GB2250125A - Illuminated visual display - Google Patents

Abstract

The invention relates to an illuminated visual display apparatus wherein an illuminating source directs light to one end of a bundle of fibres and the light is transmitted along the fibres to define a visual display remote from the illuminating source. The ends of the fibres adjacent the illuminating source 16 are clamped together and the other ends of the fibres are supported in spaced apart relationship by a support means, in the same relationship as the clamped ends of the fibres so that a pattern of light shades or colours applied to the clamped fibre ends is reproduced at the spaced apart ends. The support means 14 may be a wire, mesh or perforated means. An element carrying images having different light transmission characteristics, may be positioned between illuminating source and bundle of fibres, and this element may be recessed conveyor belts 18, 19 carrying transparencies in their recess. Cooling air may be introduced between illuminating source and bundle of fibres suitably by means of a rotatable apertured disc (32, Figure 4). <IMAGE>

Description

"IMPROVEMENTS IN OR RELATING TO VISUAL DISPLAY APPARATUS" This invention relates to visual display apparatus and, more specifically, to illuminated visual apparatus.

Illuminated visual display apparatus is well known in the art and generally comprises stacked rows of light emitting elements, such as electric bulbs or light emitting diodes (LED's), and whereby selected light emitting elements are illuminated to comprise the illuminated visual display.

In more sophisticated arrangements the illumination of the light emitting elements is controlled by a computer and whereby, under the control of the computer, selected ones or groups of illuminating elements are illuminated to afford different visual displays.

A problem with prior art illuminated visual display apparatus using electric bulbs or LED's arises from the relatively poor life of such devices and the loss of one or a small number of such light emitting elements can seriously effect the display. Thus, to maintain an effective display, failed or damaged light emitting elements must be replaced as quickly as possible and the maintenance for such displays is expensive, particularly when the visual display is in a position where the maintenance personnel must use specialised equipment, such as platform cranes, to obtain access to the apparatus.

A further problem in using electric bulbs or LED's as the light emitting elements arises from the space on the display occupied by each light emitting element and the essential spacing of the said elements from one another, and which spacings limit the number of light emitting elements as can occupy a given area of display. As the detail obtainable in a visual display is dependant upon the number of light emitting elements in the display the detail possible for any given area of display using electric bulbs or LED's is severely limited.

It is also well known in the art to use optical fibres for visual displays.

In one such arrangement a bundle of optical fibres has all the fibres in one of its ends bound together and the fibres are free for the greater part of their lengths from the bound end so that when the bound end is lowermost the fibres above the clamped end are free to adopt a bushlike form. When an illuminating source shines onto the bound ends of the optical fibres light is transmitted along the fibres and illuminates the ends of the fibres remote from the bound end.

While such a display is attractive it is incapable of displaying a controlled visual image.

In another prior art arrangement a bundle of optical fibres is clamped at both its ends with the optical fibres in the same order at both ends of the bundle. With such an arrangement an illuminated visual image applied to one end of the bundle is reproduced at the other end of the bundle, but on the same scale.

The present invention seeks to provide a method for making an illuminated visual display apparatus which is robust, capable of displaying any desired form or pattern visual display in any desired detail and which is capable of affording a wide range of different visual displays.

According to the present invention there is provided a method for generating an illuminated display comprising the steps of forming a bundle of optical fibres, securing together the end regions of all the fibres in a first end of the bundle in a desired order and supporting the end regions of the fibres in the second end of said bundle in spaced apart relationship, with the fibres at the second bundle end in the same order as for the first bundle end, and illuminating the first end of the bundle.

Preferably the method includes the steps of assembling the end regions of the fibres in the first bundle end in a series of rows in stacked relationship, with a substantially equal number of fibre end regions in each said row.

Preferably the method includes the steps of assembling the said end regions of the fibres in the first bundle end in a clamping means and using a bonding agent to assist the assembly, clamping the assembled rows of fibre end regions in said clamping means and allowing the bonding agent to set.

Preferably the method includes the steps of processing the assembled first end to allow the bonding agent to set or harden.

In a preferred embodiment the method includes the steps of supporting the fibre end regions in the said second bundle end in a support means.

Preferably the method includes the steps of selecting the support means to include a wire, mesh or perforated means, arranged to support the fibre end regions in the second bundle end in the desired spaced apart relationship.

