AU2012213330B2

AU2012213330B2 - Display device with integrated photovoltaic cells and improved brightness

Info

Publication number: AU2012213330B2
Application number: AU2012213330A
Authority: AU
Inventors: Philippe CARDI; Joel Gilbert; Remy Tasse
Original assignee: Garmin Switzerland GmbH
Current assignee: Garmin Switzerland GmbH
Priority date: 2011-01-31
Filing date: 2012-01-30
Publication date: 2015-05-07
Anticipated expiration: 2032-01-30
Also published as: WO2012104503A1; MX2013008804A; CA2826150A1; JP6195794B2; CN103688209A; EP2671115A1; KR20140021551A; EP2671115B1; AU2012213330A1; UA114285C2; JP2014509405A; KR101754726B1; RU2585312C2; RU2013140449A

Abstract

The invention relates to a display device (1), in particular a digital display screen, including integrated photovoltaic cells and comprising: (a) an array (3) of image zones (4) emitting light or backlit by a light source (2) placed behind the array (3) of image zones (4); (b) an array (6) formed by a plurality of photovoltaic cells (7, 8) and a plurality of holes (13), in which array two adjacent photovoltaic cells form a hole; and (c) a lens array (5) that can be used to focus the light emitted by the image zones (4) in the hole between two adjacent photovoltaic cells (7, 8). The device (1) is characterised in that the lens array (5) is positioned between the array (3) of image zones (4) and the array (6) of photovoltaic cells (7, 8).

