the surface plate 112 for the purpose of coloring the display device 1. A hard coat layer (also called a clear layer) 116 is laminated on top of the printed material 2.

[0024] The solar cell SC may be a photoelectric conversion element that generates electricity by absorbing light of wavelengths mainly in the visible light region, formed in the form of a thin plate with a thickness of about 0.2 mm, such as crystalline or amorphous silicon, thin-film silicon, perovskite, chalcopyrite, III-V group silicon, CdTe, or CIS. The encapsulating layer 111 may be made of a transparent material such as ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), polyolefin resin, ionomer resin, or silicon resin, surrounding the solar cell SC as shown in the figure, and formed in a layer with a thickness of about 1 mm.

[0025] The backing material 100 may be made of PET (polyethylene terephthalate), polycarbonate resin, acrylic resin, glass, or metal (such as aluminum) formed in layers, film, or plate form. The surface plate 112 may be a plate-shaped member formed to a thickness of about 3 mm from a transparent material such as polycarbonate resin, acrylic resin, or glass. The surface plate 112 and the sealing material layer 111, and the backing material 100 and the sealing material layer 111 may be bonded together by the adhesive strength of the sealing material layer 111.

[0026] The hard coat layer 116 may be laminated for the purpose of protecting the decorative layer, and may be similar to those applied to painted surfaces of vehicles, for example. The thickness of the hard coat layer 116 may be 5 to 50 μm, preferably 10 to 40 μm, and more preferably 15 to 30 μm. As the material for the hard coat layer 116, an active energy ray curable coating composition that hardens with ultraviolet irradiation or electron beams, or a thermosetting coating composition may be used.

[0027] The printed material 2 has a translucent substrate 4 and a pattern printing layer 5, and transmits light (e.g., sunlight L1 and light L2). As shown in Figure 2, the printed material 2 is a sheet for displaying a pattern, and comprises a translucent substrate 4, a pattern printing layer 5, and a translucent smoke printing layer 30.

[0028] The translucent substrate 4 is a substrate that transmits visible light. The translucent substrate 4 is, for example, made of a transparent resin. Examples of transparent resins include PET, PMMA, polyethylene, polypropylene, nylon, or fluorine. The translucent substrate 4 may also be a glass substrate. The thickness of the translucent substrate 4 is, for example, 25 μm to 250 μm. In the case of a glass substrate, the thickness of the translucent substrate 4 is, for example, several mm to 10 mm. If necessary, a surface protective layer may be provided on the surface side of the translucent substrate 4 (opposite the pattern printing layer 5).

[0029] The pattern printing layer 5 is a layer that expresses the pattern of the printed material 2. The pattern printing layer 5 comprises a first color pattern layer 10 provided on one surface 4a of the translucent substrate 4, and a second color pattern layer 20 provided on the first color pattern layer 10.

[0030] The first color pattern layer 10 is provided on surface 4a by, for example, screen printing, inkjet printing, gravure printing, or offset printing. The first color pattern layer 10 is composed of a plurality of first color dots 11, as shown in Figure 3. A "dot" is a point that constitutes an element of the printed image, and its shape is not limited to a circle, but may be rectangular, polygonal, or other shapes. Each of the plurality of first color dots 11 contains a first color binder 12 and a plurality of first color pigment chips 13 dispersed inside the first color binder 12. The content of the plurality of first color pigment chips 13 is, for example, in the range of 0.5 parts by weight or more and 20 parts by weight or less, when the first color binder 12 is 100 parts by weight.

[0031] Examples of the first color binder 12 include vinyl resins, acrylic resins, thermoplastic urethane resins, polyester resins, polycarbonate resins, or fluororesins. The thickness of the first color pattern layer 10 is, for example, 1 μm to 10 μm. The first color pattern layer 10 may contain a curing agent. In this case, the heat resistance of the first color pattern layer 10 and the adhesion of the first color pattern layer 10 to the translucent substrate 4 can be improved.