In a preferred embodiment the method includes the steps of providing a series of rows of apertures through a support plate, each aperture being capable of receiving a fibre end region therethrough, and locating each fibre end region in the second bundle end in an aperture in said support plate.

Preferably the method includes the steps of securing each fibre end region in the second bundle end in its respective aperture with a bonding agent and allowing the bonding agent to set.

Preferably the method includes the steps of locating the ends of the fibres in the assembled and clamped first bundle end in the path of an illuminating source.

In a preferred embodiment the method includes the steps of locating an element having an image of a visual display to be produced defined thereon by patterns of different light transmission characteristics, between the said ends of the fibres in the said first bundle end and the illuminating source.

In a preferred embodiment the method includes the steps of locating a diffuser plate in contact with, or adjacent, the ends of the fibres in the second bundle end.

In a preferred embodiment the method includes the steps of introducing cooling air into the space between the first bundle end and the light source.

Preferably the method includes the steps of arranging the light source and the first end of the bundle on a common axis, locating an element between the light source and the first end of the bundle and rotating said element about an axis parallel to said common axis.

Preferably the method includes the steps of providing the said element with open pockets in that annular part of said element intended to pass between the said light source and said first end of the bundle and whereby said element conveys atmospheric air into the gap between said light source and said first end of the bundle.

In a preferred embodiment the method includes the steps of forming said element in disc form from a substantially transparent material, forming apertures through said disc, and arranging said apertures on a common pitch circle concentric with the rotational axis of the disc, the radius of said pitch circle being substantially equal to the pitch between said common axis and the rotational axis of the disc.

In a preferred embodiment the method includes the steps of locating a transparent member between said first end of the bundle and said illuminating means and rotating said element between the said first bundle end and said transparent member.

The invention also envisages a display apparatus for performing the method according to any one of the preceding claims and comprising a bundle of optical fibres, a clamping means for clamping together the end regions of the fibres at one end of the bundle of fibres and a support means for supporting the other ends of the fibres in spaced apart relationship, in that order in which the opposite ends are located in the clamped end of the bundle, and an illuminating source arranged to direct light onto the fibre ends in the first end of the bundle.

Preferably the said support means comprises a wire, mesh or perforated support means arranged to support the fibre end regions in the second bundle end in the desired spaced apart relationship.

In one embodiment the support means comprises a support plate with a series of rows of apertures there through and each aperture is arranged to receive a fibre end region therethrough.

Preferably each fibre end region in the second bundle end is secured in its respective aperture in the support means with a bonding agent.

In one preferred embodiment the display apparatus is characterised by cooling means for introducing air at atmosphere temperature between the said illuminating source and the said first end of the bundle of fibres.

Preferably the display apparatus is characterised in that the illuminating source and the first end of the bundle are arranged on a common axis and an element is rotated about an axis parallel to said common axis and is arranged to project into the gap between said illuminating source and said first end of the bundle, said element being arranged to convey atmosphere air into the said gap.

In a preferred embodiment said element comprises a disc, rotated about its central axis, said disc is made from a substantially transparent material and said disc includes a plurality of apertures therethrough arranged on a pitch circle having a radius equal to the distance between the said common axis and the rotational axis of the disc.

Preferably the thickness of said element is substantially equal to half the distance between the light source and the first end of the bundle.

In a preferred embodiment the apparatus is characterised by a substantially transparent member between said illumination source and said first bundle end.

Preferably said element passes between said substantially transparent member and said first bundle end.

The invention will now be described further by way of example with reference to the accompanying drawings in which, Fig.l shows, diagrammatically, a side view of a display apparatus in accordance with the invention, Fig. 2 shows a front view of the optical fibre support plate shown in Fig. 1 and, Fig 3 shows a detail cross-section through a holder for a slide four use with the display apparatus illustrated in Fig. 1 Fig. 4 shows an axial view, on the line II II in fig. 5, of a cooling apparatus, and Fig. 5 shows a plan view of the cooling arrangement illustrated in Fig. 4.

In the embodiment illustrated in Fig. 1 a bundle, generally indicated by numeral 11, of optical fibres 12 has the end regions of all the fibres 12 at one end Ila of the bundle clamped in a clamp 13.

In the illustrated example the bundle comprises one hundred and sixty nine optical fibres 12 and the fibres 12 are so positioned in the clamping device 13 as to lie in thirteen rows, each of thirteen fibres 12.

