DE29723042U1 - Display device - Google Patents

Description

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Carl Brose GmbH 23 December 1997

42109 Wuppertal

BRO47.G8

Display device

31 pages description

10 pages with 28 claims

1 page summary

5 pages of drawings

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Description

The invention relates to a display device according to the preamble of claim 1.

A generic elongated display device is known from European patent specification No. 0 594 367 Bl, in which the dot matrix elements combined to form display segments are arranged on circuit boards, which in turn are mounted on an elongated frame that is deformable transversely to its longitudinal direction. In order to adapt the display device to a curved pane, the deformable frame is pressed against the pane via a large number of struts that run between the deformable frame and a cross member located behind the pane and installed firmly relative to the pane, and is thereby deformed in such a way that the frame and thus the display device adapt to the curvature of the pane.

A disadvantage of this display device is the gap between the individual display segments of the display surface resulting from the bending of the circuit boards. Depending on the strength of the curvature of the pane, more or less large gaps are created in the display surface between the display segments. The visual impression of the display is therefore inconsistent. This is particularly the case with conventional windows on buses or trains, where the curvature of the pane usually increases towards the outside. In these cases in particular, the display appears distorted or stretched towards the outside.

A further disadvantage is the bending load on the circuit boards on which the dot matrix elements are arranged

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The circuit boards and the galvanic or mechanical connections between the dot matrix elements and the circuit boards are subject to an increased risk of damage and thus failure due to this prestressing, not least in view of the high vibration loads often experienced by road or rail vehicles.

The invention is therefore based on the object of providing a display device of the type mentioned at the beginning, which does not have the disadvantages mentioned or has them to a lesser extent. In particular, a display device that is easy to manufacture and is adapted to curved panes is to be provided, which ensures a display that is as distortion-free as possible.

The object is achieved, starting from a device according to the preamble of claim 1, by the features specified in the characterizing part of claim 1.

The invention includes the technical teaching that a display device that is easy to manufacture and is adapted to curved panes is obtained if the surface sections of the display segments run essentially parallel to one another, the display segments being arranged in steps in the direction of the surface normal of the display segments in order to arrange the display surface behind the pane with minimal spacing, such that the curvature of the pane is approximated in the manner of a staircase by the longitudinal edge formed from the edge sections in the plane that runs perpendicular to the display surface and contains the longitudinal edge. This parallel arrangement of the display segments ensures in a simple manner that, regardless of the curvature of the pane behind which the display device is installed,

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arranged, no gaps appear in the display surface, so that the viewer does not see any distortion of the display. In the most common constellation, in which the viewer essentially looks at the display from the front, no distortion occurs, but the viewer has the impression that he is looking at a uniform, flat display.

The display segments can consist of rectangular fields of dot matrix elements. Depending on the length of the field in the direction of the long edge of the display device, i.e. depending on the number of dot matrix elements of the display segment forming the respective edge section of the long edge, a more or less good adaptation of the display device to the curved pane is possible through the stepped arrangement of the display segments. A particularly good approximation to the curvature of the pane is achieved if the display segments consist of individual rows of dot matrix elements, i.e. the edge section is formed by a dot matrix element in each case.

However, it is understood that display segments with different longitudinal extensions can also be combined with one another. For example, display segments made up of larger fields of dot matrix elements can be provided to adapt to less curved areas of the screen, while display segments consisting of individual rows of dot matrix elements can be provided to adapt to more curved areas of the screen.

It is also understood that over the length of the display device depending on the curvature of the disc, there are different step heights, i.e. perpendicular to the surface sections different distances between the surface sections

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ten adjacent display segments. If the disc is also flat over a certain area and runs parallel to the surface sections, it is also understood that the surface sections of the display segments arranged in this area lie in a common plane and thus form a common step.

In preferred embodiments of the present invention, at least the dot matrix elements of the respective display segment are arranged on a common, flat circuit board that is parallel to the surface sections. This creates a modular structure for the display device, which makes the stepped arrangement of the display segments and thus the manufacture and assembly of the display device much easier. On the other hand, bending stress on the circuit boards on which the dot matrix elements are arranged is avoided, so that the risk of failure is significantly reduced compared to the known display device. Preferably, the dot matrix elements of the display device are arranged on a common, flat circuit board that is parallel to the surface sections, which makes assembly of the display device even easier.

In particularly advantageous variants of the present invention, the dot matrix elements each forming a display segment are firmly connected to one another. For the stepped arrangement of the display segments, at least one spacer element is provided for at least the display segments whose surface section has a distance from the common circuit board that exceeds the smallest vertical distance, which is between the conductor

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plate and the display segment. In other words, no spacer elements can be provided for the display segment(s) whose surface section has the smallest vertical distance from the common circuit board, since these display segments can then be attached directly to the circuit board, resulting in the smallest possible extension of the display device perpendicular to the common circuit board. However, spacer elements can also be provided for the display segment(s) with the smallest distance from the circuit board. In any case, this further reduces the manufacturing effort for the display device, since the spacer elements ensure the required distance of the respective display segment from the circuit board, so that the respective display segment can be easily attached to the common circuit board together with the corresponding spacer element, e.g. plugged in, and then attached there in the correct position without any additional aids, e.g. by making the corresponding solder connections.

In particularly preferred variants, the spacer elements are connected to one another to form a spacer, so that the manufacture of the display device is simplified even further by, for example, first placing the spacer on the circuit board and then placing the display segments on top. This is particularly simple in preferred embodiments in which the spacer is designed as a one-piece, elongated component with a substantially flat rear side facing the circuit board and a front side facing the dot matrix elements, which is stepped in such a way that the

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The curvature of the pane is approximated by the front side in a plane running parallel to the longitudinal direction of the spacer and perpendicular to the circuit board, like a staircase. The front side can consist of steps parallel to the circuit board. However, it can also be shaped in a different way; the only important thing is the function of the steps as a spacer between the circuit board and the display segment.

