WO2010130922A1 - Led screen for displaying a video image - Google Patents

Abstract

The display element (14), in particular for a building, includes: - an electronic circuit (15) comprising diodes (18) and able to control the display of at least part of a video image by means of the diodes; and - at least one photovoltaic member (28). The element is arranged to supply the circuit with the power produced by the photovoltaic member. In the method for displaying a video image by means of a display element (14): - a photovoltaic member (28) of the element produces power; - an electronic circuit (15) of the element is supplied with the power produced; and - the circuit controls the display of at least part of the image by means of diodes (18) of the circuit.

Description

 Diode screen for displaying a video image

The invention relates to LED display panels, including large panels extending on a wall of a building. It is known to place on a wall of a building a video image display screen in which the display is performed by means of light-emitting diodes or

LED. The screen can have very large dimensions for example to cover an area of several hundred square meters. Such a screen has many advantages. It is integrated in the architecture so that it is the building that supports the screen, the latter taking part of the building to extend on a great height. The diodes produce an image with pronounced contrast even in daylight and in full sunlight. The diodes allow the display of a fast succession of images or a film with a very satisfactory rendering. Finally, one can arrange the diodes and the electronic circuit which carries them on the facade of the building without obstructing it for the occupants. Indeed, the diodes can be arranged on supports spaced apart from each other which preserve much of the view for the occupants and allow the building to enter the desired natural light.

The power consumption of such a screen can be between 200 watts and 400 watts per square meter per hour. Although it is reasonable in comparison to other large video image display modes, this level of consumption remains high so that it does not comply with certain regulations and certifications required for architecture, relating to energy savings and respect for sustainable resources.

An object of the invention is therefore to provide a screen that is more responsive to the constraints relating to the preservation of the environment.

For this purpose, there is provided according to the invention a display element, in particular for a building, which comprises:

an electronic circuit comprising diodes and able to control a display of at least a portion of a video image by means of the diodes; and - at least one photovoltaic member, the element being arranged to feed the circuit with energy produced by the photovoltaic member.

Thus, the display element itself produces at least a portion of the energy that it uses for displaying the image. This energy comes from a renewable resource. The consumption of the energy element supplied by the sector is therefore reduced or even zero. All this is also true for the screen that is formed by such elements. Advantageously, the element comprises an elongated support carrying the circuit and the photovoltaic member, the element preferably forming a bar.

Thus, the photovoltaic organ is closely integrated with the element. These organs extend over most of the screen itself while being visually discrete. The image can therefore extend over the entire screen without the need to reserve a portion of the screen photovoltaic bodies.

Advantageously, the circuit and the photovoltaic member extend on different faces of the support. Preferably, the faces are inclined relative to each other at an obtuse angle.

Thus, these faces can be configured so that they each best correspond to the functionalities of the means they carry. Thus, the face carrying the diodes will preferably be vertical so that the light emitted by the diodes is directed horizontally. The face carrying the photovoltaic member may be oriented upwards with a degree of inclination determined to better receive the sun's rays.

Preferably, the element comprises at least one battery arranged to store the energy produced by the photovoltaic member.

Thus, the possibilities offered by the element and the screen that it constitutes are softened and enriched. When the photovoltaic member provides energy, it can be directly used by the electronic circuit to produce the image. However, it can be expected that at least some of this energy is stored in the battery for later use in displaying the image. For example, it can be expected that during the day the screen is off and stores energy in the battery, then is turned on at night and operates using the energy provided by the battery.

Advantageously, the element comprises a member adapted to control a power supply of the battery in energy from the photovoltaic member and a supply of the circuit in energy from the battery.

According to the invention there is also provided a display module which comprises at least two elements according to the invention, arranged to display respective parts of the same image, the module preferably comprising a member for controlling the elements.

According to the invention there is also provided a display device which comprises several modules according to the invention, arranged to display respective parts of the same image, the device preferably comprising a system for controlling and distributing the image on modules. It is also provided according to the invention a building which comprises at least one element according to the invention, a module according to the invention or a device according to the invention.

