WO2012031576A1

WO2012031576A1 - Display unit with photovoltaic power generation

Info

Publication number: WO2012031576A1
Application number: PCT/DE2011/000462
Authority: WO
Inventors: Rudi Danz
Original assignee: Rudi Danz
Priority date: 2010-09-11
Filing date: 2011-04-29
Publication date: 2012-03-15
Also published as: DE202010012533U1; DE112011103000A5; AT516334B1; AT516334A5

Abstract

Display unit with photovoltaic power generation, comprising a planar substrate (1), on which the display symbols (2) in the form of numbers, letters, pictograms and further design features made of photovoltaic materials (solar cells), for autonomous energy supply, are assembled and are formed by diffusely reflecting coatings (3) or surfaces and/or fluorescent materials.

Description

Display unit with photovoltaic power generation

The invention relates to the display and information technology.

Display units are devices for the marking of houses (house numbers), roads, motor vehicles, companies, institutions, etc. They are also used as traffic, bidding, warning and prohibition signs, advertising media and information boards or as various markings.

Display units generally consist of a housing, which consists of a rear wall, side walls and a windshield, front panel or various identification panels. The windscreens, front panels or other identification panels to which the identification symbols required for display, e.g. Numerals, letters, pictograms and other design features are applied, serve as information carrier. For photovoltaic illumination of the display units, corresponding lamps, light-emitting diodes, accumulators (accumulator packs) for storing the solar power and electronic components for its control and switching are accommodated in the housing. For photovoltaic operation of the display units a solar module is installed in their housing - usually above the display or in his Nähe-, which supplies the display unit with solar power.

Frequently used display units with photovoltaic power supply are illuminated house numbers that relate their electrical energy from a solar module, which is either roof-shaped arranged as a separate unit on the house number or integrated above the house number number in the display unit (DE 3715943 AI, DE 3825436 AI, DE 102004044181 Al, DE 000009406807 Ul, www, so 1 ar-i n novat i on. An illuminated license plate for house numbers and signs with solar module also describes DE 19523451 AI. The solar module forms the rear wall of the display unit. Illuminated mailboxes equipped with a solar panel are claimed by DE 202007001850 Ul and US 6799716. Solar powered lighting Systems for signs, advertising and information displays and other display devices are treated by US 5435087, DE 202004003861 Ul and DE 202004009885 Ul. For the realization of simple illuminated house numbers also numbers are glued to a ground glass and arranged above the disc, a solar module and battery pack in a housing. To illuminate the house number is located above the number in the housing, a light-emitting diode (www.lampenleuchten.de/Aussenleuchten/Solarleuchten).

The main disadvantage of the inventions described is that for their photovoltaic or autonomous operation extra solar module is needed, which takes away a lot of space and is not available in all applications for the display units. The autonomous operation of the display units necessary solar module or solar panel takes away area that is needed elsewhere. If the rear wall of the display unit is designed by a solar module, its applicability is severely limited because it z. B. as a house number on a house wall can not receive radiation for energy conversion or because the back wall itself carries a label.

Furthermore, large-area variable displays are described in which the pixels are represented by solar cells with different angles of inclination to the viewer (C. Sommerer, L.Mignnoneau, M.Shamiyeh, Solar Display, A self-sustained communication display, 2008, University of Arts and Industrial Design Linz). The defined adjustment of the angle of inclination of the solar cells required for the graphic representation is realized by servomotors and corresponding electronics. The disadvantages of the invention described initially consist of a complicated and space-filling servomotor technology; It is only suitable for use with large-area displays, since only in this case the space required for the display components is available. A sufficient contrast of the displays is only given on sunny days and in direct sunlight. In cloudy skies, in the shade and on cloudy days, these displays do not work well. They are also not suitable for use in the dark, and their representations consist only of grayscale and are not colored. US 20070089784A1 deals with displays that are also powered by solar cells. The dye solar cells used are as extra package electrically interconnected and also need an extra room. As dye cells with a relatively low efficiency, their application is severely limited in terms of their electrical performance. It is therefore an object of the present invention to provide new display units with photovoltaic power generation, which have technical advantages and advantages over the prior art, are inexpensive to install and operate and eliminate the disadvantages of the prior art.

The present invention provides new display units with photovoltaic power generation in which the display symbols and display features applied to their information carriers, e.g. Digits, letters, pictograms - composed of photovoltaic materials (solar cells) and consist of optically functional layers that lead to a radiation amplification of the solar cells. A separate solar module is no longer necessary in the display units according to the invention.

