Device for producing a bundled light flux

FIELD OF THE INVENTION The present invention relates to a head-up display having a device for generating a beam of light, a light source, and a graphic representation containing a light valve. Device.

2. Description of the Related Art In order to convey information to a car driver without having to deviate the driver's field of vision from the driving road or flying space, a so-called head-up display is known, by which a graphic representing information is concentrated on the front glass of a car. In order to be able to see the graphics in bright ambient light, it is required that the graphics have high brightness. For other lighting purposes, beams of light are also needed, such as reading lights or as illumination lights for shop windows and exhibitions.

It is known from U.S. Patent Nos. 5,836,676 and 5,043,716 and Japanese Publication No. 7-130256 to use a device for generating a beam of light in a display, respectively. A lamp with beams of light rays is known from US Patent 4,935,665. However, these shown devices can hardly be used for head-up displays due to their respective beam forming characteristics and scattering characteristics.

SUMMARY OF THE INVENTION The object of the present invention is therefore to generate optical flow by means of said devices, which in particular have a small structural size and a small weight, lose as little power as possible or output as heat and are therefore also suitable for operation in automobiles .

According to the present invention, this object is achieved by a head-up display as described below. Appropriate improvements are also described below.

According to the present invention, there is provided a head-up display having a device for generating a beam of light, the head-up display having: a light source composed of an array of light-emitting diodes; and a light source for beaming and scattering light generated by the light-emitting diodes The optical device for beam forming and scattering is arranged between the light source and a light output hole, and includes a grid-shaped reflector, the reflector forms a light channel for an array point, and the light channel The wall of each light channel is reflective, and the end of each light channel facing the light source includes a condenser lens; and a pattern reproducing device containing a light valve, the pattern reproducing device is arranged on the optical device for beaming and scattering light On the output hole, a diffuser is provided between the pattern reproduction device and the light output hole.

03823307.X First shot.

In the device according to the invention, it has proven advantageous that each array point consists of a plurality of light-emitting diodes, which can also be of different colors. In addition, the present invention is not limited to the use of a unique lens for each optical channel.

A cost-effective processing of the device according to the invention is achieved by the fact that the condenser lenses of all light channels are integrally connected to a plate arranged between the light source and the grid-shaped reflector. However, this flat plate can produce an undesirable light guide in the lateral direction, and this can be avoided by this. The condenser lens is integrally connected to the bridging piece arranged between the light source and the grid-shaped reflector in a group.

An advantageous structural solution of the present invention is that the curvature of the lens is different in different directions (astigmatic lens). In this way, the light distribution in the elongated light output aperture can be improved in particular.

Another advantageous structural solution is that a pattern reproduction device containing a light valve is arranged on the light output hole. This improved solution can realize a compact device for generating high-resolution graphics, which has high optical density and uniform optical density distribution on the entire image surface. Here, the device is responsible for concentrating the light generated by the light-emitting diodes on the plane of the graphic reproduction device for beaming and scattering, without causing interference projection by a single light-emitting diode. A preferred field of application of the device according to the invention is a head-up display for the graphics of a car driver.

Through the graphics reproduction device, the device according to the present invention also has some advantages described below. That is, through the coordination between the RGB light source and the color display, the display of the color graphics of the graphics can be realized under the condition of sufficient light density in the upward-looking display. The uniform color distribution and light density distribution of the background illumination are achieved on the surface of the liquid crystal display through the joint action of the reflector and the lens.

The configurable graphic content can be displayed in color on the LCD color display. Therefore, the graphic content can be adapted to the driving situation. The installation space for the entire pattern generating device is only a few cubic centimeters in the actual implementation example. The color space to be established can be influenced by selecting the color of the light-emitting diode and the dependent display. For example, instead of an RGB light-emitting diode grating, a red-green light-emitting diode grating can be selected and the blue filter element can be replaced by a green filter element in the liquid crystal display in a corresponding manner. This results in a limited color space with a significantly brighter light density.

