GB2325656A

GB2325656A - Instrument panel with stray light reflected away from observer

Info

Publication number: GB2325656A
Application number: GB9801239A
Authority: GB
Inventors: Mario Bazzani
Original assignee: Valeo Electronics Verwaltung GmbH
Current assignee: Borg Instruments AG
Priority date: 1997-01-23
Filing date: 1998-01-22
Publication date: 1998-12-02
Also published as: GB9801239D0; DE19702235A1

Abstract

To prevent stray light from interfering with the appearance of a vehicle instrument cluster or a control and/or display panel which comprises a wall (1a, 1a'), at least one component (2) and a plate or facing (3, 3'), any light which passes through a gap (4) adjacent the component is reflected from an area (1b) of the wall against the underside (3c) of the plate or covering (3) and/or against the side face (2a) of the component (2), which is non-light-reflecting in at least some areas. The angle # between the normals (5) to the reflecting surface of said wall area (1b) and the light beams (6, 7, 8) incident on this surface is unequal to zero.

Description

1 v 1 Light reflecting wall face configuration 2325656 The invention

relates to a device, more particularly a housing, vehicle instrument cluster, or control and/or display panel, comprising at least one wall and at least one component, wherein said component is located on one side or in an opening or on top of said,iall, or is integrally moulded therewith, and said wall is at least partly covered by a plate or facing, and wherein one side of said plate or facing, in conjunction with said component, forms a gap which is at least partially delimited at its end by a light reflecting area of said wall.

Housings in their most general form, as well as dashboard panels of motor vehicle control components, comprise numerous display devices in the form of particular symbol fields illuminated in various colors depending on individual design. Also arranged in such housnas or panels (hereinbelow referred to as devices) are switches, rotary knobs, decorative or covering elements, or moulded projecions. For reasons of stability such devices are mostly made of sheet metal which, due to its metallic surface, reflects racings or ligh-:, and are usually covered with IL cover'ngs for aesthetic reasons.

2 However, given the tolerances of such front facings or coverings, which are mass-produced preferably by plastic injection moulding, there is a risk of a stray light field forming in the display front area as a result of gaps remaining between the component secured to one wall and the surrounding wall portions of the front facing or covering. Such a stray light field may blur the clearcut contours in the display front area, apArt from interfering with the viewer's unambiguous identification of illuminated components if their light is of a different color.

This stray light field is a result of the fact that light, having passed the gap, is reflected from the wall of the device underlying the front facing or covering.

A known remedy against this disadvantage is to finish the 1--ght-refiecting area behind the wall gap with an extra coating which absorbs light beams incident through the gap. This extra coating is usually a layer of black paint.

The object of the invention is to prevent the emission of stray light from the assembly gap by a employing a solut-on which involves a reduced production effort and cost.

According to the invention this Object is achieved by ensuring that the angle (p between the normal to the reflecting surface area of the wall and the light beams incident on the surface of that area is unequal to zero, so that any light incident through the gap is reflected against the underside C) f the panel or covering and/or against the side of the component, f 1 3 which is at least partially non-light-reflecting. An appropriately large angle (p is preferably achieved by making the surface of that wall area bevelled, so that the light will not be reflected back through the cap. If the component (e.g., a decorative or covering component, switch, rotary knob or pushbutton, or an indicating component such as a display or monitor screen) lies inserted against one face of the wall or in a corresponding opening thereof, the emission of reflected light from the gap can be prevented by simply bevelling or rounding off the edge of the face defining such opening or mating surface for the component in said wall. This bevelling or rounding step may also be advantageously used to save material.

Further advantageous embodiments of the invention area set forth in the respective sub-cla-ims.

The invention and advantageous embodiments thereof as set forth in the sub-claims are hereinbelow explained in detail with reference to the attached schematic drawings, wherein Fig. 1 is a cross-section through a wall of a device having a covering, with the right-hand side of Fig. 1 showing a prior-art design of the wall in the area below the gap, and the left-hand side of Fig. 1 showing a design thereof according to the invention; Fig. 2 is a cross-section through a device with a bevelled and rounded reflecting wall area; Fig. 2a shows a device with a gap and potential light paths; 4 4 Figs. 3 and 4 show further embodiments of the invention.

Referring to Fig. 1, the drawing shows a cross-section through an operating panel 1, 1' which comprises a pushbutton 2 inserted in an opening in the housing wall la, la'. The exterior face 1,lc' of said housing wall la,. la' is largely covered by a facing or cove ring 3, 3'. The component 2 is circular in -er and projects through an opening provded for diamet this purpose in the facing 3, 3'. Due to the assembly tolerances which are an inevitable result of the manufacturing/assembly process, a gap 4, 4' forms between the narrow side face 3a and the lateral face 2a of the pushbutton 2. When the edge le' of the wall la' is of conventional prior-art design, the light beam 6b' incident vertically into the gap 4' is reflected by the reflecing (usually metallized) area lb' of the wall la' and may therefore be perceived by the viewer of the operating panel. Obliquely incident light 6' is likewise reflected by the reflecting area lb' through the gap 41 so as to be perceivable to the viewer.

According to the invention the edge le of the device 1 is bevelled off so that the light beam 6 incident through the gap 4 is directed against the nonreflecting side face of the pushbutton or component 2. 7he angle or pitch of this bevelled surface is selected such that all incident light beams 7,8 within the cone of incidence or maximum aperture ang"e 5 is reflected from the area 1b against the side face 2a of the pushbutton 2 (Fig. 2). With this arrangement the aperture angle 6 characterizes all light beams 7,8 which may reach the reflecting area lb of the wall la through the gap 4. Instead of bevelling off the edge le of the wall la, the latter may also be rounded as shown on the right- hand side of Fig. 2. In this case the incident light beam 6 is reflected through the gap as represented by the light beam 6a, but this light beam 6a is not reflected toward the viewer because the surface of the pushbutton 2a is made of a lightabsorbing (i.e., non-reflecting) material.

