WO2018115830A1

WO2018115830A1 - Illumination apparatus

Info

Publication number: WO2018115830A1
Application number: PCT/GB2017/053785
Authority: WO
Inventors: Benjamin MASHEDER; Stephen Hughes; Anthony Miles
Original assignee: Dst Innovations Limited
Priority date: 2016-12-19
Filing date: 2017-12-18
Publication date: 2018-06-28
Also published as: GB201621640D0; GB2557945B; GB2557945A

Abstract

An illumination apparatus is provided, including a flexible circuit board, a plurality of light sources arranged on the flexible circuit board and configured to be electrically connected to the flexible circuit board, and at least one connector arranged on the flexible circuit board and configured to be electrically connected to the flexible circuit board, wherein the connector is arranged to connect both mechanically and electrically with a mutual similar connector.

Description

Illumination Apparatus

Field of the Invention

[0001] The present invention relates to an illumination apparatus, and particularly to a flexible illumination apparatus suitable for connection to a plurality of further flexible illumination apparatuses.

Background of the Invention

[0002] There is a desire amongst lighting companies and architects for large area lighting solutions. Traditionally large area lighting systems use incandescent, halogen, fluorescent or metal-halide lamps due to their high brightness, low capital costs and wide range of fittings and fixtures. However, these systems are relatively expensive to run due to high power consumption and can only be used in rigid arrays. Solid state l ighting (typically LED or OLED) is a superior alternative to such traditional methods because they require significantly less power, are relatively small and are increasingly being used in flexible lighting devices. Additionally solid-state lighting is an attractive option despite high initial capital costs, because it delivers a relatively high efficiency and long working life.

[0003] Light sources that are inherently flexible are finding increasing use, and are commonly constructed using electroluminescent wire (US20050213313), electroluminescent panels (US6400093) or solid state light sources attached to a flexible substrate (US20150016116, CN103629575). Flexible light sources have application in unconventional lighting requirements such as on curved and uneven surfaces. Flexible solid state lighting devices (typically using LEDs) are seen as a better option than electroluminescent panels due to a much higher brightness, larger range of colours and longer working lifetime. Rigid LED illumination devices are commonplace and typically encompass uniform light sources such as bulbs and side lit panels, however these configurations do not lend themselves to the creation of flexible lighting devices or large area lighting solutions. Flexible LED devices are created by attaching small LED SMDs to a flexible substrate, for instance by soldering to thin flexible PCBs, or using electrically conductive adhesives or anisotropic conductive adhesives to attach LEDs to polymer substrates that have been printed with conductive in ks to make circuits and electrodes. [0004] Arrayed lighting solutions which use traditional sources of illumination are commonplace, whereas solid-state lighting that can be arrayed has only recently been disclosed. In the case of WO2015168212, snap connectors are used to create mechanical and electrical interconnects between LED light panels. Additionally, US8262250 discloses a technique wherein flexible LED strips can be connected to form a modular lighting system with a single power source. However, the systems disclosed in these publications do not address all the requirements of arrayed lighting in many environments and situations. For instance, when connecting flexible lighting panels into a large array it is often necessary and desired to be able to independently support the individual lighting panels to ensure that they follow the contours of a wall, or equally to prevent them from sagging when hung from a roof. Whereas in some situations it might be essential to have a strip of the lighting panels hanging from a horizontal surface, it is also advantageous to be able to instead have the same lighting panels closely attached to the horizontal surface. This is not possible with the methods outlined in current disclosures, for instance WO2015168212 relies on separate mounting to frames which neighbouring panels are connected together to form an array, and wherein it is the separate rigid mounting frame that is for attaching to surfaces. Such frames are disadvantageously limited as being rigid or positionable, meaning that they cannot be used to attach to all types of surface, for instance horizontal, vertical, curved, uneven, or perforated whilst also being able to drape, hang or move at the same time.

Statement of the Invention

[0005] Aspects of the invention are defined by the accompanying claims.