In particularly advantageous display devices with a display device designed as a dot matrix display and divided into display segments, a device for illuminating the display surface of the display device is provided, which comprises at least one light source extending laterally along a longitudinal edge of the display device and a light guide device adjacent to the light source. The light guide device runs essentially parallel along this light source and does not cover the display surface, at least in plan view. The light guide device serves to direct at least part of the light emitted by the light source onto the display surface of the display device and is designed in such a way that the display surface is essentially evenly illuminated. This ensures that the display surface is evenly illuminated in a simple manner. The light source is preferably formed by a number of light-emitting diodes arranged in at least one row running essentially parallel to the longitudinal edge. This results in a particularly economical and also small-sized device. On the other hand, the light-emitting diodes used can be connected directly to direct current, as is the case with

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especially when used in buses or similar. When using light-emitting diodes, in contrast to the frequently encountered use of fluorescent tubes to illuminate displays, complex and bulky ballasts for the light source are not required. This results in a small size, low manufacturing costs and trouble-free operation of the display, as electromagnetic interference signals from such ballasts do not occur and therefore do not have to be shielded with complex means.

The display surface is preferably illuminated segment by segment, whereby the light source consists of light source segments arranged on the respective display segments and the light guide device consists of light guide segments assigned to the respective light source segments. This segment-by-segment illumination of the display surface significantly reduces the manufacturing effort for the respective display device, since the light source segments and the associated light guide segments are matched to the respective display segment regardless of the curvature of the respective pane and adaptation of the light source and light guide device to the respective curvature of the pane can be omitted or occurs automatically with the corresponding arrangement of the display segments. Further preferably, depending on the size of the display segments, the light source segments are each formed by a light-emitting diode or are each formed by a number of light-emitting diodes that are arranged in at least one row running essentially parallel to the respective edge section.

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The light guide segments can be formed by corresponding prisms or lenses or reflectors or light guide systems constructed from them, which distribute the light from the light source segments to the 5 surface sections in a known manner.

Preferably, the respective light guide segment is designed in a particularly simple manner in the manner of a concave reflector, which has at least one reflection surface arranged in front of, i.e. on the observer side of, the plane of the surface section, facing the light source segment and running essentially parallel to it. This reflection surface is formed from a number of reflection surfaces, each of which reflects the light from the light source segment striking it onto the surface section. At least one reflection surface is provided which reflects light from the light source segment onto the area of the surface section to be illuminated that is furthest away perpendicular to the edge section.

The reflection surface, which reflects the light onto the furthest away area of the surface section to be illuminated, ensures in a simple manner that the area of the surface section to be illuminated is completely illuminated. The area to be illuminated can be the entire surface section, for example if only one light source segment is provided along an edge section of the display device. However, if a light source with a corresponding light guide device is provided on the two opposite longitudinal edges of the display device, the light generated by the respective

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The area to be illuminated by the light source segment should ideally only extend to the middle of the surface section between the two edge sections on which the light source segments are arranged. The corresponding reflection surface must then only be designed in such a way that it reflects the light from the light source segments up to this center line between the two opposite edge sections.

Furthermore, the reflection surfaces are designed in such a way that the decrease in light intensity with the beam path between the light source segment and the surface section is compensated. This compensation of the decrease in light intensity with the distance from the light source segment can be realized in many known ways. The reflection surfaces can, for example, be arranged and aligned in such a way that the respective average beam paths between the light source segment and the respective area of the surface section onto which the respective reflection surface reflects the light striking it from the direction of the light source segment have essentially the same length. The reflector is then designed in such a way that the light between the light source segment and the surface section always travels approximately the same beam path, regardless of the distance between the point at which the light strikes the surface section and the light source segment. This can be achieved by guiding the light that impinges on areas of the surface section that are closer to the light source segment, for example, over several and/or over reflection surfaces that are further away from the light source segment and thus travels through approximately the same beam path as light that impinges on areas that are further away from the light source segment.

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hits areas of the surface section that are far from the source segment and is only guided over a reflection surface that is close to the light source segment.

Compensation is particularly simple in another preferred embodiment of the present invention, in which the surface area of the reflection surfaces is proportional to the square of the average beam path between the light source segment and the respective area of the surface section onto which the light from the light source segment is reflected. The greater the path that a portion of the light from the light source segment has to travel between this and the surface section, the lower the intensity of the light striking the surface section per unit area. This intensity per unit area decreases with the square of the beam path. The design of the reflection surfaces according to the invention compensates for this decrease in intensity in a simple manner, as the surface area of the corresponding reflection surfaces increases quadratically with the increase in the beam path, meaning that a correspondingly larger portion of the light from the light source segment is reflected into areas to which the light has to travel a greater distance.

It goes without saying that the light rays from the light source segment can also hit several reflection surfaces and be reflected by them.

In a particularly advantageous embodiment of the information display according to the invention, the reflection surface is designed in such a way that, in order to evenly illuminate the surface sections, the more light is reflected onto an area of the surface section, the flatter the

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The angle of incidence of the light coming from the reflection surface on the respective area of the surface section is thus easily compensated for the influence of the angle of incidence of the light on the reflection of the light by the surface sections in the direction of the observer, which consists in the fact that the flatter the light strikes the surface sections, the less light is reflected from the surface sections in the direction of an observer who is usually some distance in front of the surface section.

In particularly favorable variants of the information display according to the invention, the reflection surface is formed by essentially flat reflection surfaces running parallel to the respective edge section. These can be manufactured particularly easily and can also be easily aligned according to the conditions of the respective surface section.

Preferably, the light guide segments each comprise a substantially U-shaped collecting reflector surrounding the light source segment and open towards the reflection surface in order to direct the light from the light source segments that is not emitted in the direction of the reflection surface onto the reflection surface, so that as much of the light emitted by the light source segment as possible reaches the surface section, thus reducing the number of light-emitting diodes required for illumination.

A particularly space-saving design of the display device according to the invention is obtained in further variants, in which the light source segments are essentially behind

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the plane of the respective surface section. As a result, the device together with the display device has relatively small dimensions perpendicular to the surface sections, since only the reflection surface and the components of the information display that support it are arranged laterally in front of the surface sections. The smaller the distance between the surface sections and the pane, the smaller the disruptive reflection influences are when there is sufficient external light, for example strong sunlight, and the light source segments are switched off.

