DE7407095U - Signal display device for displaying light signals - Google Patents

Description

Dr. Joachim Rasper ^: ·· ^: .:. '^{; :} · "· 'W

Patent attorney 62 Wiesbaden

llMstadtir HBh 22 TtL 562842

JENAer GLASWERK
SCHOTT & GEN.

6500 Mainz
Hattenbergstrasse 10

G 117

Signal display device for displaying light signals

The object of the innovation is a signal display device for making characters, numbers or symbols visible.

Conventional signal indicators for the transmission of characters or Numbers usually consist of a grid Lamps with upstream optics to generate the desired radiation characteristics. The lamps are usually like this switched so that different characters are alternately made to light up.

The disadvantages of these signals are the poor light output, the high lamp requirement and the associated high susceptibility to failure due to lamp failure. Complicated wiring schemes and possible misinterpretation of the symbol due to lamp failure. Since several characters have common light points, only characters or numbers of the same color can be displayed. There is also one poor resolution of the characters in haze or fog as well as the downward limitation of the size of the display devices by the lamp dimensions.

It is also known to use optical fibers to represent symbols on display surfaces (Dt-OS 2 126 672, German OS 2 245 460). In these systems, however, the emission of light from the ends of the optical fibers is not satisfactory. both in terms of a favorable angle of radiation and in terms of optimal light output. These properties The aim of the present innovation is to improve.

The innovation is that at the ends of the optical fibers Light guide cones are attached with which a predetermined Beam angle achieved and the light loss in the Hegel can be kept lower than with conventional optical Systems.

The innovation is explained in more detail with reference to FIGS. 1 and 2.

7407085-9.1.75

FIG. 1 shows a display panel for luminous signals, which consists of a grid plate 4 and a diffuser 6. In the individual raster points of the plate 4 end the individual arms of one or more branched optical fiber bundles 3, which can be illuminated by an incandescent lamp 2 at their respective combined ends 1.

According to the innovation, 4 light guide cones 5 are attached to the ends of the optical fibers in the grid plate.

FIG. 2 shows the beam path in such a light guide cone and the geometrical ones necessary for its calculation Declarations.

The relationship between the entrance and exit apertures of a optically isolated cone reads:

d "

where is the maximum input aperture by the relationship

d NA = H ₁ * sin c

is limited.

Here mean (see also Figure 2):

n- the refractive index of the medium in front of the cone n ₂ the refractive index of the medium behind the cone the entry angle

, ₂ the exit angle

+ d ~ the two end face diameters of the cone

n "the refractive index of the core material and n" the refractive index of the cladding material.

By defining the cone dimensions, almost any desired radiation characteristic can be generated.

The cones are preferably cemented to the light guide end in order to reduce the number of reflective surfaces.

It is essential in the mode of operation of the light guide cone that it is not so much a change in the cross section of the emitted beam as the already described change in the exit angle et- (FIG. 2) of a light beam compared to the entry angle

It is characteristic of an optical fiber that a light beam which enters it at an angle ^ Ci, after multiple reflection within the fiber, also exits it _{again at an angle oC 1.} For this reason it is un-

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essential whether a light guide cone according to the innovation on the common Entrance of an optical fiber bundle is arranged or at the exit of each of the individual pasers. Will the latter If the path selected, which is also shown in FIG. 1, there is also a difference in the cone diameter corresponding to the difference Change in the cross-section of the emerging beam. In this way, an area enlargement can be achieved of the raster point can be achieved with simultaneously improved parallelism of the light emanating from it.

When using several fiber optic bundles, it is possible to display different symbols on the same area. This can be done so that individual optical fiber arms different bundles end together in a light guide cone or so that each fiber arm in its own cone and thus ending a separate grid point. The small dimensions of the light guide cone allow raster points several characters can be accommodated on the same surface.

The light guide cones can consist of an optically isolated, conical rod, which consists of an optically transparent Material consists. It is important that the cone has good light permeability and that on its lateral surfaces total reflection takes place on the inside.

Another variant consists in that the light guide cone itself consists of a bundle of conically widening optical fibers are composed. Since the change in the starting

aperture - compared to the entrance aperture of a cone only of depends on the diameter ratio of the end faces, it plays It does not matter whether the cone has an ideally geometrical shape or a non-linear but continuous shape.

The division of the light guides can be done in such a way that several lamps illuminate a sign, each individual lamp being the Characters fully derated. This means higher operational reliability in the event of a lamp failure and enables a gradual adjustment of the signal light intensity to the ambient helxiness.

For additional scattering effects, a correspondingly designed disk 6 can be arranged in front of the fiber cones.

Color filters 7 make it possible to transmit multicolored signals or to switch several different colored signals alternately as required.

Claims (10)

Protection claims: Signal display device for the transmission of characters, consisting of at least one multi-armed light guide, whose common end is illuminated by a light source, and whose individual ends the character to be displayed in the form of grid-like arranged points, characterized in that for enlargement or reduction the beam angle or to increase the light intensity in the axial direction at the common end of a this multi-armed light guide and / or in each grid point at the end of the single ends of one or more of these multi-armed light guides opening there, a light guide cone is appropriate. 2. Signal display device according to claim 1, characterized in that that this light guide cone is cemented to the ends of the light guide. 3. Signal display device according to claim 1 or 2, characterized in that this light guide cone consists of an optical isolated, conical rod made of an optically transparent material. 4. Signal display device according to claim 1 or 2, characterized in that this light guide cone consists of a plurality is composed of conical optical fibers. 5. Signal display device according to one of claims 1 to 4, characterized in that each individual end has a plurality of multi-armed light guides is provided with its own light guide cone and in a separate grid point flows out. 6. Signal display device according to one of claims 1 to 4, characterized in that a number of individual ends different multi-armed light guides ends in a grid point and is provided with a common light guide cone. : ^iv 7. Signal display device according to one of claims 1 to 6, ■; characterized in that to illuminate the common at the end of a multi-armed light guide several light ;, swell in a plane behind the plane of the grid points ■ are attached, each of these light sources also alone can reproduce the entire character to be displayed. ^f 8. Signal display device according to one of claims 1 to 7 » _v characterized in that in front of the in a grid area arranged light exit ends of this light guide cone ji an additional diffuser is arranged. 9. Signal display device according to one of claims 1 to 6, characterized in that color filters are attached to each of these multi-armed light guides in front of the common entry end which show the characters to be displayed in color. 10. Signal display device according to one of claims 1 to 9, characterized in that the grid points for different Characters are arranged alternately next to one another or one inside the other on a grid area.