LIGHT DISPERSION APPARATUS

Abstract: Light dispersion apparatus characterised in that it comprises a translucent screen member (24) backed with an array of light transmitting members (28) each corresponding to a discrete segment of the screen, each of the light transmitting members having a first, light transmitting end adjacent the screen and a second, light transmitting end remote from the screen, said ends being interconnected by opaque sides.

Description: TITLE "LIGHT DISPERSION APPARATUS" DESCRIPTION The present invention relates to a light dispersion apparatus. SUMMARY OF THE INVENTION In accordance with the present invention there is provided a light dispersion apparatus characterised in that it comprises an array of light transmitting members each terminated by a translucent screen which form an array of screens which may be viewed simultaneously, each of the light transmitting members having a first, light transmitting end adjacent the screen and a second, light receiving end remote from the screen, said ends being inter-connected by a means of isolating and conveying the light from the receiving end to the transmitting end. The apparatus of the present invention is arranged to be mounted, array of screens outermost, in front of an image forming apparatus which can form a light image. The array of light transmitting members causes the light from the corresponding segments of the formed light image -to be isolated from the light of adjacent segments. The light receiving ends of the light transmitting members are positioned adjacent the formed image. The light from a segment of the formed image travels through the corresponding light transmitting member of the light dispersion apparatus of the present invention and strikes the translucent screen. The translucent screen disperses the light such that an observer sees a composite tone dependent on the overall composition of that part of the formed image. The composite tone can be viewed from the front of the screen. The present invention is applicable to a wide variety of light image forming apparatuses including black and white light image forming apparatuses, but is particularly envisaged for use with colour image forming apparatuses such as colour television devices. Although the invention is of general applicability it will henceforth be described with particular reference to colour image forming apparatuses. If the formed colour image is continually changing the colour tone emitted by each of the translucent screens is continually changing. Further, the colour tone emitted by one screen may be the same as or different from colour tones emitted by adjacent screens. Since the screens are arranged so that they may be viewed simultaneously the net result is a fluid, changing pattern of colour tones corresponding to parts of the formed colour image entering the light transmitting members and being diffused by corresponding translucent screens. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:- « Figure 1 is a front elevation o a light dispersion apparatus in accordance with the present invention housed in a package; Figure 2 is a front elevation of the light dispersion apparatus of Figure 1 with a front cover sheet removed showing a screen which in this Figure is partially broken away to reveal a grid. Figure 3 is a rear elevation of the light dispersion apparatus of Figure 1 housed in a package; Figure 4 is a view similar to Figure 2 with a rear cover sheet pivoted upwardly about a hinge connection to reveal a grid. 16 Figure 5 is a side elevation of the light dispersio apparatus of Figure 1 housed in a package; and Figure 6 is a vertical cross section along the line 6-6 of Figure 2 with a rear cover sheet pivoted rear- wardly. DESCRIPTION OF THE INVENTION In Figures 1, 3 and 5 of the accompanying drawings, ther is shown a colour dispersion apparatus housed in a package comprising a front wall 10, a rear wall 12 and four sides 14. The front wall 10 (see Figure 1) comprises a rectangular cover sheet 16 which is attached to the remainder of the front wall 10 by a perforated coupling. Further, for ease of removal, a corner of the sheet 16 is provided with a part circular recess 18 to enable a finger or thumb to be engaged behind the sheet 16. The rear wall 12 (see Figure 3) comprises a rectangular cover sheet 20 which is attached at its upper end (as seen in Figure 3) to an edge of the rear wall 12 by a hinged coupling and to the remainder of the rear wall 12 by means of a perforated coupling. As with the cover sheet 15, the cover sheet 20 is provided with a part circular recess 22 in one corner to enable a finger or thumb to be engaged behind the sheet 20. A translucent screen member 24 is mounted behind the front wall 10 (see Figure 6) . Typically, the screen member 24 is adhered to the portion of the front wall 10 surrounding the cover sheet 16. The translucent screen member 24 may be formed of any light diffusing material but it has been found that it may, conveniently, be formed of a sheet of translucent paper. The screen member 24 shown in the drawings is a continuous, unitary, flat sheet. Further, between the screen member 24 and the rear wall 16 there is located a grid 26 comprising a plurality of light transmitting members in the form of cavities 28 arranged in an array extending at least over the useable area of the screen member 24 corresponding to the cover sheet 16. The cavities 28 are each in the form of a tube having a first, light transmitting end in contact with the screen 24 and a second, light transmitting end adjacent the rear wall 12. The first and second ends of the cavities 28 are interconnected by opaque sides. The cavities 28 are of substantially constant width between their first and second ends and are hollow. Preferably, the grid 26 is attached to the screen member 24 by firstly forming a layer of adhesive on the rear side of the screen member 24 and placing the grid 26 on the said layer of adhesive whilst it is still tacky. The grid 26 may be formed of an expandable material comprising a number of opaque, flexible strips having opposed major surfaces. The strips are located side by side with major surfaces of one strip facing major