In order to realize the display units according to the invention, initially optically transparent substrates made of glass or plastic are used for their information carriers, and solar cell segments in the form of numbers, letters and pictograms are applied to one of the surfaces of the optical substrates. The solar cell segments consist of laser-cut photovoltaic wafers, preferably of silicon or thin-layer applied inorganic or organic thin-film solar cells. In this case, all conventional photovoltaic semiconductor materials and thin-film cells made of amorphous and microcrystalline silicon, cadmium telluride, copper indium sulfide (CIS cells) and mixed compounds of the elements copper, selenium, sulfur, indium and gallium are applicable as wafers, the thin-film cells also can be present as films. After the electrical connection of the solar cell segments, the surfaces left free by the photovoltaic materials are provided on the optical substrate with optically functional layers composed of white diffusely reflecting materials based on matt paints and fluorescent colors or represented by diffusely reflecting structured surfaces. The optically functional layers represent, on the one hand, display characteristics and, together with the solar cell segments, for the optical contrast on the information carrier. On the other hand, they direct the radiation incident on their surface areas to the solar cell segments and lead there to a current gain. Artificial and solar radiation impinging on the surface of the optical substrate opposite the solar cell segments penetrates the optical substrate and directly reaches the photovoltaically active surfaces of the segment-like arranged solar cells for power generation. On the other hand, the radiation strikes the diffusely reflecting or fluorescent layers after penetration of the optical substrate, is diffusely reflected, in the case of the fluorescent layers converted into long-wave isotropic radiation and, as a result of total reflection within the optical substrate, directed to the adjacent solar cells, where it becomes a lead to significant radiation amplification. That is to say, with the inventive combination of segmentally applied solar cells and optically functional layers on the optical substrate, impinging radiation which does not impinge directly on the solar cell segments contributes significantly to power generation and substantially increases the efficiency of the applied solar cell segments. The combined application of solar cell segments and optically functional layers has the consequence that the display units according to the invention are very efficient in terms of their power generation.

To realize a display unit according to the invention as a warning sign to warn against nuclear radiation is used as an information carrier as an equilateral triangle with the edge lengths of about 35 cm and the thickness of 4 mm designed optically transparent substrate 1 made of glass or plastic and brings using FIG of an optical adhesive on the surface of the optical substrate as a pictogram for warning against nuclear radiation segment-like solar cells 2 with electrical back contact made of monocrystalline silicon. After the electrical connection of the solar cell segments 2, the areas left free of the solar cell materials on the optical substrate are coated with a yellow fluorescent layer 3 based on a yellow perylene fluorescent dye dissolved in an acrylate polymer. On the one hand, the yellow fluorescent layer 3 represents a display and design feature of the warning sign. On the other hand, it generates isotropic radiation which is transmitted via the Glass substrate is passed to the solar cell segments and there causes a radiation amplification. As fluorescent materials depending on the desired color in the display symbols red, green, yellow, blue or orange organic fluorescent dyes from the group of xanthenes, rhodamines, oxazines, perylenes, pyrromethenes, and naphthalimides or phosphors or fluorescent quantum dots are used , The equipped with the solar cell segments and coated with the yellow fluorescent layer and serving as an information carrier optical substrate forms the front and, if necessary, even the back of a housing for the warning sign, with the provided with the solar cells and the fluorescent layer surfaces into the interior of the housing. By virtue of this arrangement, the radiation incident on the optical substrate from the outside strikes the solar cell segments or the fluorescent layer directly after penetrating the optical substrate.

If it is cheaper for design reasons for the display unit, the solar cells may also be directed outwards in special applications.

The solar cell segments are electrically connected to the battery located in the housing for power storage. They generate an electric cable of up to 8 watts in direct sunlight. To illuminate the warning device light emitting diodes are arranged behind, above or to the side of the display symbols, which are supplied via the accumulator when needed. In the case of a backlighting arrangement (light-emitting diodes are arranged behind the optical substrate), the illumination function of the display unit according to the invention functions optimally only if the fluorescent layer applied to the optical substrate as an optically functional layer is partially transparent with an optical transmission in the visible spectral range from 40 to 70% - preferably 55%. Only then can the radiation emanating from the light-emitting diodes arranged behind the substrate penetrate the surface regions of the optical substrate covered by the fluorescent layer and emerge to the outside to detect the display symbolism. In this case, the areas of the optical substrate, which are covered with the solar cell segments and opaque to the light-emitting radiation, stand out with a strong contrast from the partially transparent fluorescent layers and cause the recognition of the display symbols. lik. If the light-emitting diodes are arranged above or laterally in front of the optical substrate carrying the display symbol, transmission values between 1% and 20%, preferably 5%, are favorable for the functional layers. Thin-film solar cells based on amorphous and microcrystalline silicon or cadmium telluride are well suited with regard to their production technologies to realize the display units according to the invention. The numbers, letters or pictograms required for the information carrier of the display unit are applied to the optical substrates, which may also be in the form of plastic films, by using plasma-assisted deposition (low-pressure coating method) or by vacuum methods with the aid of masks electrically conductive and optically transparent oxide layers are provided as electrical contacts. With the same masks and an electrically conductive layer can be applied as a back contact on the structured solar cells. The structuring and thin-film techniques used make it possible to apply complex photovoltaic active display symbols in the form of solar cells to the optical substrates as information carriers and to realize electrical contacting. It is also possible and favorable, with the aid of masks, first to apply information to the optical substrates, graphics, sequences of letters and numbers, and pictograms using white, diffusely reflecting or colored coatings, to remove the masks, and then to route the solar cells to the optical cells To seal substrates. In this way, for example, creates a display unit with white lettering and blue background in the form of solar cell materials. Using similar technology, these structures are also applied directly to the solar cells.