In manufacture all the optical fibres 12 are initially of substantially the same length and the end regions of the optical fibres 12 to be held in the clamp 13 are built up in thirteen rows, each of thirteen fibres as defined above, and the assembled optical fibre ends are clamped by the clamp 13.

Conveniently an adhesive is used to hold the ends of the optical fibres 12 in the clamp 13 whilst assembly is being effected and the adhesive may be allowed to set, or is processed until cured, after the clamp 13 has been tensioned to form the bonded and clamped ends of the optical fibres 12 and the clamp 13 into a substantially solid assembly.

The bonded and clamped end lia of the bundle is is then processed, as by grinding and polishing, to bring all the ends of the fibres 12 in the bundle end lla into a common plane.

The ends of the fibres 12 remote from the clamping device 13 are supported by a support plate 14, said plate 14 having thirteen rows of holes 14a, each row containing thirteen holes 14a, forming a regular rectangular pattern.

The holes are of such diameter as to allow an optical fibre 12 to slide therethrough.

In manufacture, the clamped ends of the fibres 12, in the clamp 13, are supported a desired distance from the support plate 14 and the optical fibres 12 are then individually threaded through their respective holes 14a in the support plate 14.

The optical fibres 12 supported in the support plate 14 are so arranged that the fibres 12 in the top row of thirteen optical fibres 12 held in the clamp 13 pass through the holes 14a in the top row of holes in the suppqrt plate 14, in the same order as that in which they lie in the said upper row in the clamp 13. The second from the top row of optical fibres 12 in the clamp 13 extend to the second row of holes 14a in the plate 14, again in the same order as that in which they are clamped in the clamp 13, and this arrangement is continued down the support plate 14 so that, in the support plate 14, each optical fibre 12 is in the same relationship to the surrounding optical fibres 12 as exists in the clamp 13.

Each optical fibre 12 is pulled through its respective hole 14a until it has the desired shape between the clamped end and the support plate 14, and which shape spaces the optical fibre 12 from adjacent optical fibres 12 to avoid interferrence between the fibres 12, and the fibres 12 are axially secured in the holes 14a by an adhesive, which may be allowed to set, or is subjected to a curing process, when all the fibres 12 are in their desired positions and shapes.

Thereafter, the ends of the fibres 12 projecting from that face of the support plate 14 remote from the clamped end lia of the bundle 11 are trimmed to lie adjacent the said faceof the support plate 14 and are then ground and polished to lie in the plane of the face of the support plate 14.

A diffuser plate 15 is applied to the surface of the support plate presenting the polished fibre ends, or is supported in close parallel relationship with the support plate 14 as shown in Fig.1.

The apparatus further includes a light source, conveniently a halogen lamp 16, in a reflector 17 positioned to direct the light from lamp 16 onto the ends of the fibres 12 bound by the clamp 13 The apparatus further includes two identical endless conveyor bands 18 and 19, arranged in side by side relationship, passing over pulleys 20, 21, 22 and 23 in such manner that the runs of bands 18 and 19 between the pulleys 20 and 21 lie in a common plane at right angles to the light path from the lamp 16 to the ends of the fibres presented by the clamp 13 with the band 18 to one side of the said light path and the band 19 to the other side of said light path.

The conveyor bands 18 and 19 support a plurality of bases 24 therebetween, the bases 24 being equally spaced apart around the bands 18 and 19 and being connected to each band 18 and 19 by a single connection 25 so as to pass readily around the pulleys 20, 21, 22 and 23, as illustrated for the pulley 20 in Fig 3.

Each base 24 has a cover member 26 associated therewith, the cover member 26 includes a recess for receiving the periphery of the base 24 therein, and the cover member presents lugs 27 which, when the cover member 26 is forced onto the base 24 are resiliently deformed and engaged behind the base 24 to retain the cover member 26 with the base 24.

The base 24 and the cover member 26 are both of hollow rectangular form, having rectangular openings 24a and 26a respectively, and the cover member 26 further includes a recess 26b, for housing a slide 28, between the cover member 26 and the base 24. The slide 28 comprises a hollow rectangular frame 28a supporting a mask element 28b. The openings 24a, 26a and the opening through the frame 28 are aligned to allow the light from lamp 16 to pass therethrough when the assembly 24, 26 lies between the lamp and the clamped end lia of the bundle 11, and in which position the light from lamp 16 will pass through the mask 28b.