surfaces of adjacent strips. The adjacent strips are bonded together at intervals with the bonding of one major surface of one strip to an adjacent strip on one side being preferably alternated with the bonding to an adjacent strip on the other side. Conveniently, this material is formed of a paper based product such as cardboard although it could be formed of any suitable material. Such a material is commercially available in cardboard under the Trade Mark "Dufalite". The material is initially in compressed condition but it may be laterally stretched out or expanded to a desired degree prior to being adhered to the screen member 24. The degree of stretching determines the particular shape of the cavities 28. However, the shape of the cavities 28 is not critical. They can be of any geometric shape such as diamond, square, triangular, round or hexagonal shape or any non-geometrical shape. In the configuration shown with the use of "Dufalite" material or an equivalent the cavities 28 formed by the material are closely packed and there are no gaps between cavities 28. In other constructions gaps could be formed but these could if desired be blanked off by any suitable means. The size of the cavities 28 is chosen depending on the desired reduction in resolution between the formed image and the viewed image. If the cavities are too small then the abstract quality of the viewed image is lost. If the cavities are too large then the complexity of the viewed image is lost. For example, each cavity 28 could have an area of less than about 5% of the viewable, useable area of the screen member 24 within the residual portion of the wall 12 after removal of the cover sheet 16. More preferably, each cavity 28 has an area less than about -2.5% of the said area of the screen members 24. In particular each cavity 28 preferably has an area less than about 1.5% of the said area of the screen member 24. The actual size of the cavities 28 varies with the overall size of the screen member 24 but sizes in the range from about 0.1" to 2" are useful: In this context, the size range is the average dimension of a cavity parallel to the screen. Further, the depth of the cavities can vary over a wide range but depths in the range from about 0.-25" to 4" are useful such as about 1" to 2". The required depth depends on the diffusing efficiency of the screen member 24 such that a screen member 24 with a high diffusing ability would require a lesser depth for the cavities 28 . The screen member 24 can be of any colour. The overall size * of the screen member 24 preferably corresponds substantially to the image area of the image forming apparatus. The colour dispersion apparatus 10 of the present invention is mainly envisaged for use with a colour television screen. The colour dispersion apparatus 10 could be used to transmit a changing colour pattern onto a reflective screen by using an image focusing apparatus. Also it could be used ith a film projector by projecting an image onto a translucent screen and mounting a colour dispersion apparatus of the present invention on the opposite side of the screen to the projector so as to receive the formed image as described herein. The internal walls of the cavities 28 are opaque and can be made reflective or non-reflective by painting, plating or incorporating a reflective material in the material of the internal walls. In use, the colour dispersion apparatus is mounted in front of a suitable colour image forming apparatus * which is typically a colour television receiver. The screen 24 is located outermost. Firstly, however, the cover sheet 16 is removed by inserting a finger or thumb into the cut out 18 and lifting the cover sheet 16. The perforated coupling of the cover sheet 16 to the remainder of the front wall 10 enables the sheet 16 to be readily separated in its entirety from the colour dispersion appatatus. This exposes the screen member 24 as shown in Figure 2. Similarly, the cover sheet 20 may be partially separated from the rear wall 12 by inserting a finger or thumb into the cut .out 22 and lifting the cover sheet 20. The cover sheet 20 is coupled along three of its sides to the remainder of the rear wall 12 by means of perforations. Thus, once the perforations are broken the cover sheet 20 can be lifted from the position shown in Figure 3 to those shown in Figures 4 and 5. This exposes the grid 26 as can be seen in Figure 4. Conveniently, the hinged cover sheet 20 is placed on top of a television receiver in the position shown in Figure 6 and retained in place by any convenient weight. The colour dispersion apparatus as a whole is quite light and so it is not difficult to retain it in place φRE OMP in this way. Any equivalent means such as suction caps or elastic tapes or straps could be used to retain the colour dispersion apparatus in place. Then the colour television receiver may be turned on. It is found that each cavity 28 of the colour dispersion apparatus takes the image from a small segment of the image forming apparatus and the corresponding segment of screen 24 diffuses this colour image into an overall colour. The segments of the screen member 24 thus have an individual colour depending on the image input into the corresponding cavity 28 and the colour of each segment of the screen members 24 is continually changing as the image input changes. Modifications and variations such as would be apparent to a skilled addrescee are deemed within the scope of the present invention. For example, the screen member 24 need not be a single unitary member but could be a number of members joined together. In one instance each cavity 28 could have its own, discrete, screen segment, such screen segments when placed side by side forming a screen member 24. Further, the light transmitting members could be moveable such that they can be repositioned within the apparatus. In this case it is envisaged that the light transmitting members would be of various shaoes. The screens could be stationary or separate, moveable members associated with respective moveable light transmitting members. Also, the grid 26 could be formed of a plastics material and be formed by for. example, an injection moulding technique.