[0032] In this embodiment, the multiple first color pigment chips 13 are multiple first interference pigments 14a, 14b of different colors that generate interference light from each other. Each of the first interference pigments 14a, 14b consists of a thin film (not shown) that transmits visible light and a metal oxide film (not shown) that covers the thin film. The light incident from the translucent substrate 4 to the first color pattern layer 10 that is reflected at the surface of the metal oxide film and the light that passes through the metal oxide film and is reflected at the surface of the thin film interfere with each other, generating interference light. By adjusting the thickness of the metal oxide film and the refractive index of the metal oxide film, interference light with a desired wavelength can be generated.

[0033] In this embodiment, each of the first interference pigments 14a and 14b is titanium dioxide-coated mica. The particle size range of the titanium dioxide-coated mica includes, for example, a range of 25 μm to 60 μm. Here, "particle size" refers to the longest diameter of the particle cross-section. The flakes constituting the first interference pigments 14a and 14b may be other than mica, for example, silica, alumina, glass, or polysilicate. The metal oxide film constituting the first interference pigments 14a and 14b may be other than titanium dioxide, for example, zirconium oxide, zinc oxide, iron oxide, or tin oxide.

[0034] When incident light E is incident on the first color pattern layer 10, each of the first interference pigments 14a and 14b generates two distinct first interference rays 15a and 15b. That is, the wavelengths of the first interference rays 15a and 15b are different from each other. As a result, the first interference pigments 14a and 14b exhibit color mixing. The first interference pigments 14a and 14b are, for example, a red interference pigment (red pearl pigment) and a gold interference pigment (gold pearl pigment). In this case, the first interference rays 15a and 15b each exhibit red and gold colors, respectively. The proportions of the first interference pigments 14a and 14b may be the same or different from each other.

[0035] The second color pattern layer 20 is provided on the first color pattern layer 10 by, for example, screen printing, inkjet printing, gravure printing, or offset printing. The second color pattern layer 20 is composed of a plurality of second color dots 21. Each of the plurality of second color dots 21 contains a second color binder 22 and a plurality of second color pigment chips 23 dispersed inside the second color binder 22. The content of the plurality of second color pigment chips 23 is, for example, in the range of 0.5 parts by weight or more and 20 parts by weight or less, when the amount of second color binder 22 is 100 parts by weight.

[0036] Examples of the second color binder 22 include vinyl resins, acrylic resins, thermoplastic urethane resins, polyester resins, polycarbonate resins, or fluororesins. The thickness of the second color pattern layer 20 is, for example, 1 μm to 10 μm. The second color pattern layer 20 may contain a curing agent. In this case, the heat resistance of the second color pattern layer 20 and the adhesion of the second color pattern layer 20 to the first color pattern layer 10 can be improved.

[0037] In this embodiment, the multiple second-color pigment chips 23 are second interference pigments 24 that generate monochromatic interference light different from the color mixing shown by the first interference pigments 14a and 14b. The second interference pigment 24 is composed of a thin flake (not shown) that is transparent to visible light and a metal oxide film (not shown) that covers the flake. The light incident from the translucent substrate 4 to the second-color pattern layer 20 that is reflected at the surface of the metal oxide film and the light that passes through the metal oxide film and is reflected at the surface of the flake interfere with each other, generating interference light. By adjusting the thickness of the metal oxide film and the refractive index of the metal oxide film, interference light with a desired wavelength can be generated.

[0038] In the first embodiment, the second interference pigment 24 is titanium dioxide-coated mica. The particle size range of the titanium dioxide-coated mica includes, for example, a range of 25 μm or more and 60 μm or less. "Particle size" means the longest diameter of the particle cross-section. The flakes constituting the second interference pigment 24 may be other than mica, for example, silica, alumina, glass, or polysilicate. The metal oxide film constituting the second interference pigment 24 may be other than titanium dioxide, for example, zirconium oxide, zinc oxide, iron oxide, or tin oxide.

[0039] When incident light E enters the second color pattern layer 20 from the second interference pigment 24, a monochromatic second interference light 25 is generated. As a result, the second interference pigment 24 exhibits a monochromatic appearance. The second interference pigment 24 can be any interference pigment that generates a monochromatic second interference light 25 that is different from the color mixture shown by the first interference pigments 14a and 14b, for example, a green interference pigment (green pearl pigment). In this case, the second interference light 25 will appear green.