[0006] According to the present invention, a modular illumination apparatus is provided that may be formed into one or two dimensional linear arrays. In particular, a flexible circuit board is provided that includes a plurality of light sources arranged on it, and also includes one or more connection points which allow the flexible circuit board to be connected to another similar flexible circuit board both mechanically and electrically at a single point. In particular, the connection point is highly advantageous as it allows a number of similar flexible circuit boards to be connected together in a modular manner to form an array, wherein the entire array may be both electrically connected and mechanically held together using only said connection points. In the first instance, this allows the entire array to be mechanically connected without the need for a separate rigid frame element, hence allowing the flexible nature of the flexible circuit boards to be exploited, for instance by use on, around or over objects which are contoured instead of flat. In the second instance, this allows this entire array to be electrically connected through said connection points, ensuring that the entire array may be powered by a single power source connected to a single flexible circuit board, wherein electrical power may be conducted through connected circuit boards via the connection points.

[0007] In an aspect of the invention, the above is achieved by the connection points being formed of a conductive metal ring defining a physical hole through the flexible circuit board, such that a securing mechanism may be passed through the hole to bring the connectors into both mechanical and electrical contact. The securing means may for instance be a nut and bolt arrangement. In an aspect of the invention, the securing means may be suitable for also securing the flexible circuit board to an external surface such as the object it is intended to be attached to. For instance, the securing means may be a screw.

[0008] Further, the connection points are versatile in that they are designed such that the user may selectively and dynamically configure the connection points for mechanical connection only. In an aspect of the invention, this achieved by locating a non-conductive material between two connectors, wherein the non-conductive material is compatible with said securing means such that the connectors may be held together mechanically but are nonetheless kept in electrical isolation. Advantageously, when the user wants the connectors to be brought back into electrical connection, the non-conductive material may be removed. Hence when creating the array the user is afforded the option to electrically isolate certain areas of the array from other areas, for instance to allow for separate illumination operation of distinct areas of the array.

Brief Description of the Drawings

[0009] There now follows, by way of example only, a detailed description of preferred embodiments of the present invention, with reference to the figures identified below.

Figure 1 shows a view of a single light panel. Figure 2 shows a linear array of the light panels as shown in Figure 1.

Figure 3 shows a two-dimensional array of light panels of the previous figures. Figures 4A to 4C show a method of connection of panels to form a two- dimensional array. Detailed Description of the Embodiments

[0010] In the following description, functionally similar parts carry the same reference numerals between figures. Preferred embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings.

[0011] Figure 1 shows a schematic top view of a single light panel 100. The panel 100 is shown as being rectangular in shape, however many other shapes would also be suitable, for instance the edges of the panel 100 may be curved or hyperbolic, as would be understood by the skilled person. The panel 100 comprises a flexible substrate, such as for instance polyimide, polyether ether ketone or transparent conductive polyester, wherein a printed circuit is created on the flexible substrate in a manner known to the skilled person. For instance, the printed circuit may comprise conductive 101 and non- conductive areas 102. The printed circuit design may for instance be formed by screen printing an appropriate circuit design onto a non-conductive material 102, such as 175μιη thick polyethylene terephthalate, using for instance CI-1036 flexible conductive silver ink (from Engineered Conductive Materials (TM)) for the conductive areas 101 and a hand operated screen printing unit. The printed circuit design also includes busbars 103, that may for instance be relatively wide and extend along the two opposite edges of the panel 100. Busbars 103 on flexible light panels might be created by printing a wide electrode using conductive ink. Alternatively, the busbar 103 might be created by adding in a highly conductive flexible element to the circuit, such as, but not limited to metallic foils, carbon-coated substrates, or metallic wires. Other configurations as understood by the skilled person would be equally appropriate. The panel 100 further includes light sources 104, for instance LEDs or OLEDs, or any other suitable light source as would be understood by the skilled person. The light sources may for instance be formed on the flexible substrate using a pick and place machine and a conductive adhesive dispenser. Other methods as known to the skilled person would be equally appropriate. [0012] Connectors 105 are preferably formed on the busbars 103, as this will ensure that the resistance between the individual panels 100 is maintained as low as possible. The connectors 105 may for instance be formed on the peripheries of the panel 100, for instance the connectors 105 may be formed at each corner of the panel 100. The connectors 105 are conductive, for instance metal, such that in use electrical current may flow through the busbars 103 and into the connectors 105. The connectors 105 may for instance include an eyelet or through hole, such that a securing means may pass through the connector 105, and may further or alternatively be magnetic. Further, where the connectors 105 are magnetic, they may be plated with a highly conductive material such as copper to increase their electrical conductivity properties. The arrangement of arrays of panels 100 will be discussed in further detail with reference to Figures 2 to 4.

