GB2305154A

GB2305154A - Motor vehicle instrument display

Info

Publication number: GB2305154A
Application number: GB9519805A
Authority: GB
Inventors: Geoffrey Howard Kerr; Peter Taylor
Original assignee: Delco Electronics Overseas Corp
Current assignee: Delco Electronics Overseas Corp
Priority date: 1995-09-14
Filing date: 1995-09-14
Publication date: 1997-04-02
Anticipated expiration: 2015-09-14
Also published as: GB9519805D0; GB2305154B

Abstract

An instrument display (10) for a motor vehicle comprising a main control board (12); a gauge (18) mounted on the main control board and including gauge graphics lying on an arc of a circle, a pointer (16) pivotally movable about an axis (A) which substantially defines the centre of the circle, and a gauge mechanism (14) for pivotally driving the pointer; and an electronic display (24) positioned adjacent the gauge with the gauge positioned between the electronic display and the main control board, the electronic display being electrically connected to the main control board and having a housing (26) of a shape and size to partially cover the pointer and leave the gauge graphics uncovered.

Description

INSTRUMENT DISPLAY The present invention relates to an instrument display for a motor vehicle.

Conventional instrument displays in motor vehicle comprise one or more gauges providing an analogue readout for the vehicle operator and/or one or electronic displays providing simulated analogue readouts or digital readouts. The instrument displays may also include one or more warning symbols. It is conventional practice to provide an instrument display with these gauges and/or electronic displays and/or symbols positioned adjacent each other across a substantially planar face.

It is an object of the present invention to provide an improvement to the previously known arrangements.

An instrument display for a motor vehicle in accordance with the present invention comprises a main control board; a gauge mounted on the main control board and including gauge graphics lying on an arc of a circle, a pointer pivotally movable about an axis which substantially defines the centre of the circle, and a gauge mechanism for pivotally driving the pointer; and an electronic display positioned adjacent the gauge with the gauge positioned between the electronic display and the main control board, the electronic display being electrically connected to the main control board and having a housing of a shape and size to partially cover the pointer and leave the gauge graphics uncovered.

By positioning the electronic display in front of the gauge, use is made of the area of the gauge around the pivot axis of the gauge pointer which in previous arrangements is empty of information. An instrument display in accordance with the present invention therefore has a reduced display area.

The present invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of an instrument display in accordance with the present invention; and Figure 2 is an exploded view of the instrument display of Figure 1 with the main control board and gauge mechanism omitted for clarity.

Referring to the drawings, the instrument display 10 comprises a main control board 12 (typically, a printed circuit board) on which is mounted a gauge mechanism 14 for pivotal operation the pointer 16 of a gauge 18 about an axis A. The gauge 18 further includes a light guide 22 on which is secured a coverfilm 20 which displays pre-printed graphics 23 of the gauge. The gauge graphics 23 lie on an arc of a circle which is substantially centred on the axis A. The arrangement of the gauge 18 can be any known arrangement and will not be described in detail. The gauge 18 may, for example, be the speedometer of a motor vehicle.

Positioned in front of the gauge 18, that is, on the opposite side of the gauge to the main control board 12, is an electronic display 24. The electronic display 24 comprises a housing 26, preferably moulded from polycarbonate material, on which is mounted a coverfilm 28. The coverfilm 28 of the electronic display 24 is preferably pre-printed with any required graphics which may be visible before, or only on, illumination. The coverfilm 28 is preferably pre-formed and then adhered to the housing 26 on the side of the housing remote from the gauge 18. As an alternative, the coverfilm 28 with the graphics and the housing 26 may be moulded in one-piece, or the housing may be moulded to the pre-formed coverfilm.

