EP1323153A2

EP1323153A2 - Screen

Info

Publication number: EP1323153A2
Application number: EP01972026A
Authority: EP
Inventors: Maik GLÄTZER
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-09
Filing date: 2001-09-07
Publication date: 2003-07-02
Also published as: WO2002021486A2; US20030164807A1; AU2001291838A1; DE10044664A1; WO2002021486A3; CN1468425A

Abstract

The invention relates to a screen comprising a visible surface (1)which is divided up into pixels (2). The pixels (2) thereof respectively emit light and are connected to a light distributor by means of optical waveguides (3). The light distributor has rotating light sources (10) disposed on a rotor (20) and arranged at a distance from an axis of rotation (22). The light emitted from said light sources is radiated to the receptors (7) of a coupling device (5) located at the ends of the wave guides (3) and reaches the visible surface (1) of the screen via the individual waveguides (3), thereby producing a visible picture for an observer, composed of individual pixels (2). The disadvantage of conventional screens is that the design thereof is necessarily large while displaying weaknesses in terms of contrast and light. The aim of the invention is to cause the rotating light sources arranged in the light distributor to emit light parallel to the axis of rotation (22) and radiate it to the receptors (7) of the coupling device (5), one particular advantage thereof being a flat design.

Description

screen

The invention relates to a screen with a viewing area divided into pixels, the pixels of which each emit light and are connected via optical waveguides to a light distributor which has rotating light sources arranged on a rotor, which are arranged at a distance from the axis of rotation and whose emitted light in at the ends the optical waveguide radiates arranged receptors of a coupling-in arrangement, reaches the visible surface of the screen via the individual optical waveguides, and there produces an image that is visible to the viewer and is composed of the individual pixels.

Conventional screens are usually based on the principle of the Braun tube. Both the domestic television and most data processing systems use this technology to visualize information. Here, an imaging screen is bombarded with accelerated electrons, which, depending on their kinetic energy, generate visible light emission when they hit the screen. The trajectory of the electron and the position of the impact on the screen are controlled by means of an external magnetic field. A major disadvantage of such a device is the large design, in particular the structural depth, which is essential for distortion-free images. Furthermore, such an arrangement is only suitable for screens up to a certain maximum size.

Liquid crystal displays have recently been used increasingly for flat screens. These have become particularly common in the field of portable computers

Screening devices have been tried and tested. However, since these screens have a based on complex manufacturing, the end product is extremely expensive. In addition, each variant of previously known liquid crystal displays requires polarization of the light perceived by the user. Since polarization is accompanied by a loss of light intensity of over 50%, these screens are extremely faint and low in contrast. Viewing such a screen can be very stressful for the human eye.

In addition to the widespread methods, the applicant's European patent application EP 99 927 828.6 describes a screen which is also illuminated as needed using optical fibers. However, this invention requires a light modulator between the light source and the visible surface of the screen, which preferably consists of so-called shutters. The manufacture of such a light modulator requires a highly developed special technology and is therefore extremely expensive.

A generic screen is also known from US Pat. No. 3,744,048, in which the light is distributed to the individual optical fibers by means of a cylindrical rotor. The screen is illuminated column by column, with complete columns being sequentially supplied with light in the row direction. However, the technology proposed has several

Disadvantage. Firstly, the light rays in the optical fibers from the rear side of the rotating cylinder by 180 ° to the visible surface of the

Screen are deflected, which greatly increases the losses in the optical fibers. Furthermore, the proposed arrangement is extremely extensive and thus makes a modular structure, for. B. in the manner of contiguous

Display modules, almost impossible. An additional disadvantage arises from the vibrations caused at high speeds due to the imbalance of the cylindrical rotor, which in addition to strong noise emissions also result in high wear.

Based on the described disadvantages of the prior art

The invention has for its object to develop the screen of the type mentioned in the form that a flat design of such a screen, even with a large viewing area, preferably in a modular manner is made possible and the user has a high degree of brightness and contrast available.

To achieve this object, the invention proposes, starting from the screen of the type mentioned at the outset, that the rotating light sources arranged in the light distributor emit light parallel to the axis of rotation and radiate them into the receptors of the coupling arrangement.

The particular advantage of the screen according to the invention lies in the flat design according to the invention. In contrast to the previously known screen, the light is guided from the light sources to the visible surface of the screen with minimal deflection by the shortest route using the optical waveguides. In addition to the advantage of a minimal space requirement, loss of intensity is also avoided in this way.