In particularly preferred embodiments of the invention, the light-emitting diodes are designed as light-emitting diodes with directed radiation in an angular range of essentially 15° at most. This makes the targeted and uniform illumination of the surface sections particularly simple, since the respective light-emitting diode and the light cone emitted by it simply have to be aligned accordingly. The respective light source segment preferably comprises at least two rows of light-emitting diodes that are essentially parallel to one another. The radiation directions of the light-emitting diodes run parallel to one another within the respective row. For targeted illumination of the respective surface section, the areas of the reflection surface onto which the light from the rows impinges are then aligned differently, so that they reflect the light from the rows of light-emitting diodes directed at them in different directions and thus onto different areas of the surface sections. In addition or alternatively, the respective radiation directions of the rows of light-emitting diodes can also be aligned with one another.

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inclined. This makes it particularly easy to adjust the uniform illumination of the surface sections.

In variants that are particularly advantageous in terms of manufacturing technology, the respective light source segment is arranged to the side of the dot matrix elements on the circuit board of the dot matrix elements, so that a closed structural unit that is particularly quick and easy to manufacture is produced.

In other preferred embodiments of such display devices, the display device is divided into a number of display segments, the surface sections of which are inclined to one another in order to arrange the display surface behind the pane with minimal spacing, such that the curvature of the pane is approximated in the manner of a polygon by the longitudinal edge formed by the edge sections in the plane running perpendicular to the display surface and containing the longitudinal edge. In these variants too, good illumination of the entire display surface is thus ensured in a particularly simple manner by the described segment-by-segment illumination of the surface sections according to the invention.

In particularly advantageous display devices according to the invention, a box-shaped housing is provided which is open on the viewer side and encloses at least the dot matrix elements of the display device. The edge of the housing on the opening side is designed to be connectable to a transparent front panel in an at least dust-tight manner to encapsulate the interior of the housing in an at least dust-tight manner. Furthermore, the components of the display device which generate heat to a significant extent, in particular

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in particular the components for controlling or regulating the display device are arranged outside the housing. The encapsulation prevents contamination of the display surface, but in particular of the light source and the light guide device, so that good readability of the display is always guaranteed. By arranging the main heat generators of the display device outside the housing, it is ensured that the function of the dot matrix elements is not impaired by excessive heating. It goes without saying that the electrical connection lines between the components arranged outside and inside the housing are made through a corresponding, also at least dust-tight, lead-through through the housing.

Preferably, the opening-side edge of the housing has a contact surface facing forward, the curvature of which essentially corresponds to the curvature of the pane in the respective contact area, whereby the distance of the contact surface perpendicular to the respective surface section in planes perpendicular to the longitudinal edge or to the respective edge section essentially does not fall below the largest extent of the associated light-conducting segment on the viewer side of the surface section perpendicular to the respective surface section. This ensures that neither the display device nor the light-conducting device protrude from the housing, so that the housing can be easily connected to the front pane to be attached to it.

Further preferably, the distance of the contact surface perpendicular to the respective surface section in planes perpendicular to the respective edge section is selected such that

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that the distance between the display surface and the disk is minimized, resulting in a particularly small display device.

The front screen can be a separate component. Preferably, however, the screen behind which the display device is to be arranged, for example the screen of a road or rail vehicle, forms the front screen and the opening-side edge of the housing is designed to create at least a dust-tight connection between the housing and this screen. This not only saves another component - the separate front screen for the housing - but also further reduces the dimensions of the display device when installed.

In particularly favorable variants, the contact surface is designed to be glued to the pane and has sufficient expansion to absorb the loads acting on the display device through the bonding. Separate suspension devices for the display device can then be omitted.

Accordingly, in an arrangement according to the invention comprising a transparent pane, in particular of a road or rail vehicle, and a display device according to the invention, the housing and the pane are glued together to encapsulate the interior of the housing in an at least dust-tight manner. Preferably, the bond is designed as a bond sufficient to absorb the loads acting on the display device. Such arrangements can, for example, be supplied as a finished subassembly during manufacture.

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of such road or rail vehicles.

In a favorable further development of this arrangement, the pane is then provided with a coating that at least partially obstructs the viewer's view, at least in the area that is laterally adjacent to the display surface from the viewer's perspective. This results in a screen that is easy to produce and that covers the areas adjacent to the display surface. The coating can be completely obstructive, but there can be a smooth, increasingly obstructive transition between the display surface and the areas adjacent to it. The coating can be on the side of the pane facing the viewer and/or facing away from it.

Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below together with the description of the preferred embodiment of the invention using the figures. They show:

Figure 1 is a plan view of a preferred embodiment of the invention,

Figure 2 shows a partial section through the embodiment of Figure 1 along the line II-II,

Figure 3 is a sectional view of the embodiment of Figure 1 along the line III-III,

Figure 4 is a sectional view of another preferred display device according to the invention,

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Figure 5 shows a partial section of another preferred embodiment of the invention.

Figure 1 shows an embodiment of the display device according to the invention with a display device 1, which is made up of dot matrix elements 2. The display device 1 is divided into display segments 1.1, which in the example shown are each formed by a row of dot matrix elements 2 extending between the two longitudinal edges 3 and 4 of the display device 1.

The longitudinal edges 3 and 4 of the display device 1 extend in one of the main extension directions of the display device 1. The display segments 1.1 each form an edge section 3.1 or 4.1 of the longitudinal edge 3 or 4 and a rectangular surface section 5.1 of the display surface 5.

Furthermore, a device 6 is provided for illuminating the display surface 5 of the display device 1. The device 6 comprises two light sources 7 and 8, each extending laterally along one of the two longitudinal edges 3 and 4 of the display device 1, and light guide devices 9 and 10, each adjacent to and running parallel to these, which direct the light emitted by the respective light source 7 or 8 onto the display surface 5. The light sources 7 and 8 each consist of a row of light-emitting diodes 11 arranged parallel to the respective longitudinal edge 3 or 4.

