WO2006046106A2

WO2006046106A2 - Improved slim-line luminous sign

Info

Publication number: WO2006046106A2
Application number: PCT/IB2005/003170
Authority: WO
Inventors: Giancarlo Miani
Original assignee: Giancarlo Miani
Priority date: 2004-10-26
Filing date: 2005-10-25
Publication date: 2006-05-04
Also published as: WO2006046106A3; ITTO20040742A1

Abstract

A slim-line luminous sign (1) having a box casing (2) without one of its lateral walls; a transparent sheet (3) fixed to the box casing (2) to define the missing lateral wall of the box casing (2); at least one longitudinal light source (10, 16) housed inside the box casing (2) to generate a light beam that issues from the front face (3a) of the transparent sheet (3) ; and a semitransparent decorative film (4) covering the front face (3a) of the transparent sheet; the luminous sign (1) also having a spacer frame (5), which covers the peripheral edge of the front face (3a) of the transparent flat sheet (3), is interposed between the decorative film (4) and the front face (3a) of the transparent sheet to keep the decorative film (4) at a predetermined distance from the transparent flat sheet (3), and is so shaped that at least one (5a) of its inner sides is defined by a flat surface sloping with respect to the surface of the front face (3a) of the transparent flat sheet (3) by an angle (α) ranging between 40° and 70°.

Description

IMPROVED SLIM-LINE LUMINOUS SIGN

TECHNICAL FIELD The present invention relates to an improved slim¬ line luminous sign. BACKGROUND ART

As is known, at present, the most commonly used luminous signs substantially comprise a parallelepiped- shaped box casing without one of the two major lateral walls; a transparent Plexiglas sheet fixed to the box casing to form the missing major lateral wall; a semitransparent decorative film fixed to the front or outer face of the Plexiglas sheet; and a number of fluorescent gas-discharge lamps with a straight fluorescent tube - commonly referred to as "neon tubes" - fixed inside the box casing to illuminate the rear or inner face of the Plexiglas sheet so that the writing or decoration on the decorative film is visible from the outside.

Obviously, for the semitransparent decorative film on the front face of the Plexiglas sheet to be evenly illuminated, the fluorescent gas-discharge lamps must be arranged accordingly at the bottom of the box casing, and the Plexiglas sheet must be located at least 3 or 4 centimetres away from the lamps.

Given the above dimensional restrictions and the total height of the fluorescent gas-discharge lamps, the depth of the luminous sign as a whole varies between 10 and 15 centimetres, depending on the desired uniformity and quality of the backlighting, and may be incompatible with certain types of installation. To reduce the depth of luminous signs of the type described above, slim-line luminous signs have recently been devised and marketed, in which the light produced by the gas-discharge lamps penetrates the Plexiglas sheet through the sides of the sheet, and is trapped inside the sheet by virtue of the same physical principle employed in optical fibres. In luminous signs of this type, the light issues gradually through the front face of the Plexiglas sheet, to backlight the decorative film fixed to it, through a number of small dead holes appropriately arranged over the whole front face surface of the Plexiglas sheet to outwardly divert the light trapped inside the sheet. The rear face surface of the Plexiglas sheet, on the other hand, is covered with a reflecting opaque film to prevent the light from issuing accidentally from the wrong side.

Unfortunately, location of the "neon tubes" close to the sides of the Plexiglas sheet, and the fastening means normally used to fasten the Plexiglas sheet and the "neon tubes" removably inside the box casing, result in anomalous propagation of the light and unsightly, unevenly bright bands at the lateral edges of the Plexiglas sheet. DISCLOSURE OF INVENTION

It is an object of the present invention to provide a slim-line luminous sign designed to eliminate the aforementioned drawbacks.

According to the present invention, there is provided a slim-line luminous sign as claimed in Claim 1 and possibly in any one of the following Claims depending directly or indirectly on Claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows an exploded view in perspective, with parts in section and parts removed for clarity, of a slim-line luminous sign in accordance with the teachings of the present invention;

Figure 2 shows a lateral section of the slim-line luminous sign in Figure 1;

Figure 3 shows a side view, with parts in section and parts removed for clarity, of a first variation of the slim-line luminous sign in Figures 1 and 2;

Figure 4 shows a side view, with parts in section and parts removed for clarity, of a second variation of the slim-line luminous sign in Figures 1 and 2. BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in Figures 1 and 2 indicates as a whole a slim-line luminous sign substantially comprising a preferably, though not necessarily, substantially parallelepiped-shaped box casing 2 without one of its major lateral walls; a transparent flat sheet 3 complementary in shape to the missing major lateral wall, i.e. substantially rectangular, and fixed to box casing 2 to form the missing major lateral wall; and a sem±transparent decorative film 4, also complementary in shape to the missing major lateral wall, and which covers the front or outer face 3a of transparent flat sheet 3.

