NZ754438A

NZ754438A - An animated illuminated sign

Info

Publication number: NZ754438A
Application number: NZ75443819A
Authority: NZ
Inventors: Stuart Hunter Richard
Original assignee: Stuart Hunter Richard
Priority date: 2019-06-10
Filing date: 2019-06-10
Publication date: 2019-11-29
Also published as: WO2020250150A1

Abstract

The present invention relates to an edge-lit sign with an animated image. The edge-lit sign includes a light distribution assembly 1 and a lighting assembly. The light distribution assembly includes a first black-out sheet 3 and a second black- out sheet 4, the first black-out sheet including a cut-out portion 5 in the shape of an image to be animated, and a light distribution panel 2 including a plurality of independent light-conducting paths 6 which extend into a region of the light-conducting panel adjacent the cut-out portion. The lighting assembly, which attaches to the light distribution assembly, includes a lighting circuit having a plurality of independently activatable light sources, one for each of the light-conducting paths. The lighting circuit includes a switching device configured to activate or de-activate light from the light sources to independently light each of the independent light-conducting paths in a predetermined sequence, which may provide animation of the image.

Description

AN ANIMATED ILLUMINATED SIGN TECHNICAL FIELD The present disclosure relates to improvements in illuminated signs, and more particularly to edge-lit signs capable of displaying animated information.

BACKGROUND ART Edge-lit signs are typically used as a relatively low-cost, high reliability, devices for displaying static images in reduced or low light conditions. Edge-lit signs require few parts and are highly tolerant to adverse operating conditions, unlike many more complex illuminated signs.

Due to their high reliability and tolerance to adverse conditions one common application for edge-lit signs is to indicate emergency egress points from a building. Such signs are a requirement of most building codes around the world for commercial buildings, cinemas and show venues, aircraft and the like.

Some common characteristics of edge-lit signs include: reliability; the ability to be self-contained; low power consumption; high tolerance to heat; tolerance to shock; high humidity and other adverse conditions. These characteristics make edge-lit signs ideally suited for use in common signs, such as emergency exit signs. Edge-lit signs also provide the flexibility of being configurable either as single-sided or double-sided signs at very little additional cost and usually requiring no additional electronics.

Emergency exit signs have evolved to a standardised form, often determined by regulation, depicting a person entering a doorway and featuring a directional arrow indicative of the direction of the nearest exit, both of which are typically shown in white over a green background.

Edge-lit signs are commonly formed from a sandwich construction technique, where a light conductive core panel is either screen printed directly with the sign information or has a graphic image panel with the sign information printed thereon. In use edge lighting provided to the core panel is diffusely emitted evenly over the surface of the core panel to provide an even backlight to the image panels. The edge lighting is typically provided at either the top, or on one side of the core panel; however, edge lighting may be provided on any, or all sides, depending on the size of the sign and the requirements of an installation. Emergency exit signs are typically edge-lit from the top edge, or one side, usually on the edge that is mounted to a wall or ceiling.

Whilst conventional edge-lit signs are highly reliable and highly effective at illuminating a static image, the static nature of the information on the edge-lit sign does not draw the eye to the extent that a moving, flashing, or otherwise animated image will do. Whilst flashing the edge lighting of an edge-lit sign can be used to provide a limited form of animation, in some cases it is undesirable. For example, in many emergency situations the emergency exit sign also provides the necessary illumination for a person to find and navigate to the exit of a building, particularly when power to the building is lost.

Emergency exit signs typically incorporate their own power source or are powered from an emergency backup power source and may provide the only illumination to the area. For this reason it is important that a uniform and stable light source is provided by the emergency exit sign. Flashing the illumination to a sign on and off to draw attention to the sign is not ideal as all the information on the sign is flashed, making it difficult to read what the sign may be saying, or which direction is being indicated.

Backlit signs that provide moving or animated features, such as arrows, are known. For example, US 2016/0027266 A1 teaches a backlit sign having a matrix of LEDs embedded on a printed circuit board (PCB) that is positioned behind part of the image to be lit. The LEDs in the matrix are switched on and off by a programmed microprocessor, so that various effects (colour, strobe, etc) can be achieved. For example, some of the LEDs can be selected to form an arrow sign on the sign surface. These can be selectively activated to provide the appearance of an animated moving arrow.

However, this arrangement has several disadvantages. Incorporating LEDs into the sign panel greatly increases the complexity of manufacturing the sign and limits the ability to alter the sign if required.

LEDs must be located on a PCB at every location on the sign where illumination is required. This can result in a large number of LEDs being used (in comparison with a conventional edge-lit sign) with commensurate increases in cost. Further, a greater degree of complexity is required to integrate electronics into such a panel’s edge light interface, which can increase manufacturing cost and potentially reduce reliability.