As will be appreciated from Fig. 2a, the bevel along the edge le reduces the maximum aperture angle 81.

Indeed, the aperture angle (5 determines that portion of the edge le whose surface must be designed or shaped such that for all light beams 7, 8 which may reach any point of the surface of the area lb, the normal (s) to said surface will be at an angle (p in respect to these light beams so that these light beams 7,8 will not be reflected into the viewer's eye through the gap 4.

As indicated in the drawings, the pushbutton 2 may have projecting portions 2b which may take the form of a flange and cover the gap 9 between the pushbutton 2 and zhe wall la, which is likewise a necessary result of the manufacturing/assembly process, so that the light bea-ns 10 directed from inside the control panel 1 toward the gap 9 or the gap 4, respectively, cannot reach the viewer's eye through said gaps 4,9.

Figs. 3 and 4 illustrate further embodiments of the invention. Fig. 3 shows a housing 1 having a wall la with a projection 11 integral therewith. This integral projection 11, with its interior face 12, defines a recess 14 in which a covering or decorative plate 3 is inserted. Between the interior face 112 of the recess 11 and the panel 3, there extends a gap 4 which allows 6 the wall Ia. Due to the bevel in the area Ig between the projection 11 and the wall la, the light beams 6 are reflected by the reflecting surface lb against the non-reflecting underside and/or the bevelled mating surface 3d of the plate 3. Depending on the width of the gap 4, the pitch of the bevelled surface lb must be selected such that the angle (p will be sufficiently large to prevent light beams 6a from being reflected back through the gap 4 toward the viewer's eye.

As shown in Fig. 4, the mating edge 1g may also be rounded instead of beyel-le-d off.

7 List of reference _numerals 1, 1, Device (housing, vehicle instrument cluster, control and/or display panel la, la' Wall 1b, 1b' Gap delimiting area of wall la 1c, 1c, Exterior side of wall la ld, ld' interior side of wall la le, le, Face of wall la which forms the gap 4 if, if' Wall face or opening 1g Mating edge of wall la 2 Component (e.g., pushbutton, light emitting diode, switch, etc.) 2a Non-reflecting side face of component 2 2b Flange or projecting portion of component 2 3 Plate or covering 3a Side which, together with the component 2, forms the gap 4 3b Side of plate 3 facing away from wall la 3c Side of plate 3 facing the wall la 3d Underside and bevelled mating edge of plate 4, 4' Gap Normal to the surface of area Ib 6 Light beam incident into gap 4 6a Light beam reflected from area lb 6' Light beam incident into gap 4 6a', 6b' Light beam reflected from area 1b' toward the v4-ewer through gap 4 7, 71, 8 _Tight beams incident into gap 4 8 9 Gap between wall la and component 2 10 Light beams directed from interior of device 1 toward gap 4 11 Projection of wall la (integral therewith) 12 Interior face of recess 14 of wall la 13 Display, monitor screen, etc. 14 Recess in wall la Bl Width of area lb' defining one end of gap 4 B2 Width of gap 4 H1, H11 Height of gap 4 or 4', respectively H2 Distance between face of plate 3 facil-g wall la and upper edge of component 2 (P - Angle between normal 5 to the surface of area lb and light beams 6,7,8 incident into the gap 4 Maximum aperture angle for incident light beams 6,7,8

Claims

Patent Claims

1. Device (1, 1'), more particularly a housing, vehicle instrument cluster, or control and /. or display panel, comprising at least one wall (1a, la') and at least one component (2), wherein said component is located on one side (if, if') or in an opening (if, if,) or n top[ of said wall (1a, ial), or is integrally moulded therewith, and said wall (1a, ial) is at least partly covered by a plate or facing (3, 31, and wherein one side (3a) of said plate or facing (3, 3 1), in conjunction with said component (2), forms a gap (4) which is at least partially delimited at its end by a light reflecting area (1b, ibl) of said wall (1a, ial), characterised in that the angle p between the normals (5) to the reflecting surf ace of said area (ib) and the light beams (6, 7, 8) incident on this surface is unequal to zero, such that the light beams incident through the gap (4) are reflected against the underside (3c) of the plate or covering (3) and / or against the side face (2a) of the component (2), which is nonlight reflecting in at least some areas.

2. Device (1) as set forth in claim 1, characterised in that on the face (if) defining the opening or mating surface of said wall (1a) for said component (2), the edge (le) thereof which delimits the gap (4) is bevelled or rounded.

10-

3. Device (1) as set forth in claim 2, characterised in that the component (2) projects through the opening in the wall (1a) from the interior side (1d) toward the exterior side (1c) thereof, said wall (1a) consisting of one or more parts.

4. Device (1) as set forth in claim 3, characterised in that part of said component (2) which lies inside the device has portion (2b), and more particularly a flange, projecting beyond the edge of said opening.

5. Device (1) as set forth in any of the preceding claims, characterised in that said component (2) is a decorative or covering component, switch, rotary knob, pushbutton or display element (specifically a display, monitor screen or illuminating means), or a projection (11) integral with said wall.

6. Device (1) as set forth in any of the preceding claims, characterised in that the surface of said wall (1a) is metallized at least in the area (1b) of said gap (4).

7. A device as claimed in claim 1 substantially as herein described with reference to the description and drawings.