Unlike known luminous signs, luminous sign 1 also comprises a spacer frame 5, which is substantially the same shape as the peripheral edge of transparent flat sheet 3, i.e. as the peripheral edge of the missing major lateral wall, covers front face 3a, or rather the peripheral edge, of transparent flat sheet 3, and is interposed between decorative film 4 and front face 3a of transparent flat sheet 3 to keep decorative film 4 substantially parallel to and facing front face 3a of transparent flat sheet 3, and at a predetermined distance - obviously equal to the thickness of spacer frame 5 - from front face 3a of transparent flat sheet 3. More specifically, spacer frame 5 is substantially rectangular, and is fixed to transparent flat sheet 3 and/or box casing 2 so that its rear face rests on, and so covers, the peripheral edge of front face 3a of transparent flat sheet 3; while the peripheral edge of decorative film 4 is fixed to the front face of spacer frame 5 to keep decorative film 4 taut over transparent flat sheet 3, and substantially parallel to and facing front face 3a of transparent flat sheet 3.

With reference to Figures 1 and 2, in addition to the above, spacer frame 5 is shaped so that at least one of its inner sides, i.e. at least one of its sides facing the centre of the frame and hereinafter indicated 5a, is defined by a flat surface sloping with respect to the surface of front face 3a of transparent flat sheet 3 by an angle α ranging between 40° and 70° and preferably, though not necessarily, of 45°.

With reference to Figure 1, in the example shown, box casing 2 is defined by a straight supporting beam 6 with a substantially ω-shaped cross section and preferably, though not necessarily, made of metal or plastic; and by two flat end covers 7 fixed to the two ends of supporting beam 6 to form, with the sides of the beam, a substantially rectangular peripheral frame, inside which transparent flat sheet 3 is locked.

More specifically, supporting beam 6 is shaped to comprise a flat central portion 6a extending parallel to the longitudinal axis of the beam; and two substantially C-shaped lateral portions 6b specular with respect to each other and projecting from the sides of central portion 6a to form two longitudinal cavities or seats 8, which extend seamlessly along the whole length of supporting beam 6 and parallel to the longitudinal axis of the beam.

With reference to Figure 1, in the example shown, the two lateral portions 6b of supporting beam 6 terminate with two parallel, facing, substantially coplanar, flat portions 6c, which define a rectangular opening over central portion 6a of supporting beam 6 and, more generally, over the bottom of box casing 2.

More specifically, in the example shown, flat portions 6c of supporting beam 6 substantially lie in the same plane parallel to and appropriately detached from the plane defined by central portion 6a of supporting beam 6, so as to define, with central portion 6a of supporting beam 6, a gap in which transparent flat sheet 3 is inserted to completely close the rectangular opening defined by flat portions 6c of supporting beam 6.

In the example shown, each of flat end covers 7 is defined by a flat, substantially rectangular metal sheet 7 preferably, though not necessarily, made of the same material as supporting beam 6, and sized to completely close the end of supporting beam 6 to prevent withdrawal of transparent flat sheet 3.

Flat end cover 7 may, obviously, be complementary in shape to the cross section of supporting beam 6. With reference to Figures 1 and 2, transparent flat sheet 3 is preferably, though not necessarily, made of polymethyl methacrylate (so-called Plexiglas or PMMA) or similar plastic material (e.g. polyester) , and is of a thickness approximately equal to but no more than the distance between the surface of central portion 6a of supporting beam 6 and the plane defined by the two flat portions 6c, so as to be insertable inside the gap between the rectangular opening, bounded laterally by flat portions 6c, and the bottom of box casing 2, or rather central portion 6a of supporting beam 6.