Description

- 1 Display device with integrated photovoltaic cells, with improved luminosity The invention relates to the field of display devices, 5 and more particularly to the field of backlit display screens. Such screens comprising a large number of backlit pixels have been known for some time and used in television sets, computers and portable devices of small size, such as mobile telephones, games consoles 10 and calculators. Here, the term "backlit" image zone is intended to mean an image zone which is situated in front of a light source which illuminates it from the rear. The image 15 zone may for example be a pixel, a plurality of pixels or a part of a pixel (for example a liquid crystal pixel) or else a strip of film on which an image has been printed. In a backlit screen, a diffuse light source is placed behind the plane of the pixels, so as 20 to improve the contrast. Portable devices are generally powered by electric batteries, the duration between charges being a significant factor in convenience of use. With the aim 25 of increasing this duration between charges, photocells have been integrated into these portable devices, which produce part of the current required for the operation of said device. Insofar as the space available for arranging photocells on the external surface of said 30 portable devices is very restricted, it would be desirable to integrate the photocells into the display screen. The prior art shows a certain number of examples of 35 such integration. A first approach consists in depositing semitransparent photovoltaic cells (see EP 1 174 756 (ETA), US 7,206,044 (Motorola), WO 2009/052326, US 2010/284055, WO 2009/065069 (Qualcomm), US 2010/245731 (Intel)). Another approach - 2 consists in depositing photovoltaic layers in the form of strips between which the light from the pixels passes (see US 2002/0119592 (BP), US 4,795,500 (Sanyo), WO 2009/098459 (M-Solv)). All these approaches lead to 5 screens which are either not very luminous, or the surface area of the photovoltaic cells, which is, for a given cell type, proportional to the energy converted, is small. 10 Document US 2007/0102035 (X. Yang) shows another approach to such integration, in which photocells covering zones arranged on the surface of the screen collect the ambient diffuse light, while a system of lenses arranged behind the display screen focuses the 15 back-illuminating light onto zones that are not covered with photocells. However, these photocells must not degrade either the imaging characteristics or the luminosity of the screen 20 in which they have been integrated, and this is why the total area available for these photocells is in fact very restricted; indeed, the width of the photocells cannot be significantly greater than the space between two pixels, a space that it is desirable to minimize in 25 order to improve the resolution of the screen. If the photocells are larger, and a fortiori when they partially cover the surface of the pixels, as is the case in the embodiment discussed above in document US 2007/0102035, the luminosity and the resolution of 30 the image generated by the screen are degraded. This same document comprises another embodiment in which the back-illumination light is focused in the space between the photocells by a lens situated between the back illumination light source and the substrate on which 35 the array of pixels is located; this embodiment presents the drawback of requiring extremely precise positioning of the lens, both as regards its lateral position, but especially its distance with respect to the photocells. Moreover, it does not make it possible - 3 to integrate the light source for the backlighting directly into the substrate of the field effect transistors which control the liquid crystals forming the pixels of the screen. 5 The discussion of the background to the invention included herein including reference to documents, acts, materials, devices, articles and the like is included to explain the context of the present invention. This is 10 not to be taken as an admission or a suggestion that any of the material referred to was published, known or part of the common general knowledge in Australia or in any other country as at the priority date of any of the claims. 15 Where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or 20 components, but not precluding the presence of one or more other features, integers, steps or components, or group thereof. It would be desirable that the present invention provides 25 a display screen with integrated photovoltaic cells, which allies a high proportion of photovoltaically active surface with a high luminosity of the display. Preferably, this integration of photovoltaic cells does not require substantial modifications to the design of 30 the display screen, and in particular of the "pixel control" part, so as to be able to use known screen designs. Within the framework of the present invention, three 5 essential elements are included in judicious association with each other: an array of pixels which generates an image, a plurality of photovoltaic cells, and a plurality of lenses forming a lenticular array. Each of these three elements is characterized by its shape, its dimension and 10 its positioning with respect to the other, to form a digital display screen with integrated photovoltaic cells. Viewed from one aspect, the present invention provides 15 a display device, with integrated photovoltaic cells, comprising: (a) an array of image zones emitting light or backlit by a light source placed behind the array of image zones; (b) an array formed by a plurality of photovoltaic cells 20 and a plurality of orifices formed between two neighbouring photovoltaic cells of the array; and (c) a lenticular array configured to focus the light emitted by said image zones into the orifice between two neighbouring photovoltaic cells, 25 wherein the lenticular array is positioned between said array of image zones and said array of photovoltaic cells. In some embodiments, the device is a digital display - 4a screen. The device according to the invention comprises an array of image zones. This may entail pixels. Here, the term 5 "pixel" encompasses either an individual pixel of single colour, or a plurality of parts of a pixel (typically three, namely coloured blue, red and green) which cooperate to create a light spot of a colour which is determined as a function of the intensity emitted by each 10 zone. These image zones or pixels form an ordered array; the techniques of pixel-based display are known to the person skilled in the art. The screen according to the invention may