The mask 28b has areas of different light transmission characteristics over its surface and defines the light pattern applied to the clamped ends of the fibres 12 to be displayed as an illuminated visual display at the face of the support member 24.

The endless bands 18 and 19 are rotatable by a stepping motor 29, whereupon the bands 18 and 19 and their attached bases 24 and cover members 26 can be stepped to bring all the masks 28b housed in said bases 24 and cover members 26 successively into the path of the light from lamp 16.

It will be seen from the above that the only restriction on the number of light emitting elements per unit area of visual display is the pitch of the holes 14a, and which pitch can be relatively small, so that relatively fine detail visual displays can be obtained. Further, the dimensions of the visual display can be as large as is desired and the number of optical fibres in the bundle can be any number desired.

Further, a number of illuminated display apparatus of the type described above can be arranged in line, or in stacked lines, and each display apparatus can illuminate a visual display individual thereto so that the line or stacked array can display a composite illuminated display.

In one advantageous array a line of display apparatuses, each apparatus having thirty seven masks 28b with each mask arranged to show a letter of the alphabet, a number from one to zero or a blank individual thereto, can be arranged to have their respective stepping motors controlled by a computer, and whereby a multiplicity of different messages can be displayed according to the computer programme.

In the embodiment illustrated in the Figs. 4 and 5 the clamped end lla of the optical fibres 12 and the illumination source 16 are arranged on a common axis X-X and the slides 28, supported by their respective bases 24, pass between the light source 16 and the end lla.

A transparent member 31,-conveniently a glass plate, is supported by a fixed part F of the machine frame to extend in a plane at right angles to the common axis X-X between the bases 24 and the end 11a and the member 31 has such dimensions that all the light from the light source 16 directed to the end 11a must pass through the member 31.

A disc 32 is mounted on a shaft 33 and arranged for rotation by a motor 34 about an axis Y-Y, concentric with the disc 23 and parallel to the axis X-X. The disc 32 is made from a substantially transparent material and four apertures, 32a, 32b and 32c and 32d therethrough the axes of which are parallel to the axis Y-Y. The apertures 32a, 32b, 32c and 32d are equally spaced circumferentially about a pitch circle concentric with the axis Y-Y and the radius of the pitch circle substantially equal to the distance between the axes X X and Y-Y.

It should be noted from Fig. 5 that the distance between the end Ila and the adjacent face of the disc 32 is small and in fact the distance will preferably be in the region of 1 mm. The distance between the transparent member 31 and the adjacent face of the disc 32 is also small, and again will be in the region of 1 mm. The thickness of the disc will preferably be in the region of 10 to 15 mm, conveniently 12mm.

In use, the motor 34 will rotate the disc 32 in a clockwise direction, as viewed in Fig.4, so that the apertures 32a, 32b, 32c and 32d pass successively between the light source 16 and the end ila each said aperture 32a, 32b, 32c and 32d pass into the path from the light from source 16 to end ila said apertures convey air into the gap between the end lia and transparent member 31 to cool the end lia.

Thus, by this means, the end ila is being continuously exposed to air at atmospheric temperature and is effectively cooled thereby.

The disc 32 is preferably rotated at a speed greater than 12 rotations/second, so that the apertures 32a to 32d pass through the light source at a rate of more than 50 apoertures/second so that any differences in the light transmission characteristics between the apparatus and the disc parts therbetween is substantially smoothed out and the visual display can be viewed without flicker.

Claims (28)

1. A method for generating an illuminated display comprising the steps of forming a bundle of optical fibres, securing together the end regions of all the fibres in a first end of the bundle in a desired order and supporting the end regions of the fibres in the second end of said bundle in spaced apart relationship, with the fibres at the second bundle end in the same order as for the first bundle end, and illuminating the first end of the bundle.

2. A method according to claim 1, including the steps of assembling the end regions of the fibres in the first bundle end in a series of rows in stacked relationship, with a substantially equal number of fibre end regions in each said row.

3. A method according to claim 1 or 2, including the steps of assembling the said end regions of the fibres in the first bundle end in a clamping means and using a bonding agent to assist the assembly, clamping the assembled rows of fibre end regions in said clamping means and allowing the bonding agent to set.

4. A method according to claim 3, including the steps of processing the assembled first end to allow the bonding agent to set or harden.