In addition, transparent flat sheet 3 is wider than the distance between the ends of the two flat portions 6c of supporting beam 6, and is approximately the same length as, but no longer than, supporting beam 6, so that the minor lateral edges of transparent flat sheet 3 rests against the two flat end covers 7.

In other words, transparent flat sheet 3 is sized so that the central portion of its rear or inner face 3b rests on central portion 6a of supporting beam 6, and some portions of the peripheral edge of front face 3a rest on flat portions 6c of supporting beam 6.

With reference to Figures 1 and 2, spacer frame 5 substantially comprises four straight sections of appropriate cross section, which are fixed end to end to one another in parallel facing pairs to form the four sides of a rectangle.

More specifically, in the example shown, spacer frame 5 is defined by two longitudinal members 9 with a cross section substantially in the form of a right isosceles triangle, and by two flat elongated rectangular plates, which are arranged in parallel facing pairs to form the two major sides and two minor sides of the rectangle respectively.

More specifically, with reference to Figures 1 and 2, the two longitudinal members 9 are fixed directly to the two flat portions 6c of supporting beam 6, so that the flat lateral surface of longitudinal member 9 defined by one of the two catheti of the right isosceles triangle rests on front face 3a of transparent flat sheet 3 to cover the major lateral edge of transparent flat sheet 3, and the flat lateral surface defined by the hypotenuse of the right triangle faces the centre of spacer frame 5 to define the inner side 5a of spacer frame 5. In this case, the flat surface of inner side 5a therefore slopes at a 45° angle with respect to the surface of front face 3a of transparent flat sheet 3.

The two flat elongated rectangular plates forming the rest of spacer frame 5 are defined by two flat portions of flat end covers 7 closing the axial ends of supporting beam 6. In spacer frame 5 so formed, the two minor inner sides are each defined by a flat surface substantially perpendicular to the surface of front face 3a of transparent flat sheet 3, and the two major inner sides - hereinafter indicated 5a - are each defined by a flat surface sloping 45° with respect to the surface of front face 3a of transparent flat sheet 3.

Spacer frame 5 may, obviously, also be made from four right-triangle-section members, so that each of the four inner sides of the frame is defined by a flat surface sloping with respect to the surface of front face 3a of transparent flat sheet 3 by an angle α ranging between 40° and 70° and preferably, though not necessarily, of 45°.

With reference to Figures 1 and 2, luminous sign 1 also comprises two fluorescent gas-discharge lamps 10 or similar longitudinal, low-consumption light sources, each located below a respective major inner side 5a of spacer frame 5.

In the example shown, each of the two fluorescent lamps 10 comprises a straight fluorescent tube 10a approximately the same length as, but no longer than, supporting beam 6, i.e. box casing 2, and is fixed inside box casing 2 with fluorescent tube 10a facing rear or inner face 3b of transparent flat sheet 3 and alongside a corresponding major lateral edge of transparent flat sheet 3.

More specifically, in the example shown, each fluorescent lamp 10 is housed, lying on one side, inside a corresponding longitudinal seat 8 of box casing 2, so that straight fluorescent tube 10a and the corresponding supporting base 10b are both adjacent to both the surface of rear face 3b of transparent flat sheet 3 and the back of box casing 2, with the supporting base 10b of the fluorescent lamp facing the centre of box casing 2.

Preferably, though not necessarily, luminous sign 1 also comprises a film, metal plate, or other opaque cover 3170

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sheet 12, possibly reflecting, which covers the surface of rear face 3b of transparent flat sheet 3 directly- facing fluorescent lamps 10, to prevent the light produced by the lamps from directly penetrating transparent flat sheet 3 through rear or inner face 3b of the sheet. More specifically, in the example shown, the film, metal plate, or other opaque cover sheet 12 covers substantially the whole surface of rear or inner face 3b of transparent flat sheet 3. With reference to Figures 1 and 2, in addition to the above, luminous sign 1 also comprises two prismatic bodies 13 made of transparent material, and each of which is located just below a respective major inner side 5a of spacer frame 5, and extends between a major lateral side of transparent flat sheet 3 and the adjacent fluorescent tube 10a of fluorescent lamp 10 to conduct the light produced by the lamp into transparent flat sheet 3 through the side of the sheet; which light then issues from the surface of front face 3a of transparent flat sheet 3 to backlight semitransparent decorative film 4.