be backlit by means of a source of light placed behind the array of image zones or pixels (for 15 example in the case of a screen of LCD (Liquid Crystal Display) type or in the case of an advertising panel comprising image zones in the form of printed parallel strips, preferably translucent) and/or the pixels may actively emit light (for example electroluminescent 20 pixels). The screen may be a flexible or rigid screen. On its external face it may comprise a tactile film or layer, so as to allow the user to enter data by way of a tactile pathway. In other embodiments, the image zones, pixels and/or 25 parts of pixels are ordered in such a way that various groups of image zones, pixels and/or parts of pixels generate different images. The device according to the invention moreover comprises - 4b a plurality of photovoltaic cells which form or contain a plurality of orifices through which the light from the image zones or pixels can pass. Said orifices may have any shape, for example rectangular or circular. Said 5 cells may be deposited on an appropriate substrate, for example a plate or a film; we shall subsequently refer to the photovoltaic cells deposited 10 15 - 5 on their substrate as a "photovoltaic plate", this in no way implying that they are mechanically rigid. On the contrary, said substrate may be flexible, bendable. Said photovoltaic cells may have any shape, but 5 preferably rectangular. They may take the form of parallel strips which alternate with empty strips (orifices), i.e. not comprising any photovoltaic cells. These strips are 10 preferably equidistant, forming an ordered array. By virtue of the orifices, the photovoltaic plate is partially transparent; the so-called external optical transmission (Text) of the photovoltaic plate is determined in large part by the surface fraction 15 occupied by the photovoltaic cells, and by their intrinsic optical transmission. Said photovoltaic cells are advantageously thin-film photovoltaic cells based on amorphous or 20 microcrystalline silicon, since cells of this type are particularly suitable for converting low-intensity light (diffusing light, light inside rooms); but these photovoltaic cells may also be made with any other suitable technology, for example based on CdTe or CIGS 25 (copper - indium - gallium - selenium) or based on polymers. They may entail junctions of p-i-n or p-n type, or else tandem cells, i.e. comprising two overlaid cells which preferentially absorb a different part of the luminous spectrum. They may be designed to 30 convert visible light and/or ultraviolet light and/or infrared light into electricity. They may be at least partially transparent to visible light. They may be protected by a protective layer, which is advantageously provided with an antireflection layer. 35 The device according to the invention also comprises a plurality of lenses. Here, the term "lens" is understood to mean any device made of a transparent material, isotropic or otherwise, having the property - 6 of deviating and/or concentrating or diverging the light rays. In this broad definition, the term "lens" here comprises prisms, parabolic concentrators, Fresnel lenses. Typically this plurality of lenses takes the 5 form of a film or a lenticular plate, which comprises a plurality of lenses. These may be circular circumference lenses, but preference is given to a lenticular array comprising a juxtaposition of identical rectilinear lenses, the longitudinal axis of 10 which is parallel to the strips of photovoltaic cells. Here, we shall refer to this plurality of lenses as "lenticular plates" or "lenticular array", regardless of its embodiment. 15 Advantageously, the plane of the photovoltaic plate, the plane of the lenticular array and the plane of the pixels are substantially parallel, but these planes may be domed (while remaining parallel), especially in the case where the screen is a flexible screen. The 20 lenticular plates may be made of an appropriate transparent plastic, such as PET. According to the invention, the shape of the lenses, their optical characteristics and their positioning 25 with respect to the photovoltaic plate are such that a light beam originating from an image zone (for example from a pixel or from part of a pixel) and passing through a lens will have on exiting the lens, typically through the effect of an optical deviation and/or 30 concentration, a direction enabling it to pass through at least partly, but preferably entirely, the orifice between two adjacent photovoltaic cells. If the entire luminous intensity originating from the pixels passes into the orifices, the so-called internal optical 35 transmission (Ti) of the photovoltaic plate is a maximum. However, the aim of the invention may be achieved even if part of the light originating from the pixels is absorbed by the photovoltaic plate. Typically, to each lens there corresponds an orifice of - 7 suitable shape and suitable size. In a general manner, the lenses forming the lenticular plate (and which are advantageously arranged in such a way as to form a lenticular array) may have any appropriate shape and 5 appropriate characteristic; they may in particular be plane-convex or biconvex lenses, or else spherical and/or aspherical lenses, or else symmetric or asymmetric lenses, or else variable-index lenses. 10 More particularly, the array of image zones is advantageously positioned with respect to the lenticular plate and with respect to the photovoltaic plate in such a way that the light originating from each image zone or part of an image zone and received 15 by the corresponding lens of the lenticular plate is deviated and/or concentrated by this lens in such a way as to pass fully, or at least in large part, through one of the orifices of the photovoltaic plate. 20 In an advantageous embodiment, said lenticular array comprises a juxtaposition of identical rectilinear lenses, the longitudinal axis of which is parallel to the strips of photovoltaic cells. 25 To avoid parasitic reflections on passing from the lenticular plate to the photovoltaic plate and vice versa, the two plates may be glued or may constitute just a single plate comprising the photovoltaic cells and also the lenses. 30 In a general manner, to at least partly eliminate the reflection of the ambient light on the surface of the photovoltaic plate, the latter may comprise at least one antireflection layer. Here, this term encompasses a 35 specific coating or a surface treatment of said photovoltaic plate, or else an optical micro structuration of the surface, or else a multilayer coating comprising layers of different refractive indices.

