WO2015040339A2

WO2015040339A2 - Instrument panel for a motor vehicle dashboard

Info

Publication number: WO2015040339A2
Application number: PCT/FR2014/052340
Authority: WO
Inventors: Vincent LAINE; Stephane Feron
Original assignee: Peugeot Citroen Automobiles Sa
Priority date: 2013-09-23
Filing date: 2014-09-22
Publication date: 2015-03-26
Also published as: WO2015040339A3; FR3010949B1; FR3010949A1

Abstract

The invention relates to an instrument panel comprising: a back projection screen (20) formed by a dished transparent substrate (21) and by a diffusing layer (25) covering the rear face of said substrate except in a peripheral zone (23); a chassis (10) comprising a support frame (11) for the screen (20); a video projector (30) for projecting a digital image from the rear towards the chassis (10), said chassis (10) comprising a back wall (12) extending rearwards from the support frame (11), said back wall taking the form of a funnel that tapers to an opening in an identical manner to the diffusing layer (25) but with reduced dimensions, the magnification ratio between the opening and the diffusing layer (25) being determined such that the projection surface on the screen (20) of the part of the light beam passing through the opening matches the surface area of the substrate (21) covered by the diffusing layer (25).

Description

Title of the invention

Combined instruments for dashboard of motor vehicle Field of the invention

The present invention relates to an instrument cluster for a motor vehicle dashboard.

Background of the invention

Conventionally composed of a plurality of analog dials with hands associated with indicator lights, the instrument handsets are used to provide the driver with a multitude of data relating to the operation of a motor vehicle, such as, for example, its instantaneous speeds and average engine speed, fuel level or even average fuel consumption. They also make it possible to display warning signals (excessive engine temperature, insufficient oil level or even non-closing of a door) and indicators indicating the activation of certain vehicle devices (turn signals, parking brake, lights). position, crossing or road).

The mid-1990s saw the emergence of new types of instrument handsets devoid of needle dials and featuring a rectangular flat-screen liquid crystal display (LCD) displaying all the necessary information to the driver. Such a handset is for example described in the German patent application DE 196,23,406.

Recently, some mid-range and high-end vehicles are equipped with digital instrument handsets featuring an active matrix LCD color display panel (LCD-TFT), similar to those found on televisions and TVs. computer monitors.

The latter, which offer a very good image quality in terms of resolution, contrast and brightness, are further configurable by the driver of the vehicle via controls located on the steering wheel or below the display panel. This one can therefore choose at least some of the modules you want to see on the screen as well as their style and background.

However, due to the flatness of their display, these digital instrument handsets currently do not provide the driver with an optimal visual experience.

In addition, the incorporation of such a large rectangular flat screen within a dashboard, induces a consequent limitation of the possibilities of style and thus imposes a particularly important integration effort in the design phase of this dashboard.

Although recent developments point to the prospect of curved and non-rectangular LCD-TFT panels, the technical difficulties are still numerous and the cost associated with this type of screen will remain prohibitive for many years before their use can be envisaged. in series in the automotive field.

Object and summary of the invention

The present invention therefore aims to provide a digital instrument cluster providing a more pleasant visual experience for the driver and whose integration on the dashboard of a motor vehicle is facilitated.

It proposes for this purpose a instrument cluster for a motor vehicle dashboard characterized in that it comprises:

- a rear projection screen formed by a curved transparent substrate and a thin diffusing layer covering the rear face of said substrate, with the exception of an uncoated peripheral zone;

a frame comprising a support frame for said screen; - A projector for projecting from the rear and in the direction of said frame supporting the screen, a digital image generated by a graphics computer and representing a multitude of indicator modules for the driver of said vehicle; said frame further comprising a bottom wall extending rearwardly and in the extension of said support frame, said bottom wall having a funnel shape centered on the optical axis of said screen and narrowing to a opening of identical shape to that of the diffusing layer but of reduced dimensions,

the magnification ratio between said aperture and said diffusing layer, being predetermined as a function of the distance between said aperture and the screen as well as the projection angle of the projector so that the projection surface on the screen of the portion of the light beam passing through said aperture coincides with the surface area of the substrate covered by the diffusing layer.

