FR3059790A1 - OPTICAL DISPLAY DEVICE FOR DASHBOARD AND DASHBOARD INTEGRATING THE SAME - Google Patents

Abstract

The present invention relates to an optical display device (1) for a dashboard comprising: first display means (2) adapted and intended to emit at least a first light beam (3) to form a first image presenting a luminance L1, second display means (5) adapted and adapted to emit at least one second light beam (6) to form a second image having a luminance L2, a partially reflecting element (8) having a total reflectance Rt, adapted and intended on the one hand to transmit the first light beam (3) and on the other hand to reflect the second light beam (6) to form a virtual image of the second image, the reflectance Rt of the partially reflecting element ( 8) is less than 50%, preferably between 15% and 49%, in that the luminance L1 of the first display means (2) is smaller than the luminance L2 of the second display means (5).

Description

DESCRIPTION

The present invention relates to the field of optical display devices for dashboards, in particular for motor vehicles.

We know in the distant field of entertainment, the publication US 2012/0313839 Al which discloses a device for displaying virtual objects on a stage. This apparatus comprises a real object forming a background image, a means for displaying a virtual object, such as a screen, and a separating blade positioned at an angle of 45 degrees between the screen and the real object.

Publication US 2006/0176242 in the medical field discloses an augmented reality device which also combines real objects and virtual objects.

The object of the present invention is to provide an improved and energy-efficient display device in the field of application specified in the introduction.

To this end, the present invention relates to an optical display device for dashboard comprising:

first display means suitable and intended for emitting at least a first light beam to form a first image having a luminance L1, second display means suitable and intended for emitting at least a second light beam to form a second image presenting a luminance L2, a partially reflecting element having a total reflectance Rt, suitable and intended on the one hand for transmitting the first light beam and on the other hand for reflecting the second light beam to form a virtual image of the second image, device for display characterized in that the reflectance Rt of the partially reflecting element is less than 50%, preferably between 15% and 49%, in that the luminance L1 of the first display means is less than the luminance L2 of the second display means, and in that the display device is arranged so that the first image and the virtual image are arranged in planes

-2 commons or disjoint preferentially parallel and overlapping each other to form an overall resulting image for an observer.

The present invention also relates to a dashboard characterized in that it comprises the optical display device described above.

The invention will be better understood from the following description, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the appended schematic drawings, in which:

Figure IA is a schematic front view of the display device according to the invention, Figure IB is a schematic side view of the display device shown in Figure IA, Figure IC is a schematic side view of the device display shown in Figure IB showing the path of light rays, Figure 1D is a schematic side view of the display device shown in Figure IB showing a virtual image, Figure 2A is a view of a resulting image overall formed by the display device according to the invention seen by an observer in the optical axis, FIG. 2B is a view of a global resulting image formed by the display device according to the invention seen by an offset observer with respect to the optical axis, FIG. 3A is a front view of the display device according to the invention, FIG. 3B is a side view of the display device shown in FIG. 3 A, and Figure 4 is a schematic view of a dashboard in which is integrated the display device according to the invention.

The optical display device 1 for dashboard 12 comprises:

first display means 2 suitable and intended to emit at least a first light beam 3 to form a first image 4 having a luminance L1 (FIGS. IA to 1D, 3A and 3B)

-3 second display means 5 suitable and intended to emit at least one second light beam 6 to form a second image 7 having a luminance L2, (FIGS. 1A to 1D, 3A and 3B) a partially reflecting element 8 having a reflectance total Rt, suitable and intended on the one hand for transmitting the first light beam 3 and on the other hand for reflecting the second light beam 6 to form a virtual image 7 ′ of the second image 7 (FIGS. 1A to 1D, 3A and 3B ).

According to the invention, the display device 1 is characterized in that the reflectance Rt of the partially reflecting element 8 is less than 50%, preferably between 15% and 49%, in that the luminance Ll of the first display means 2 is less than the luminance L2 of the second display means 5, and in that the display device 1 is arranged so that the first image 4 and the virtual image 7 'are arranged in common planes or preferentially parallel and mutually overlapping to form an overall resulting image 9 for an observer, (FIGS. 2A and 2B)

Advantageously, the first display means 2 make it possible to form a first background image 4 and the second display means 5 combined with the partially reflecting element 8 make it possible to form a virtual image 7 ’in the foreground. The result is an overall resulting image 9 visible by an observer located opposite the partially reflecting element 8 and the first display means 2, in which the first background image 4 and the virtual image 7 ′ can appear to be superimposed (Figures 2A and 2B). Because the partially reflecting element 8 has a reflectance Rt of less than 50%, the transmittance of the partially reflecting element 8 is increased. It is thus possible to reduce the luminance L1 of the first display means 2 compared to the luminance L2 of the second display means 5. This configuration thus makes it possible to limit the energy losses, by reducing the energy to be supplied at the level first display means 2 and by limiting the heat dissipation produced by the first display means 2. In addition, because the partially reflecting element 8 has a reflectance Rt of less than 50%, the parasitic reflections are reduced .

Preferably, the size of the first image 4 can be greater than that of the size of the second image 7.

Advantageously, in this configuration the energy losses are also minimized for the second display means 5. As a result, the optical display device 1 is optimized in terms of cost and heat dissipation.

The partially reflecting element may consist of a strip 8 having a transmittance Tb and a first surface 8 'of which, suitable and intended to be impacted by the second light beam 6, may be covered with a reflective surface layer having its own reflectance Rc, preferably comprised between 25% and 35% (Figures IA to 1D).