[0040] The transparent smoke printing layer 30 has the function of attenuating light coming from the viewpoint side that penetrates the printed material 2. The transparent smoke printing layer 30 is provided on the outermost surface opposite to the translucent substrate 4 relative to the pattern printing layer 5. In this embodiment, the transparent smoke printing layer 30 is provided on the second color pattern layer 20 as shown in Figure 2. The transparent smoke printing layer 30 is provided on the second color pattern layer 20 by, for example, screen printing, inkjet printing, gravure printing, or offset printing, using an ink in which a small amount of carbon black is dispersed in a resin binder such as vinyl, acrylic, urethane, or polyester. The thickness of the transparent smoke printing layer 30 is, for example, 1 μm to 10 μm.

[0041] In printed material 2, the image is represented by additive color mixing of the first interference light 15a and 15b generated by the first interference pigments 14a and 14b, and the second interference light 25 generated by the second interference pigment 24.

[0042] The total light transmittance of printed material 2 is, for example, 30% to 90%. In particular, to suppress the decrease in the power generation efficiency of the solar cell SC of the display device 1, the total light transmittance of printed material 2 may be 50% or more. Total light transmittance refers to the value measured using a spectrophotometer (for example, a spectrophotometer UV-3600 manufactured by Shimadzu Corporation).

[0043] As described above, in the printed material 2 according to this embodiment, the first color pattern layer 10 contains first interference pigments 14a and 14b, and the second color pattern layer 20 contains a second interference pigment 24, so that a three-dimensional image can be expressed even with a small number of printing layers. Furthermore, in printed material 2, only the first color pattern layer 10 contains interference pigments that generate different interference light from each other, among the first color pattern layer 10 and the second color pattern layer 20, so that the color matching and registration work during printing can be simplified. Therefore, printed material 2 can express a three-dimensional image even with a small number of printing layers, and the color matching and registration work during printing can be simplified. While obtaining these effects, printed material 2 has transmittance to sunlight for solar cells SC, so that the decrease in the power generation efficiency of solar cells SC can be suppressed.

[0044] In this embodiment, the printed material 2 includes a transparent smoke printing layer 30 provided on the second color pattern layer 20. This improves the color development between the first color pattern layer 10 and the second color pattern layer 20. Furthermore, because the transparent smoke printing layer 30 is transparent, the decrease in the power generation efficiency of the solar cell SC is effectively suppressed.

[0045] In this embodiment, each of the first interference pigments 14a, 14b and the second interference pigment 24 contains titanium dioxide-coated mica with a particle size of 25 μm or more and 60 μm or less. When titanium dioxide-coated mica with a particle size of 25 μm or more is included, the transparency and color development of the pattern printing layer 5 can be improved. When titanium dioxide-coated mica with a particle size of 60 μm or less is included, a decrease in the resolution and gradation of the pattern printing layer 5 can be suppressed.

[0046] In this embodiment, the content of the multiple first-color pigment chips 13 is within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the first-color binder 12 is 100 parts by weight, and the content of the multiple second-color pigment chips 23 is within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the second-color binder is 100 parts by weight. Since the content of the multiple first-color pigment chips 13 is within the range of 0.5 parts by weight or more, the pattern of the first-color pattern layer 10 is well expressed. Since the content of the multiple first-color pigment chips 13 is within the range of 20 parts by weight or less, a decrease in the coating film properties and transparency of the first-color pattern layer 10 can be suppressed. Similarly, since the content of the multiple second-color pigment chips 23 is within the range of 0.5 parts by weight to 20 parts by weight when the second-color binder 22 is 100 parts by weight, the pattern of the second-color pattern layer 20 is well expressed while suppressing a decrease in the coating film properties and transparency of the second-color pattern layer 20.

[0047] In this embodiment, the total light transmittance of the printed material 2 is 30% to 90%. When the total light transmittance is 30% or more, when the printed material 2 is placed in front of the solar cell SC, the image printing layer 5 becomes difficult to see due to the light from the screen image, and the image is more clearly visible. When the total light transmittance is 90% or less, even if the screen is black, the image on the image printing layer 5 does not appear dark, which can be suppressed.