The drawings illustrate that the present invention can realize a large number of embodiments. In the figure, it is shown schematically with the help of multiple figures

03823307.X Some of these implementations are listed and described below. In the drawings: FIG. 1 is a cross-sectional view of an embodiment, FIG. 2 is a top view of the grid-shaped reflector of the embodiment in FIG. 1, FIG. 3 is a cross-sectional view of another embodiment, and FIG. 4 is for explaining the difference An enlarged view of a partial section shown in detail, FIG. 5 is an enlarged view of a partial section of another embodiment, and FIG. 6 is a part of the lens screen.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments according to FIGS. 1 and 2, there is a 4×8 group of gratings as a light source, each group has four light-emitting diodes 1, which are assembled on a substrate 2. The bridge piece 3 is located between the groups, and its inclined surface serves as a reflector.

A lens screen 4 is located on the light source, and a grid-shaped reflector 5 is connected to the lens screen.

The obliquely extending surface 6 of the bridge piece 3, the lens screen 4 and the grid-shaped reflector 5 play a role of evenly distributing light. In order to avoid light shielding due to the bridging sheet 7 of the reflector 5, a frame 8 is provided, which acts as a gap between the reflector 5 and the liquid crystal display 9. A diffusion sheet 10 is located under the liquid crystal display 9 to further improve the uniformity of the backlight of the liquid crystal display 9.

The frame 8 affects the tilt position of the liquid crystal display, so that the light incident from the upper part is not reflected in the same direction, in which direction the light also leaves the liquid crystal display to reach the observer.

FIG. 2 shows the device according to FIG. 1, but with the liquid crystal display 9 and the diffusion sheet 10 removed. In the view according to FIG. 2, the light-emitting diode 1 itself can be seen through the lens screen 4. However, for the sake of simplicity, the corresponding distortion of the light-emitting diode 1 is not shown.

The embodiment according to FIG. 3 shows a light emitting device in which the light output hole is composed of a glass plate 18 which is located on a frame 17. The other parts of this embodiment are constructed in the same manner as the embodiment in FIG. 1.

Fig. 4 shows an enlarged partial cross-sectional view of Fig. 1 and is used to explain the details of the liquid crystal display and the light source. The liquid crystal display 9 has a liquid crystal panel 13 and a color filter 14 between two glass plates 11 and 12. The color filter consists of a grating with three color points of different colors, which are represented by different hatching in FIG. 4. Control electrodes not shown are provided in relation to the grating of the color filter, which respectively form a light valve with the liquid crystal panel. Polarizers 15, 16 having mutually perpendicular polarization planes are located outside the glass plates 11, 12.

03823307.X In Fig. 4, the light source briefly described in Fig. 1 is also shown in detail.

The four light-emitting diodes 1 are protrudingly arranged at the center of a hole formed by the bridge piece 3 on a submount 20. The light-emitting diodes are connected to the wires 25 through the connecting wires 21, and they are only schematically represented by the hatching of the surface occupied by them. In a preferred embodiment one LED emits red light, two emits green light and the fourth emits blue light. In this arrangement the light is mixed into white. The space between the sub-assembly station 20 and the bridge piece 3 is filled with a white casting material 22, and its surface 24 serves as a reflector for the light emitted from the side of the light emitting diode 1. A transparent casting material 23 prevents the formation of cavities.

The connection between the light source and the lens screen 4 is achieved in the embodiment shown in FIG. 4 by a silica gel layer 26, a polarization conversion film (PCF) layer 27 and a suitable adhesive layer 28.

The function of the PCF layer 27 is to allow only those light polarized in the direction of the lower polarizer 15 among the light generated by the light-emitting diode to pass, so the light will not be lost in the PCF layer 27 through polarization. The other polarized light is reflected by the PCF layer and then returns from the surface 24. The component having the corresponding polarization effect still arrives through the PCF layer 27 additionally, so the PCF layer is generally beneficial to improve the brightness.

Figure 5 shows an embodiment without a PCF layer. Furthermore, the partial section shown in FIG. 5 is located on the edge of the device.

FIG. 6 shows a lens screen 31, which has eight lenses, which are fixed together by bridge pieces 32. The four lens screens shown in FIG. 6 are arranged adjacently in the embodiment according to FIGS. 4 and 5.

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