When organic solar cells are used, casting, printing and spraying techniques in conjunction with microelectronic technologies for producing the photovoltaic display symbols on the optical substrates serving as information carriers are suitable. In this way, z. As autonomously illuminated timetables, to be illuminated nameplates and other signs with photovoltaically active digits, letters, and pictograms that produce electricity and electric accumulators and Light emitting diodes - preferably planar organic light emitting diodes - equipped to fulfill the lighting function.

According to FIG. 2, to realize solar-illuminated house numbers (FIG. 2A) and motor vehicle license plates (FIG. 2B), first thin-film solar cells 2 for shaping the numbers and letters are applied to the electrically conductive and transparent surface of the thin-film process using masks applied to both optical substrates 1. The optically functional layer used is a diffusely reflecting opal-like or white lacquer coating 3 based on the light-scattering pigments barium sulfate and / or titanium dioxide with an optical transmission of 55%, which leads to a radiation amplification on the structured solar cells. In an asymmetrical display symbolism to be designed as numbers and letters thin-film solar cells shown in FIG. 2 are reversed applied to the optical substrates, as they show after mounting the substrates as windscreens of a housing in its interior and only then viewed from the outside in their for the viewer to recognize correct representation. In appropriate housings for house numbers and license plates required for lighting accumulators, light-emitting diodes and electronic components are housed. The motor vehicle license plates according to the invention generate electric power for their own lighting, which can also be used for sensors arranged in the vicinity of the license plate or is fed into the vehicle electrical system. In this way, the display units according to the invention provide electrical power for the operation of sensors, mechanical and acoustic signal systems (ringing) or electronic components, alarm systems, etc. available. Likewise, the display symbols and hands of clocks made of photovoltaically active materials can be designed and generate electricity for their autonomous operation. Furthermore, with the invention, autonomous photovoltaically active display units can be used as logo's, symbols, trademarks, information and advertising carriers for traffic signs, information, prohibition and trademarks as well as for company signs, for motor vehicle and other product symbols, for key rings with lighting function , for garment products, such as illuminated vests, satchels, rucksacks, bags of all kinds, road lege, for mobile phones and mobile computer technology, and as stickers and stickers realize. The invention is also applicable when the photovoltaically active display symbols are applied to non-transparent substrates of metal, plastic, wood or even on an optical diffuser and generate electricity.

The display units according to the invention have a number of advantages and technical advantages. For their autonomous operation, no external solar module is needed that takes up space and limits the installation of the display unit in terms of their space requirements and hindered. The solar cell segments and structured thin-film solar cells used for photovoltaic power generation are an integral part of the display unit and provide local electrical power. In addition, additional areas for solar energy generation are created with the invention, which are otherwise not used. The invention substantially extends the potential of photovoltaic applications by providing new hitherto unachievable applications, e.g. autonomously lit timetables and information boards or heated display units that can not fog up and freeze, created. Another advantage of the invention consists in the radiation amplification of the solar cell segments and structured thin-film solar cells, which leads to a significant increase in efficiency of the solar cells and has a very favorable low-light performance. In particular, in the application of the display units according to the invention in the shade, under cloudy skies and under artificial light, the invention leads to an electrical performance increase of the solar cells used by up to 50%. This positive effect also occurs when the solar cells are partially polluted by dust and other particles when water droplets frozen or liquid or condensation water forms on the solar cells.