- 8 The device according to the invention preferably exhibits an internal transmission of the photovoltaic plate (Ti) which is high, and a low external 5 transmission (Text), this being obtained by virtue of the judiciously chosen and positioned lenticular plate, as indicated hereinabove. Thus, a well-resolved and luminous image and significant photovoltaic conversion of the external light are obtained at one and the same 10 time. On the other hand, in the absence of the lenticular plate, the two transmissions Ti, and Text are of the same order of magnitude, and the quality of the image is to the detriment of the photovoltaic conversion. 15 Another subject of the invention is an assembly consisting of a photovoltaic plate and an associated lenticular array which can be bonded to a digital display screen to form a digital display screen with 20 integrated photovoltaic cells, as described previously. More particularly, the assembly can consist of a transparent film or substrate, preferably flexible or semi-rigid, typically made of a polymer, on which said lenticular array has been deposited, and on which an 25 array of photovoltaic cells has been deposited. The latter are optionally protected, as indicated hereinabove, by a protective layer, for example a surface deposition (thin layer) or a flexible film. Said protective layer may be continuous or 30 discontinuous. This assembly, which we shall refer to here as a "photovoltaic film (or plate) with integrated lenses" may be bonded and fixed, for example by gluing, onto the external surface of a digital display screen. This external surface is preferably smooth; it may be 35 flat or domed, rigid or flexible. This photovoltaic film or plate with integrated photovoltaic cells also comprises the electrodes, typically thin-film electrodes, required to connect the photovoltaic cells together and to collect the current.