In other animated signs of the prior art a plurality of light conductive sheets are overlaid on one another, with each additional sheet having the next image of the animation sequence. Signs of this type have several disadvantages. For example, each light conductive sheet must include an image that adds to the images of the previous sheets, the creation of which can be time and labour intensive, adding to costs, and registration of the layered images can be critical to production of a quality effect. Further, the number of sheets and associated edge lighting adds to the overall cost of materials, and hence of the sign.

It is an object of the present invention to address at least one of the foregoing problems, or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although some prior art publications may be referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, i.e., in the sense of “including, but not limited to”.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION According to one aspect of the present invention there is provided an edge-lit sign including: a light distribution assembly; and a lighting assembly, wherein the light distribution assembly includes: a first black-out sheet and a second black- out sheet, the first black-out sheet including a first cut-out portion in the shape of an image to be animated: and a light distribution panel sandwiched between the first black-out sheet and the second black-out sheet, the light-distribution panel including at least two independent light- conducting paths which extend into a region of the light-conducting panel adjacent the first cut- out portion, and wherein the independent light-conducting paths are optically modified in the region of the first cut-out portion to transmit light from the light-conducting path through the first cut-out portion, wherein the lighting assembly is configured to attach to the light distribution assembly and hold it in place, and includes a first lighting circuit having at least two independently activatable first light sources, and the first lighting circuit is configured to provide edge lighting from the at least two independently activatable first light sources, one of which is configured to provide edge lighting to one of the independent light-conducting paths and the other is configured to provide edge lighting to the other independent light-conducting path, and the lighting circuit includes a switching device configured to activate or de-activate light from the two first light sources to independently light each of the two independent light-conducting paths in a predetermined sequence.

This embodiment of the present invention may provide a single-sided sign with an animated image. Light is transmitted from the lighting circuit into independent light-conducting paths in the light distribution panel which then transmit the light to the region of the image to be animated. Light entering each independent light-conducting path may be switched on or off by means of the switching device.

Consequently, animation of the image (first cut-out portion) may be achieved by selectively turning the light in each independent light-conducting path on and off, or changing the colour of the light, in a predetermined sequence.

An advantage of the present invention over prior art methods of animation may be that only one light- distribution panel is required (rather than multiple overlaid panels of some of the prior art signs). This may reduce cost of material, reduction in the weight of the sign (easier handling and easier to fix in place), reduce the labour costs of producing multiple images for the animation, and reduce issues with registration of the multiple panels of the prior art signs.

Reference to a light-conducting path throughout this specification should be understood to mean any means capable of containing and transmitting light from an edge of the edge-lit sign to a region of the light distribution panel away from the edge.

In a preferred embodiment the first black-out sheet and the second black-out sheet each include an opaque material sandwiched between two cover sheets. Inclusion of the opaque material, preferably a carbon material, ensures that all light is blocked from transmission through the black-out sheets.

In a preferred embodiment the light distribution panel includes a light-conducting acrylic material.

In a preferred embodiment the independent light-conducting paths are formed by removing the light- conducting acrylic material on either side of each of the independent light-conducting paths.

In a preferred embodiment a laser is used to remove the light-conductive acrylic material on either side of the independent light-conducting path.

In a preferred embodiment one end of each of the independent light-conducting paths is located near a first edge of the light distribution panel, being the edge of the light distribution panel adjacent the lighting circuit assembly when the sign is assembled.

In a preferred embodiment the first edge of the light distribution panel includes two transparent projections configured such that a dimension of the first black-out sheet is equal to a combined dimension of the light distribution panel and the transparent projections.

In a preferred embodiment the first light source is located within a light entrapment gulley formed between the lighting circuit assembly and the first edge of the light distribution panel.

An important advantage of this arrangement may be that, locating the first light source within the light entrapment channel may prevent stray light from the first light source from leaking into other parts of the edge-lit sign.

In another embodiment the light-conducting paths of the light distribution panel include light- conducting material attached to a substrate. For example, the light-conducting paths may include light conducting ribbons or fibres, where the light conducting material may be optically modified as required to allow light to be transmitted towards the cut-out portion.

In a preferred embodiment the optically modified surface of the independent light-conducting path includes a dot matrix formed by screen printing a translucent ink onto a surface of the light-conducting path. Preferably, the dot matrix is printed onto a rear face of the light distribution panel, being the face adjacent the second black-out sheet and behind the first cut-out portion. Preferably, the dots of the dot matrix are configured to direct incident light from the rear surface of the light distribution panel directly towards the opposite surface of the light distribution panel (the front surface).

Essentially, each dot is formed as a lens configured to focus the light back in a direction normal to the front surface of the light distribution panel. An advantage of this may be that the light entering each dot may be preferentially transmitted directly towards the front surface of the light distribution panel (where it illuminates the cut-out portion in the first black-out sheet), rather than being scattered into a wider region within the light distribution panel. This may provide brighter illumination of the cut-out portion of the first black-out sheet.