Embodiment 1

To produce an autonomously illuminated house number on an optically transparent and provided on one side with an electrically conductive oxide layer substrate made of glass or plastic with the dimensions 20cm by 20cm and the Thickness of 2.5 mm using a thin-film method and a mask thin-film solar cells based on amorphous and microcrystalline silicon structured as numbers for the house number applied. With asymmetrical numbers, such as 66, their application to the optical substrate is reversed, so that they are recognizable from the outside as a real representation of the house number. After the electrical interconnection of the structured thin-film solar cells, the same surface of the substrate is then coated with a diffusely reflecting white lacquer layer containing titanium dioxide and / or barium sulfate additives as a scattering agent. The diffusely reflecting lacquer layer conducts the radiation incident on the substrate from the outside to the structured solar cells, where it causes a radiation or current amplification. The optical substrate provided with the structured solar cells and the diffusely reflecting layer is used as a front screen in the housing of the house number, in which light-emitting diodes, an accumulator and electronic components are accommodated. In order for the radiation emanating from the light-emitting diodes mounted on the rear wall of the housing to penetrate into the exterior space through the contrast-forming and light-distributing diffusely reflecting layer, the diffusely reflecting layer is made partially optically permeable by the choice of the concentration of its additives and its thickness with a transmission of 60%. In a house number equipped with two-digit numbers, the solar cell segments generate an output of approximately 1.5 watts in direct sunlight.

Embodiment 2

To produce an autonomously illuminated information panel for displaying companies, institutions, medical centers, etc., one starts from an optically transparent substrate provided with an electrically conductive layer, which for example has the dimensions 60 cm by 80 cm and a thickness of 3 mm. The black informational font, numerals, and other design features are produced by cadmium telluride thin film solar cells on the substrate by patterning them with a vacuum process and providing them with patterned back electrodes. The white background of the information panel is diffused by a white, also applied to the optical substrate. Opaque matt lacquer layer as a functional layer, which also leads to a radiation gain at the structured thin-film solar cells or realized by a surface structuring of the surface of the substrate. The optical substrate provided with the thin-film solar cells and the functional layer is combined as a front panel with a housing for the display unit, in which the further components for autonomous lighting operation of the display unit are housed.

Claims

A display unit comprising a planar substrate on which are arranged as display symbols digits, letters, pictograms and other design features of photovoltaic materials (solar cells) for autonomous power supply and are formed by diffuse reflective coatings or surfaces and / or fluorescent materials.

Display unit according to claim 1, characterized in that the solar cells of wafers of silicon, gallium arsenide and - indium phosphide compounds, germanium, selenium, gallium indium phosphide, gallium indium arsenide and nitride and other mixed compounds of these elements and consist of thin-film cells of amorphous and microcrystalline silicon, cadmium telluride, cadmium sulfide, copper indium gallium diselenide, copper indium sulfide, copper indium gallium sulfur selenium and other mixed compounds of these elements and of organic materials and the thin-film cells are also present as films.

Display unit according to claim 1 and 2, characterized in that the diffuse reflective coatings consist of paints containing titanium dioxide and / or barium sulfate and other light scattering pigments as additives or consist of opaline materials and the diffuse reflective surfaces are structured

Display unit according to claim 1 to 3, characterized in that the fluorescent materials are selected from the group of organic fluorescent dyes, phosphors and quantum dots.

Display unit according to claim 1 to 4, characterized in that the fluorescent dyes and phosphors are selected from the group of xanthenes, rhodamines, oxazines, perylenes pyrromethenes and naphthalimides or from the group of rare earth metals, doped phosphates, silicates, Germanates, garnets, vanadates, tungsten, molybdates, aluminates, gallates, nitrides and borates.

Display unit according to claim 1 to 5, characterized in that the substrate consists of glass or light-conducting plastic made of compact material or foil or of metal, wood or an optically non-transparent plastic.

Display unit according to claim 1 to 6, characterized in that the diffuse-reflecting and fluorescent materials on their incident radiation to the display symbolism forming solar cell segments lead and there lead to a radiation concentration and current gain.

Display unit according to claim 1 to 7, characterized in that the transmission of the diffuse and fluorescent coatings in the range of 40 to 70% - preferably 55% - or in the range of 1% to 20% - preferably 5% -.

Display unit according to claim 1 to 8, characterized in that the applied on the flat substrate in the form of photovoltaic materials display symbols generate after impact of artificial and solar radiation electric power, which is fed to a battery pack for storage and lighting purposes, for heating and / or autonomous operation of sensors, mechanical, acoustic, and / or electronic components and components is used.

10. Display unit according to claim 1 to 9, characterized in that the optical contrast of the display symbols and design features is generated by solar cells, diffusely reflecting layers and surfaces and by colored fluorescent materials.

1 1. Display units according to claim 1 to 10, characterized in that they as autonomous and photovoltaic active Logo's, symbols, trademarks, Information and advertising media for traffic signs, warning and warning signs, company signs, for motor vehicle and other product symbols, for key rings with lighting function, for clothing products, such as safety vests, for school bags and rucksacks, for bags, for watch dials, for street documents, for mobile phones and mobile computer as well as other communication technology, for information boards and timetables, for house number and name badges as well as license plates and advertising technology and as stickers and stickers of all kinds.