- 9 Another subject of the invention is a method of manufacturing a digital display screen by using the photovoltaic plate with integrated lenses according to 5 the invention, which comprises the following steps: a digital display screen comprising a smooth external surface is provided, a photovoltaic plate with integrated lenses according to the invention is provided, and said photovoltaic plate with integrated 10 lenses is bonded and fixed, preferably by gluing, onto said digital display screen so as to form a digital display screen with integrated photovoltaic cells. After bonding the photovoltaic plate onto the external surface of the screen, an electrical connection is 15 established between the electrodes of the photovoltaic plate with integrated lenses and an element for electrically powering the screen, so that the electrical energy generated by the photovoltaic cells can contribute to electrically powering the portable or 20 fixed electronic apparatus in which said screen is integrated; this power may be supplied directly or indirectly (by charging an electrical energy storage means, such as a rechargeable cell or a capacitor). 25 Figures 1 to 9 schematically illustrate embodiments of the invention, but do not limit the invention. It is understood that all the embodiments and all the variants presented may be combined together. These figures do not show certain components which are 30 indispensable to the operation of a display screen, in particular the layer of field effect transistors which is essential for generating an image in a liquid crystal screen. 35 Figure 1 schematically shows a first embodiment of the invention. The figure represents a cross section through a display screen according to the invention. The display screen 1 according to the invention comprises an array 3 of image zones 4 (which may be - 10 pixels) backlit by a light source 2, typically flat, placed behind the array 3 of image zones 4. The flat light source 2 may be a diffusing plate. In a variant of these embodiments, the array 3 of pixels 4 is not 5 backlit by a light source 2, but each pixel 4 itself constitutes a light source, for example by electroluminescence. As indicated above, each pixel 4 may be formed by a plurality of units of different colour, typically by three units (red, blue, green). 10 This is illustrated in Figure 1 and applies to all the embodiments of the present invention. The screen 1 according to the invention also comprises an array 6 of strips of photovoltaic cells 7, 8; the 15 figure does not show the substrate on which they have been deposited. The screen 1 also comprises a lenticular array 5 which comprises a juxtaposition of identical rectilinear lenses, the longitudinal axis of which is parallel to the strips of photovoltaic cells 20 7, 8. Said lenticular array is positioned between said array 3 of image zones 4 and said array 6 of photovoltaic cells 7, 8. The lenticular array 5 may consist of a juxtaposition of identical, rectilinear or other lenses 12, which may be of plane-convex or 25 biconvex type, or the like; they may be of symmetric or asymmetric, spherical or aspherical type. Advantageously, said lenticular array 5 generates an individual-lens effect for each pixel 4, focusing the light originating from the pixel 4 into the orifice 13. 30 As represented by the dotted line, the light beam coming from a pixel 4 is concentrated by a corresponding lens of the lenticular array, in order to be directed as precisely as possible through a 35 corresponding orifice 13 of the photovoltaic array 6. As explained below, in the case where a portion of the light beam emitted by the pixel 4 experiences parasitic reflexions disabling it to pass through an orifice, the quality of the image perceived by observer 9 could be - 11 somewhat diminished, but it will still be possible to regain the non transmitted but diffused light energy, in order to generate an incremental photovoltaic energy from photovoltaic cells arranged on the inner surface 5 of the photovoltaic plate, which is oriented toward the pixels 4. In a general manner, the image zones 4 do not all need to be in the same plane, but they may be arranged on 10 several substantially parallel planes. The pixels 4 may be subdivided into cells, for a colour display, according to technologies known to the person skilled in the art, for example each pixel may be subdivided into three cells coloured red, green and blue. 15 In all the embodiments of the invention, the photovoltaic cells 7 may use any known and appropriate thin-film technology. For screens intended for devices used indoors, it is preferable to use cells which have 20 good efficiency of conversion at low luminosity (for example cells based on amorphous or microcrystalline silicon), since said cells will principally capture diffusing light. 25 In all the embodiments of the invention, the screen 1 according to the invention may comprise other components which improve its characteristics or which adapt them to certain particular situations of use. By way of example, it may also comprise one or more 30 following elements: a colour filter, a polarizing filter, a lenticular element, a light diffuser, a protective layer. The screen 1 may also be a flexible screen. 35 Figure 2 schematically shows a variant of this first embodiment, that can be combined with all the other embodiments of the invention, in which the array 6 of photovoltaic strips is protected by a protective layer 17 which may be rigid or flexible, continuous or - 12 discontinuous. For example, it may be a polymer film. This layer may comprise an antireflection layer 11, advantageously on the external face (i.e. the face turned towards the observer 9). Said protective layer 5 17 may form the substrate on which said array 6 of strips of photovoltaic cells 7, 8 has been deposited. Figure 3 schematically shows in a simplified manner another representation of a similar embodiment. The 10 array of pixels 3 is backlit (white arrows), the light source is not shown in this figure. The optical paths of the beams originating from each of the three zones of the pixels 4 are clarified. 15 Figure 4 schematically shows in a simplified manner another particular embodiment in which the light beam 21 originating from the image zone 4 is divergent; this may be achieved for example with a pixel 4 of LCD type backlit by a divergent light beam 22 (as shown in 20 figure 4), or by an electroluminescent pixel of LED or OLED type (variant not shown in the figure). In this case the corresponding lens 12 is advantageously convergent with a first convex face 34 and if needed a second convex face 35, so as to reduce the focal length 25 of the lens 12 and thus obtain a convergent light beam 23 focused on the orifice 13 after passing through the lens 12 and/or to increase the exit angle of the exiting light beam. 30 In another embodiment shown schematically and in a simplified manner in Figure 5, the light beam 21 originating from the pixel 4 is convergent; this may be achieved for example with a pixel 4 of LCD type backlit by a convergent light beam 22. The corresponding lens 35 12 may then be divergent, with a first concave face 24 and if needed a second concave face 25 so as to increase the focal length of the lens 12 and thus obtain a convergent light beam 23 focused onto the orifice 13 and whose focal plane will have been offset - 13 by shifting away from the pixel. This need may arise for example in order to increase the overall thickness of the lenticular plate and/or to reduce the exit angle of the light beam. 5 In another embodiment shown schematically and in a simplified manner in Figure 6, the light beam 21 originating from the image zone 4 is parallel; this may be achieved for example with a pixel of LCD type 10 backlit by a parallel light beam 22. In this case the corresponding lens 12 may be convergent, with a convex face so as to create a convergence of the light beam into a focal plane close to the corresponding orifice 13 of the photovoltaic plate 6. 15 In yet another embodiment shown schematically and in a simplified manner in Figure 7, the orifices 50, 51, 52 of the photovoltaic plate 6 and the lenses 60, 61, 62 of the lenticular plate 5 are in correspondence with 20 the light emitted by a part 40, 14, 42 only of the pixel 4. This part 40, 41, 42 of the pixel 4 may correspond for example to a particular zone, corresponding to one of the colours, red, green or blue, of an LCD pixel; its light is deviated by the 25 corresponding lens 60, 61, 62 so as to each be focused in a corresponding orifice 50, 51, 52. In yet another embodiment shown schematically and in a simplified manner in Figure 8, to each lens 12 there 30 corresponds a group of pixels 43, 44, 45 whose assembly of exiting light beams are deviated by a lens 12 associated with this group of pixels 43, 44, 45 which focuses them in the orifice 13. 35 In all the embodiments, it is not strictly necessary for the focusing of the light originating from the pixels 4, 43, 44, 45 or parts 40, 41, 42 of pixels to occur in the orifice 13, 50, 51, 52, but focusing in - 14 the orifice gives the best luminosity and quality of display. The photovoltaic plate 6 still comprises the 5 electrodes, typically thin-film electrodes, required to connect the photovoltaic cells together and to collect the current (not shown in the figures). In a particular embodiment, not illustrated by a 10 figure, the device 1 according to the invention comprises two different assemblies of photovoltaic cells, one dedicated to the photovoltaic conversion of the ambient light 20 (referred to as "external light"), and the other dedicated to the photovoltaic conversion 15 of the diffusive light originating from the pixels and/or from their backlighting (referred to here as "internal light") . For example, a first assembly of photovoltaic cells may be arranged on the external face of the photovoltaic plate (and are then preferably 20 protected by a protective film or layer), intended to convert the external light, and a second assembly of photovoltaic cells may be arranged on the internal face of the photovoltaic plate, intended to convert the internal light. 25 The digital display screen 1 according to the invention may be incorporated into a fixed or portable electronic apparatus; this apparatus forms another subject of the invention. It may in particular be a portable 30 telephone, an electronic book, a portable television screen, a portable computer screen. There may also be fixed apparatuses of more significant size, for example a fixed television screen or advertising display. The digital display screen 1 according to the invention can 35 comprise a tactile coating or film, that is to say one which is touch sensitive, so as to obtain a tactile screen.