The rotation of the light sources, which move at a distance from the axis of rotation of the rotor, allow temporally successive illumination of pixels or groups of pixels. A correspondingly high speed of rotation of the rotating light sources requires a perception of an average brightness of the individual pixels of the human eye. Depending on the number of light sources, the pixels and the speed of the rotor, the frequency of the image construction can advantageously be increased with little effort, so that the visible surface is always flicker-free for the human eye. Here, the embodiment according to the invention benefits from the minimal space requirement, since the unbalance and the vibrations that arise can be reduced to a minimum. In contrast to existing solutions of the prior art, the novel screen technology is not based on a principle-related weakening of the light intensity. Luminous intensity and flicker-free images enable large-format, relaxing viewing. While conventional picture tubes do not allow distortion-free images to be produced on a large viewing area of, for example, several square meters, there is no principle-related limitation of the format with the technique according to the invention. The problems which arise with liquid crystal screens and the required accuracy of layered ceilings are also eliminated. According to the invention, a modular structure can be implemented extremely simply. It is conceivable here to construct the visible surface of a screen from a plurality of individual modules arranged one above the other and next to one another, each of which has its own rotor.

In order to ensure a uniform structure and uniform brightness of the visible surface of the screen, it is useful if the receptors of the optical fibers are arranged equidistantly in the coupling arrangement in the circumferential direction of the rotary movement of the rotor.

For a particularly high light yield, it is expedient if the light sources, in particular light-emitting diodes, are operated with a pulsed voltage. A light emitting diode, which is operated with a pulsed voltage, shines a maximum of almost ten times brighter than when operated with a constant voltage.

In the interest of particularly good illumination of the visible surface of the screen, it is also expedient if the voltage with which the light source is operated is pulsed in such a way that the light source only lights up if it leads directly to the visible surface of the screen opposite the receptor Optical fiber is located. On the one hand, the maximum brightness of this light source increases due to the operation of the light source, preferably a light-emitting diode, with a pulsed voltage, and on the other hand for switching off the light source at times when the transmission to the visible surface of the screen is interrupted, to a lower energy requirement.

An advantageous development of the invention provides that the operating voltage for the light source is controlled in such a way that the light from the light sources shines at a certain angle, deviating from the vertical incidence, into the receptors of the optical waveguides. The incidence of light can be influenced by a corresponding time offset of the pulsing of the operating voltage in such a way that there is always a constant angle of rotation offset between the receptor and the light source. The angle of incidence in the optical waveguide to the visible surface causes a constant cross section of the Optical fiber for the length provided an identical exit angle of the light from the optical fiber on the visible surface. In this way it is possible to generate a particularly high-contrast, well-illuminated image for certain viewing angles or to bring about a stereoscopic effect. The creation of puzzle images or even three-dimensional representations is possible in this way.

An advantageous development of the invention provides that the rotor is equipped with three different types of light emitting diodes. The light-emitting diodes preferably emit red, green or blue light. The light sources located on the rotor radiate light one after the other into the receptors of the optical waveguides combined to form the coupling arrangement.

In addition to varying the angle of incidence in the circumferential direction of the rotor, a targeted change in the angle of incidence in the radial direction of the rotor is also conceivable. For this purpose it is provided according to the invention that individual light sources can be displaced by means of an actuator. Other effects can be achieved by moving the rotor or the coupling arrangement by means of actuators. Because the actuators only have short distances due to the small dimensions, piezo elements are extremely suitable. In addition to the almost wear-free mode of operation, piezo elements enable the components to be moved to be moved very quickly.

The rotor is preferably disc-shaped or star-shaped. This ensures minimal dimensions, unbalance and moments of inertia. Particularly in the case of a star-shaped design of the rotor, it is expedient to attach the light sources to the rotor in an articulated manner so that the light sources automatically center in the operating position when the speed is recorded due to the centrifugal forces. This prevents a wobbling imbalance. The individual joints can advantageously also be designed as springs or folding hinges. If necessary, the articulated, star-shaped supports of the light sources can have a sliding support at their outer ends, which is expediently made of Teflon. Magnetic support for the slide support is also conceivable. For the visualization of still and also moving images, it is useful if the voltage supply of the light sources takes place via a control which converts video signals depending on the angle of rotation of the rotor into the corresponding voltage pulses for the light sources. With a pulsed light source adapted to the frequency of the scanning of the receptors, this signal is advantageously modulated in accordance with the image to be displayed in such a way that the red, green and blue components of the light emitted by the image point correspond to the image to be displayed on the visible surface. So that the phase angle of the rotation of the rotor is always aligned with the control of the light sources, it is useful if the light distributor sends a signal to the control at least once per revolution of the rotor. A specification of the pulsing or the clock frequency of the control of the light source by the speed of the rotor in such a way that a clock pulse is sent to the control each time a light emitter with a receptor is scanned, reliably guarantees a constant synchronization of the rotor and control.