[0048] For example, as shown in Table 1 below, when the total light transmittance is less than 30%, the visibility of the design is good, but the power generation efficiency is not good, and when the total light transmittance is 90% or more, the power generation efficiency is good, but the visibility of the design is not good. In contrast, when the total light transmittance is 30% or more and less than 90%, the visibility of the design is good, and the power generation efficiency is also good. In Table 1, "visibility of the design" is marked with "○" if, when printed material 2 is superimposed on the solar cell, there is no problem as a design from a distance of 1m, and with "×" if there is a problem. "Power generation efficiency" is marked with "○" if, when printed material 2 is superimposed in front of the solar cell, the ratio of the amount of power generated with and without printing is 0.5 or more. [Table 1]

[0049] In this embodiment, the printed material can be modified in various ways. Below, a modified printed material will be described. Figure 4 is a schematic cross-sectional view of a modified printed material 2A. Figure 5 is a schematic cross-sectional view of the white pattern layer 40 of the printed material 2A shown in Figure 4. In the following description of the modified material, descriptions that overlap with those described above will be omitted as appropriate.

[0050] The printed material 2A comprises a translucent substrate 4 and a pattern printing layer 5. The printed material 2A further comprises a white pattern layer 40 provided on the second color pattern layer 20. The white pattern layer 40 is provided on the second color pattern layer 20 by, for example, screen printing, inkjet printing, gravure printing, or offset printing. The white pattern layer 40 is composed of a plurality of silver dots 41. Each of the plurality of silver dots 41 contains a silver binder 42 and a plurality of silver pigment chips 43 dispersed inside the silver binder 42. The content of the plurality of silver pigment chips 43 is, for example, in the range of 0.5 parts by weight or more and 20 parts by weight or less, when the silver binder 42 is 100 parts by weight.

[0051] Examples of silver binders 42 include vinyl resins, acrylic resins, thermoplastic urethane resins, polyester resins, or polycarbonate resins. The thickness of the white pattern layer 40 is, for example, 1 μm to 10 μm. The white pattern layer 40 may contain a curing agent. In this case, the heat resistance of the white pattern layer 40 and the adhesion of the white pattern layer 40 to the second color pattern layer 20 can be improved.

[0052] The modified printed material 2A includes a white pattern layer 40 provided on the second color pattern layer 20, which is composed of a plurality of silver dots 41, and each of the plurality of silver dots 41 contains a silver binder 42 and a plurality of silver pigment chips 43 dispersed inside the silver binder 42. As a result, the color development of the first color pattern layer 10 and the second color pattern layer 20 is excellent, and the pattern printing layer 5 can have a pattern that gives a whitish impression.

[0053] Figure 6 is a schematic cross-sectional view showing a printed material 2B that is a different modification from Figure 4. Printed material 2B comprises a translucent substrate 4 and a pattern printing layer 5. Printed material 2B does not include a translucent smoke printing layer 30 and a white pattern layer 40. Even with the configuration of printed material 2B described above, the same effects and advantages as printed material 2 described above are achieved.

[0054] Figure 7 is a schematic cross-sectional view showing a printed material 2C that is a different modification from Figures 4 and 6. Printed material 2C comprises a translucent substrate 4, a pattern printing layer 5, a white pattern layer 40, and a translucent smoke printing layer 30. The white pattern layer 40 is provided on the second color pattern layer 20, and the translucent smoke printing layer 30 is provided on the white pattern layer 40. Even with the configuration of printed material 2C described above, the same effects and advantages as printed material 2 described above are achieved.

[0055] Next, the display unit 50 will be described with reference to Figure 8. The display unit 50 is, for example, a transmissive-reflective liquid crystal display device in which the display pixels inside the liquid crystal are divided into a transmissive display area and a reflective display area. The liquid crystal mode is VA (Vertical Alignment) mode, in which the display pixels are divided into a transmissive area 62 and a reflective area 61. The reflective area 61 forms a reflective metal layer composed of a metal with high reflectivity, such as aluminum or silver. Sunlight L1 is reflected by the reflective area 61 and becomes reflected display light. The liquid crystal mode may also be ECB (Electrically Controlled Birefringe) mode.