The light source 7 is divided into light source segments 7.1, whereby each display segment 1.1 is assigned a light source segment 7.1. The light source segments 7.1 each extend laterally along the respective

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Edge section 3.1 of the longitudinal edge 3 of the display device 1. In the example shown, they each consist of two light-emitting diodes 11 arranged parallel to the respective edge section 3.1. The same applies to the light source 8, which is divided into light source segments 8.1 arranged accordingly along the longitudinal edge 4.

The light guide device 9 is divided into light guide segments 9.1, each of which is assigned to a light source segment and runs parallel to it. They direct the light emitted by the assigned light source segment 7.1 onto the surface section 5.1 of the display segment 1.1. The same applies to the light guide device 10, which is divided into light guide segments 10.1 assigned to the light source segments 8.1.

The light source segments 7.1 and 8.1 illuminate the adjacent half of the surface section 5.1 of the associated display segment 1.1 up to the horizontal center line 1.2 via the associated light guide segments 9.1 and 10.1, so that complete illumination of the respective surface section 5.1 and thus of the display surface 5 is achieved.

It goes without saying that if the display surface is small enough or the number of LEDs per light source is large enough or the light intensity of the individual LEDs is high, fewer light sources can be provided. It may even be the case that a single light source made up of a corresponding number of LEDs with a correspondingly bright light is sufficient to illuminate the entire display if the associated light guide device is suitably designed.

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surface. It is also possible that a single brightly emitting light diode is sufficient to illuminate the respective surface section.

The display device 1 and the device 6 for illuminating the display surface 5 are enclosed by a box-shaped housing 12, which is open on the side facing the viewer of the display surface 5 and closed on all other sides.

Figure 2 shows a partial section through the embodiment from Figure 1 up to the horizontal center line 1.2 of the display device, which is arranged behind a pane 13. The half of the display device not shown in this partial section is constructed symmetrically.

The light-emitting diodes 11 forming the light source segment 7.1 are arranged to the side of the dot matrix elements 2 forming the display segment 1.1 on a common circuit board 14 parallel to the surface section 5.1 of the display segment 1.1, which is fixed in the housing 12 using suitable fastening means, in the example shown fastening screws 12.1. The circuit board 14 carries all electrical connecting lines to the dot matrix elements 2 or the light-emitting diodes 11. In order to achieve the smallest possible dimensions perpendicular to the plane of the surface section 5.1, the light-emitting diodes 11 are arranged behind, i.e. on the side of the plane of the surface section 5.1 facing away from a viewer of the display.

The light guide segment 9.1 is, as can be seen in Figure 2, designed in the manner of a concave reflector, whereby it

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a reflection surface 15 arranged in front of, i.e. on the observer side of the plane of the surface section 5.1, which faces the light source segment 7.1 and reflects the light from the light source segment 7.1 striking it onto the surface section 5.1. The reflection surface 15 runs parallel to the light source segment 7.1 and thus also parallel to the edge section 3.1 of the display device 1.

The reflection surface 15 is made up of flat reflection surfaces 16.1, 16.2 and 16.3 that run parallel to the edge section 3.1 and have different inclinations to the plane of the surface section 5.1. The reflection surface 16.1 runs so steeply inclined to the plane of the surface section 5.1 that, as indicated by the beam path 17.1, the light striking it from the direction of the light source segment 7.1 is reflected onto the area of the surface section 5.1 to be illuminated that is perpendicular to the edge section 3.1 and furthest away from the light source segment 7.1, which ends at the horizontal center line 1.2. The remaining reflection surfaces 16.2 and 16.3 run flatter to the plane of the surface section 5.1 and, as indicated by the beam paths 17.2 and 17.3, reflect the light striking them from the direction of the light source segment 7.1 onto areas of the surface section 5.1 that are closer to the light source segment 7.1, thereby achieving complete illumination of the surface section 5.1.

The surface area of the reflection surfaces is proportional to the square of the average beam path of the light between the light source segment 7.1 and the respective area of the surface section 5.1 onto which the respective

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Reflection surface reflects the light coming from the direction of the light source segment 7.1, so that the influence of the decrease in the intensity of the light with increasing beam path between the light source segment 7.1 and the surface section 5.1 is compensated.

To compensate for the influence of the angle of incidence of the light on the surface section 5.1, which consists in the fact that the flatter the light hits the surface section 5.1, the less light is reflected from the surface section 5.1 in the direction of an observer who is usually some distance in front of the surface section 5.1, the light guide segment 9.1 comprises a further reflection surface 16.4, which reflects the light hitting it from the direction of the light source segment 7.1 onto the reflection surface 16.2, from where it is reflected, as the beam path 17.4 indicates, onto the area of the surface section 5.1 to be illuminated that is furthest away from the light source segment 7.1. The additional amount of light that reaches this area compensates for the influence of the very flat angle of incidence of the light reflected into this area by the reflection surface 16.1. This gives the observer an impression of uniform brightness across the surface section 5.1.

It is understood, however, that the compensation of the impact angle influence could also be achieved solely by appropriate size ratios between the reflection surfaces 16.1 to 16.3. It is also understood that in other embodiments of the invention, depending on the requirements for the uniformity of the illumination of the surface section, a finer division of the reflection surface into

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a larger number of reflection surfaces up to a reflection surface with essentially constant curvature can be selected.

In order to project as much of the light emitted by the light source segment 7.1 as possible onto the surface section 5.1, the light guide segment 9.1 also includes a collective reflector 18 which surrounds the light source segment 7.1 formed by light-emitting diodes 11 in a U-shape. The collective reflector 18 also runs parallel to the edge section 3.1 of the display device 1 and is open towards the reflection surface 15. It is shaped in such a way that it guides the light striking it onto the reflection surface 15, from which it reaches the surface section 5.1.

The light guide segment 9.1 is designed as a one-piece component that has a base 17 on the circuit board side in the area of the collecting reflector 18, which is provided with a mounting opening 18.2. This mounting opening 18.2 is guided over a mounting base 15 of the display segment 1.1, on which the light source segment 7.1 is mounted, for the exact alignment of the light guide segment 9.1 with the light source segment 7.1. The light guide segment 9.1 is then connected to the mounting base 11.1 by suitable means for final fixation. The mounting base 19 and the dot matrix elements 2 of the display segment 1.1 are firmly connected to one another and thus form a closed assembly.