5. A method according to claim 1, 2, 3 or 4, including the steps of supporting the fibre end regions in the said second bundle end in a support means.

6. A method according to claim 5, including the steps of selecting the support means to include a wire, mesh or perforated means, arranged to support the fibre end regions in the second bundle end in the desired spaced apart relationship.

7. A method according to any one of the preceding claims, including the steps of providing a series of rows of apertures through a support plate, each aperture being capable of receiving a fibre end region therethrough, and locating each fibre end region in the second bundle end in an aperture in said support plate.

8. A method according to claim 7, including the steps of securing each fibre end region in the second bundle end in its respective aperture with a bonding agent and allowing the bonding agent to set.

9. A method according to any one of the preceding claims, including the steps of locating the ends of the fibres in the assembled and clamped first bundle end in the path of an illuminating source.

10. A method according to any one of the preceding claims, including the steps of locating an element having an image of a visual display to be produced defined thereon by patterns of different light transmission characteristics, between the said ends of the fibres in the said first bundle end and the illuminating source.

11. A method according to any one of the preceding claims, including the steps of locating a diffuser plate in contact with, or adjacent, the ends of the fibres in the second bundle end.

12. A method according to any one of the preceding claims, including the steps of introducing cooling air into the space between the first bundle end and the light source.

13. A method according to claim 12, including the steps of arranging the light source and the first end of the bundle on a common axis, locating an element between the light source and the first end of the bundle and rotating said element about an axis parallel to said common axis.

14. A method according to claim 13, including the steps of providing the said element with open pockets in that annular part of said element intended to pass between the said light source and said first end of the bundle and whereby said element conveys atmospheric air into the gap between said light source and said first end of the bundle.

15. A method according to claims 13 or 14, and including the steps of forming said element in disc form from a substantially transparent material, forming apertures through said disc, and arranging said apertures on a common pitch circle concentric with the rotational axis of the disc, the radius of said pitch circle being substantially equal to the pitch between said common axis and the rotational axis of the disc.

16. A method according to claims 13, 14 or 15, including the steps of locating a transparent member between said first end of the bundle and said illuminating means and rotating said element between the said first bundle end and said transparent member.

17. A display apparatus for performing the method according to any one of the preceding claims and comprising a bundle of optical fibres, a clamping means for clamping together the end regions of the fibres at one end of the bundle of fibres and a support means for supporting the other ends of the fibres in spaced apart relationship, in that order in which the opposite ends are located in the clamped end of the bundle, and an illuminating source arranged to direct light onto the fibre ends in the first end of the bundle.

18. A display apparatus according to claim 17, and wherein said support means comprises a wire, mesh or perforated support means arranged to support the fibre end regions in the second bundle end in the desired spaced apart relationship.

19. A display apparatus according to claim 17 or 18, and wherein the support means comprises a support plate with a series of rows of apertures therethrough and each aperture is arranged to receive a fibre end region therethrough.

20. A display apparatus according to claim 18 or 19, and wherein each fibre end region in the second bundle end is secured in its respective aperture in the support means with a bonding agent.

21. A display apparatus according to any one of claims 17, 18, 19 or 20, characterised by cooling means for introducing air at atmosphere temperature between the said illuminating source and the said first end of the bundle of fibres.

22. A display apparatus according to claim 21, characterised in that the illuminating source and the first end of the bundle are arranged on a common axis and an element is rotated about an axis parallel to said common axis and is arranged to project into the gap between said illuminating source and said first end of the bundle, said element being arranged to convey atmosphere air into the said gap.

23. A display arrangement according to claim 22, characterised in that said element comprises a disc, rotated about its central axis, said disc is made from a substantially transparent material and said disc includes a plurality of apertures there through arranged on a pitch circle having a radius equal to the distance between the said common axis and the rotational axis of the disc.

24. A display apparatus according to claims 22 or 23, characterised in that the thickness of said element is substantially equal to half the distance between the light source and the first end of the bundle.

25. A display apparatus according to claims 22, 23 or 24, characterised by a substantially transparent member between said illumination source and said first bundle end.

26. A display apparatus according to claim 25, characterised in that said element passes between said substantially transparent member and said first bundle end.

27. A display apparatus substantially as hereinbefore defined with reference to and as illustrated in Figs. 1, 2, 3 and 4 accompanying drawings.

28. A metod for generating a visual display apparatus substantially as hereinbefore described with reference to the accompanying drawings.