Each of the two prismatic bodies 13 is substantially the same length as transparent flat sheet 3, is housed inside the corresponding longitudinal seat 8 of box casing 2 with a first end resting on the major lateral side of transparent flat sheet 3, and a second end resting on the body of the adjacent fluorescent tube 10a, and is shaped to collect the light emitted by respective fluorescent lamp 10, and then divert the light to the corresponding major lateral side of transparent flat sheet 3 along a substantially U-shaped path.

More specifically, in the example shown, the two prismatic bodies 13 are made of transparent polycarbonate, and are glued directly to the two major lateral sides of transparent flat sheet 3. Alternatively, the two prismatic bodies 13 may be made of other transparent materials, such as polymethyl methacrylate

(PMMA.) or polyester. The two prismatic bodies 13 may, obviously, even be formed in one piece with transparent flat sheet 3, by appropriately bending the ends of transparent flat sheet 3.

With reference to Figures 1 and 2, luminous sign 1 may also comprise, for each fluorescent lamp 10, a shell or guard 14, which is made of reflecting material, is housed inside longitudinal seat 8 of the box casing to surround the whole length of fluorescent lamp 10 inside the seat, and is shaped to divert the light produced by the lamp onto the end of the prismatic body 13 resting on fluorescent tube 10a of the lamp. The shell may also be made of electrically insulating material to enhance the passive safety of luminous sign 1.

With reference to Figure 1, luminous sign 1 preferably, though not necessarily, also comprises a rectangular retaining collar 15 sized to fit onto spacer frame 5, and which has a peripheral flange 15a projecting towards the centre of the collar so as to rest on the front face of spacer frame 5 and grip the peripheral edge of decorative film 4.

To complete the above, it should be pointed out that, like certain known luminous signs, transparent flat sheet 3 comprises a number of small dead holes (not shown) appropriately distributed over the whole surface of front face 3a to gradually divert outwards the light trapped inside the body of transparent flat sheet 3, and so backlight decorative film 4 covering front face 3a of the sheet. In combination with or instead of the above solution, the surface of front face 3a of transparent flat sheet 3 may be sanded to produce a rough surface finish.

Operation of luminous sign 1 is easily deducible from the foregoing description with no further explanation required.

As regards spacer frame 5, on the other hand, tests show that inner sides 5a, with flat surfaces sloping at an angle α with respect to the surface of front face 3a of transparent flat sheet 3, provide for maximizing the area of decorative film 4 backlighted by the light from front face 3a of transparent flat sheet 3, and for concealing the two flat portions 6c of supporting beam 6 and everything beneath them, including the two prismatic polycarbonate bodies 13 for directing the light into transparent flat sheet 3 through the lateral sides of the sheet.

Close to inner sides 5a, the light rays impinging on the surface of front face 3a of transparent flat sheet 3 with an. angle of incidence, with respect to the vertical, substantially equal to the specific limit angle of the material are reflected again onto decorative film 4 without encountering any obstacles, and can therefore reach a point of decorative film 4 extremely close to the peripheral edge of decorative film 4 and not directly illuminated by front face 3a of transparent flat sheet 3.

The advantages of luminous sign 1 as described and illustrated herein are obvious: by virtue of the particular construction solutions employed, the whole surface of decorative film 4 of luminous sign 1 is backlighted uniformly, so that a number of luminous signs 1 can be arranged adjacent to one another to form large- size modular signs. In addition, the overall depth of luminous sign 1 is much less than that of conventional luminous signs, with no increase in manufacturing cost.

Clearly, changes may be made to luminous sign 1 as described and illustrated herein without, however, departing from the scope of the present invention.

For example, in the Figure 3 variation, instead of two fluorescent gas-discharge lamps 10, luminous sign 1 comprises two rows of light-emitting diodes, or so-called LEDs, 16 housed inside spacer frame 5, so that each substantially faces front face 3a of transparent flat sheet 3, and is parallel to and alongside a respective major lateral edge of the sheet.

More specifically, the two rows of light-emitting diodes 16 are located between transparent flat sheet 3 and decorative film 4, outside the perimeter of transparent flat sheet 3, and are each housed in the rear or concealed face of an elongated rectangular flat plate 17, which is fixed to box casing 2 with one lateral side resting on the surface of front face 3a of transparent flat sheet 3. Flat plate 17 also slopes at a predetermined angle α with respect to the surface of front face 3a, so that the front or exposed face of flat plate 17 defines the flat surface of inner side 5a of spacer frame 5.