Instead of a galvanic connection of the light sources via sliding contacts with a voltage source or the control, it is expedient if the rotating light sources are supplied inductively with the operating energy by means of an external magnetic field.

According to the invention, it is provided that the rotor is driven by means of an electric motor. It is also expedient to design the rotor itself as an armature of a direct current or alternating current motor, in particular when standing light sources are used. In the interest of a flat design without any sliding contact and long-lasting storage, the drive of the rotor should be designed as an electric motor with an external rotor design. Here, the rotor itself can form the external rotor.

To minimize the interfaces between rotating and standing

Components it is useful if the control of the light sources forms an integral part of the rotor. Complex video signals are advantageously not connected to sliding contacts for actuation in the rotor transmit, but optically transfer to the control integrated in the rotor.

The optical fibers used can consist of both polymers and glass fibers. The use of polymers has the advantage that polymer fibers are much cheaper and have almost identical functions, especially with regard to their transmission behavior. Instead of the commonly used core cladding fibers, it is more appropriate to use plexiglass fibers, since the efficiency of the total reflection of plexiglass fibers is approximately 100%.

A production-friendly and space-saving arrangement of the optical waveguides results if the receptors of the coupling arrangement for individual screen segments are arranged on a straight line and the corresponding straight lines are each arranged in a star shape around the axis of rotation of the rotor. In this way, the visible surface can advantageously be subdivided into lines or line sections which lead to a receptor group arranged on a straight line. Such groups of optical fibers of lines or line sections can each be carried out identically in a standardized manner. It is expedient here to design the coupling arrangement from identical circular or ring segments in which the receptors for individual screen segments are arranged. A corresponding modularization would be possible in the sense that light source conductors arranged on the side facing the visible surface of the screen are arranged one behind the other in a row or column element of rectangular cross-section and at the other end also arranged one behind the other in a pie-shaped spatial shape to form a circle or ring segment are. In this way, a multi-modular structure can also be realized. For example, lines or line sections can be combined in the manner described above to form basic modules and, for example, can be combined into four-part circles on the side of the coupling arrangement, or into a quarter segment of the visible surface of the screen. Here, each basic module could be designed identically, as well as every quartered visible surface coupling arrangement component. An advantageous development of the invention provides that the parts of the coupling arrangement belonging to individual screen segments are provided with digital or analog coding and an optical reading device is arranged on the rotor, by means of which the respective part of the coupling arrangement is identified. In this way, a synchronization between the position of the rotor and the control of the screen is always guaranteed.

To reduce the reflection of extraneous light that shines on the screen from the outside, it makes sense if the visible surface of the screen is darkened with a low reflection or colored black except for the exit openings of the optical fibers. In addition, it is expedient if the optical waveguides on the part of the coupling arrangement open into a low-reflection or black-colored environment in which only the light sources emit light. If the rotor is designed as a disk, black coloring on the side of the rotor facing the end face of the optical waveguide is expedient.

In the interest of a high transmission efficiency of the optical waveguides, it makes sense to mirror the longitudinal walls of the optical waveguides at the coupling and / or decoupling points in the area of the summary of the coupling arrangement or the visible surface. In this way, the contact of the optical fibers with the adjacent components is almost harmless for the efficiency of the transmission or the reflection on the lateral boundary walls of the optical fibers. For a rigid and vibration-resistant combination of rotor, drive, optical fiber bundles and visible surface, it is expedient if the rotor is driven by a drive which is located between the rotor and the visible surface of the screen and is arranged centrally between the optical fibers. The large number of optical fibers forms a stable bond that is ideally suited for fastening the drive.