[0013] The electrical configuration of the panel 100 is not described here in further detail, however the light sources 104 and the busbars 103 will be arranged in any manner that facilitates the illumination of at least some of the light sources 104 when a power source is connected to at least some of the connectors 105 in a manner as would be understood by the skilled person. For instance, it may be possible to illuminate only a single row or column of light sources 104 when a suitable power source is connected. Advantageously, the panel 100 is flexible as described above, and therefore may be hung from, or for instance draped over, an object, and may therefore substantially follow or conform to the contours of said object.

[0014] Figure 2 shows an array of the light panels 100 of Figure 1. The light panels 100 are formed identically in the manner as described above in relation to Figure 1. To create a linear array 200 of panels 100, the connectors 105 of one panel 100 must be aligned with the connectors of another panel 100, and the connectors 105 must then be secured together. As described above, in one embodiment, the connectors 105 are an eyelet or through hole that may be secured together using a securing means 201, thus ensuring a strong mechanical connection between the panels 100, and therefore creating a linear array 200. For instance, the securing means 201 may comprise a screw, wherein the screw is screwed into place through the connectors 105 of both the aligned panels 100, and secured in a conventional manner for instance using a cooperating bolt. The securing means 201 should be tightened sufficiently such that a good mechanical and electrical connection is made between the connector 105 of one panel 100 and the connector 105 of the panel 100 to which it is being connected. A good electrical connection is defined as one which has a resistance of less than 10 ohms, preferably less than 1 ohm, and more preferably less than 0.1 ohms. Hence, when the panels 100 are secured in the manner of the present invention, the linear array 200 is created wherein the two panels 100 are in electrical connection with each other through the securely attached connectors 105. Hence, advantageously the panels 100 of the linear array 200 are securely connected together both mechanically and electrically using a single connector 105, therefore reducing the number of connectors 105 and increasing the simplicity and utility of the panels 100. Further advantageously, as can be seen, the electrical and mechanical connection between panels 100 is achieved such that a linear array 200 of panels is created without the need to use a separate frame element, as separate frame elements are disadvantageously both bulky and weighty. Further, separate frame elements are also disadvantageous in that they are not flexible, hence when illumination arrays are assembled using separate frame structures, especially when used in combination with flexible substrates such as in the present invention, the frame constrains the ability of the panel 100 to flex and also for instance to be attached to surfaces of uneven contouring. The present invention advantageously overcomes this disadvantage by allowing the panels 100 to be connected directly, such that the panels 100 in the linear array 200 rely on their own structural integrity. In other words, the panels 100 of the claimed invention form their own frame structure once connected into a linear array 200. Hence, the linear array 200 of the present invention advantageously allows for a lighting system that can for instance flexibly extend around a corner of a wall, whilst still maintaining electrical connection.

[0015] Advantageously, the securing mechanism 201 may alternatively be a conductive adhesive or conductive resin/polymer composite, wherein connecting the connectors 105 together and securing panels 100 to surfaces may be achieved by applying the suitable conductive adhesive and bringing the surfaces into physical contact.

[0016] The arrangement of the connectors 105 and the securing means 201 is configured such that the busbars 103 of all panels 100 in the linear array 200 are correctly aligned, such that electrical communication between neighboring panels 100 in the linear array 200 is facilitated and maintained. Further, the configuration of the light sources 104 on each of the panels 100 is such that when panels 100 are connected in a linear array 200, the pitch of the light sources 202, that is their relative spacing, is maintained across all panels 100 of the linear array 200. Advantageously, this creates a seamless visual transition between panels 100, such that the overall appearance of the linear array 200 when the light sources 104 are illuminated is uniform.

