GB1594819A

GB1594819A - Devices for illuminating the dials of display instruments

Info

Publication number: GB1594819A
Application number: GB4644177A
Authority: GB
Original assignee: Mannesmann VDO AG
Current assignee: Mannesmann VDO AG
Priority date: 1976-11-10
Filing date: 1977-11-08
Publication date: 1981-08-05
Also published as: IT1087487B; DE2651283A1

Description

(54) IMPROVEMENTS IN DEVICES FOR ILLUMINATING THE DIALS OF DISPLAY INSTRUMENTS (71) We, VDO ADOLF SCHINDLING AG, of 103 Graftstrasse, Frankfurt/Main, Germany, a body corporate organized according to the laws of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a device for illuminating the dials of display instruments arranged in a common housing, in particular to the display field of an instrument panel for motor vehicles and one or more symbol field groups arranged laterally at the housing.

Devices of this type are already known, wherein for illuminating the display field two to three incandescent lamps, and for each symbol field group a further incandescent lamp are provided. The incandescent lamps for illuminating the display field are arranged in the rear portion of the housing, the light generated by them being radiated on to the display field along, in each particular instance, a light-conducting element extending transversely to the longitudinal axis of the housing and projecting into the space between the viewing panel and the display field. These known devices have the disadvantage that the components are expensive and they consume a great deal of power.

It is an object of the present invention to overcome partially or wholly the above disadvantages by providing a device the power consumption of which is as low as possible.

According to the present invention there is provided a device for illuminating the display field of an instrument panel for motor vehicles arranged in a housing, and one or more symbol field groups arranged laterally at the panel, including: a single light-generating element mounted on an external surface of said housing and a plurality of lightconductors arranged externally of the housing between the light-generating element and the panel and each projecting into the interior of the housing, at the location of the panel, with a light-irradiating end zone, for illumination of the display field and the symbol field group or groups.

Thus, due to the above, a device is provided with a small number of components and entirely satisfactory illumination of the display field and of the symbol field group or groups is possible. The power consumption of the device is extremely small, since only a single light-generating element is used. A special advantage of the invention consists in that it can be carried into effect with a smaller financial outlay than the known devices, since relatively costly components, such as incandescent lamps, are replaced by relatively inexpensive components, such as light-conductors made from polymethylmethacrylate.

If the light-generating element is arranged at a location which, when the instrument housing is installed in the dashboard, is freely accessible at the housing, this being quite readily possible due to corresponding laying of the light-conductor, then replacement of a defective light-generating element by a new one can be effected without removing the instrument housing from the dashboard. This is a further special advantage of the invention.

In a preferred form, there are associated with the display instruments two light-conductors and with each symbol field group one light-conductor.

The present invention will now be described in greater detail by way of example with reference to the accompanying drawing, wherein the sole figure is a perspective view of one preferred form of a device for illuminating the dials of display instruments.

Referring to the drawing the device comprises a housing I in which the display instruments 2 are located. At the front, the housing 1 is sealed off with a viewing panel 3 located in a frame 4. Arranged at the right hand side of the housing 1 is a series of symbol fields 5 and a series of switches 6, each of which is associated with a respective symbol field 5. The switches 6 serve for the switching on or off of the external lighting, of the windscreen wipers, of the direction indicators, hazard indicators, the rear window heating and other. electrical devices of the motor vehicle and, correspondingly, the appropriate symbols such as those now conventionally used on motor vehicles are displayed in the fields 5.

In order to illuminate the display instruments 2 and the symbol fields 5 there is provided a single incandescent lamp 7 located in a holder 8 on the upper surface of the housing, and three light-conductors 9, 10 and 11, each of which has one end secured in the holder 8. The other ends of the lightconductors 9 and 10 each project through respective apertures 12 and 13 into the interior of the housing and are so designed that uniform illumination of all the display instruments is effected.

The light conductor 15 also projects through an aperture 14 into the interior of the housing and extends along the line of symbol fields 5. In order to achieve uniform illumination of all the symbol fields 5, the surface of the portion 15 of the light conductor 11 extending over the line of symbol fields is designed, so as to have a phase continuously varying along the line of symbol fields.

In the case where there are a large number of symbol fields, there may be arranged in a plurality of lines, a light conductor being provided for each line.

WHAT WE CLAIM IS: I. A device for illuminating the display field of an instrument panel for motor vehicles arranged in a housing, and one or more symbol field groups arranged laterally at the panel. including: a single light-generating element mounted on an external surface of said housing and a plurality of lightconductors arranged externally of the housing between the light-generating element and the panel and each projecting into the interior of the housing, at the location of the panel with a light-irradiating end zone for illumination of the display field and the symbol field group or groups.

2. A device according to Claim I, wherein the light-generating element is at a location which is freely accessible when the instrument is installed in the dashboard.

3. A device according to Claim 1 or 2, wherein two light-conductors are associated with the display instrument and one lightconductor is associated with each symbol field group.

4. A device for illuminating the dials of display instruments constructed substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

instruments 2 are located. At the front, the housing 1 is sealed off with a viewing panel 3 located in a frame 4. Arranged at the right hand side of the housing 1 is a series of symbol fields 5 and a series of switches 6, each of which is associated with a respective symbol field 5. The switches 6 serve for the switching on or off of the external lighting, of the windscreen wipers, of the direction indicators, hazard indicators, the rear window heating and other. electrical devices of the motor vehicle and, correspondingly, the appropriate symbols such as those now conventionally used on motor vehicles are displayed in the fields 5.

In order to illuminate the display instruments 2 and the symbol fields 5 there is provided a single incandescent lamp 7 located in a holder 8 on the upper surface of the housing, and three light-conductors 9, 10 and 11, each of which has one end secured in the holder 8. The other ends of the lightconductors 9 and 10 each project through respective apertures 12 and 13 into the interior of the housing and are so designed that uniform illumination of all the display instruments is effected.

The light conductor 15 also projects through an aperture 14 into the interior of the housing and extends along the line of symbol fields 5. In order to achieve uniform illumination of all the symbol fields 5, the surface of the portion 15 of the light conductor 11 extending over the line of symbol fields is designed, so as to have a phase continuously varying along the line of symbol fields.

In the case where there are a large number of symbol fields, there may be arranged in a plurality of lines, a light conductor being provided for each line.

WHAT WE CLAIM IS: I. A device for illuminating the display field of an instrument panel for motor vehicles arranged in a housing, and one or more symbol field groups arranged laterally at the panel. including: a single light-generating element mounted on an external surface of said housing and a plurality of lightconductors arranged externally of the housing between the light-generating element and the panel and each projecting into the interior of the housing, at the location of the panel with a light-irradiating end zone for illumination of the display field and the symbol field group or groups.
2. A device according to Claim I, wherein the light-generating element is at a location which is freely accessible when the instrument is installed in the dashboard.
3. A device according to Claim 1 or 2, wherein two light-conductors are associated with the display instrument and one lightconductor is associated with each symbol field group.
4. A device for illuminating the dials of display instruments constructed substantially as herein described with reference to the accompanying drawing.