For the precise arrangement of the individual optical fibers, in particular on the coupling arrangement, it is expedient to add a large number of optical fibers

To summarize flat ribbon assemblies. These flat band composites can advantageously be in a circular or annular shaped piece, for example by Pouring with synthetic resin, can be summarized. The ribbon connection ensures in particular the distance between the individual optical fibers.

In order to avoid contamination, structure-borne noise and flow noises, the drive or the rotor or a complete screen module or the entire screen or all of these components can be made gas-tight. In the field of medical technology, a gastight design of the device facilitates the hygiene treatment.

The invention is explained in more detail below on the basis of a special exemplary embodiment with reference to drawings. Show it.

Fig. 1: A schematic diagram of the structure and

Operation of a screen according to the invention shown against the direction of view of a viewer and

Fig. 2: A partially cut, schematic

Representation of a screen according to the invention transversely to the visible surface.

In the illustrated embodiment, the visible surface 1 of the screen is designated by the reference number 1. The visible surface 1 is subdivided into a plurality of pixels 2, which are each connected to a light guide 3. On the side of the viewing surface 1 of the screen facing the viewer (not shown), the viewing surface 1 is colored black with little reflection apart from the outlet openings of the optical waveguides 3. The entire viewing area 1 is divided into four identical image segments 4.

From the viewer's perspective, there is a coupling arrangement 5 behind the visible surface 1 of the screen. The coupling arrangement 5 is also divided into four modules 6 in accordance with the division of the visible surface 1 into four image segments 4. In the individual modules 6, the optical waveguides 3 emanating from the image segments 4 of the visible surface 1 and which form receptors 7 for incident light are combined at their ends. In each case one line 8 of pixels 2 of an image segment 4 is guided onto the coupling arrangement 5 by means of the optical waveguides 3 starting from the pixels 2, the optical fibers 3 of each line 8 being combined into a flat ribbon composite and arranged on the coupling arrangement 5 on a straight line which extends through the center of the coupling arrangement 5.

The coupling arrangement 5 is round, wherein it is provided with a central recess 9. The individual flat band composites 10 of the optical waveguides 3 are combined on the part of the visible surface 1 to form elements 11 of rectangular cross section segmented in pixels 2. The individual elements 11 consist of cast resin and are joined together by means of tongue and groove connections.

On the side of the coupling arrangement 5, the optical waveguides 3 belonging to a flat ribbon composite 10 are each provided with an encircling sprue 12 in the form of an annular segment or pie piece, which also consists of synthetic resin. The basic elements 13 consisting of the elements 11 of rectangular cross-section, the flat band assemblies 10 of the optical waveguides 3 and the pie-shaped sprues 12 are standardized and identical for the entire visible surface 1 of the screen. The basic elements 13 are first assembled in the course of the production by the coupling arrangement 5 to form quarter-circle modules 6. Then the image segments 4 and the modules 6 are assembled to the visible surface 1 or the coupling arrangement 5. In the area of the combination of the optical waveguides 3 on the part of the visible surface 1 and the coupling arrangement 5, the boundary surfaces extending in the longitudinal direction of the optical waveguides 3 are mirrored, so that the

Transmission efficiency of the optical waveguide 3 is not deteriorated by contact with the resin gate.

Each module 6 is provided with a binary coding (not shown) on the coupling arrangement 5 side. For this purpose, the ends on the side of the coupling arrangement 5 of the optical fibers 3 of the ribbon assemblies 10 are colored in different sequences, so that by means of one not shown scanning laser through the transmissive resin of the sprue 12, an individual binary code can be read.

Viewed from the viewer, behind the coupling arrangement 5, the rotor 20 is arranged, which is set in rotation by a drive 21. The rotor 20 rotates as shown about a central axis of rotation 22 in the center of the coupling arrangement 5. Starting from the axis of rotation 22 in a star shape, three arms 23 are attached to the rotor 20, which are provided with LEDs 24 in the region of the receptors 7 of the coupling arrangement 5 , The light-emitting diodes 24 radiate into the receptors 7 as required. The arms 23 are each provided with a joint 25 between the axis of rotation 22 and the light-emitting diodes 24, which enables the arms 23 to move in the direction of the axis of rotation 22. In this way, each arm 23 is automatically centered without wobble by the centrifugal forces of the rotation.