- 15 Figure 9 schematically shows the method of manufacturing a display screen 1 with integrated photovoltaic cells according to the invention: the photovoltaic plate, comprising the array 6 of 5 photovoltaic cells (typically photovoltaic strips) which are optionally covered with a protective layer 17 (itself optionally covered with an antireflection layer 11), associated with the lenticular array 5 (optionally deposited directly on this lenticular array or 10 separated by a plate or a film, not shown in the figure) forms a photovoltaic plate with integrated lenses assembly 65 which may be bonded to a digital display screen 66 to form a digital display screen 1 with integrated photovoltaic cells as described 15 previously. More particularly, said photovoltaic plate with integrated lenses 65 may consist of a transparent film 64, preferably flexible or semi-rigid, typically made of a polymer, on which said lenticular array 5 has been deposited, on which said array 6 of photovoltaic 20 cells 7, 8 has been deposited on at least one of their faces, the latter possibly protected, as indicated hereinabove, by a protective layer 17, for example a surface deposition (thin layer) or a flexible film. 25 This photovoltaic plate with integrated lenses 65 may be bonded and fixed, for example by gluing, onto the external surface 63 of a digital display screen 66, as indicated by arrows in Figure 9. This external surface 63 is preferably smooth; it may be flat or domed, rigid 30 or flexible. This photovoltaic film with integrated lenses 65 also comprises the electrodes, typically thin-film electrodes, required to connect the photovoltaic cells together and to collect the current (not shown in the figures). 35 Figure 10 shows yet another embodiment of the invention. The display device 1 comprises an array 90 of the image zones 91, which are typically deposited or printed on a substrate 92 and backlit. Said substrate - 16 92 is advantageously transparent or at least translucent; it may be a flat light source. The image zones 91 may form parallel strips, the lengthwise direction of which is parallel to that of the lenses 12 5 forming the lenticular array 5. As in the other embodiments, the lenticular array 5 focuses the light originating from the image zones. This embodiment is particularly well suited to display devices of large size presenting fixed images, for example advertising 10 posters, signs, decorative plates arranged outside or inside buildings. Figure 11 schematically shows an example of a photovoltaic plate with integrated lenses according to 15 the invention which has been made in the following manner: a photovoltaic cell of p-i-n type based on hydrogenated amorphous silicon has been deposited on a flexible glass substrate 17 with a thickness H2 of around 500 im covered with a conductive and transparent 20 layer of ZnO 2 , on which cell has then been deposited a layer of ITO. This photovoltaic cell produces an open circuit voltage of around 8 V. By wet etching of the ITO layer with acid, followed by reactive ion etching (RIE) in a plasma formed from an atmosphere of SF 6 for 25 silicon, parallel strips have been cut in this photovoltaic cell, to obtain an array of photovoltaic strips 6. A lenticular plate 5 made of PET with a thickness H3 of 30 around 125 tm has been used with cylindrical lenses having a pitch L3 of 91 im, a height H4 of around 26 im and an aperture angle of 1200, marketed by the company Microsharp. 35 The photovoltaic plate and the lenticular plate have been assembled to form a photovoltaic plate with integrated lenses. This plate, with a dimension of around 4.2 cm x 3.7 cm, has been glued onto the screen of a portable telephone of SGH-F490 type marketed by - 17 the company Samsung, fitted with a glass plate with a thickness H1 of around 700 im behind which is the array 3 of pixels of individual width L1 of around 160 im. An electrical link between the photovoltaic plate and the 5 power supply circuit of the telephone has been established in such a way as to allow the recharging of the battery by the photovoltaic plate. List of labels: 10 1 Display device 2 Light source 3 Array of image zones 4 Image zone 5 Lenticular array 15 6 Array of photovoltaic cells 7,8 Photovoltaic cells - 18 9 Observer 11 Antireflection layer 12 Lens 13 Orifice 17 Protective layer 20 External light 21,22,23 Light beam 24,25 1 St and 2 "d concave face 34,35 1 St and 2 "d convex face 40,41,42 Part of an image zone 43,44,45 Group of image zones 50,51,52 Orifices 60,61,62 Lenses 63 External surface 64 Transparent film 65 Photovoltaic plate with integrated lenses 66 Digital display screen