In a preferred embodiment the group of independent light-conducting paths are bounded at least partially by an opaque barrier. An opaque barrier may be inserted into the light distribution panel to separate the light distribution panel into two regions, a first region containing the light-conducting paths and a second region (the remainder of the light distribution panel). A function of the opaque barrier may be to limit light from the first region escaping into the second region (and potentially to the edges of the light distribution panel).

Preferably, the lighting circuit assembly is configured to attach to an edge of the light-distribution assembly opposite an end of the light paths in the light distribution panel. The lighting circuit assembly may be attached to the top, bottom, left or right-side edges of the sign, as required. The lighting circuit assembly is commonly used to attach the sign to a structure (e.g. a wall or ceiling) and this may decide which side of the light distribution panel is attached to the lighting circuit assembly and consequently the initial orientation of the light-conducting paths (which is always initially directly away (i.e. normal) to the lighting circuit assembly.

In a preferred embodiment the switching device of the lighting circuit includes a microprocessor configured to selectively activate the independently activatable first light sources in a predetermined sequence.

A benefit of including a microprocessor in the lighting circuit may be that it may be programmed to provide a multitude of effects in the illuminated sign, therefore enabling detailed animation of any part of the image. Another benefit may be that the appearance of the image on the sign panel may be readily altered by reprogramming the microprocessor, which may save labour and manufacturing costs for the altered sign.

In an alternate embodiment the switching device is configured to independently enable light to enter each of the at least two independent light-conducting paths. This embodiment could, for example, have an end of each of the at least two independent light-conducting paths coated with a material that can be switched from transparent to opaque, for example by application of a voltage change under control of the microprocessor.

In a preferred embodiment the independently activatable first light sources are LEDs. 40 Advantages of using LEDs may be that they can be chosen from a range of colours, the technology is well-known, and they are a relatively small and inexpensive way to provide illumination. Furthermore, different lighting effects (including, for example, colour or intensity) may be provided independently in each of the independent light-conducting paths.

In a preferred embodiment each of the at least two independently activatable first light sources includes a pair of light sources, one of the pair of light sources providing a first colour and the other one of the pair of light sources providing a second colour.

Preferably the first colour is white, and the second colour is green. Conventionally, only two colours (white and green) are used in emergency edge-lit signs. Those skilled in the art will appreciate that other types of sign may use other colours as required by the design.

Preferably, only one light source of each pair of light sources is lit at any time. Preferably, the microprocessor is programmed to switch each light source of each pair of light sources on and off independently when required.

An advantage of this embodiment may be the simplicity of designing a lighting circuit, including programming the microprocessor, to activate or deactivate each light of the at least two independently activatable first light sources.

According to another aspect of the present invention there is an edge-lit sign substantially as described above wherein a dimension of the dots of the dot matrix increases with a distance from the first light source along the light-conducting path.

Light is emitted from the light-conducting path as it passes behind the first cut-out portion. Some of the light is transmitted towards the front face of the light distribution panel, thus reducing the intensity of the light being transmitted further along the light-conducting path. By increasing the dimension of the dots along the light-conducting path it may be possible to compensate for the decrease in intensity of the light along the light-conducting path. An advantage of this may be that illumination along the light- conducting path is more uniform than would be the case otherwise.

According to another aspect of the present invention there is provided a double-sided edge lit sign, substantially as described above, further including an animated image to be displayed on both sides of the double-sided edge-lit sign.

In a preferred embodiment, the double-sided edge-lit sign includes a second cut-out portion formed in the second black-out sheet, the second cut-out portion configured in the shape of an image to be animated, and the light distribution panel includes at least two independent light-conducting paths which extend into a region of the light distribution panel adjacent the second cut-out portion.

Typically, the second cut-out portion is a mirror image of the first cut-out portion on the first black-out sheet (i.e. the second black-out sheet is a mirror image of the first black-out sheet). In this way the same animated image may be displayed on both sides of the edge-lit sign, using the same light conducting paths and switching sequence.

In other embodiments the second cut-out portion may be of a different image from the first cut-out portion, in which case the second cut-out portion should be in a different location from the first cut-out portion so that the two animated images do not interfere with one another. The second cut-out portion may be adjacent to the same set of independent light-conducting paths as the first cut-out portion or may be adjacent to a separate set of independent light-conducting paths, in which case a different 40 sequence of lights may be used for the animation of the second cut-out portion.

According to yet another aspect of the present invention there is a single-sided edge-lit sign substantially as disclosed above, the single sided edge-lit sign further including: a first photometric light distribution panel configured to overlay the first black-out sheet; a first graphic overlay configured to overlay the first photometric light distribution panel, wherein the lighting circuit includes a second light source configured to provide edge lighting to the first photometric light distribution panel, and the first graphic overlay includes a first translucent image which overlays the first cut-out portion of the first black-out sheet and a second translucent image; and a surface of the first photometric light distribution panel is optically modified.