The opening-side edge 21 of the housing 12 has a contact surface 21.1 facing forwards, i.e. in the direction of an observer, to the pane 13. The contact surface 21.1

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is bonded to the pane 13 via an adhesive 22, so that the interior of the housing 12 is dust-tightly encapsulated. The contact surface 21.1 is designed in terms of its size and surface quality so that the adhesive 22, if designed accordingly, absorbs the entire weight of the display device as well as the loads acting on the display device during operation. Further fastening of the display device to the pane or surrounding components is therefore not necessary.

In the example shown, only the dot matrix elements 2, the light-emitting diodes 11 and the circuit board 14 are arranged inside the housing 12 as current-consuming or current-carrying components. All components of the display device that generate a significant amount of heat - not shown in Figures 1 to 3 - such as the control device of the display device and the control or regulating device of the light source, are arranged outside the housing 12. They can be attached to the outer wall of the housing 12, but it goes without saying that they can also be arranged elsewhere. The connection of these components to the dot matrix elements 2 or the light-emitting diodes 11 takes place via connecting lines 14.1 arranged on the circuit board 14, which are guided through the housing 12 in a sealed manner depending on the encapsulation of the interior of the housing.

Spacer elements 20.1 are arranged between the display segment 1.1 and the circuit board 14, each of which is a component of a spacer 20 that extends in the direction of the longitudinal edge 3. The spacer element 20.1 determines the distance of the display segment 1.1 from the circuit board

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14 perpendicular to the surface section 5.1. The height of the spacer element 20.1, i.e. its extension perpendicular to the circuit board 14, is selected so that the front edge 15.1 of the light guide segment 9.1, where the greatest extension of the light guide segment 9.1 perpendicular to the surface section 5.1 is present, has a minimum distance from the pane. In the example shown, this distance corresponds approximately to the layer thickness of the adhesive 22. It is understood that this distance varies depending on the strength of the curvature of the pane along the edge section 3.1, i.e. it can be greater at other points on the edge section 3.1. In other words, the distance between the contact surface 21.1 and the height of the spacer element 20.1 are coordinated in such a way that the light guide segment 9.1 does not protrude forwards from the housing 12 through the envelope surface of the housing 12 spanned by the contact surface 21.1, but rather at best touches this envelope surface of the housing 12. This ensures that the surface section 5.1 has the smallest possible distance from the disk 13.

It is understood that the light guide segment 9.1 can also be offset further back relative to the envelope surface of the housing 12 spanned by the contact surface 21.1, whereby the distance between the surface section 5.1 and the disk 13 then increases.

As can be seen from Figures 1 and 2, the front edge 15.1 of the light guide segment 9.1 ends so far to the side of the surface section 5.1 that the latter is not covered by the light guide segment 9.1 in the top view, i.e. when viewed perpendicular to the surface section 5.1. This ensures that the surface section 5.1 is clearly visible.

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The rotating plates of the dot matrix elements 2 forming the surface section 5.1 have on their colored side - the other side is blackened in the usual way for such displays - a color coating that corresponds to the color of the light emitted by the LEDs 11. This colored light is in a wavelength range with a high degree of brightness sensitivity for an observer. Such light, which is perceived as particularly bright, is in a wavelength range between 900 and 1150 nm for daytime vision, although this range shifts to slightly lower wavelengths (by about 90 nm) for nighttime vision. It goes without saying that by completely or partially changing the wavelength of the light emitted by the LEDs, the information displayed on the surface section can be designed to be particularly vivid and easy to read for an observer.

The pane 13 is provided with a coating 23 which obstructs the viewer's view of the areas of the display device located to the side of the display surface 5. The coating 23 thus forms a screen which covers the area of the pane 13 adjacent to the display surface 5. It goes without saying that the coating can also be arranged on the inside of the pane in other variants. A corresponding screen can also be arranged inside the pane.

Figure 3 shows a section through the embodiment from Figure 1 along line III-III in the state arranged behind the curved disk 13. As can be seen from this figure, the display segments 1.1 are on the common flat

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Circuit board 14. The surface sections 5.1 of the display segments 1.1 run parallel to one another and to the circuit board 14. The display segments 1.1 and thus also the light source segments 7.1 and light guide segments 9.1 assigned to them are arranged in steps in the direction of the surface normal of the display segments 1.1 due to the spacer elements 20.1 arranged between the circuit board 14 and the display segments 1.1, which are connected to form a spacer 20, such that the curvature of the disk 13 is approximated by the edge sections 3.1 in the manner of a staircase. The front edges 15.1 of the light guide segments 9.1, which run parallel to the edge sections 3.1, therefore also approximate the curvature of the pane 13 in a stepped manner and, depending on the curvature of the pane 13, have the minimum distance to the pane 13 at at least one point, which, as described in Figure 2, in the example shown corresponds approximately to the layer thickness of the bond 22 between the contact surface 21.1 of the housing 12 and the pane 13. The curvature of the contact surface 21.1 in the section plane shown corresponds to the curvature of the pane 13 in the respective contact area.

In the example shown, no spacer element is provided for the two outer display segments, the surface section of which has the smallest vertical distance from the circuit board, whereby the extension of the display device in this direction is minimized. However, it is understood that spacer elements can also be provided for these display segments if necessary.

Furthermore, the display segments can be used in variants of the invention in which no illumination of the display surface and thus no light-guiding segments are provided,

BRO47.G8 - 28 -

of course, have to be moved closer to the screen. The distance between the display segments, which are arranged in stages in the same way as in the variant described, and the screen must then be at least large enough to allow the display plates of the dot matrix elements to be folded over.

Figure 4 shows a further embodiment of the invention, which is essentially similar in its structure to the embodiment in Figures 1 and 2, so that only the differences will be discussed here. The position of the partial section through the further embodiment of the invention shown in Figure 4 corresponds approximately to the position of the line IV-IV in Figure 1.