In the example shown, flat plate 17 is made of metal to dissipate operating heat more effectively, and is fixed to the body of box casing 2 by known screws 18. In this variation, the two prismatic bodies 13 are located inside box casing 2, partly above front face 3a of transparent flat sheet 3, so that a first end rests on the major lateral side of transparent flat sheet 3, and a second end rests on the row of light-emitting diodes 16. In this case too, the two prismatic bodies 13 are obviously shaped to collect the light emitted by light- emitting diodes 16, and then divert the light onto the major lateral side of transparent flat sheet 3 along a substantially V- or L-shaped path. In the Figure 4 variation, fluorescent lamps 10 or the rows of light-emitting diodes 16 rest directly on the lateral sides of transparent flat sheet 3, beneath the two longitudinal members 9, so that luminous sign 1 has 005/003170

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no prismatic bodies 13.

Obviously, the sides in question must still be covered and masked by corresponding inner sides 5a of spacer frame 5. In a further variation, not shown, luminous sign 1 may even comprise only one light source, be it a fluorescent lamp 10 or a row of light-emitting diodes 16, for illuminating the side of transparent flat sheet 3 either directly or via a prismatic body 13.

Claims

1) A slim-line luminous sign (1) comprising a box casing (2) without one of its lateral walls; a transparent sheet (3) fixed to the box casing (2) to define the missing lateral wall of said box casing (2) ; at least one longitudinal light source (10, 16) housed inside the box casing

(2) to generate a light beam that issues from the front face (3a) of said transparent sheet (3) ; and a semitransparent decorative film (4) covering said front face (3a) of said transparent sheet (3) ; the luminous sign (1) being characterized by also comprising a spacer frame (5) covering the peripheral edge of the front face (3a) of said transparent flat sheet (3) and interposed between the decorative film (4) and said front face (3a) to keep the decorative film (4) at a predetermined distance from the transparent flat sheet

(3) ; said spacer frame (5) being so shaped that at least one (5a) of its inner sides is defined by a flat surface sloping with respect to the surface of the front face (3a) of said transparent flat sheet (3) by a predetermined angle (α) ranging between 40° and 70°.

2) A luminous sign as claimed in Claim 1, characterized in that said predetermined angle (α) is substantially 45°.

3) A luminous sign as claimed in Claim 1 or 2, characterized in that said at least one longitudinal light source (10, 16) is housed in the box casing (2) , B2005/003170

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parallel to and alongside a corresponding lateral side of said transparent sheet (3) , and below said inner side (5a) of the spacer frame (5) .

4) A luminous sign as claimed in Claim 3, characterized in that said at least one longitudinal light source (10, 16) is housed in the box casing (2), resting on the lateral side of said transparent sheet (3).

5) A luminous sign as claimed in Claim 3, characterized in that said at least one longitudinal light source (10, 16) is housed in the box casing (2) , parallel to and alongside a corresponding lateral side of said transparent sheet (3) , and facing the front face

(3a) or rear face (3b) of said transparent sheet (3) ; said luminous sign (1) also comprising a light-diverting body (13) located below said inner side (5a) of the spacer frame (5) and extending between said lateral side of the transparent sheet (3) and said light source (10) to direct onto said lateral side the light produced by the light source (10) .

6) A luminous sign as claimed in Claim 5, characterized by also comprising an opaque cover member (12) interposed to cover the surface of the rear face (3b) of said transparent sheet (3) . 7) A luminous sign as claimed in any one of the foregoing Claims, characterized in that said light source (10) comprises a fluorescent gas-discharge lamp (10) .

8) A luminous sign as claimed in any one of Claims 1 003170

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to 6, characterized in that said light source (16) comprises a row of light-emitting diodes (16) .

9) A luminous sign as claimed in any one of the foregoing Claims, characterized in that said box casing (2) comprises a straight supporting beam (6) , and two flat end covers (7) fixed to the two ends of said supporting beam (6) .

10) A luminous sign as claimed in any one of the foregoing Claims, characterized in that said transparent sheet (3) comprises a number of dead holes appropriately arranged on the surface of one of its two faces (3a, 3b) .