Illumination – Revolving
Reexamination Certificate
1998-10-08
2001-05-15
Nguyen, Thong (Department: 2872)
Illumination
Revolving
C362S084000, C362S331000, C362S332000, C349S057000, C349S065000, C349S066000
Reexamination Certificate
active
06231201
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The invention relates to a display unit, in particular in a vehicle, having a display, an image on the display optionally being visible from a first viewing angle region or from a second viewing angle region.
Such display units are used, for example, for satellite navigation and for representing a television image in present day motor vehicles, and are known in practice. In the case of the known display units, the display has a viewing screen which is mounted such that it can pivot about a vertical axis in a center console of the motor vehicle. This means that the viewing screen can optionally be pivoted toward the driver or the passenger, with the result that the image is visible only from the viewing angle of the passenger or of the driver. Alternatively, the display can be brought to a central position in which the image can be seen by both in a large angular region. Consequently, for example, the passenger can pivot the display in his direction during the journey and follow a television program without distracting the driver from the traffic situation. However, it is also possible for the driver and passenger to look jointly on the same display at, for example, the image of a street map or a satellite navigation display.
It is disadvantageous in the known display unit that the display is expensive to mount and that it is difficult to lay the connecting lines for the display. Moreover, the arrangement of the display unit in the motor vehicle turns out to be very difficult, since, for example, a display which is assembled in a center console and pivoted toward the passenger can frequently nevertheless be seen from the viewing angle of the driver. The driver is therefore distracted from the traffic situation all the same.
SUMMARY OF THE INVENTION
It is the object of the invention to provide a display unit of the type mentioned at the beginning such that it reliably prevents the driver from being distracted by an image intended for the passenger, and it can be mounted in the motor vehicle as simply as possible at a prescribed position—for example in an instrument panel or in a center console.
According to the invention, this object is achieved by virtue of the fact that there are provided a first optical element for radiating directed light from the display and a second optical element for deflecting the light directed by the first optical element, and that the optical elements can be pivoted toward one another or can be displaced relative to one another in their plane.
By the invention, the light radiated by the display can be directed into a prescribed angular region and/or into a prescribed direction by pivoting or displacing the optical elements. Consequently, a driver of the motor vehicle cannot detect any image on the display when the latter radiates light exclusively in the direction of the passenger. The driver is thereby reliably prevented from being distracted by an image intended for the passenger. Since the display requires no complicated mounting, its assembly proves to be particularly simple. The display unit can be fixed at virtually any position, for example in the dashboard of the motor vehicle.
The optical elements could, for example, have prisms or concave lenses. The light emanating from the first optical element can thereby optionally be deflected into one or other direction by the projecting action of the second optical element. However, in accordance with an advantageous feature of the invention, the second optical element is capable of deflecting the directed light with a particularly high intensity into a specific angular region when the second optical element has a cylindrical lens array. Furthermore, by comparison with an arrangement having prisms or concave lenses, the optical elements thereby have a particularly shallow overall depth.
The optical elements could be arranged in front of the display, for example. However, the image on the display is thereby impaired by the optical elements. In accordance with another advantageous feature of the invention, it is simple to avoid impairment of the image by the optical elements when the display can be transilluminated and when the two optical elements are arranged on a side of the display averted from a viewer.
If a separate light source such as, for example, an incandescent lamp, a LED or an fluorescent tube is used for transillumination, it is particularly advantageous for an image which is free from impairment if the two optical elements are arranged between a light source and the display.
However, the first optical element preferably has a light source which can, for example, be an electroluminescent film or an LED combined with an optical conductor, as the case may be. This renders the display unit particularly compact and requires little installation space.
The display unit according to the invention is of particularly cost effective configuration when the first optical element has strip-shaped light-radiating regions arranged parallel to the cylindrical lens array.
In accordance with another advantageous feature of the invention the second optical element deflects the light in a particularly small angular region when the width of a light-radiating region and the mutual spacing of two light-radiating regions together have approximately the width of a cylindrical lens of the cylindrical lens array.
The first optical element could, for example, be arranged in front of a light box. The display unit according to the invention has, however, a particularly shallow overall depth and a high stability when the first optical element has a plate-shaped optical conductor.
In accordance with another advantageous development of the invention, the first optical element has a particularly low weight when it consists of a plastic.
The display unit has a particularly compact design when, in accordance with an advantageous development of the invention, the light-radiating regions are arranged in a region of the first optical element which is averted from the second optical element.
A particularly uniform illumination of the display and a simple possibility of producing the first optical element are to be achieved when, in accordance with an advantageous development of the invention, the light-radiating regions of the first optical element scatter light diffusely. In a very simple form, the light-radiating regions are roughened areas of the optical conductor, but they can also, for example, be formed by electroluminescent films or by an LED, possibly having an optical conductor.
In order to improve the delimitation of the first and second viewing angle regions, in a region of its side averted from the light-radiating regions, the first optical element advantageously has stops arranged approximately between the light-radiating regions.
In accordance with another advantageous development of the invention, losses inside the optical conductor can be kept particularly low when the stops are mirrored on the side facing the interior of the first optical element.
In accordance with another advantageous development of the invention, the display can be uniformly transilluminated with a small light source when the light source is provided for launching the light into a lateral region of the optical conductor.
In accordance with another advantageous feature of the invention, it is easy to enlarge a particularly small angular region of the light directed from the optical elements when a diffusing screen is arranged between the second optical element and the display. Due to this arrangement, when the display is transilluminated in a manner directed onto the passenger, the image is also visible for passengers of different heights and from different seating positions. Furthermore, this configuration smoothes out the light deflected by the cylindrical lens array to such an extent that the individual cylindrical lenses cannot be detected.
It is possible to arrange the first optical element with the optical conductor in a displaceable fashion with respect to the second optical element. However, the
Curtis Craig
Farber Martin A.
Mannesmann VDO AG
Nguyen Thong
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