The housing 26 has a recessed area 30 in its side adjacent the gauge 18 with an aperture 32 through the housing within the recessed area. A liquid crystal display (LCD) glass 34 is positioned within the recessed area 30. A light guide 36 for transmitting light from an illumination source (not shown), such as a light bulb or a light emitting diode, to the LCD glass 34 is also positioned in the recessed area 30. Positioned between the light guide 36 and the LCD glass 34 is a diffuser 38 for balancing the light from the light guide. The diffuser 38 and the light guide 36 may be integrally moulded in one-piece as a semi-opaque moulding. A secondary control board 40 (typically, a printed circuit board) is positioned within the housing 26 and is electrically connected to the LCD glass 34 by a flexible or elastomeric connector 42.Any other suitable connection may be made between the secondary control board 40 and the LCD glass 34. The secondary control board 40 is secured to the housing 26 by screws (not shown) or by clips (not shown) moulded integrally with the housing to secure the LCD glass 34, diffuser 38, and light guide 36 within the recessed area 30 in the housing.

The secondary control board 40 preferably has an aperture 44 therethrough for light from the illumination source (which is preferably mounted on the main control board 18) to reach the light guide 36. In this case, the coverfilm 20 and the light guide 22 of the gauge 18 will have corresponding apertures or cut-away areas 46. The illumination source may act as a common illumination source for both the gauge 18 and the electronic display 24, or may be separate sources. As an alternative, the illumination source for the electronic display 24 may be mounted on the secondary control board 40.

The electronic display 24 is secured to the gauge 18 by way of screws (not shown) or any other suitable means. Electrical connection between the main control board 12 and the secondary control board 40 may be made in any suitable manner, for example, male and female mating connectors on the boards, interconnecting pins on the boards, or by a flexible circuit bonded to both boards. The latter arrangement would allow the main and secondary control boards 12,40 to be assembled together before assembly of the instrument display 10.

The shape of the housing 26 and the arrangement of the electronic display 24 is such that it does not interfere with the operation of the gauge 18. The shape and size of the housing 26 is such that the electronic display 24 covers a portion of the pointer 16 adjacent its pivot axis A, but leaves uncovered, and therefore clearly viewable, the gauge graphics 23. In the preferred arrangement shown in Figures 1 and 2, part of the outer surface 27 of the housing 26 defines an arc of a circle which has a smaller radius than the circle defining the arc for the gauge graphics 23, and which is also substantially centred on axis A when the instrument display 10 is assembled. It will be appreciated that other shapes could be used for the housing.

The electronic display 24 may include warning or other information symbols on the coverfilm 28 which are illuminated when appropriate. In this case, the housing 26 will include additional apertures (not shown) which will allow light emitting diodes (not shown) mounted on the secondary control board 40 to illuminate the symbols.

As an alternative to a liquid crystal display, the electronic display may incorporate a vacuum fluorescent, or similar, display. As a further alternative, the secondary control board 40 may be omitted, and the LCD glass 34 may be electrically connected directly to the main control board 12.

In comparison to the previously known layouts for instrument displays, the present invention provides an instrument display of reduced size and a reduced number of parts.

Claims

Claims:

1. An instrument display for a motor vehicle comprising a main control board; a gauge mounted on the main control board and including gauge graphics lying on an arc of a circle, a pointer pivotally movable about an axis which substantially defines the centre of the circle, and a gauge mechanism for pivotally driving the pointer; and an electronic display positioned adjacent the gauge with the gauge positioned between the electronic display and the main control board, the electronic display being electrically connected to the main control board and having a housing of a shape and size to partially cover the pointer and leave the gauge graphics uncovered.

2. An instrument display as claimed in Claim 1, wherein the housing has an outer surface lying on an arc of a circle which has a radius smaller than the circle defining the arc for the gauge graphics and which is substantially centred on the pivot axis of the pointer.

3. An instrument display as claimed in Claim 1 or Claim 2, wherein the electronic display comprises a liquid crystal display electrically connected to the main control board.

4. An instrument display as claimed in any one of Claims 1 to 3, wherein the electronic display is illuminated by an illumination source mounted on the main control board.

5. An instrument display as claimed in any one of Claims 1 to 4, wherein a coverfilm is positioned on the housing.

6. An instrument display as claimed in Claim 5, wherein the electronic display includes symbols which remain hidden until illuminated.

7. An instrument display as claimed in any one of Claims 1 to 6, wherein the electronic display includes a secondary control board mounted within the housing and electrically connected to the main control board.

8. An instrument display substantially as herein described with reference to, and as shown in, the accompanying drawings.