It is further provided according to the invention a method for displaying a video image by means of a display element, wherein:

a photovoltaic element of the element produces energy;

an electronic circuit of the element is supplied with the energy produced; and

the circuit controls the display of at least part of the image by means of diodes of the circuit. Preferably, the photovoltaic member charges a battery of the element with the energy produced and the battery supplies the circuit.

Other features and advantages of the invention will become apparent in the following description of several embodiments given as non-limiting examples with reference to the accompanying drawings in which: - Figure 1 is a perspective view of a building in its environment and whose facade comprises a display device according to the invention;

FIG. 2 is a view showing a part of this facade as seen from inside the building of FIG. 1 and highlighting the effect of transparency; - Figure 3 is an elevational view of one of the modules forming the facade of the building of Figure 1;

FIG. 4 is a perspective view of one of the modules of the module of FIG. 3;

FIG. 5 is a perspective view of one of the faces of the bar of FIG. 4; FIG. 6 is a front view of the bar of FIG. 4;

FIG. 7 is a partial sectional view of a module of FIG. 3 illuminated by the rays of the sun;

- Figure 8 is a diagram showing the control circuit of the modules of the facade of the building of Figure 1; - Figure 9 is a sectional view of a bar in another embodiment; and

- Figure 10 is a partial front view of a bar in another embodiment.

The building 2 illustrated in Figure 1 has, on its respective sides, several facades which are here four in number. One of them, the facade 4, is a facade according to the invention insofar as it comprises a device or screen for displaying images. -AT-

video. The screen extends vertically and has a generally flat rectangular shape, as well as its front face.

The screen 6 comprises several modules 8, one of which is shown in FIG. 3, arranged in rows and columns to form an array of coplanar modules forming the screen. Each module 8 also has a generally flat rectangular shape, as well as its front face. The modules thus extend from top to bottom depending on the height of the facade and from one side to the other of the latter along its width.

Each of the modules 8 comprises display elements 14 of rectilinear elongate shape and here forming profiled bars such as that illustrated in FIG. 4. The bars 14 are here arranged horizontally in the same vertical plane while being all parallel to one another and at a distance and facing each other. For each pair of consecutive bars in the succession, the space delimited between them is thus left entirely free. It is limited at its ends only by the lateral uprights of a frame 42 of the module. Each strip has here, in section perpendicular to its longitudinal direction, a profile in the form of a rectangular trapezoid. The two parallel sides of the trapezium form in this case the front 16 and rear 17 of the bar. The lower face 19 of the bar is perpendicular to the two previous while its upper face 21 is inclined relative to the vertical and horizontal directions. It is therefore inclined with respect to the front face 16 forming with the latter an obtuse angle visible in Figure 4. This angle is for example 135 °.

Each strip 14 carries an electronic circuit 15 extending on the front face 16. The circuit comprises diodes 18 or LEDs (for Light Emitting Diode), which are identical in kind SMD (Surface Mounting Dot). The diodes of each bar are aligned and regularly spaced from each other. In the present example, the center distance e illustrated in Figure 5 and designating the distance between the axes of two successive diodes of the bar is 5 cm. This spacing will preferably be chosen so that it is large compared to the actual dimensions of the diodes. Thus, if the diameter of each diode is less than 1 cm, this spacing may be equal to five times the diameter of the diodes. The circuit 15 comprises a support 20 forming a printed circuit or substrate to which the diodes 18 are fixed. In this case, each diode is surmounted by a primary optical element 26 of lens type that directs the light emitted by the diode to one or more privileged areas for viewing the screen. In this case, it is to send the light in a direction opposite to that of the building and also not to send the light to the sky, the observers being on the ground or in other buildings. Each circuit also includes electronic components 22 and 24 known in themselves and which serve to control the display of a portion of the video image by the diodes 18. In fact, the diodes are the pixels of the image, form a network of these pixels and constitute each one of the elements of the image to display. As seen in particular in Figure 7, the bars 14 are arranged so that their front faces 16 are coplanar and vertical. The light rays emitted by the diodes are therefore directed towards the front.