In this variant, the light source segment 7.1' comprises three rows 24.1, 24.2 and 24.3 of light-emitting diodes 11' parallel to the edge section 1.1' of the display segment 1.1'. The light-emitting diodes 11' of the rows 24.1, 24.2 and 24.3 are light-emitting diodes with directed radiation in an angular range of approximately 15°, i.e. they emit a light cone with a half opening angle of 5° around their respective radiation direction 25.1, 25.2 or 25.3. The LEDs 11' are aligned by mounting base parts 26.1, 26.2 and 26.3 of a mounting base 26 that are beveled at their end facing the viewer so that the emission directions of the LEDs 11' within the rows 24.1, 24.2 and 24.3 run parallel to each other, while emission directions 25.1, 25.2 and 25.3 are arranged at an angle to each other. The emission directions 25.1, 25.2 and 25.3 are each directed towards one of the flat reflection surfaces 16.1', 16.2' and 16.3' attached to the housing part 28, which form the reflection surface 15' of the light guide segment 9.1'. The reflection surfaces

BRO47.G8 - 29 -

The pivots 16.1', 16.2' and 16.3' are connected to the housing part 28 via swivel joints 27 that can be locked in any swivel position, which in turn is firmly connected to the mounting base 26 via corresponding fastening means, in the example shown screws 29.

The pivot axes of the swivel joints 27 run parallel to the edge section 3.1' of the display segment 1.1'. The swivel joints 27 can be locked in any position, allowing a simple, if necessary subsequent, adjustment of the illumination of the surface section 5.1' to the given requirements by appropriately aligning the angle of inclination of the reflection surfaces 16.1', 16.2' or 16.3' to the plane of the surface section 5.1'.

The arrangement of the reflection surfaces 16.1', 16.2' and 16.3' and their inclination to the plane of the surface section 5.1' is selected in the embodiment shown so that the average beam paths of the light emitted by the individual rows 24.1, 24.2 and 24.3 between the respective LEDs 11' and the surface section 5.1' only differ slightly. These differences in the average beam paths or the resulting intensity differences of the light striking the different areas of the surface section 5.1' are compensated in this design by the fact that the angle of incidence of the light is correspondingly flatter due to the arrangement and alignment of the reflection surfaces 16.1', 16.2' and 16.3', the shorter the average beam path. Thus, the beam 25.1 reflected from the reflection surface 16.1' into the area of the surface section 5.1' to be illuminated that is perpendicular to the edge section 1.1' and furthest away from the light source segment 7.1' has a longer

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BRO47.G8 - 30 -

Beam path than the beams 25.2 and 25.3 directed by the reflection surfaces 16.2' and 16.3' to areas of the surface section 5.1' that are closer to the light source segment 7.1'. However, this difference in beam length is compensated by the correspondingly steeper angle at which beam 25.1 hits the surface section 5.1'. The same applies to beam 25.2 compared to beam 25.3, so that complete and even illumination of the surface section 5.1' is achieved.

It goes without saying that in other designs of this type, depending on the requirements for the uniformity of the illumination of the surface section, a finer gradation of the reflection surface into a larger number of reflection surfaces is possible. Likewise, more or fewer rows of LEDs can be provided. It is of course also possible for several rows of LEDs to radiate in directions parallel to one another.

The display segment 1.1' and the mounting base 26 are arranged on a common circuit board 14', which is fixed to a mounting step 30 in the housing 12' using appropriate fastening means 12.1'. In the example shown, these are screws 12.1'. If the display segments 1.1' are to be arranged in steps analogous to the embodiment of the invention described in Figures 1 to 3, there are essentially two possibilities for this. If the circuit board 14' is a common circuit board for all display segments 1.1', then appropriate spacers are provided between the display segments 1.1' located further in the middle of the display device and the associated mounting base 26.

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elements. However, it is understood that in design variants in which a separate circuit board 14' is provided for each display segment 1.1', the gradation of the display segments can be achieved by means of a correspondingly graduated mounting step 30.

The rotating plates of the dot matrix elements 2 forming the surface section 5.1' have a coating of a luminescent, for example fluorescent or phosphorescent material on their information-bearing, colored reflective side - the other side is blackened in the usual way for such displays. Furthermore, the light-emitting diodes 11' emit light that has a wavelength range that causes the coating material to luminesce when the light from the light-emitting diodes 11' hits the side of the rotating plates provided with the coating. This increases the readability of the display when the lighting is switched on. On the other hand, with phosphorescent coatings, this is guaranteed for a certain period of time even if the lighting fails.

It goes without saying that here too, by completely or partially changing the wavelength of the light emitted by the LEDs, the information displayed on the surface section can be made particularly vivid and easy to read for a viewer.

Figure 5 shows a further embodiment of a display device according to the invention. The design shown in Figure 4 essentially corresponds to a section along the line IV-IV in Figure 5, so that here only

BRO47.G8 - 32 -

the differences to the variant described in Figure 4 will be discussed.

In the display device shown in Figure 5, the display segments 1.1' and the associated light source segments 7.1' and light guide segments 9.1' are each arranged on a separate circuit board 14'. These circuit boards 14' are attached to mounting bases 30' in the housing 12', the mounting surfaces 30.1' of which are inclined to one another in such a way that, in the section plane shown, the curvature of the disk 13 is approximated by the longitudinal edge 3' formed by the edge sections 3.1' in the manner of a polygon. Consequently, the curvature of the disk 13 is also approximated by the front edge 28.1" of the respective light guide segment 9.1', which runs parallel to the respective edge section 3.1', in the manner of a polygon. The display surface 5' can therefore be arranged with the small distance shown from the disk 13'.

It is understood that in other variants of this display device the light source segments and the light guide segments can also be designed analogously to the embodiment shown in Figure 2.

The invention is not limited in its implementation to the preferred embodiments given above. Instead, a number of variants are conceivable which make use of the solution presented even in fundamentally different implementations.