This embodiment may be used to create a single-sided edge-lit sign including both an animated image and a static image on a front face.

Preferably the single-sided edge-lit sign includes a three-sided frame which is configured, in conjunction with the lighting circuit assembly, to hold the light distribution assembly, the first photometric light distribution panel and the first graphic overlay, firmly together. Preferably the frame includes a translucent material which may allow light to be emitted around the edges of sign. An advantage of this may be that light from the edges of the sign may provide emergency lighting around the sign.

In this embodiment the second light source is contained in the lighting circuit assembly in a location outside the first black-out sheet and adjacent an edge of the first photometric light distribution panel.

The first photometric light distribution panel provides backlighting to the first graphic overlay, including the second translucent image (static image).

In a preferred embodiment the optically modified surface of the first photometric light distribution panel includes a dot matrix formed by screen printing a translucent ink onto a surface of the first photometric light distribution panel in a similar manner to that described above for the light distribution panel. As previously described, a dimension of the dots increases with distance from the second light source (i.e. the lighting assembly).

An edge-lit sign according to this embodiment may be able to display both an animated image (through the first translucent image as described above) and a static image (through the second translucent image).

In yet another embodiment there is provided a double- sided edge-lit sign substantially based on the single-sided edge-lit sign as described above, further including: a second photometric light distribution panel configured to overlay the second black-out sheet; and a second graphic overlay configured to overlay the second photometric light distribution panel, wherein the second graphic overlay includes a third translucent image which overlays the cut- out portion of the second black-out sheet and a fourth translucent image, and a surface of the second photometric light distribution panel is optically modified to provide light to the third translucent image and the fourth translucent image.

Preferably, the double- sided edge-lit sign includes a three-sided frame substantially as described above.

Preferably, the optical modification of the surface of the second photometric light distribution panel is as described above for the first photometric light distribution panel.

This embodiment may provide a double-sided edge-lit sign capable of displaying a stationary image and an animated image on each side of the sign.

BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which: shows an isometric front view of an edge-lit sign according to a preferred embodiment of the present invention; shows a schematic front view of a first black-out sheet according to the embodiment shown in Fig. 1; shows a schematic front view of a second black-out sheet according to the embodiment shown in Fig. 1; shows an isometric view of a single-sided edge-lit sign according to the embodiment shown in Fig. 1; shows a front view of a light distribution panel according to the embodiment shown in Fig. 1; shows a front view of an alternative light distribution panel according to the embodiment shown in Fig. 1; shows a schematic view of a lighting circuit according to the embodiment shown in Fig. shows a closeup view of a portion of the light distribution assembly of the embodiment shown in Fig. 1; -9l show a lighting sequence according to the embodiment shown in Fig. 1; shows a face of a second black-out sheet according to another embodiment of the present invention; shows a photometric light distribution panel according to another embodiment of the present invention; shows a schematic view of a lighting circuit according to the embodiment of Fig. 11; shows a view of a graphic overlay according to the embodiment of Fig. 11; shows an isometric view of a single-sided edge lit sign according to the embodiment of Fig. 11; shows an isometric view of a double-sided edge lit sign according to another embodiment of the present invention; shows a view of a black-out sheet according to the embodiment shown in Fig. 15; shows a photometric light distribution panel according to the embodiment of Fig. 15; shows a schematic view of a lighting circuit according to the embodiment of Fig. 15; shows a view of a graphic overlay according to the embodiment of Fig. 15; shows an isometric view of an edge-lit sign according to the embodiment of Fig.15.

DETAILED DESCRIPTION The present invention is illustrated below by reference to several embodiments of an emergency exit sign, where the illuminated edge-lit sign is: single-sided with an animated image; double-sided with an animated image, single-sided with both a static and an animated image; and double-sided with a static and an animated image. Reference to an embodiment as an emergency exit sign is for simplicity and clarity only, as such a sign is familiar to many people in a static form. Further, it may be used to illustrate the different aspects of the present invention as disclosed above.

It will be apparent to the person skilled in the art that there are many other types and uses of edge-lit signs to which the present invention may be applied, such as (without limitation) advertising signs, billboards, road signage and applications for signage in the mining industry and navigation (shipping and aircraft) among others, so that reference to an emergency exit sign only throughout this specification should not be seen as limiting.

All embodiments of the present invention are based on a light distribution assembly, generally indicated by arrow 1 in Fig. 1. The light distribution assembly 1 includes a rectangular light distribution panel 2 of dimension (in mm) 350x175x3. The light distribution panel is sandwiched between a first black-out sheet 3 and a second black-out sheet 4; both black-out sheets having the same dimensions as the light distribution panel. The first black-out sheet 3 and the second black-out sheet 4 are both formed by sandwiching an opaque sheet, typically a layer of carbon material, between two cover sheets. Suitable products include Carrolex Viprint 3800 .