[0017] Hence, by the above configuration and considerations, the light sources 104 of the entire linear array 200, that is the light sources 104 of both panels 100, can be powered by a single electrical power source 204 connected to the connectors 105 at one edge 205 of the linear array 200. The electrical connection of the electrical power source 204 to the connectors 105 is done in a manner that would be understood by the skilled person, for instance the electrical connection of the power source 204 to the connectors 105 may be achieved by attaching crimp ring driver outputs to the connectors 105 of the edge 205, and by securing them into place through the eyelets or through holes of the connectors 105 using further securing means 201.

[0018] The connectors 105 may further be magnetic, wherein the magnetic strength of the connectors 105 is sufficient such than when the connectors 105 of two separate panels 100 and magnetic polarities are aligned, they will connect magnetically and secure the two panels 100 together to form a linear array 200. Hence, the magnetic characteristic of the connectors 105 in this configuration serves to advantageously further increase the mechanical strength of the connection between the connectors 105 of adjacent panels, and further can advantageously assist the user in aligning the panels 100 whilst in the process of creating a linear array 200, thus improving speed of construction. In certain configurations, the connectors 105 are of sufficient magnetic strength such that no further securing means 201 is required, and the mechanical connection is formed solely by the magnetic attractive strength between two magnetic connectors 105.

[0019] Once the linear array 200 has been securely constructed using the above described method, the linear array 200 may be put in any desired location. For instance, the array may be draped over a surface, or may be hung from a ceiling, or around a corner of a wall. For instance, the panel 100 of the linear array 200 that has connectors 203 that are not secured to another panel 100 may instead be used to attach the linear array 200 to a desired object. For instance, non-conductive hooks or screws may be passed through the unused connectors 203 such that the entire linear array 200 can be hung from or attached to a wall.

[0020] Hence, in each of the embodiments of the described invention, advantageously the securing mechanisms 201 may be used to not only attach the panels 100 together to form arrays, but may further be advantageously used to securely attach the arrays to a surface, for instance a contoured surface that it is desired that the panel or array is attached to. In this way, the same connectors 105 and securing mechanisms 201 may be used to both mechanically connect panels 100 together, electrically connect panels 100 together where desired, and also to secure entire two-dimensional arrays as described below to surfaces that may be contoured. Advantageously, in the present invention the configuration of the connectors 105 as described allows panels to be connected together and further still to be attached to a surface without the need for a separate frame, thus avoiding the bulk and weight of a frame, reducing the costs of the components required, and allowing the entire two-dimensional flexible array 300 to be unconstrained in the shape and form it may take in use.

[0021] Figure 3 shows a two dimensional array 300. The two-dimensional array 300 comprises at least a linear array 200 as described in Figure 2 above, connected to at least a panel 100 as described in the previous figures above. However, as will be appreciated by the skilled person, a two-dimensional array of any size may be formed by connecting any number of panels 100 together in a manner as herein described. For instance, the two-dimensional array 300 may comprise any number of linea r arrays 200 connected together adjacently in the x-direction.

[0022] The construction of the two-dimensional array 300 requires substantially the same manner of connection as described above in relation to the linear array 200 of Figure 2. However, a mere connection of the panels 100 as described above, wherein all panels 100 that are connected together at connectors 105 are secured in both mechanical and electrical connection by a securing means 201, would result in electrical short-circuiting of the two-dimensional array 300 as the busbars 103 of panels 100 adjacent in the x-direction would be in electrical connection. Hence, to avoid this, panels 100 must be electrically insulated from each other in suitable locations. For instance, the panels 100 may be electrically insulated from each other in the adjacent x-direction, whilst maintaining the electrical connection between panels 100 in the y-direction. This is advantageously achieved in the present invention using the means of connection as shown and described in relation to Figure 4.

