DE2542590A1 - DISPLAY DEVICE - Google Patents

Description

254259Q

SIEMEFS AKTIENGESELLSCHAFT y Munich 2, 24-9.1975 Berlin and Munich. Wittelsbacherplatz 2

VPA 75 P 7166 BED

Display device

The invention relates to waveguides, particularly for a display device .

As is known, waveguides are designed in such a way that they transmit optical waves with as little loss as possible between two predetermined locations transfer. For this purpose, all sources that give rise to signal losses are avoided as far as possible. The ones guided in the waveguides Waves should only reach the outside through the end faces.

The object of the invention is to specify waveguides in which guided waves at predetermined locations through the jacket surface are radiated outside, as well as applications of such waveguides.

This object is achieved according to the invention by the characterizing part of the claim 1 solved.

Scattering centers come from inhomogeneities in the waveguide material conditions. Targeted foreign substances are advantageously incorporated into and / or the waveguide material as scattering centers Roughened surface.

Any material that is a different one is suitable as a foreign material Has refractive index than the material of the waveguide.

By adding fluorescent material to the waveguide or its surroundings, the intensity of the

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Increase radiation and on the other hand change the wavelengths of the waves guided in waveguides.

By suitable combinations of these waveguides, advantageously visible alphanumeric characters or images (also 3-dimensional) can be built up.

As light sources, which are coupled to the waveguide, luminescence diodes, lasers or classic light sources can be used insert.

The variety of display options and their advantages are based on exemplary embodiments in the description of the figures explained.

FIG. 1 shows a waveguide according to the invention, the figures 2a, 2b and 2c show the front and the rear or a cross section of an integrated multiple display device, FIG. 3 shows a section from a display device with several waveguides lying one on top of the other, FIG. 4 shows a control circuit for a display device and FIG. 5 shows a display device with optical fibers and a optical channel selector.

In FIG. 1, a waveguide 30 made of glass is shown in cross section. It can be a kernmantle or a gradient waveguide be in fiber form or in planar construction on a substrate. The waveguiding material has here, for example, in three predefined areas of scattering centers. In the areas and 32 particles 34 are made of one in the waveguide material Material e.g. made of glass with a different refractive index than that of the waveguide material embedded. Therefore, an im Light wave 35 running inside the waveguide 30 is partially scattered outwardly (36) by the particles 34. Because the waveguide

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is roughened in the area 31 on its outer surface 37, a light wave 38 guided onto this outer surface 37 is scattered outward there according to the arrow 38.

In the area 32, the waveguide 30 is surrounded by a fluorescent material 39, so that one running through this material 39 Light wave 40 is changed in their light intensity and in their wavelength. , '

The latter also applies to a light wave 41 »that after penetration in the area 33 »in which a fluorescent material is embedded, also with a modified intensity and Wavelength is scattered outwardly by the roughened surface 43.

FIGS. 2a and 2b show an embodiment for displaying numbers and letters. FIG. 2a shows from the front side, FIG. 2b from the rear and FIG. 2c in a cross section along the line II ^f, a transparent substrate 1 made of glass with the elements for a display located thereon.

On the front side of the substrate 1 according to FIG. 2a (viewing direction according to the arrow 1a in Figure 2c), four waveguides 2 are built in integrated technology, which at the opposite Have front surfaces absorber or mirror 3. The waveguides 2 consist of a highly scattering material (e.g. Photoresist, plastic, glass) or a fluorescent one Material whose refractive index is greater than that of the substrate 1. Each waveguide 2 is over an optical cement or a transparent adhesive 4 each with a point radiating Light emitting diode 5 coupled. The coupling points and the luroinescence diodes are outside the image field. you are through a non-transparent mask 6 covered, since stronger scattering can occur at the coupling points. To enter at intersections of closely spaced waveguides

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To avoid crosstalk aes light, are arranged crossed Waveguide 7 arranged on the back of the substrate 1 according to Figure 2b.

When controlling specified waveguides via the luroinescent diodes 5 connected electrical leads 8 can be due to the illustrated positions of the individual waveguides 2 and represent different numbers and letters.

Since the waveguide used as a display is in any Shape made - sharp kinks must be composed of two waveguides - this indication is also for individually shaped lettering and suitable for pictorial representations. In the case of curved display tracks, make sure that the difference in refractive index between the waveguide and the waveguide environment is sufficiently large to ensure wave guidance at the curvatures.

A decoder can have an integrated design for certain codes on the substrate 1 at an invisible through the cover 6 Place to be provided.

The structure shown in FIGS. 2a to 2c is particularly suitable for small to medium-sized multiple displays.

Because the substrate with the waveguides are very thin can (approx. 0.2 mm) and is transparent, many layers of such displays can be stacked on top of one another. If you put it, for example three of the gate directions shown in Figures 2a to 2c 'one above the other and are used for each pair of transverse mutually extending waveguides 2 and 7 different colored light emitting diodes as light sources, with a thickness of approx. 2 mm (with covers and housing) all are alphanumeric Characters can be displayed in three colors, even with the appropriate electrical switching of the luminescent diodes each one Characters can be represented in three colors.