The first black-out sheet 3, shown in Fig. 2, includes a first cut-out portion 5, which is laser cut in the form of the image to be animated. In this embodiment the first cut-out portion is configured as a horizontal arrow pointing to the right of the sign. Animation may be provided by sequentially illuminating the arrow from the left to the right of the sign.

Those skilled in the art will appreciate that the animated image may take numerous forms. In the case of an emergency sign the arrow may be horizontal with the arrow point left or right or may be vertical with the arrow point up or down. However, in other types of sign an arrow (for example) may be oriented at any angle to the vertical.

The first black-out sheet overlays the front face of the light distribution panel 2 which can be seen through the first cut-out portion 5 in Fig. 1. The light distribution panel 2 includes a plurality of independent light-conducting paths 6 that are oriented vertically. Features of the light distribution panel are discussed in more detail below.

The second black-out sheet 4, shown in Fig. 3, overlays the rear face of the light distribution panel 2. In this embodiment the second black-out sheet does not include a cut-out portion, i.e. it comprises a blank sheet that blocks all light emitted from the rear face of the light distribution panel 2.

Light is provided to each of the independent light-conducting paths 6 by a plurality of independently activatable light sources 7 (shown in Fig. 5) contained within the lighting circuit assembly 8.

Basic single-sided edge-lit sign with an image capable of animation A basic edge-lit sign 9, as shown in Fig. 4, may provide a single-sided edge-lit sign with an animated image. The sign is formed by attaching the lighting circuit assembly 8 to the top edge of the light distribution assembly 1, together with a frame 10 (shown by a dashed outline in Fig. 4 to allow a view into the sign) which surrounds the other three sides of the light distribution assembly, so that the frame and the lighting circuit assembly hold the light distribution assembly firmly in place.

The light distribution panel 2 is shown (schematically) in more detail in Fig. 5. The light distribution panel is formed from a light-conducting acrylic sheet (Shinko Lite or similar) which in this embodiment is 300 mm wide, 175 mm tall and 3 mm thick. A plurality of independent light-conducting paths, 11a – 11l, each 10 mm wide, are laser cut in the light-conducting acrylic sheet. Each of the light conducting paths is labelled sequentially from left, 11a, to right, 11l. For clarity, only 11a, 11f and 11l are indicated in the figures. This convention is used throughout the figures when multiple images of the same item are shown in the same figure.

Each of the light-conducting paths has one end located near a first edge 12 of the light distribution panel 2, the first edge being the top edge, i.e. the edge which lies adjacent the lighting circuit assembly 8 when the sign is assembled. In this embodiment, each light path is oriented vertically. The distal end of each of the light-conducting paths is open and terminates within the light-conducting acrylic sheet in a location beyond the first cut-out portion 5 of the first black-out sheet 3. The independent light-conducting paths are located on the light-conducting acrylic sheet such that part of the at least two (preferably all 12) of the light-conducting paths lie adjacent to the first cut-out portion 5.

The light-conducting paths, 11a – 11l, of the present embodiment have a uniform width. However, it will be appreciated that the width of the independent light-conducting paths may be chosen to suit the application, including some embodiments where some light-conducting paths having a different width to others on the same light distribution panel.

A three-sided opaque barrier 13 encloses the group of independent light-conducting paths, 11a – 11l.

The barrier 13 extends from near the first edge 12 of the light distribution panel 2 on one side of the independent light-conducting paths, around the paths and terminates near the first edge 12 of the light distribution panel on the other side of the light-conducting paths.

The three-sided opaque barrier, 13, separates the light distribution panel 2 into two regions: a first region 14, which includes the light-conducting paths; and a second region 15. A function of the opaque barrier 13 is to contain light transmitted into the light-conducting paths within the first region 14 of the light distribution panel, thus limiting (or preventing) stray light from entering the second region 15, or, conversely, any stray light from the second region 15 from entering the first region 14.

The rear face of the light-conducting acrylic sheet in the first region 14 is optically modified by screen printing a dot matrix 16a-16c onto the face, using a translucent ink. The dots are printed in a lens shape to focus light entering the dot back towards the other (front) face of the light-conducting acrylic sheet, and especially into the first cut-out portion 5 of the first black-out sheet 3. The size of the dots (essentially the height of each dot) gets progressively larger with the distance from the first edge 12 of the light distribution panel 2. The rate of increase in size is chosen to compensate for the decrease in intensity of light in the light-conducting path as light is progressively removed from it (i.e. by transmission into the first cut-out portion).

For convenience and simplicity, the progressive increase in size of the dots in the dot matrix is represented by a change of density of the dot matrix, from low density,16a, through medium density, 16b to high density 16c, as shown in Fig. 5. This representation is intended to illustrate that the properties of the dot matrix change with distance from the lighting assembly. In practice, it is the height of each dot that increases with distance from the lighting assembly. Rather than an abrupt change, as illlustrated in Fig. 5, the height of the dots increase in a gradual, smooth transition from the top of each light-conducting path, 11a – 11l, to the bottom.