[0056] For example, the display unit 50 has a display pixel unit 51 and a backlight 65 located on the opposite side from the printed material 2 (see Figure 13, etc.) as viewed from the display pixel unit 51. The backlight 65 has, for example, a white LED 66. The display pixel unit 51 has the function of reflecting sunlight L1. The display pixel unit 51 has the function of transmitting light L2 from the backlight 65. The display pixel unit 51 has a transmissive unit 62 that transmits sunlight L1 and a reflective unit 61 which is a reflective metal layer that reflects sunlight L1. In this embodiment, the transmissive unit 62 is the part of the pixel electrode where sunlight L1 does not hit the reflective unit 61.

[0057] For example, the display pixel section 51 includes a polarizing plate 52, a λ / 4 plate 53, a diffusing adhesive 54, a glass substrate 55, a color filter 56, a COM electrode 57, an alignment film 58, a liquid crystal layer 59, a transistor 60, a reflective section 61, and a transmitting section 62. The color filter 56 includes, for example, an R filter 56b, a G filter 56c, and a B filter 56d. The color characteristics of the light transmitted through the color filter 56 are such that the average Y value of white (RGB) is 33 or higher, and the Y values ​​of each RGB satisfy RY value ≥ 21, GY value ≥ 58, and BY value ≥ 15. Furthermore, the x of the whiteness (x,y) satisfies 0.290 to 0.320, and the y of the whiteness (x,y) satisfies x - 0.010 ≤ y ≤ x + 0.030.

[0058] As an example, in the display pixel section 51, the polarizing plate 52, λ / 4 plate 53, diffusion adhesive 54, glass substrate 55, color filter 56, COM electrode 57, alignment film 58, liquid crystal layer 59, transmission section 62, glass substrate 55, λ / 4 plate 53, and polarizing plate 52 are arranged in this order along the direction in which sunlight L1 is irradiated. However, the configuration of the display pixel section 51 is not limited to the above example and can be changed as appropriate.

[0059] Figure 9 is a schematic diagram showing a modified display unit 70. The display unit 70 can be used in place of the display unit 50 described above. The display unit 70 is, for example, a liquid crystal display device in which the display pixels inside the liquid crystal are not divided into a transmissive display area and a reflective display area. The liquid crystal mode is FFS (Fringe Field Switching) mode, and the display pixels are not divided into a transmissive area 62 and a reflective area. The liquid crystal mode may also be VA mode or TN (Twisted Nematic) mode.

[0060] For example, the display unit 70 has a display pixel unit 71 and a backlight 85 located on the opposite side from the printed material 2 when viewed from the display pixel unit 71. The backlight 85 has, for example, a high color rendering LED 86. The backlight 85 having a high color rendering LED 86 is, for example, a high color rendering backlight using a white LED that combines a blue LED with a green phosphor / red phosphor. By providing this backlight 85, the color reproduction of the transmitted display can be improved.

[0061] The display pixel section 71 has a reflective polarizing plate 84 located in the part facing the backlight 85, and a diffusion layer 83 located on the opposite side from the backlight 85 when viewed from the reflective polarizing plate 84. The diffusion layer 83 is, for example, a diffusion adhesive layer. Note that the reflective polarizing plate 84 may be located on the backlight 85 instead of the display pixel section 71. By providing the diffusion layer 83 and the reflective polarizing plate 84, the brightness (reflectance) of the reflective display can be improved by 40% or more compared to the case where the diffusion layer 83 and the reflective polarizing plate 84 are not provided.

[0062] For example, the display pixel section 71 includes a polarizing plate 72, an ITO layer 73, a glass substrate 74, a color filter 75, an overcoat layer 76, an alignment film 77, a liquid crystal layer 78, a transistor 79, a pixel electrode 80, a diffusion layer 83, and a reflective polarizing plate 84. The color filter 75 has a configuration similar to that of the color filter 56 described above, and includes an R filter 75b, a G filter 75c, and a B filter 75d.