Due to the particular characteristics of the screen and the bottom wall, the driver of the vehicle views a curved image whose contour coincides with that of the diffusing layer and which seems to float levitated above the periphery of the bottom wall. the chassis which is seen in transparency through the peripheral zone of the screen not covered by the diffusing layer.

The visual experience offered is thus much richer and more pleasing than the flat and rectangular display of current digital handsets.

On the other hand, the combined instrument of the invention can be easily integrated and particularly harmonious to any type of dashboard of a motor vehicle, since the shape, size and curvature of the screen can be modulated almost limitless to best match the configuration and style of this dashboard.

According to preferred features of the invention, taken alone or in combination:

said instrument cluster further comprises at least one ambient light source located at the rear of said screen, at the peripheral periphery of said bottom wall of the chassis;

said frame is made of a non-diffusing opaque material, said handset further comprising a plurality of ambient light sources fixed against the internal face of said bottom wall; said frame is made of a diffusing translucent material;

said instrument cluster further comprises a plurality of ambient peripheral light sources fixed against the outer face of said bottom wall;

said instrument cluster comprises means enabling said driver of the vehicle to at least partially modify the display configuration of said digital image projected on the screen;

said instrument cluster comprises at least one deflection mirror capable of returning the light beam coming from the video projector towards said chassis;

said screen has, in its central part, a convex zone defining a sphere portion, and said projected image comprises a central indicator module with a circular contour whose projection surface on said screen coincides with said convex zone;

said projector is a pico or mini-projector type miniature model offering a brightness of at least 500 lumens and a contrast greater than or equal to 10000: 1; and or

said substrate is made of a polymethyl methacrylate (PMMA) and has a thickness of between 2 and 4 mm.

Brief description of the drawings

The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration but without limitation, with reference to the appended drawings, in which:

- Figure 1 shows an exploded perspective view of three quarters before a combined instrument according to the invention;

FIG. 2 represents a perspective view of three quarter front of the instrument cluster of FIG. 1 after assembly; - Figure 3 shows a perspective view of three quarter rear of the frame that comprises the combination of instruments according to the invention; and

- Figure 4 shows a view similar to Figure 2 but showing the instrument cluster in its service configuration.

Detailed description of several embodiments

Figure 1 shows an exploded view of a instrument cluster 1 for a motor vehicle dashboard according to a preferred embodiment of the invention.

The instrument cluster 1 comprises a generally bean-shaped frame 10 which supports a rear projection screen 20.

In addition to the chassis 10 and the screen 20, the handset 1 also comprises a video projector 30 connected to a graphics computer not shown in the figures, a deflection mirror 40 and two peripheral light sources 50.

The rear projection screen 20 is formed by a curved transparent thermoplastic substrate 21 whose rear face (that located opposite the driver of the vehicle) is partially covered with a diffusing layer 25. The screen 20 furthermore has in its central portion, a convex zone 22 defining here a sphere portion.

The substrate 21, which has a general bean form, is preferably made from a polymethyl methacrylate (PMMA), this material having the advantage of having excellent transparency and being insensitive to scratching. Its thickness is here between 2 and 4 mm, and preferably equal to 3 mm.

The diffusing layer 25 is conventionally formed by semi-transparent mineral microparticles agglomerated in a binder. It is in the form of a thin translucent film preferably having a dark gray color tending to black for a better luminance, which is deposited on the surface of the substrate 21 in its final molding phase. The diffusing layer 25 has an inverted saucer-like contour, and covers the whole of the rear face of the substrate 21 (including the convex zone 22), with the notable exception of a peripheral zone 23 not covered (FIG. 2). .

The frame 10 which is made here in an opaque and non-diffusing thermoplastic material, comprises a support frame 11 delimiting a reception opening for the screen 20 and a bottom wall 12 extending rearwardly in the extension. of the support frame 11.