The drive 21 of the rotor 20 is arranged centrally in the coupling arrangement 5 and between the optical fibers 3. By the central

Recess 9 of the coupling arrangement 5 is a drive shaft 30 of the

Drive 21 guided on the rotor 20. A control 40 for the light-emitting diodes 24 rotates together with the rotor 20

Receiver 41 arranged for video signals. The video signals are transmitted from an infrared transmitter 42 to the receiver 41 and from the

Control 40 evaluated, which gives the corresponding voltage pulses to the LEDs 24. The control 40 and the drive 21 are supplied with energy inductively. The drive 21 is designed as an external rotor with an internal coil arrangement 51 and a ferritic external rotor 50.

Claims

claims

1. A screen with a viewing area (1) divided into pixels (2), the pixels (2) of which each emit light and are connected via optical waveguides (3) to a light distributor which has rotating light sources (10) arranged on a rotor (20) , which are arranged at a distance from the axis of rotation (22) and whose emitted light radiates into receptors (7) of a coupling arrangement (5) arranged at the ends of the optical fibers (3), via the individual optical fibers (3) to the visible surface (1) of the Arrives on the screen and produces an image visible to the viewer and composed of the individual pixels (2), characterized in that the rotating light sources (10) arranged in the light distributor emit light parallel to the axis of rotation (22) and into the receptors (7) irradiate the coupling arrangement (5).

2. Screen according to claim 1, characterized in that the light sources (10) are operated with a pulsed voltage.

3. Screen according to claim 2, characterized in that the voltage is pulsed in such a way that the light sources (10) only light up when they are directly almost centrally in a receptor (7) leading to the screen of the coupling arrangement (5) of an optical waveguide (3) radiate.

4. Screen according to claim 1, characterized in that the operating voltage for the light sources (10) is controlled such that the light from the light sources (10) at a certain angle deviating from the vertical incidence in the receptors (7) of the optical waveguide (3rd ) shines in.

5. Screen according to claim 1, characterized in that the individual light sources (10) or the rotor (20) or the coupling arrangement (5) are displaceable by means of an actuator.

6. Screen according to claim 1, characterized in that the rotor (20) is disc-shaped or star-shaped.

7. Screen according to claim 1, characterized in that the voltage supply of the light sources (10) via a control (40), which signals (14) depending on the angle of rotation of the rotor (20) in the corresponding voltage pulses for the light sources (10) implements and the light distributor sends a signal to the control (40) at least once per revolution of the rotor (20).

8. Screen according to claim 1, characterized in that in the rotor (20) a voltage generator is integrated, the rotating light sources (10) are inductively supplied with voltage due to an external magnetic field.

9. Screen according to claim 1, characterized in that the control (40) of the light sources (10) is an integral part of the rotor (20).

10. Screen according to claim 9, characterized in that the signals (14) are optically transmitted to the control (40) integrated in the rotor (20).

11. Screen according to claim 1, characterized in that the light sources (10) are articulated to the rotor (20) and move into the operating position when the speed is increased due to centrifugal forces.

12. Screen according to claim 1, characterized in that the

Receptors (7) of the coupling arrangement (5) for individual screen segments are arranged on a straight line and the straight lines are each arranged in a star shape around the axis of rotation (22) of the rotor (20).

13. Screen according to claim 1, characterized in that the coupling arrangement (5) consists of identical circular or ring segments in which the receptors (7) are arranged for the individual screen segments.

14. Screen according to claim 1, characterized in that the parts of the coupling arrangement (5) belonging to individual screen segments are provided with digital or analog coding and on the rotor (20) an optical reading device is arranged, by means of which the respective part of the coupling arrangement (5) is identified.

15. Screen according to claim 1, characterized in that each pixel (2) of the visible surface (1) has an outlet opening for an optical waveguide (3) and the surface around the outlet opening is darkened or colored black.

16. Screen according to claim 1, characterized in that the longitudinally extending boundary walls of the optical waveguide (3) at the coupling and / or decoupling points are each mirrored in the region of the summary for the coupling arrangement (5) or the visible surface (1).

17. Screen according to claim 1, characterized in that the rotor (20) is driven by a drive () which is located between the rotor (20) and the visible surface (1) of the screen and is arranged centrally between the optical fibers (3).

18. Screen according to claim 1, characterized in that in each case a plurality of optical fibers (3) are combined to form ribbon assemblies.

19. Screen according to claim 1, characterized in that the drive and / or the rotor and / or a screen module and or the entire screen are gas-tight.