[0063] As an example, in the display pixel section 71, the polarizing plate 72, ITO layer 73, glass substrate 74, color filter 75, overcoat layer 76, alignment film 77, liquid crystal layer 78, alignment film 77, pixel electrode 80, glass substrate 74, polarizing plate 72, diffusion layer 83, and reflective polarizing plate 84 are arranged in this order along the direction in which sunlight L1 is irradiated. However, the configuration of the display pixel section 71 is not limited to the above example and can be changed as appropriate.

[0064] Figure 10 is a graph showing an example of the relationship between the wavelength of light and the relative spectral brightness in a backlight 85, which is a high color rendering backlight using a white LED combined with a blue LED and a green / red phosphor according to the embodiment, and in a backlight using a conventional pseudo-white LED (blue LED + yellow phosphor) according to the comparative example. Figure 11 is a graph showing an example of the relationship between the wavelength of light and the relative spectral brightness in a color filter 56 according to the embodiment and in a filter of a conventional transmissive liquid crystal display device according to the comparative example. Figure 12 is a chart showing the chromaticity in a color filter 56 according to the embodiment and in a filter of a conventional transmissive liquid crystal display device according to the comparative example. As shown in Figures 10, 11, and 12, when using the color filter 56 of the embodiment, which has lower color purity and is brighter than the comparative example, the brightness (reflectance) of the reflective display can be increased. Furthermore, when a backlight 85, which is a high color rendering backlight, is provided, both the color reproducibility of the transmissive display and the brightness of the reflective display can be achieved.

[0065] Next, examples of the display device will be described. Note that the present invention is not limited to the following examples. In the experiments relating to the examples, the total light transmittance of printed materials was measured for the display devices according to Examples 1 to 5 and Comparative Examples 1 to 3, and the design was evaluated, as well as whether or not the battery ran out. (Example 1) The display device comprises a printed material 2 having a translucent substrate 4, a first color pattern layer 10, a second color pattern layer 20, and a translucent smoke printing layer 30 as shown in Figure 2, a display unit 50 as shown in Figure 8, and a solar cell SC. (Example 2) The display device comprises a printed material 2 having a translucent substrate 4, a first color pattern layer 10, a second color pattern layer 20, and a translucent smoke printing layer 30 as shown in Figure 2, a display unit 70 as shown in Figure 9, and a solar cell SC. (Example 3) The display device comprises a printed material 2A having a translucent substrate 4, a first color pattern layer 10, a second color pattern layer 20, and a white pattern layer 40 as shown in Figure 4, a display unit 50 as shown in Figure 8, and a solar cell SC. (Example 4) The display device comprises a printed material 2B having a translucent substrate 4, a first color pattern layer 10, and a second color pattern layer 20 as shown in Figure 6, a display unit 50 as shown in Figure 8, and a solar cell SC. (Example 5) The display device comprises a printed material 2C having a translucent substrate 4, a first color pattern layer 10, a second color pattern layer 20, a white pattern layer 40, and a translucent smoke printing layer 30 as shown in Figure 7, a display unit 50 as shown in Figure 8, and a solar cell SC. (Comparative Example 1) The display device comprises a printed material as an opaque sheet containing a pigment, a display unit 50 shown in Figure 8, and a solar cell SC. (Comparative Example 2) The display device does not include printed materials and comprises a display unit 50 shown in Figure 8 and a solar cell SC. (Comparative Example 3) The display device comprises a printed material 2 having a translucent substrate 4, a first color pattern layer 10, a second color pattern layer 20, and a translucent smoke printing layer 30 as shown in Figure 2, a display unit which is a general monitor different from the display units 50 and 70, and a solar cell SC.

[0066] (Total light transmittance) The total light transmittance of the printed material for the display devices in Examples 3 and 4 was 65%, the total light transmittance of the printed material for the display devices in Examples 1 and 2 and Comparative Example 3 was 60%, the total light transmittance of the printed material for the display device in Example 5 was 55%, and the total light transmittance of the printed material for the display device in Comparative Example 1 was 5%.

[0067] (Design) The design aesthetics of the display device according to Comparative Example 2, which did not have printed materials, were not good, whereas the design aesthetics of the display devices according to Examples 1 to 5 and Comparative Examples 1 and 3, which did have printed materials, were good.