Claims: 1*2 . _________ 1.. A light dispersion apparatus characterised in that it comprises an array of light transmitting members each terminated by a translucent screen which form an array of screens which may be viewed simultaneously, each of the light transmitting members having a first, light trans¬ mitting end adjacent the screen and a second, light receiving end remote from the screen, said ends being inter-connected by a means of isolating and conveying the light from the receiving end to the transmitting end. 2. A light dispersion apparatus according to claim 1, characterised in that the translucent screen segments adjoin each other in a continuous array. 3. A light dispersion apparatus according to claim 2, characterised in that the screens are formed by a continuous, unitary screen member. 4. A light dispersion apparatus according to any one of the preceding claims, characterised in that the screens form a flat array. 5. A light dispersion apparatus according to any one of the preceding claims, characterised in that the light transmitting members are of substantially constant width between the said ends thereof. 6." A light dispersion apparatus according to any one of the preceding claims, characterised in that the screens are formed of translucent paper. 7. A light dispersion apparatus according to any one of the preceding claims, characterised in that the first ends of the light transmitting members are in contact with the screens. 8. A light dispersion apparatus according to claim 7, characterised in that the said first ends are adhered to the screens. 9. A light dispersion apparatus according to any one of the preceding claims characterised in that .the light transmitting members are hollow. 10. A light dispersion apparatus according to any one of the preceding claims, in which the said ends of the light transmitting members are interconnected by opaque sides. 11. A light dispersion apparatus according to any one of the preceding claims, characterised in that the array of light transmitting members is formed from an expandable material comprising a number of opaque, flexible strips having opposed major surfaces, in which a number of strips are located side by side with major surfaces facing one another, and adjacent major surfaces are bonded together at intervals, the bonds of one strip to an adjacent strip on one side being alternated with the bonds to an adjacent strip on the other side. 12. A light dispersion apparatus according to claim 11, characterised in that the expandable material is formed of paper, cardboard or the like. 13. A light dispersion apparatus according to any one of the preceding claims, characterised in that each cavity defines an area of less than about 5% of the viewable screen area. 14. A light dispersion apparatus according to claim 13, characterised in that each cavity defines an .area of less than about 2.5% of the viewable screen area. 15. A light dispersion apparatus according to claim 14, characterised in that each cavity defines an area of less than about 1.5% of the viewable screen area. 16. A light dispersion apparatus according to any one of the preceding claims, characterised in that each cavity has an average dimension parallel to the array of screens in the range from 0.1" to 2". 17. A light dispersion apparatus according to any one of the preceding claims characterised in that it has a depth in the range from about 0.25" to 4". 18. A light dispersion apparatus according to claim 17, characterised in that it has a depth in the range from about 1" to 2". e 19. A light dispersion apparatus according to any one of the preceding claims, characterised in that it is housed in a package comprising front and rear cover sheets joined at least partially to the remainder of the package by perforated couplings. 20. A light dispersion apparatus according to claim 19, characterised in that the rear sheet has a hinged coupling along one side so that it can serve to retain the apparatus in place when in use.

Inventors: CROOKE MICHAEL DAVID, TER-HORST ALBERT, CROOKE, MICHAEL, DAVID, TER-HORST, ALBERT
Applicants: CROOKE MICHAEL DAVID, HORST ALBERT TER, CROOKE, MICHAEL, DAVID, TER-HORST, ALBERT
Application year: 1982
Main classification: G02B5
IPC codes: F21V11, G02B5, H01J29, H04N5