The electronic circuit 15 preferably comprises a non-illustrated layer of a transparent material such as flexible silicone. This protective layer extends on the side of the circuit opposite to its support, that is to say on the outer side with reference to the position of the circuit when it is in place on the facade. This layer protects the diodes and the electronic circuit against dirt. It also protects against weather when the circuit extends outside the building.

The module 8 further comprises a control member 40 connected to the electronic circuits 15 of the bars 14 of the module. It extends for example along one of the lateral uprights of the frame 42. This member comprises for example an electronic control card which allows to control for the pixel module 18 per pixel 18 the image fraction to be displayed.

Each bar 14 comprises photovoltaic members or cells 28 arranged in this case on the upper face 21. The cells in this case have a square shape. The cells here are arranged aligned in rows and columns to form a network or array. The lines of the table are parallel to the longitudinal direction of the bar. There are for example three cells aligned in the direction perpendicular to the longitudinal direction of the bar and several tens of cells aligned in its longitudinal direction. As illustrated in FIG. 7, while the front face of the strips is oriented towards the front so that the light produced by the diodes is sent horizontally, the upper face 21 carrying the photovoltaic cells 28 is oriented upwards. It is thus possible to optimize the sun's exposure to photovoltaic cells as well as to light in general. Each bar further comprises one or more batteries 29 extending inside the bar. The cells 28 are connected to each other and connected to the batteries so as to be able to charge the latter with electric current when the cells are illuminated by the rays of the sun 31 as illustrated in FIG. 7. It can be provided that predetermined groups of the cells 28 are associated with certain predetermined batteries 29. The strip also comprises means 31 for managing the power supply of the circuit 15. With reference to FIG. 5, these means 31 are connected downstream to the power supply terminals of the circuit 15. Upstream, they are connectable in parallel on the one hand to the batteries 29 themselves connected to the photovoltaic cells 28, and on the other hand to the power supply network 33. The means 31, which may comprise electrical or electronic components or a control microprocessor, are able to control the power supply of the circuit 15 or by the batteries 29 or by the sector 33 depending on the circumstances. Thus, it can be expected that, during the day, the circuit 15 is supplied with energy from the mains while the cells 28 charge the batteries 29. Moreover, at night, the screen 6 is illuminated from the energy supplied. by the batteries 29 which are thus in discharge mode. Alternatively, it can be provided that the circuit 15 is supplied with energy by default from the batteries 29 and that, only if the charge level of the latter falls below a predetermined threshold, the means 31 control the power supply of the battery. circuit by means of the sector and no longer by means of batteries.

FIG. 8 illustrates the control scheme of the screen. A device 35 such as a computer capable of producing a video signal is provided upstream. Rather than a computer 35, we can use for sending the signal a video player. This signal is transmitted to a general control device 37 which controls itself downstream a system 39 for controlling and distributing the video signal. This system is intended to distribute the different parts of the signal between the different modules 8. It is connected for this purpose to the members 40 of the respective modules 8. The system 39 will for example be a "CitySmart Controller" type system. The modules 8 simultaneously display the respective parts of the image. In each module 8, the bars 14 simultaneously display the respective portions of the corresponding portion of the image.

The video signal can have an analog or digital format. The images displayed on the screen can be fixed or animated. They may include photos, films, drawings, texts, etc. The screen can present color images. The diodes in effect can each take several colors to choose from.