[0068] (Whether the battery is dead or not) In the display device according to Comparative Example 1, which has a printed material as an opaque sheet, and the display device according to Comparative Example 3, which is a general monitor, battery depletion occurred. In contrast, in the display devices according to Examples 1 to 5 and Comparative Example 2, which have a display unit 50 or a display unit 70, battery depletion did not occur. From this, it was found that in display devices equipped with a display unit 50 or a display unit 70, the consumption of power generated by the solar cell SC and stored in the battery can be reduced.

[0069] As shown in Figure 13, the display device according to the embodiments, modifications, and examples described above comprises a printed material (e.g., printed material 2, printed material 2A, printed material 2B, printed material 2C, or printed material 2D) having a light-transmitting substrate 4 and a pattern printing layer 5, and the printed material is positioned on the light-receiving surface SC1 side of the solar cell SC. Since light is transmitted through the printed material, the solar cell SC receives the light that has passed through the printed material. Therefore, by the solar cell SC receiving sunlight L1 and generating electricity, sufficient power can be stored in the battery R, ​​thus suppressing the occurrence of premature battery depletion. Because the printed layer has a pattern printing layer 5, the pattern of the pattern printing layer 5 can be seen, thus improving the aesthetic appearance. The printed material and the display unit (e.g., display unit 50 or display unit 70) are held in the housing B. Therefore, because the solar cell SC, printed material, and display unit are all housed in the housing B, the appearance of the display device 1 can be improved and the display device 1 can be made easy to carry.

[0070] As shown in Figure 8, the display unit 50 may have a display pixel unit 51 and a backlight 65 located on the opposite side from the printed material when viewed from the display pixel unit 51. At least one of the display pixel unit 51 and the backlight 65 may have the function of reflecting sunlight L1, and the display pixel unit 51 may have the function of transmitting light L2 from the backlight 65. In this case, when using the display device 1 outdoors, it is not necessary to increase the brightness of the display unit 50, and power consumption can be reduced. Furthermore, since sunlight L1 can be used for display, visibility outdoors can be improved.

[0071] As mentioned above, the display pixel section 51 may have a color filter 56. The color characteristics of the light transmitted through the color filter 56 may be such that the average Y value of white of RGB is 33 or more, and the Y values ​​of each RGB satisfy RY value ≥ 21, GY value ≥ 58, and BY value ≥ 15, and the x of whiteness(x,y) is 0.290 to 0.320, and the y of whiteness(x,y) is x - 0.010 ≤ y ≤ x + 0.030. In this case, the transmittance and reflectance of light in the display pixel section 51 can be increased, power consumption can be further reduced, and visibility outdoors can be improved.

[0072] The embodiments, various modifications, and examples of the display device according to this disclosure have been described above. However, the display device according to this disclosure is not limited to the embodiments, modifications, or examples described above, and may be further modified without departing from the gist of the claims. That is, the configuration, shape, size, material, number, and arrangement of each part of the display device according to this disclosure can be appropriately changed within the scope of the gist described above.

[0073] For example, the aforementioned display device 1 can be applied to various display devices. For example, display device 1 is an outdoor signage display. Alternatively, display device 1 may be a display for an information terminal. The information terminal may be, for example, a terminal for warehouse management, inventory management, or process management, or it may be a handheld terminal, wearable terminal, wireless terminal, measuring instrument terminal, POS terminal, ATM terminal, or gas station terminal. [Explanation of symbols]