In this case, this display device 1 is suitable and intended to present a total luminance Lt after crossing the partially reflecting element which satisfies the following relationship:

Lt = Tb X Ll + Rc (L2 -Tbx Ll)

By way of nonlimiting example, for a luminance

-2 -2

Ll = 500cd.m ', a luminance L2 = 1000cd.m' and an own reflectance Rc = 35%, the total luminance Lt is equal to 640 cd.m ² .

In this example, the blade 8 may include a second surface 8 "opposite the first surface 8" and covered with an anti-reflective surface layer.

Advantageously, this anti-reflective surface layer makes it possible to further reduce the stray reflections.

Preferably, the blade 8 can have an angle of incidence approximately equal to 45 degrees.

Advantageously, the first display means 2 and the second display means 5 can be arranged respectively in intersecting planes, preferably orthogonal.

In this case, the partially reflecting element 8 can be arranged in a plane situated between the planes in which the first display means 2 and the second display means 5 are respectively disposed.

For example, the plane in which the partially reflecting element 8 is arranged can form an angle of 45 degrees with the planes in which the first display means 2 and the second display means 5 are disposed respectively.

The first and second display means 2, 5 can be chosen from the following elements: a liquid crystal screen, a liquid crystal screen of the TFT LCD type, a screen of the OLED type, a screen of the passive OLED type, a screen of the active OLED type, a screen of the VFD type.

Preferably, the first and second display means 2, 5 can be flat screens, for example of rectangular appearance.

The partially reflecting element 8 has a size greater than the size of the first and second display means 2, 5.

As illustrated in FIGS. 3A and 3B, the display device 1 can be mounted on a device support 10, 11 intended to be integrated in a reception area of the dashboard 12.

On the device support 10, 11 can be mounted the first and second display means 2, 5 and the blade 8.

For example, and as illustrated in FIG. 3B, the device support can comprise a square 10 comprising a vertical plate 10a and a horizontal plate 10b arranged at right angles on which the first and second display means 2, 5 are respectively mounted. The horizontal plate 10a can be arranged above the vertical plate 10b.

The display device 1 may also include a blade support 11 on which the blade 8 is mounted (Figures 3A and 3B). For example, this blade support 11 may include an inclined plane 11 ′ substantially at 45 degrees relative to the vertical and horizontal plates 10a, 10b.

As illustrated in FIG. 3A, the bracket 10 may also comprise fixing holes 10 ′ which can be crossed by fixing means (not shown), which can be of the screw nut type by way of nonlimiting example or the like .

According to the invention, the dashboard 12 is characterized in that it comprises the optical display device 1 as described above, as illustrated in FIG. 4.

The dashboard 12 may include a reception area integrating a device support 10 as described above on which the optical display device 1 is mounted.

By way of nonlimiting example, the dashboard 12 according to the invention can be adapted to and integrated into a motor vehicle.

Of course, the invention is not limited to the embodiment described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (11)

1. Optical display device (1) for dashboard (12) comprising: first display means (2) capable and intended to emit at least a first light beam (3) to form a first image (4) having a luminance L1, second display means (5) suitable and intended to emit at least a second light beam (6) to form a second image (7) having a luminance L2, a partially reflecting element (8) having a total reflectance Rt, suitable and intended on the one hand for transmitting the first light beam (3 ) and on the other hand to reflect the second light beam (6) to form a virtual image (7 ') of the second image (7), display device (1) characterized in that the reflectance Rt of the element partially reflecting (8) is less than 50%, preferably between 15% and 49%, in that the luminance L1 of the first display means (2) is less than the luminance L2 of the second display means (5) , and in that it disposes display yew (1) is arranged so that the first image (4) and the virtual image (7 ') are arranged in common or disjoint planes preferably parallel and overlapping each other to form a global resulting image (9) for an observer. 2. Device according to claim 1, characterized in that the partially reflecting element consists of a strip (8) having a transmittance Tb and of which a first surface (8 ') suitable and intended to be impacted by the second light beam (6 ) is covered with a reflective surface layer having a specific reflectance Rc preferably between 25% and 35%. 3. Device according to claim 2, characterized in that it is able and intended to present a total luminance Lt after crossing of the partially reflecting element which satisfies the following relationship: Lt = Tb X Ll + Rc (L2 -Tbx Ll) 4. Device according to any one of claims 2 to 3, characterized in that the blade (8) comprises a second surface (8 ”) -8 opposite the first surface (8 ’) and covered with an anti-reflective surface layer. 5. Device according to any one of claims 2 to 4, characterized in that the blade (8) has an angle of incidence approximately equal to 45 degrees. 6. Device according to any one of claims 1 to 5, characterized in that the first display means (2) and the second display means (5) are arranged respectively in intersecting planes, preferably orthogonal. 7. Device according to claim 6, characterized in that the partially reflecting element (8) is arranged in a plane situated between the planes in which the first display means (2) and the second display means are disposed respectively. (5). 8. Device according to any one of claims 1 to 7, characterized in that the first and second display means (2, 5) can be chosen from the following elements: a liquid crystal screen, a liquid crystal screen of the TFT LCD type, a screen of the OLED type, a screen of the passive OLED type, a screen of the active OLED type, a screen of the VFD type. 9. Device according to any one of claims 1 to 8, characterized in that it is mounted on a device support (10, 11) intended to be integrated in a reception area of the dashboard (12). 10. Dashboard characterized in that it comprises the optical display device (1) according to any one of claims 1 to 9. 11. Dashboard according to claim 10, characterized in that it comprises a reception area integrating the device support (10, 11) on which the optical display device (1) is mounted. 5, L2