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To mutual covers of the superimposed waveguides To avoid large-thickness displays of the same type, it is advantageous to offset the waveguides laterally according to their waveguide width (e.g. 0.1 mm), as shown in FIG. 3. There the integrated waveguides 10 and transverse waveguides 11 are laterally arranged on a plurality of substrates 9 next to one another offset from one another by 0.1 mm in such a way that their path shape can be clearly seen from the viewing direction 12. At a greater distance from the observer, however, the waveguides seem to lie on top of one another due to their small mutual offset. When controlling different ones on top of each other When the waveguide is lying down, the observer therefore sees the same typeface.

By stacking a variety of display substrates on top of each other A three-dimensional display is also possible at specified intervals. . - - - ·

FIG. 4 shows a control device for a display device specified above. Instead of the light emitting diodes 5, however, a laser 13 is used here as a common light source for all waveguides 2 and 7, for example.

The light emitted by laser 13 is evenly coupled into a number of low-scatter optical fibers 16 corresponding to the number of waveguides 2 and 7 via coupling optics 14 and an exchangeable color filter 15, which are connected to waveguides 2 and 7 by coupling devices 17. ¹ The light guided in the optical fibers 16 is optionally fed to the waveguides 2 and 7 by a device 18 with a corresponding number of on-off switches;

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This display device can be manufactured in a minimum thickness and excited by a light source arranged separately from the display device.

For medium-sized advertisements and for multiple advertisements that are used, for example, for advertising purposes or information boards, instead of the substrate-bound waveguides are suitable for optical fibers, the core material of which scatters particularly strongly. When using individually controllable optical fibers can be very fine-line, high-resolution Displays are produced (line width approx. 0.1 / µm). Purely wide-line displays are advantageously used for special ones thick light guide rods or a large number of adjacent ones Pars that are optically coupled with each other and only from one Light source can be controlled.

In the figure 5 is a display device for the number 3 and one associated optical control circuit shown. A light-feeding low-scatter optical fiber 28 is via an optical ¥ oak 20 divided into two individual low-scatter optical fibers 19 and via coupling devices 21 two strongly scattering display fibers 22 supplied. Each of these display fibers 22 can be used side by side for a wide range of lines of lying pasers. Since the optical fibers have a thickness of approx. 0.15 μm, they can be used for individual symbols to be displayed be arranged one above the other. With only 20 symbols you get a display unit of approx. 5 mm thickness including a cover and a base plate. For reasons of stability, a correspondingly stable base plate must be provided for special large-area displays will. The strands 22 are encapsulated with a transparent compound, e.g. cast resin 23, for fixing at predetermined locations.

Instead of the solid, transparent mass, a plastically deformable mass can also be used. In this case, the shape of the optical fibers 22 vary in time to represent different characters.

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AO

Several optical fibers are controlled here via a mechanical input selector 24. Serves as a light source in particular a powerful laser 25, which is connected to the input selector 24 via an exchangeable color filter 26 and a stray low Optical fiber 27 is connected.

Only one input selector is required for 34 alphanumeric characters for switching from fiber 27 to 34 pas 28.

The optical control circuit according to FIG. 4 or according to FIG. 5 can be optimally selected depending on the problem.

To increase the brilliance of such display devices, a base plate with a layer of paint can be used.

.15 Claims
5 figures

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Claims (15)

Claims /Ί.^ Waveguide in particular for display devices thereby characterized in that the waveguiding material has scattering centers (34,37,39,42, 43), which is guided in the waveguide (2,7,10,22,30) Scatter waves partially outwards. 2. Waveguide according to claim 1, characterized in that _; net that a scattering center forming material (34,42) is embedded in the wave-guiding material. 3 # waveguide according to claim 1, characterized net that the scattering centers (37,39,43) on the surface of the waveguide are formed. 4. Waveguide according to claims 1 to 3, characterized in that in and / or around the waveguide Material a fluorescent material (39,42) is arranged. 5. Display device with at least one waveguide according to one or more of the preceding claims characterized in that visible alphanumeric characters or images are built up in the form of tracks. 6. Display device according to claim 5, characterized in that the waveguide (2,7,10) in integrated Technique on opposite surfaces of a substrate (1) or in one or more layers on top of each other lying substrates (9) are arranged. VPA 9/710/5039 7098U / 0833 7. Display device according to claim 5, characterized in that the waveguide optical fibers (22) are. 8. Display device according to claim 7, characterized in that the positions and curvatures of the optical fibers (22) are variably adjustable. 9. Display device according to claim 7, characterized in that the optical fibers (22) in one transparent mass (23) are firmly cast. 10. Display device according to claim 9, characterized in that a plurality of optical fibers (22) one above the other are arranged. 11. Display device according to claim 9> characterized in that a plurality of optical fibers (22) side by side are arranged. 12. Display device according to one or more of claims 6 to 11, characterized in that each Waveguide (2,7) connected directly to a respective light source (5) is. 13. Display device according to one or more of claims 6 to 11, characterized in that several Waveguide (2,7.22) via low-scatter optical fibers (16,18, 19,27) and an optical switch (18,24-) with a light source (13.25) are connected. VPA 9/710/5039 7098U / 0833 14. Display device according to claim 13, characterized g e k e η η shows that the optical switch is a channel selector (24) between the one with the light source (25) connected low-scatter optical fiber (27) and with the low-scatter optical fibers connected to the waveguide (22) (28) is arranged. 15. Display device according to claim 13, characterized in that g e k e η η indicates that the optical switch (18) consists of on-off sehaltern ", which are built into the low-scatter optical fibers (16). VPA 9 / 7IO / 5O39 709814/0833