The vertically oriented portions of the independent light-conducting paths, 11a – 11l, as shown in Fig. 5, are appropriate for animating a horizontal image from left to right (or vice versa) of the sign.

Fig. 6 shows another embodiment of a light distribution panel 17 in which the independent light- conducting paths, 11a’ – 11l’, are aligned horizontally in the region of a cut-out portion to be animated.

This arrangement may be used to animate a vertically oriented cut-out portion, such as a downward- pointing arrow. The animation may be created by first lighting the horizontal portion of 11a’, follow by illumination of 11b' and so on. The rear surface of the light distribution panel 17 is screen printed with a dot matrix (16a’-16c’). The increase in size of the dots is once again illustrated as changes in density of the dot matrix, from low density,16a’, through medium density 16b’, to high density 16c’. As discussed above, in preferred embodiments the density of the dot matrix does not change; rather the size of the dots (essentially the height of each dot) gets progressively larger as the light travels further along each light-conducting path.

The light distribution panel 2 includes protrusions 18 which are laser-cut out of the light-conducting acrylic sheet to form part of the first edge 12 of the light distribution panel. This provides a first edge in the form of a castellation. A top edge 19 of each protrusion 18 is flush with the top edge 20 of the first black-out sheet and the top edge 21 of the second black-out sheet (see closeup view shown in Fig. 7).

When the sign is assembled, the edges, 19, 20 and 21, are held firmly against a contact surface of the PCB 22 by the lighting circuit assembly 8 and the attached three-sided frame 10 (neither shown in Fig.7), to form a light entrapment channel 24.

The lighting circuit assembly 8 for this embodiment, as shown in Fig. 8, includes a contact surface formed by a printed circuit board (PCB) 22 onto which are mounted the first light sources in the form of 12 pairs of LEDs, 23a -23l, each pair including a white light LED and a green light LED. White and green are the only colours that can be used (by regulation/convention) with emergency exit lights.

The 12 pairs of LEDs, 23a -23l, are mounted onto the PCB 22 so that, when the sign is assembled, the first light source is located within the light entrapment channel 24, with one of the pairs of LEDS, 23a - 23l, facing the leading edge opposite one of the independent light-conducting paths, 11a – 11l, respectively.

The lighting circuit assembly 8 also includes a microprocessor 25 programmed to selectively activate or de-activate each of the pairs of LEDS, 23a -23l, and consequently each of the independent light- conducting paths, 11a – 11l.

The lighting circuit 8 is configured to mount the edge-lit sign to a surface of a structure, e.g. a ceiling or a wall. For mounting to a ceiling, the lighting circuit may be attached to the top of the light distribution assembly, while for mounting to a wall the lighting circuit may be attached to a side of the light distribution assembly.

Animation of the arrow (see Fig. 1) can be achieved by progressively switching the light in each independent light-conducting path from white (the default) to green (shown as grey in the drawings) using the microprocessor to switch each pair of LEDs sequentially. In the initial step of the sequence, as shown in Fig. 9a, white light is provided to all 12-independent light-conducting paths, 11a – 11l, i.e. all white LEDs are on and all green LEDs are off. In the second step (Fig. 9b), involving the first pair of LEDs, 23a, which is located opposite the first light-conducting path, 11a, the white LED is switched off and the green LED is switch on, with the remaining pairs of LEDs, 23b – 23l, all providing white light. This step results in the first light-conducting path, 11a, illuminated with a green light, while the remaining light- conducting paths are illuminated with a white light.

In the next step (Fig. 7c), involving the second pair of LEDs, 23b, the white LED is switched off and the green LED is switch on, while the remaining pairs of LEDs, 23c – 23l, all provide white light. After this step the first two light-conducting paths, 11a and 11b, are lit by green light, with the remaining light- conducting paths, 11c – 11l, all lit with white light.

This sequence continues (see Fig. 9d to Fig. 9h) until all light-conducting paths, 11a – 11l, are sequentially lit with green light (some of the steps have been amalgamed in the figures for simplicity). At this point the sequence reverts to the first step, as shown in Fig. 9a, with all light-conducting paths, 11a – 11l, lit with white light. A viewer of the edge-lit sign may see a white arrow which progressively changes to green from the base of the arrow to the tip, until the whole arrow is green.

Double-sided edge-lit sign with an image capable of animation on both the front and rear faces In another embodiment a double-sided animated edge-lit sign may be readily formed by including a second cut-out portion, 26, in the second black-out sheet, 4, as shown in Fig. 10. When the light paths are lit according to the above embodiment both sides of the edge-lit sign may show a white arrow which progressively changes to green from the base of the arrow to the tip, until the whole arrow is green.

Single-sided edge-lit sign with an image capable of animation and a static image In this embodiment, a single-sided edge-lit sign includes a static back-lit image as well as an animated image.