As is particularly clearly seen in FIG. 3, this bottom wall 12 of the frame 10 has a funnel shape centered on the optical axis of the screen 20 and narrows to an opening 14 of identical shape to that of the diffusing layer 25 but of reduced dimensions.

The two peripheral light sources 50 are each constituted by a printed circuit (PCB) comprising a plurality of blue LEDs associated with transparent light guides. They are located at the rear of the screen 20, at the periphery of said bottom wall 12 of the frame 10 and fixed on either side of the bottom wall 12, against its inner face.

The projector 30 is a miniature model pico or mini-projector with a brightness of at least 500 lumens and a contrast greater than or equal to 10000: 1.

It is connected to a graphics computer, not shown in the figures, which transmits in real time a digital image comprising a number of indicator modules (central instantaneous speed module, FM radio module, fuel gauge module, module account towers, etc.) drawn in a certain style (for example "classical" reproducing the display of analog dials or "digital" in which all information is displayed in the form of digital numbers).

This digital image is of course updated in real time according to the evolution of the data collected by the box of Intelligent Servitude (BSI) of the vehicle to which this graphic calculator is connected. It is also configurable by the driver of the vehicle using commands located for example on the steering wheel or below the screen 20, so that the latter can at least partially select the display modules to display and choose the style to apply them.

The video projector 30 projects the image thus generated via a light beam which strikes the deflection mirror 40 located at the rear of the frame 10. This mirror 40 which has a reflectivity coefficient close to 100%, returns this light beam towards of the chassis 10 so that the latter is centered on the optical axis of the screen 20.

The use of the mirror 40 makes it possible to reduce the depth necessary for the operation of the instrument cluster 1. In order to further improve the compactness of this handset, the video projector 30 will preferably be placed below the crossbar of the dashboard. vehicle or at the level of the overhanging cap.

A central portion of the beam from the mirror 40 passes through the opening 14 of the frame 10 and strikes the screen 20 while its peripheral portion is absorbed entirely by the bottom wall 12 of the frame 10.

More precisely, it should be noted that the magnification ratio between the dimensions of the opening 14 at the rear of the frame 10 and those of the diffusing layer 25 of the screen 20 is predetermined as a function of the distance between this opening 14 and the screen 20 as well as the projection angle of the projector 30, so that the projection surface on the screen 20 of the portion of the light beam passing through this opening 14 coincides with the covered surface area by the diffusing layer 25.

Figure 4 illustrates the vision offered by the instrument cluster 1 when in its service configuration where the video projector 30 and the two peripheral light sources 50 are activated.

In this figure, it can be seen that the arrangement of the indicator modules on the image generated by the graphic computer is predetermined so that these modules are projected at the desired location on the diffusing layer 25 in the shape of a saucer. In particular, the central indicator module displaying the instantaneous speed of the vehicle appears in the form of a dial with a circular contour whose projection surface on the diffusing layer coincides with the convex zone 22 as a portion of a sphere.

The driver of the vehicle thus views an inverted saucer shaped curved display area grouping all the information modules and which seems to float levitatively above the ambient light device from the two light sources 50.

According to a first variant embodiment not shown, the two ambient light sources do not comprise transparent light guides and are fixed against the outer face of the bottom wall of the frame, the latter being made of a translucent thermoplastic material diffusing . In addition, and so that the peripheral portion of the light beam reaching this bottom wall does not disturb the ambient lighting from these two sources, the projected image then has a particularly dark peripheral area and poor light. In this case, the visual effect for the driver of the vehicle differs in that the ambient mood lighting is more homogeneous.

According to a second alternative embodiment not shown, the instrument cluster does not include light sources such as 50, the frame being made of a diffusing translucent material and the projected image having a luminous peripheral area. The visual effect for the driver is then very close to that offered by the first variant but here the peripheral ambient lighting is produced by the peripheral portion of the beam of the projector 30 reaching the bottom wall of the frame. According to a third variant embodiment not shown, the instrument cluster does not include light sources such as 50, the chassis remaining opaque and non-diffusing. In this case, the driver of the vehicle always views a curved display area in the form of a saucer grouping all the information modules but which seems to float here levitating above the bottom wall of the chassis.