The spacing between the consecutive diodes makes it possible to define the resolution of the display screen as well as the level of transparency desired for the observation of the exterior by the occupants of the building. As can be seen in particular in FIG. 2, the vertical spacing between the bars 14 is sufficiently large to allow the occupants of the building to easily see outside of the latter and to allow the light of day or sun to enter the building. It can thus be seen that the screen according to the invention integrates means for producing and storing solar energy which enables it to dispose of all or part of the energy which is necessary for its operation. The display will be able to use the power provided by the network when the battery charge is insufficient due to lack of light or when the light provided during the day has been insufficient to allow operation of the screen during the night. The invention thus provides a self-powered screen. This screen, which draws all or part of its energy from solar energy that is renewable, can easily be realized to comply with the current regulations in architecture and be certified in this regard. The screen may extend outside the building, in front of an external face of the latter. Alternatively, the screen can be placed behind at least one window 27, as in Figure 7, to protect the screen from the weather. One can also consider having the screen between two windows 27 or each module 8 between two panes. In one embodiment, it will be possible to provide each module 8 with a double glazing comprising two panes between which the strips extend with the electronic circuit. The modules 8 can thus be arranged in front of the windows of the building, that is to say outside the latter, or on the contrary behind its windows, that is to say inside the windows. building, or to constitute in themselves the windows when they are provided with one or more windows as aforesaid. Such a screen can be arranged in other places than on a building. It may in particular be erected independently, in the absence of a building in the immediate vicinity. Such a screen can also be suspended from a supporting structure.

Screen maintenance is easy as each module can be disassembled independently of others, for example to be repaired or replaced. In another embodiment illustrated in Figure 9 which has a strip 14 in section in a plane transverse to its longitudinal direction, the latter has a flat shape. It carries on its front face 16 the diodes 18 and on its rear face 17 the photovoltaic cells 28. Each of the bars is rotatably mounted about a horizontal axis parallel to its longitudinal direction. Each module comprises means for rotating the bars. Each bar can thus have a first position, illustrated in FIG. 9, in which its front face 16 extends vertically and is directed towards the outside of the building so that the image is displayed by means of the diodes 18. Each strip may also have a second position in which the rear face 17 is oriented forwards or upwards to capture the sun's rays. The front face 16 is then directed downwards or backwards. The screen can therefore take a first configuration in which it displays the video image and a second configuration in which it charges the batteries 29.

In another embodiment illustrated in Figure 10, each strip 14 has on its front face 16 photovoltaic cells 28 and diodes 18 which extend for example between the cells. The cells and the diodes are therefore arranged on the same face. The screen can be charged with energy or self-powered while displaying an image using the diodes.

Of course, we can bring to the invention many changes without departing from the scope thereof. It can be provided that the screen covers the entire facade or, on the contrary, only part of the latter.

Claims

1. Display element (14), in particular for a building (2), characterized in that it comprises: - an electronic circuit (15) comprising diodes (18) and able to control a display of a part at less than one video image by means of the diodes; and - At least one photovoltaic member (28), the element being arranged to supply the circuit with energy produced by the photovoltaic member. 2. Element according to the preceding claim, which comprises an elongate support (14) carrying the circuit (15) and the photovoltaic member (28), the element preferably forming a bar. Element according to at least one of the preceding claims, wherein the circuit (15) and the photovoltaic member (28) extend on different faces (16, 21; 16, 17) of the support (14). , the faces being preferably inclined relative to each other at an obtuse angle (a). 4. Element according to at least one of the preceding claims, which comprises at least one battery (29) arranged to store the energy produced by the photovoltaic member (28). 5. Element according to the preceding claim, which comprises a member (31) adapted to control a power supply of the battery (29) energy from the photovoltaic member (28) and a power supply circuit (15) energy from drums. 6. Display module (8) characterized in that it comprises at least two elements (14) according to at least one of the preceding claims, arranged to display respective parts of the same image, the module comprising preferably a member (40) for controlling the elements (14). 7. Display device (6), characterized in that it comprises a plurality of modules (8) according to the preceding claim, arranged to display respective parts of the same image, the device preferably comprising a system (39) of control and distribution of the image on the modules (8). 8. Building (2) characterized in that it comprises at least one element (14) according to any one of claims 1 to 5, a module (8) according to claim 6 or a device (6) according to the preceding claim . 9. Method for displaying a video image by means of a display element (14) characterized in that: a photovoltaic member (28) of the element producing energy; - An electronic circuit (15) of the element is supplied with the energy produced; and the circuit controls the display of at least part of the image by means of diodes (18) of the circuit. 10. Method according to the preceding claim, wherein the photovoltaic member (28) charges a battery (29) of the element with the energy produced and the battery feeds the circuit (15).