[0074] 1…Display device, 2,2A,2B,2C…Printed material, 4…Translucent substrate, 5…Pattern printing layer, 10…First color pattern layer, 11…First color dot, 12…First color binder, 13…First color pigment chip, 14a…First interference pigment, 14b…First interference pigment, 15a…First interference light, 15b…First interference light, 20…Second color pattern layer, 21…Second color dot, 22…Second color binder -, 23…Second color pigment chip, 24…Second interference pigment, 25…Second interference light, 30…Transmitting smoke printing layer, 40…White pattern layer, 41…Silver dot, 42…Silver binder, 43…Silver pigment chip, 50…Display unit, 51…Display pixel unit, 52…Polarizing plate, 53…λ / 4 plate, 54…Diffusing adhesive, 55…Glass substrate, 56…Color filter, 56b… R filter, 56c...G filter, 56d...B filter, 57...COM electrode, 58...Alignment layer, 59...Liquid crystal layer, 60...Transistor, 61...Reflective layer, 62...Transmitting layer, 65...Backlight, 70...Display layer, 71...Display pixel layer, 72...Polarizing plate, 73...ITO layer, 74...Glass substrate, 75...Color filter, 75b...R filter, 75c...G filter, 75d...B filter, 76...Overcoat layer, 77...Alignment layer, 78...Liquid crystal layer, 79...Transistor, 80...Pixel electrode, 83...Diffusion layer, 84...Reflective polarizing plate, 85...Backlight, 100...Back material, 111...Sealing material layer, 112...Front plate, 116...Hard coat layer, B...Housing, E...Incident light, L1...Sunlight, L2...Light, R...Battery, SC...Solar cell, SC1...Light receiving surface.

Claims

1. A solar cell having a light-receiving surface that receives sunlight, Displaced on the light-receiving surface side of the solar cell, the printed material has a light-transmitting substrate and a pattern printing layer and transmits light, The aforementioned printed material includes a display unit that displays information by irradiating it with light from the opposite direction to the sunlight, A housing that holds the solar cell, the printed material and the display unit, Equipped with, Display device.

2. The pattern printing layer comprises a first-color pattern layer composed of a plurality of first-color dots, and a second-color pattern layer provided on the first-color pattern layer and composed of a plurality of second-color dots. Each of the plurality of first color dots comprises a first color binder and a plurality of first color pigment chips dispersed within the first color binder. Each of the plurality of second-color dots comprises a second-color binder and a plurality of second-color pigment chips dispersed within the second-color binder. One of the plurality of first color pigment chips and the plurality of second color pigment chips is a plurality of first interference pigments of multiple colors, each generating different first interference light from each other. The other of the plurality of first color pigment chips and the plurality of second color pigment chips is a second interference pigment that generates a monochromatic second interference light different from the color mixture shown by the plurality of first interference pigments, Multiple first interference rays and second interference rays are additively mixed. The display device according to claim 1.

3. The aforementioned pattern printing layer further comprises a white pattern layer provided on the second color pattern layer and composed of a plurality of silver dots, Each of the multiple silver dots includes a silver binder and multiple silver pigment chips dispersed within the silver binder. The display device according to claim 2.

4. The printed material further comprises a translucent smoke printing layer provided on the outermost surface opposite to the translucent substrate relative to the pattern printing layer. The display device according to claim 1 or claim 2.

5. Each of the first interference pigment and the second interference pigment contains titanium dioxide-coated mica having a particle size of 25 μm or more and 60 μm or less. The display device according to claim 2 or claim 3.

6. The content of the multiple first color pigment chips is within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the first color binder is 100 parts by weight. The content of the multiple second-color pigment chips is within the range of 0.5 parts by weight or more and 20 parts by weight or less, when the amount of the second-color binder is 100 parts by weight. The display device according to claim 2 or claim 3.

7. The display unit has a display pixel section and a backlight located on the opposite side from the printed material when viewed from the display pixel section. At least one of the display pixels and the backlight has the function of reflecting sunlight, The display pixel portion has the function of transmitting light from the backlight. The display device according to claim 1 or claim 2.

8. The display pixel portion has a transparent portion that transmits sunlight and a reflective portion that is a reflective metal layer that reflects sunlight. The display device according to claim 7.

9. The display pixel section includes a reflective polarizing plate located in the area facing the backlight, and a diffusion layer located on the opposite side from the backlight when viewed from the reflective polarizing plate. The backlight has a white LED in which a blue LED is combined with green and red phosphors. The display device according to claim 7.

10. The display pixel section has a color filter, The color characteristics of the light transmitted through the aforementioned color filter are: The average Y value of white is 33 or higher, and the Y values ​​of each RGB are R-Y value ≥ 21, G-Y value ≥ 58, and B-Y value ≥ 15, and the x of the whiteness (x, y) is between 0.290 and 0.320, and the y of the whiteness (x, y) is x - 0.010 ≤ y ≤ x + 0.

030. The display device according to claim 9.

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