According to still other embodiments not shown:

the substrate 21 is made of a thermoplastic material other than PMMA, such as, for example, polycarbonate, which also has excellent transparency and has better mechanical strength than PMMA but whose sensitivity to scratching is greater;

the instrument cluster does not have a deflection mirror such as 40 in order to simplify the adjustments and to reduce the cost price, or conversely the latter comprises several of them in order to further improve its compactness; and or

the deposition of the diffusing layer on the substrate is carried out by other known methods such as the adhesiveness of a self-adhesive film, the screen printing, the paint coating, the sputtering or the spin-coating.

Of course, the present invention is not limited to the embodiments described and shown, but encompasses any other embodiment. In particular, the shape and size of the diffusing layer, those of the screen and its curvature may be different from those just described for the instrument cluster 1. The invention thus makes it possible, by the simple making a few minor modifications to a basic version (the non-visible elements of the instrument cluster such as the projector and the mirror remaining the same), to offer at a low cost a wide variety of aesthetically very different instrument combination models one another. It is in particular conceivable to propose such combined instruments with large displays and for a small additional cost, contrary to current handsets whose cost price increases exponentially with the size of the display panel.

Claims

1. Instrument cluster for a motor vehicle dashboard characterized in that it comprises:

a rear projection screen (20) formed by a curved transparent substrate (21) and a diffusing thin layer (25) covering the rear face of said substrate (21), with the exception of an uncovered peripheral zone (23); ;

a frame (10) comprising a support frame (11) for said screen (20);

- a projector (30) for projecting from the rear and in the direction of said frame (10) supporting the screen, a digital image generated by a graphics computer and representing a multitude of indicator modules for the driver of said vehicle;

said frame (10) further comprising a bottom wall (12) extending rearwardly and in the extension of said support frame (11), said bottom wall (12) having a funnel shape centered on the optical axis of said screen (20) and narrowing to an opening (14) of shape identical to that of the diffusing layer (25) but of reduced dimensions,

the magnification ratio between said opening (14) and said diffusing layer (25) being predetermined as a function of the distance between this opening (14) and the screen (20) and as a function of the angle of projection of the video projector (30), so that the projection surface on the screen (20) of the portion of the light beam passing through said opening (14) coincides with the surface area of the substrate (21) covered by the diffusing layer (25). ).

2. Combined instrument according to claim 1, characterized in that it further comprises at least one ambient light source (50) located at the rear of said screen (20), at the peripheral periphery of said wall bottom (12) of the frame (10).

Instrument cluster according to claim 2, characterized in that said frame (10) is made of a non-diffusing opaque material, said handset further comprising a plurality of ambient light sources (50) fixed against the inner face of said bottom wall (12).

4. Instrument cluster according to claim 2, characterized in that said frame (10) is made of a diffusing translucent material.

5. Combined instrument according to claim 4, characterized in that it further comprises a plurality of peripheral light sources ambient (50) fixed against the outer face of said bottom wall (12).

Instrument cluster according to one of claims 1 to

5, characterized in that it comprises means allowing said driver of the vehicle to at least partially modify the display configuration of said digital image projected on the screen (20).

Combined instrument according to one of claims 1 to

6, characterized in that it comprises at least one deflection mirror (40) adapted to return the light beam from the projector (30) towards said frame (10).

An instrument cluster according to one of claims 1 to

7, characterized in that said screen (20) has, in its central part, a convex zone (22) defining a sphere portion, and in that said projected image comprises a central indicator module with a circular contour whose projection surface on said screen (20) coincides with said convex zone (22).

Instrument cluster according to one of claims 1 to

8, characterized in that said projector (30) is a miniature pico-type model or mini-projector providing a brightness of at least 500 lumens and a contrast greater than or equal to 10000: 1.

10. Combined instrument according to one of claims 1 to

9, characterized in that said substrate (21) is made in a polymethylmethacrylate (PMMA) and has a thickness of between 2 and 4 mm.