[0023] Figure 4 shows a method of connecting a linear array 200 with at least a panel 100 to form a two-dimensional array 300 as shown in Figure 3. The connectors 105 are identical to connectors 105 as described above in relation to Figures 1 and 2. Further, the method of connecting the connectors 105 is substantially as described above, including a securing means 201 passing through the connector 105 and securing connectors 105 of adjacent panels 100 together mechanically. However, where connection between adjacent connectors 105 in the x-direction would create a potential short-circuit, e.g. as when the busbars 103 of at least three separate panels 100 are connected together at a multi-panel connection point 301, an extra non-conductive element 403 is included to prevent the possibility of short-circuiting, and therefore to maintain the functionality of the two-dimensional array 300 such that all of the light sources 104 can be illuminated. Hence, in the present example for instance, each linear array 200 in the x-direction should be kept in electrical isolation from each linear array 200 adjacent to it in the x- direction, whilst all panels 100 in the y-direction should be in electrical communication. This is achieved when connecting the connectors at 301 for instance by placing a non- conductive element 403, for instance a plastic or rubber spacer, between panels 100 in locations where electrical isolation is desired. Subsequently, as described above in relation to linear array 200, the panels 100 are all connected together using a securing mechanism 201 passing through each lined up connector 105, and for instance being held together by a complementing bolt 402. In this manner, the user is able to construct a two-dimensional array 300 of any number of panels 100. Hence, in use, the user must construct the two-dimensional array 300 by including non-conductive elements 403 in locations between panels 100 which need to be kept electrically isolated, and should not include the non-conductive elements 403 in locations between panels wherein the electrical connection needs to be facilitated. [0024] The electrical configuration of the two-dimensional array 300 can be achieved in a number of ways. For instance, if the panels 100 are connected as described above, an electric power source may be connected to the two top or bottom connectors 105 of each column of the two-dimensional array 300 as described in relation to Figure 2. In other words, each panel 100 or linear array 200 adjacent in the x-direction will have its own power source connected, such that each column of the two-dimensional array 300 is separately powered. Alternatively, if the non-conductive elements 403 are located in an appropriate manner, then all panels 100 of the two-dimensional array 300 may be connected in a series manner using a single power source. That is, all columns of the two-dimensional array 300 can be connected in a series manner, for instance if the electronic power source is attached to the bottom panel 100 of column 1, then the top panels 100 of column 1 and adjacent in the x-direction column 2 are electrically connected, and the bottom of column 2 and column 3 are electrically connected, etc. In such a configuration, the electronic power source may be connected to the bottom connectors 105 of a column of the two-dimensional array 300, and the electrical current may pass between columns in the two-dimensional array 300 by passing relatively 'up' one column and then across to the next column, and then 'down' that column etc. In this way, the entire two-dimensional array 300 is electrically connected in series. Further, any other electrical configuration as would be appreciated by the skilled person is possible, wherein in each case the user is advantageously able to locate the non-conductive elements 403 in the respective location that would facilitate their desired electrical configuration.

[0025] Advantageously, the configuration of the light sources 104 on each of the pane ls 100 is such that when panels 100 are connected into a two-dimensional array 300, the pitch of the light sources 104, that is their relative spacing, is maintained across all panels 100 of the two-dimensional array 300. Further, as described above, in the circumstance wherein the two-dimensional array 300 is to be hung from a surface, non-conductive hooks or screws may be passed through the unused connectors 203 such that the entire linear array 200 can be hung from or attached to a wall.

[0026] In each of the embodiments described, when desired the panels 100 may each be formed with additional means for securing and attaching panels 100 together, including for instance magnetic connectors including simple flat magnets or male/female magnetic parts, wherein either element may be attached to the busbar 103 and/or the panels 100 using an non-conductive adhesive, non-conductive mechanical fastener such as a screw or crimp, or using any other technique known to the skilled person such that it will not affect the electrical operation of the panels 100 in the arrays. This advantageously allows for further secure attachments between panels to ensure a strong mechanical connection is made.

Alternative Embodiments

[0027] The embodiment described above is illustrative of, rather than limiting to, the present invention. Alternative embodiments apparent on reading the above description may nevertheless fall within the scope of the invention.