Claims (28)

BRO47.G8 - 33 - Claims 1. Display device for arrangement behind a transparent pane (13; 13'), in particular of a road or rail vehicle, with a display device (1; 1') which consists of a number of dot matrix elements (2; 2') and is divided into a number of display segments (1.1; 1.1'), each of which forms an edge section (3.1, 4.1; 3.1', 4.1') of at least one of the longitudinal edges (3, 4; 3', 4') of the display device (1; 1') extending in one of the main extension directions of the display device (1.1; 1.1') and a substantially flat and substantially rectangular surface section (5.1; 5.1') of the display surface (5; 5') of the display device (1.1; 1.1'), characterized, that the surface sections (5.1; 5.1') of the display segments (1.1; 1.1') run essentially parallel to one another, the display segments (1.1; 1.1') being arranged in steps in the direction of the surface normal of the display segments (1.1; 1.1') in order to arrange the display surface (5; 5') behind the pane (13; 13') with minimal spacing, such that the curvature of the pane (13; 13') is approximated in the manner of a staircase by the longitudinal edge (3, 4; 3', 4') formed from the edge sections (3.1, 4.1; 3.1', 4.1') in the plane running perpendicular to the display surface (5; 5') and containing the longitudinal edge (3, 4; 3', 4'). BRO47.G8 - 34 - 2. Display device according to claim 1, characterized in that at least the dot matrix elements (2; 2') of the respective display segment (1.1; 1.1') are arranged on a common, flat circuit board (14; 14') parallel to the surface sections (5.1; 5.1'). 3. Display device according to claim 2, characterized in that the dot matrix elements (2; 2') of the display device (1; 1') are arranged on a common, flat circuit board (14; 14') which is parallel to the surface sections (5.1; 5.1'). 4. Display device according to claim 3, characterized in that the dot matrix elements (2) each forming a display segment (1.1) are firmly connected to one another and at least one spacer element (20.1) is provided for the stepped arrangement of the display segments (1.1), at least for the display segments (1.1) whose surface section (5.1) has a distance from the circuit board (14) that exceeds the smallest vertical distance, which is arranged between the circuit board (14) and the display segment (1.1). 5. Display device according to claim 4, characterized in that the spacer elements (20.1) are connected to one another to form a spacer (20). 6. Display device according to claim 5, characterized in that the spacer (20) is designed as a one-piece long BRO47.G8 - 35 - elongated component with an essentially flat rear side facing the circuit board (14) and a front side facing the dot matrix elements (2), which is stepped in such a way that the curvature of the disc (13) is approximated by the front side in a plane running parallel to the longitudinal direction of the spacer (20) and perpendicular to the circuit board (14) in the manner of a staircase. 7. Display device, in particular according to one of the preceding claims, with a display device (1; ¹ ') designed as a dot matrix display and divided into display segments (1.1; 11'), characterized in that a device (6; 6') is provided for illuminating the display surface (5; 5') of the display device (1; 1'), which has at least one light source (7, 8; 7', 8') extending laterally along a longitudinal edge (3, 4; 3', 4') of the display device (1; 1') and a light guide device (9, 10; 9', 10') adjacent to the light source (7, 8; 7', 8'), running essentially parallel thereto and not covering the display surface (5; ^5' ) at least in plan view, for directing at least part of the light emitted by the light source (7, 8; 7', 8') onto the Display surface (5; 5') of the display device (1; 1'), wherein the light-guiding device (9, 10; 9', 10') is designed such that the display surface (5; 5') is substantially uniformly illuminated. 8. Display device according to claim 7, characterized in that the light source (7, 8; 7', 8') is supplied by a BRO47.G8 - 36 - number of light-emitting diodes (11; 11') which are arranged in at least one row (24.1, 24.2, 24.3) running essentially parallel to the longitudinal edge (3, 4; 3', 4'). 9. Display device according to claim 7 or 8, characterized in that the light source (7, 8; 7', 8') consists of light source segments (7.1, 8.1; 7.1', 8.1') arranged on the respective display segments (1.1; 1.1') and the light guide device (9, 10; 9', 10') consists of light guide segments (9.1, 10.1; 9.1', 10.1') assigned to the respective light source segments (7.1, 8.1; 7.1', 8.1'). 10. Display device according to claim 9, characterized in that the light source segments (7.1, 8.1; 7.1', 8.1') are each formed by a light-emitting diode (11; 11') or are each formed by a number of light-emitting diodes (11; 11') which are arranged in at least one row (24.1, 24.2, 24.3) running essentially parallel to the respective edge section (3.1, 4.1; 3.1', 4.1'). 11. Display device according to one of claims 7 to 10, characterized in that the light guide segments (9.1, 10.1; 9.1', 10.1') are each designed in the manner of a concave reflector which has at least one reflection surface arranged in front of, ie on the observer side of the plane of the surface section (5.1; 5.1'), facing the light source segment (7.1, 8.1; 7.1', 8.1') and running essentially parallel to it, formed from a number of reflection surfaces (16.1, 16.2, 16.3; 16.1', 16.2', 16.3'). a» BRO47.G8 - 37 - surface (15; 15') which reflects the light of the light source segment (7.1, 8.1; 7.1', 8.1') incident on it onto the surface section (5.1; 5.1'), wherein at least one reflection surface (16.1; 16.1') is provided which reflects light from the light source segment (7.1, 8.1; 7.1', 8.1") onto the area of the surface section (5.1; 5.1') to be illuminated which is furthest away perpendicular to the edge section (3.1, 4.1; 3.1', 4.1'), and wherein the reflection surface (15; 15') is designed in such a way that the decrease in light intensity with the beam path between the light source segment (7.1, 8.1; 7.1', 8.1') and the surface section (5.1; 5.1') is compensated. 12. Display device according to claim 11, characterized in that the surface area of the reflection surfaces (16.1, 16.2, 16.3; 16.1', 16.2', 16.3') is proportional to the square of the mean beam path between the light source segment (7.1, 8.1; 7.1', 8.1') and the respective area of the surface section (5.1; 5.1') onto which the respective reflection surface (16.1, 16.2, 16.3; 16.1', 16.2', 16.3') reflects the light incident on it from the direction of the light source segment (7.1, 8.1; 7.1', 8.1'), or that the reflection surfaces (16.1, 16.2, 16.3; 16.1', 16.2', 16.3') are arranged and aligned in such a way that the respective average beam paths between the light source segment (7.1, 8.1; 7.1·, 8.1') and the respective area of the surface section (5.1; 5.1') onto which the respective BRO47.G8 - 38 - Reflection surface (16.1, 16.2, 16.3; 16.1 ¹ , 16.2', 16.3') which reflects the light incident on it from the direction of the light source segment (7.1, 8.1; 7.1 ¹ , 8.1') have substantially the same length. 