GB2325772A

GB2325772A - Display signs

Info

Publication number: GB2325772A
Application number: GB9711249A
Authority: GB
Inventors: Malcolm Ponsford
Original assignee: QUEENSBURY INTERNATIONAL LIMIT
Current assignee: QUEENSBURY INTERNATIONAL LIMIT
Priority date: 1997-05-31
Filing date: 1997-05-31
Publication date: 1998-12-02
Also published as: GB9711249D0

Abstract

An edge-lit single-sided display sign comprising a light transmissive sheet 12 having an opaque backing 13 and a design sheet 14 disposed over the front surface thereof, an array of essentially opaque dots 15 being applied to the light-transmissive sheet beneath the design sheet is described. By producing such a sign the expense of applying a matrix of dots to both surfaces of a light-transmitting sheet is avoided by virtue of the provision of an opaque backing sheet or coating layer. The density of the dots in the array may increase towards the centre of the sheet.

Description

DISPLAY SIGNS This invention relates to illuminated display signs, of the edge-lit single-sided display type.

Back-lit illuminated display signs are known, for example for marking the exits of a building, and comprise a panel to which translucent lettering or other indicia has been applied, the sign being substantially box-shaped and enclosing a light source. Illuminated display signs are also known for other purposes such as advertising hoardings, and it is with such signs that the present invention is especially concerned. Known illuminated advertising hoardings may be back-lit but may also be edge-lit, in which they are illuminated either from the top, from the bottom or from at least one side edge.

Such signs are generally used with translucent display panels and proposals have previously been made for improving the transmission of light from the edge towards the centre of the sign, to provide overall evenness or uniformity of illumination. For example, WO 92/05535 discloses a single-sided illuminated display system including an edge-lit transmitting sheet having two opposed surfaces with dots applied to each surface, in which the dots are formed as a matrix of etched, painted or screen-printed dots substantially covering the surfaces. An opaque backing sheet is positioned in contact with one surface of the light-transmitting sheet with the design applied to the other surface over the dots.

It is an object of the present invention to provide a single-sided edge-lit display sign which avoids the expense of applying a matrix of dots to both surfaces of the light-transmitting sheet.

Accordingly, the present invention provides in one aspect a single-sided edge-lit display sign comprising a lighttransmissive sheet having an opaque backing and a design sheet disposed over the front surface thereof, in which an array of essentially opaque dots is applied to the light-transmissive sheet beneath the design sheet.

The opaque backing may be applied as a coated layer to the light-transmissive sheet but it preferably comprises a separate sheet material which may be a plastics material or metallic. The opaque backing is advantageously reflective to light.

The design sheet is preferably a flexible lighttransmissive sheet substrate carrying a design applied for example by painting, printing or stencilling, such that the illumination from behind will enhance the appearance of the design. The sheet is preferably spaced from the front surface of the light-transmissive sheet to avoid causing physical damage to the array of dots.

Optionally, the front surface of the light-transmissive sheet carries an intermediate barrier layer, sheet or film over the array of dots, over which the design sheet is disposed.

Advantageously, at least two edges of the sign are lit, preferably from opposed edges. That is, two light sources may illuminate the sign respectively from the top and bottom edges or from both side edges. Preferably, fluorescent light tubes are used, although other light sources such as light-emitting fibre optic cables may be used, for example disposed about all edges of the sign.

The array of essentially opaque dots preferably comprises a matrix of dots painted, screen printed or etched onto the surface of the light transmissive sheet. Painted or screen printed dots are, advantageously, white such that they do not affect the colour rendition of the design.

The density of the dots preferable increases towards the centre of the sheet, to maintain uniformity of illumination over the entire surface of the sheet. The density of the dots may be increased either by increasing the size of the individual dots or by decreasing the spaces therebetween. Typically, the dots cover 3% of the surface close to the light source rising to about 12% at the furthest point from the light source. The other surface of the light transmissive sheet is generally of mill finish.

Optionally, reflectors may be used behind each light source to reflect more light towards the edges of the light transmissive sheet.

Display signs according to the invention are generally contained in a housing or casement comprising protective box members at least for the light sources and including reflectors to direct maximum light output or flux density at the edges of the light transmissive sheet while minimising light leakage.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawing which is a partially cut away perspective view of an illuminated poster display sign edge-lit from the opposed side edges.

With reference to the drawing, an illuminated poster display sign, generally indicated 10, includes two fluorescent light tubes 11, a light transmissive acrylic sheet 12, an opaque backing sheet 13 and a translucent poster 14. The housing is shown in broken outline.

Opaque white dots 15 are screen printed onto the outer face of the sheet 12.

Claims

CLAIMS:

1. A single-sided edge-lit display sign comprising a light-transmissive sheet having an opaque backing and a design sheet disposed over the front surface thereof, in which an array of essentially opaque dots is applied to the light-transmissive sheet beneath the design sheet.

2. A display sign according to claim 1 in which the opaque backing is applied as a coated layer.

3. A display sign according to claim 1 in which the opaque backing comprises a plastics or metallic sheet material.

4. A display sign according to any preceding claim in which the opaque backing is reflective to light.

5. A display sign according to any preceding claim in which the design sheet comprises a flexible lighttransmissive sheet substrate carrying a design applied thereto.

6. A display sign according to any preceding claim in which the design sheet is spaced from the front surface of the light-transmissive sheet.

7. A display sign according to any preceding claim in which the front surface of the light-transmissive sheet carries an intermediate barrier layer, sheet or film over the array of dots.

8. A display sign according to any preceding claim in which at least two edges of the sign are lit.

9. A display sign according to claim 8 in which the sign is lit from opposed edges.

10. A display sign according to any preceding claim in which the sign is lit by means of fluorescent light tubes.

11. A display sign according to any preceding claim in which the array of essentially opaque dots comprises a matrix of dots painted, screen printed or etched onto the surface of the light transmissive sheet.

12. A display sign according to any preceding claim in which the dots are white.

13. A display sign according to any preceding claim in which the density of the dots in the array increases towards the centre of the sheet.

14. A display sign according to claim 13 in which the density of the dots is increased by increasing the size of the individual dots.

15. A display sign according to claim 13 in which the density of the dots is increased by decreasing the spaces between the dots.

16. A display sign according to any of claims 13 to 15 in which the dots cover about 3% of the surface close to the light source, rising to about 12% of the surface at the furthest point from the light source.

17. A display sign according to any preceding claim, further comprising reflectors behind each light source.

18. A display sign according to any preceding claim, in which the sign is contained in a housing or casement comprising protective box members.

19. A display sign substantially as hereinbefore described with reference to Figure 1.