Claims

1. A display device, with integrated photovoltaic cells, the device comprising: (a) an array of image zones emitting light or backlit 5 by a light source placed behind the array of image zones; (b) an array formed by a plurality of photovoltaic cells and a plurality of orifices formed between two neighbouring photovoltaic cells of said array; and (c) a lenticular array configured to focus the light 10 emitted by said image zones into the orifices between neighbouring photovoltaic cells, wherein the lenticular array is positioned between said array of image zones and said array of photovoltaic cells. 15

2. The display device according to Claim 1, wherein the display device is a digital display screen.

3. The display device according to Claim 2, wherein the digital display screen is a flexible screen.

4. The display device according to any one of Claims 20 1 to 3, wherein said image zones are pixels.

5. The display device according to any one of Claims 1 to 4, wherein said lenticular array comprises a juxtaposition of identical rectilinear lenses, the longitudinal axis of which is parallel to the array of 25 photovoltaic cells. - 20

6. The display device according to any one of Claims 1 to 5, wherein the lenses of said lenticular array are selected from the group including: plane-convex, biconvex, symmetric, asymmetric, spherical and/or 5 aspherical lenses, or variable-index lenses.

7. The display device according to any one of Claims 1 to 6, wherein said array of photovoltaic cells is protected by a protective layer.

8. The display device according to Claims 7, 10 wherein said protective layer is provided with an antireflection layer.

9. The display device according to any one of Claims 1 to 8, wherein said photovoltaic cells are thin-film cells based on amorphous or microcrystalline silicon, 15 based on CdTe or based on CIGS or based on polymers.

10. The display device according to any one of Claims 1 to 9, wherein said photovoltaic cells are at least partially transparent to visible light.

11. The display device according to any one of Claims 20 1 to 10, wherein said image zones include pixels and/or parts of pixels and are ordered in such a way that various groups of image zones including pixels and/or parts of pixels, generate different images.

12. The display device according to any one of Claims 25 1 to 11, wherein the device includes an external face - 21 comprising a tactile film or layer.

13. The display device according to any one of Claims 1 to 12, wherein the device includes two different sets of photovoltaic cells, namely one set dedicated to the 5 photovoltaic conversion of ambient or external light, and another set dedicated to the photovoltaic conversion of internal of diffused light provided by one or both of the pixels and the backlighting light source.

14. The display device according to any one of Claims 10 1 to 13, wherein the device includes a first set of photovoltaic cells arranged on an external surface of a photovoltaic plate in order to convert the external light, and a second set of photovoltaic cells arranged on an internal surface of the photovoltaic plate in order 15 to convert the internal light.

15. A portable or fixed electronic apparatus incorporating a digital display device according to any one of Claims 1 to 14.

16. A photovoltaic plate with integrated lenses for 20 the manufacture of a display device according to any one of Claims 1 to 14, the plate comprising a transparent film or substrate, said film comprising a lenticular array and an array of photovoltaic cells.

17. The photovoltaic plate of Claim 16, wherein the 25 film is flexible or semi-rigid. - 22

18. The photovoltaic plate of Claim 16 or Claim 17, wherein the photovoltaic cells are protected by at least one continuous or discontinuous protective layer.

19. A method of manufacturing a display device with 5 integrated photovoltaic cells according to any one of Claims 1 to 14, in which a digital display screen comprising a smooth external surface is provided, and in which a photovoltaic plate with integrated lenses according to Claim 16 is provided, and in which said 10 photovoltaic film with integrated lenses is fixed onto said digital display screen so as to form a digital display screen with integrated photovoltaic cells.

20. The method according to Claim 19, wherein the photovoltaic film with integrated lenses is fixed by 15 gluing onto the digital display screen.