US 1967548 A
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ARRANGEMENT FOR PRODUCING MULTIPLE TOTAL REFLECTIONS Filed June 16, 1955 I w r" a 5 i i i 1 I i i 1% w QR 240/151,
Patented July 24, 1934 1,961.50" ARRANGEMENT FOR PRODUCING I TIPLE TOTAL REFLECTIONS l riedrich Bartels, Hamburg, Germany Application June 16, In Germany 1938, Serial March 1, 1932 No. creme 1 Claim. ion. 240-1) This invention relates to an arrangement for producing multiple total reflections of light rays in the interior of translucent bodies, such as glass panes, through which characters or'the like provided on the body are rendered luminous. In the" known arrangements of this kind it is either necessary to arrange the source of light along the edge or very close to the edge of the glass pane in order to project the light rays into the trans lucent body in the first instance directly and in 10 the second instance by reflections oi the correspondingly arranged pane edges, and to thus cause the characters or the like provided on the glass pane to become luminous; or ii it is desired to ar range the source of light behind the pane in order.
to thus produce total reflection even in the case of panes the edge of which is inaccessible, a prism had to be cut in the side of the glass pane remote from the source of light in. order to thus produce reflecting edges which reflect the impingfi ing rays longitudinally of the pane within the 'Thisinvention is based on a different principle in that the side of the pane directed towards the moved without difliculty and fltted as; desired at any point of the glass pane, and radiated bye. 4 source of light, the rays 01' which implngeqin known manner only on the reflector. The light rays are reflected in different direction by this reflector. so that those rays which areoutside the V critical angle 01' total reflection remain in the glass. It thus becomes possible, to illuminate characters or the like around the reflector in a radiusot action corresponding to the source of light. Therefore it is only necessary to arrange a certain number of sources of light behind a display window andto lit a' corresponding number of reflectors in front thereof, opposite thesources of light, in order to cause characters arranged over the entire surface or the display window ,to illuminate. i
' An embodiment of the invention is illustrated by wayotexample in cross section in the only flgure oi the accompanying drawing.
On the inner side of a display window a, a
1 source of light surrounded by a reflector c is fixed for example by means of rubber suckers b. i A refleeting plate 2 is stuck tightly on the outer side of the paneopposite the source of light, for example by means of a'textilematerial coated with a light coloured rubber solution for eflecting a tight adhesion tothe'pane. 'The beams of light impinging on this" reflecting plates are reflected and diflused, so that-therays which lie outside the critical angle 1 are 'compelledby the total reflection on'the surfaces or the glass pane a to remain inthe glass. They can then only leave the glass in"v known manner when they encounter characters or-the like reacting to difl'used light and fltted on' the surface oithe pane a, so that these characters areilluminated.
An arrangement. for producing multiple total reflections of light rays in the interior oi translucent bodies for illuminating characters mounted 9o thereon, comprising 1 in combination with the translucent body a source 01 light arranged on the inner side of said body, and aflat reflector stuck onto the outer side of said body adapted to receive all the rays oilight from said source of light .and to reflect the same in diflused state towards the interior of said body. a