Claims

1. An illumination apparatus comprising: a flexible circuit board; a plurality of light sources arranged on the flexible circuit board and configured to be electrically connected to the flexible circuit board; and at least one connector arranged on the flexible circuit board and configured to be electrically connected to the flexible circuit board; wherein the connector is arranged to connect both mechanically and electrically with a mutual similar connector.

2. The illumination apparatus of claim 1, wherein the at least one connector is further suitable for mechanically connecting the flexible circuit board to a surface external to the flexible circuit board.

3. The illumination apparatus of any preceding claim, wherein the at least one

connector comprises a conductive material defining a hole through the flexible circuit board.

4. The illumination apparatus of any preceding claim, wherein the flexible circuit board is a first flexible circuit board, and further comprising a second flexible circuit board as described in claim 1.

5. The illumination apparatus of claim 4, wherein the first flexible circuit board is both mechanically and electrically connected to the second flexible circuit board by the mutual interaction of the connectors, such that the light sources of the second flexible circuit board may be illuminated by electrica l current transferred through the connectors from the first flexible circuit board.

6. The illumination apparatus of claim 5, wherein the connectors are magnetic and the mutual interaction is a magnetic interaction.

7. The illumination apparatus of claim 5 or claim 6, wherein the connectors are

connected by a non-conductive securing means being passed through both the connectors.

8. The illumination apparatus of claim 5 or claim 6, wherein the connectors are

mechanically connected by a non-conductive securing means being passed through the connectors and a non-conductive means located in-between the connectors, such that the connectors are brought into mechanical connection but are kept in electrical isolation.

9. The illumination apparatus of claim 7 or claim 8, further including a third flexible

circuit board as described in claim 1, wherein the third flexible circuit board is connected to the connector of the first flexible circuit board and/or the connector of the second flexible circuit board in a manner as described in either of claims 7 or 8 such that a two dimensional array of flexible circuit boards is formed.

10. The illumination apparatus of any of claims 7 to 9, wherein the non-conductive

securing means is suitable for also securing the circuit boards to a surface external to the circuit boards.

11. The illumination apparatus of claim 10, wherein the non-conductive securing means comprises a screw and the connectors comprise a mutual thread, or wherein the non- conductive securing means comprises a screw and bolt arrangement.

12. The illumination apparatus of any preceding claim, wherein a power source is

electrically connected to at least one connector such that the light sources of at least one flexible circuit board may be illuminated.

13. The illumination apparatus of any preceding claim, wherein the each circuit board comprises a further connector as described in claim 1.

14. The illumination apparatus of any preceding claim, wherein the flexible circuit boards further comprise busbars.

15. The illumination apparatus of claim 14, wherein the connectors are located on the busbars.

16. The illumination apparatus of any preceeding claim, further comprising separate

mechanical connectors located on the circuit boards and configured to mechanically connect the circuit boards to each other or to a surface external to said circuit boards.

17. A method of forming an illumination apparatus, comprising: selecting a first flexible circuit board comprising: a plurality of light sources arranged on the first flexible circuit board and configured to be electrically connected to the first flexible circuit board; and at least one connector arranged on the first flexible circuit board and configured to be electrically connected to the first flexible circuit board, wherein the connector is arranged to connect mechanically and electrically with a mutual similar connector; selecting a second flexible circuit board to the first flexible circuit board comprising: a plurality of light sources arranged on the second flexible circuit board and configured to be electrically connected to the second flexible circuit board; and at least one connector arranged on the second flexible circuit board and configured to be electrically connected to the second flexible circuit board, wherein the connector is arranged to connect mechanically and electrically with a mutual similar connector; and connecting the connector of the first flexible circuit board to the connector of the second flexible circuit board such that the first flexible circuit board is both mechanically and electrically connected to the second flexible circuit board.

18. The method of claim 17, wherein each circuit board further comprises a second

connector.

19. The method of any of claims 17 or 18, further comprising connecting a power source to at least one of the connectors such that electrical power is conducted through at least some of the light sources of both the first and the second flexible circuit boards.