13. Display device according to claim 11 or 12, characterized in that the reflection surface (15; 15') is shaped such that, for uniform illumination of the surface section (5.1; 5.1'), the more light is reflected onto a region of the surface section (5.1; 5.1'), the flatter the angle of incidence of the light coming from the reflection surface (15; 15') onto the respective region of the surface section (5.1; 5.1'). 14. Display device according to one of claims 11 to 13, characterized in that the reflection surface (15; 15') is formed by substantially flat reflection surfaces (16.1, 16.2, 16.3; 16.1', 16.2', 16.3') running parallel to the edge portion (3.1, 4.1; 3.1', 4.1'). 15. Display device according to one of claims 11 to 14, characterized in that the light guide segments (9.1, 10.1) for directing the light of the respectively associated light source segment (7.1, 8.1) not emitted in the direction of the reflection surface (15) to the reflection surface (15) comprise a substantially U-shaped collecting reflector (18) surrounding the light source segment (7.1, 8.1) and open towards the reflection surface (15). BRO47.G8 - 39 - 16. Display device according to one of claims 7 to 15, characterized in that the light source segments (7.1, 8.1; 7.1', 8.1') are arranged substantially behind the plane of the respective surface section (5.1; 5.1'). 17. Display device according to one of claims 8 to 16, characterized in that the light-emitting diodes (H') are designed as light-emitting diodes with directed radiation in an angular range of substantially at most 15°. 18. Display device according to claim 17, characterized in that the respective light source segment (7.1', 8.1') comprises at least two rows (24.1, 24.2, 24.3) of light-emitting diodes (H') which are essentially parallel to one another, the emission directions (25.1, 25.2, 25.3) of the light-emitting diodes (H') within the respective row (24.1, 24.2, 24.3) running parallel to one another, and for the targeted illumination of the surface section (5.1 ¹ ), the areas of the reflection surface (15') onto which the light from the rows (24.1, 24.2, 24.3) respectively strikes are aligned differently and/or the respective emission directions (25.1, 25.2, 25.3) of the rows (24.1, 24.2, 24.3) run at an angle to one another. 19. Display device according to one of claims 8 to 18, characterized in that the respective light source segment (7.1, 8.1; 7.1', 8.1') is arranged laterally of the dot matrix elements (2, 2') on the circuit board (14; 14') of the dot matrix elements (2, 2'). ■ G8 · ·«
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· · · ···· · • • * BRO47 - 40 20. Display device according to one of claims 7 to 19, characterized in that the surface sections (5.1') of the display surface (5 ¹ ) for the minimum distance arrangement of the display surface (5 ¹ ) behind the pane (13 ¹ ) are inclined to one another in such a way that the curvature of the disc (13') is approximated in the manner of a polygon by the longitudinal edge (3', 4') formed from the edge sections (3.1', 4.1') in the plane running perpendicular to the display surface (5') and containing the longitudinal edge (3', 4'). 21. Display device according to one of the preceding claims, characterized in that a box-shaped housing (12; 12') is provided which is open on the viewer side and encloses at least the dot matrix elements (2; 2') of the display device (1; 1'), wherein the opening-side edge (21; 21') of the housing (12; 12') is designed to be connected to a transparent front panel (13; 13') in an at least dust-tight manner for at least dust-tight encapsulation of the interior of the housing (12; 12') and wherein the components of the display device which generate heat to a significant extent, in particular the components for controlling or regulating the display device (1; 1'), are arranged outside the housing (12; 12'). 22. Display device according to claim 21, characterized in that the opening-side edge (21; 21') of the housing (12; 12') has a forward-facing contact surface (21.1; BRO47.G8 - 41 - 21.1 ¹ ), the curvature of which essentially corresponds to the curvature of the pane (13; 13') in the respective contact region, wherein the distance of the contact surface (21.1; 21.1') perpendicular to the respective surface section (5.1; 5.1') in planes perpendicular to the respective edge section (3.1, 4.1; 3.1', 4.1') essentially does not fall below the greatest extent of the associated light guide segment (9.1, 10.1; 9.1', 10.1') on the observer side of the surface section (5.1; 5.1') perpendicular to the respective surface section (5.1; 5.1'). 23. Display device according to claim 22, characterized in that the distance of the contact surface (21.1; 21.1') perpendicular to the respective surface section (5.1; 5.1') in planes perpendicular to the respective edge section (3.1, 4.1; 3.1', 4.1') is selected such that the distance between the display surface (5; 5') and the pane (13; 13') is minimized. 24. Display device according to one of claims 21 to 23, characterized in that the opening-side edge (21; 21') of the housing (12; 12") is designed to produce an at least dust-tight connection between the housing (12; 12') and the pane (13; 13'). 25. Display device according to claim 24, characterized in that the contact surface (21.1; 21.1') is designed to be adhesively bonded to the pane (13; 13') and has an extension sufficient to absorb the loads acting on the display device through the adhesive bond. BRO47.G8 - 42 - 26. Arrangement comprising a transparent pane (13; 13'), in particular of a road or rail vehicle, and a display device according to one of claims 20 to 23, characterized in that the housing (12; 12') is glued to the pane (13; 13') in an at least dust-tight manner for at least dust-tight encapsulation of the interior of the housing (12; 12'). 27. Arrangement according to claim 26, characterized in: that the bond (22) is designed to be sufficient to absorb the loads acting on the display device. 28. Arrangement according to claim 26 or 27, characterized in that the pane (13) is at least partially provided with a coating (23) which at least partially obstructs the view of the viewer in the area which laterally adjoins the display surface from the viewpoint of the viewer.