This embodiment includes a first photometric light distribution panel 27, illustrated in Fig. 11, which overlays the first black-out sheet 3. The first photometric light distribution panel 27 includes a light- conducting transparent acrylic panel 28, a face of which 28’ (the face located adjacent the first black-out sheet) is optically modified with a high-build screen printed dot matrix. As described above the height of the dot matrix increases with distance from the lighting circuit to compensate for a decrease in intensity of the light as it moves away from the light source. A function of the first photometric light distribution panel 27 is to provide uniform backlighting to the sign.

The lighting circuit 29 in this embodiment, as illustrated in Fig. 12, includes first light sources, 23a -23l, as described above and shown in Fig.8, as well as second light sources configured to provide edge light to the first photometric light distribution panel. The second light sources include an array of LEDs, 30, mounted on the PCB, 22, with each LED of the array located opposite a top edge of the first photometric light distribution panel 27. In keeping with the convention for emergency exit signs, each of the LEDs 30 provides white light only. In this embodiment each of the LEDs, 30, is mounted on the PCB 22 in a location outside of the first black-out sheet 3, the contact point of which is shown as a dashed line, 30, in Fig. 12.

The second light source 30 provides white backlighting to a first graphic overlay 31, shown in Fig. 13, which is configured to overlay the first photometric light distribution panel, 29. The first graphic overlay 31 includes a first translucent image 32, which overlays (precisely) the first cut-out portion 5 of the first black-out sheet 3, and is illuminated by light from the independent light-conducting paths 11a – 11l of the light distribution panel 2.

The first photometric light distribution panel also includes a second translucent image 33 which overlays the first photometric light distribution panel, 29, and is located away from the first cut-out portion 5 of the first backing sheet. The second translucent image, which in this embodiment is a static image in the form of a running figure entering a door, is constantly backlit by the white light from the second light source 30. When the light-distribution assembly 1, first photometric light distribution panel 27 and first graphic overlay 31, are assembled together as shown in Fig. 14; this arrangement together with the lighting assembly 8 (including the lighting circuit 29) and the frame 10 (see Fig. 4), forms a single-sided edge-lit sign 34 with both a static image and an animated image.

Double-sided edge-lit sign with an image capable of animation and a static image on both the front and rear faces of the sign In yet a further embodiment a double-sided edge-lit emergency sign 35 with both a static and an animated image on each face is shown in Fig. 15. A front face of this embodiment includes a first single- sided edge-lit sign with both static and animated images as described above (see 34 in Fig. 14). A rear side of the sign is configured as the mirror image (through the light distribution panel 2) of the components of the front side of the edge-lit sign.

The second black-out sheet 4’ in this embodiment includes a second cut-out portion 5’which is the mirror image of the first cut-out portion 5, as shown in Fig. 16.

A second photometric light distribution panel 36, which overlays the second black-out sheet 4’, includes a light-conducting acrylic panel 37, one face 37’ of which (the face located adjacent the second black-out sheet) is optically modified with a high-build screen printed dot matrix. As described above the height of the dot matrix increases with distance from the lighting circuit to compensate for a decrease in intensity of the light as it moves away from the light source.

The lighting circuit 38 in this embodiment, as illustrated in Fig. 18, includes a second light source configured to provide edge light to the second photometric light distribution panel. The second light source includes the array of LEDs, 23a -23l, which are located outside the first black-out sheet 3 and a further array of LEDs, 39, mounted on the PCB 22 in a location outside the second black-out sheet 4’,shown by the dashed line 37’ in Fig. 18, with each LED of the array 40 located opposite a top edge of the second photometric light distribution panel 37. In keeping with the convention for emergency exit signs, each of the LEDs 39 provides white The LEDs 39 provide white backlighting to a second graphic overlay 40 (Fig. 19) which is configured to overlay the second photometric light distribution panel, 36. The second graphic overlay includes a third translucent image 41, which overlays (precisely) the second cut-out portion of the second black-out sheet 5, and is illuminated by light from the independent light-conducting paths 11a – 11l of the light distribution panel 2.

The second photometric light distribution panel also includes a fourth translucent image 42 which overlays the second photometric light distribution panel 36. The second translucent image, which is a static image in the form of a running figure running through a door, is constantly backlit by white light from the LEDs 39.

Fig. 20 shows an isometric view of a two-sided edge-lit sign with a static and an animated image on each side. In this embodiment the sign looks the same whether viewed from the front or the back. In order from the front to the rear we have the first graphic overlay, 31, the first photometric light distribution panel, 27, the light distribution assembly, 1, the second photometric light distribution panel, 36, and the second graphic overlay, 42. In this embodiment the second black-out sheet includes a second cut-out portion, 4’, as shown in Fig. 16.

It should be appreciated that, although the embodiments of the edge-lit sign described above include a flat rectangular shape, the various components may be curved and of any desired shape as required by the design of the sign. Similarly, there is no limitation on the configuration of the images, both static and to be animated.

The invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features.

Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

1. An edge-lit sign including: a light distribution assembly; and a lighting assembly, wherein the light distribution assembly includes: a first black-out sheet and a second black- out sheet, the first black-out sheet including a first cut-out portion in the shape of an image to be animated: and a light distribution panel sandwiched between the first black-out sheet and the second black-out sheet, the light-distribution panel including at least two independent light-conducting paths which extend into a region of the light-conducting panel adjacent the first cut-out portion, and wherein the independent light-conducting paths are optically modified in the region of the first cut-out portion to transmit light from the light-conducting path through the first cut-out portion, wherein the lighting assembly is configured to attach to the light distribution assembly and hold it in place, and includes a first lighting circuit having at least two independently activatable first light sources, and the first lighting circuit is configured to provide edge lighting from the at least two independently activatable first light sources, one of which is configured to provide edge lighting to one of the independent light-conducting paths and the other is configured to provide edge lighting to the other independent light-conducting path, and the lighting circuit includes a switching device configured to activate or de-activate light from the two first light sources to independently light each of the two independent light- conducting paths in a predetermined sequence.

2. An edge-lit sign as claimed in claim 1 wherein the independently activatable first light sources are LEDs.

3. An edge-lit sign as claimed in claim 1 wherein each of the first light sources includes two lights, one providing a first colour and the other providing a second colour.

4. An edge-lit sign as claimed in any one of claims 1 to 3, wherein the switching device includes a microprocessor configured to selectively activate the two independently activatable light sources in a predetermined sequence.

5. An edge-lit sign as claimed in any one of claims 1 to 4, wherein one end of each of the at least two independent light-conducting paths is located near a first edge of the light distribution panel, being the edge of the light distribution panel adjacent the lighting circuit assembly.

6. An edge-lit sign as claimed in any one of claims 1 to 5 wherein the first edge of the light distribution panel includes a transparent projection configured such that a dimension of the first black-out sheet is equal to a combined dimension of the light distribution panel and the transparent projection.

7. An edge-lit sign as claimed in any one of claims 1 to 6, wherein each of the first light sources is located within a light entrapment gulley formed between the lighting circuit assembly and the first edge of the light distribution panel.

8. An edge-lit sign as claimed in any one of claims 1 to 7, wherein the first light source includes two independently switchable first light sources located within the light entrapment channel, wherein the two independently switchable first light sources are arranged such one or other of the independently switch-able first light sources is located opposite an end of one or other of the at least two light-conducting path.

9. An edge-lit sign as claimed in any one of claims 1 to 8, wherein the light-conducting paths include light-conducting material attached to a substrate.

10. An edge-lit sign as claimed in any one of claims 1 to 9, wherein the light distribution panel includes a light-conducting acrylic material.

11. An edge-lit sign as claimed in any one of claims 1 to 10, wherein the independent light- conducting paths are formed by removing the light-conducting acrylic material on either side of each of the independent light-conducting paths.

12. An edge-lit sign as claimed in any one of claims 1 to 11, wherein the optically modified surface of the light-conducting path includes a dot matrix formed by screen printing a translucent ink onto a surface of the light-conducting path.

13. An edge-lit sign as claimed in claim 12 wherein a dimension of the dots of the dot matrix increases with a distance from the first lighting source.

14. An edge-lit sign as claimed in any one of claims 1 to 13 wherein the independent light- conducting paths are bounded at least partially by an opaque barrier.

15. An edge-lit sign as claimed in any one of claims 1 to 14, including a second cut-out portion formed in the second black-out sheet, the second cut-out portion configured in the shape of an image to be animated, and the light distribution panel includes at least two independent light-conducting paths which extend into a region of the light distribution panel adjacent the second cut-out portion.

16. An edge-lit sign as claimed in claim 15 including: a first photometric light distribution panel configured to overlay the first black-out sheet; and a first graphic overlay configured to overlay the first photometric light distribution panel, wherein the lighting circuit includes a second light source configured to provide edge lighting to the first photometric light distribution panel, and the first graphic overlay includes a first translucent image which overlays the first cut-out portion of the first black-out sheet and a second translucent image; and a surface of the first photometric light distribution panel is optically modified.

17. An edge-lit sign as claimed in claim 16, wherein the optically modified surface of the first photometric light distribution panel includes a dot matrix formed by screen printing a translucent ink onto a surface of the first photometric light distribution panel.

18. An edge-lit sign as claimed in any one of claims 14 to 17, wherein the edge-lit sign includes: a second photometric light distribution panel configured to overlay the second black- out sheet; and a second graphic overlay configured to overlay the second photometric light distribution panel, wherein the second graphic overlay includes a third translucent image which overlays the cut-out portion of the second black-out sheet and a fourth translucent image, and a surface of the second photometric light distribution panel is optically modified to provide light to the third translucent image and the fourth translucent image.