FR3065816A1 - IMAGE PROJECTION DEVICE FOR HEAD-UP DISPLAY - Google Patents

Abstract

The invention relates to an image projection device (20) for a head-up display, comprising: - a support (40), - a blade (22) at least partially reflecting, and - adjustment and locking means (30) the orientation of said blade relative to said support. According to the invention, said adjusting and locking means comprise: - a rod (31) extending along a longitudinal axis, which is rotatably mounted in the support about said longitudinal axis, and with respect to which said blade is locked in rotation about said longitudinal axis, and - two operating means (32, 33) accessible to the user, which are respectively mounted on both ends of said rod, a first means of maneuver is locked in rotation relative to at the rod about said longitudinal axis and a second means of maneuver is adapted to lock the rotational mobility of said rod in the support about said longitudinal axis.

Description

Holder (s): VALEO COMFORT AND DRIVING ASSISTANCE Simplified joint-stock company.

Extension request (s)

Agent (s): VALEO COMFORT AND DRIVING ASSISTANCE.

to4) DEVICE FOR PROJECTING IMAGES FOR A HEAD-UP DISPLAY.

FR 3,065,816 - A1 (57) The invention relates to an image projection device (20) for a head-up display, comprising:

- a support (40),

- an at least partially reflecting strip (22), and

- Means for adjusting and blocking (30) the orientation of said blade relative to said support.

According to the invention, said adjustment and blocking means comprise:

a rod (31) which extends along a longitudinal axis, which is mounted to rotate freely in the support around said longitudinal axis, and with respect to which said blade is locked in rotation about said longitudinal axis, and

- two maneuvering means (32, 33) accessible to the user, which are mounted respectively on the two ends of said rod, of which a first maneuvering means is locked in rotation relative to the rod around said longitudinal axis and one of which second operating means is adapted to lock the rotational mobility of said rod in the support around said longitudinal axis.

Image projection device for a head-up display

Technical field to which the invention relates

The present invention relates generally to driving aids for motor vehicles.

It relates more particularly to an image projection device for a head-up display, comprising:

- an at least partially reflective strip, and

- Means for adjusting and blocking the orientation of said blade relative to a support.

It also relates to a head-up display comprising an image generation unit and an image projection device as mentioned above, arranged so as to receive the light beam emitted by the image generation unit.

TECHNOLOGICAL BACKGROUND

To make driving easier and safer, we want to avoid the driver being forced to look away from the road he is taking.

For this, it is known to use a head-up display adapted to display information (vehicle speed, direction to follow, presence of obstacle, ...) at the level of the driver's gaze.

For this purpose, a head-up display includes an image-forming device and a device for projecting these images into the field of vision of the driver of the vehicle.

More precisely, such a head-up display makes it possible to generate virtual images so that they are perceived by the driver as if they were displayed at a great distance from the driver. In this way, the driver's eyes have no accommodation to do to simultaneously perceive the projected images and the road.

The driver's face being located more or less high relative to the projection device (due to the size of the driver and / or the height of the seat relative to the floor of the vehicle), it is necessary to equip this device projection of a means for adjusting its orientation so that the driver can see the projected virtual images.

For this, the head-up display is generally equipped with an electric motor making it possible to control the adjustment of the orientation of the image projection device, and with a button allowing the driver to control this electric motor.

The disadvantage of this solution is that it is particularly expensive and that it makes the device difficult to maintain and repair.

Object of the invention

In order to overcome the aforementioned drawbacks of the prior art, the present invention proposes to make manual control of the orientation of the image projection device.

More particularly, according to the invention, an image projection device as defined in the introduction is proposed, in which said adjustment and blocking means comprise:

a rod which extends along a longitudinal axis, with respect to which said blade is locked in rotation about said longitudinal axis, and which is adapted to be mounted to rotate freely in the support around said longitudinal axis, and

- two maneuvering means accessible to the user, which are mounted respectively on the two ends of said rod, of which a first maneuvering means is locked in rotation relative to the rod around said longitudinal axis and of which a second maneuvering means is adapted to lock the rotational mobility of said rod relative to the support around said longitudinal axis.

Thus, thanks to the invention, one of the operating means makes it possible to adjust the orientation of the blade when the other of the operating means makes it possible to lock the rotational mobility of this blade.

The various components of the adjustment and blocking means are inexpensive and are also easily removable, which allows easy maintenance and easy replacement of these various components.

Other advantageous and non-limiting characteristics of the image projection device according to the invention are as follows:

- The blade is equipped with a holding base which is engaged on the rod and the second operating means is adapted to lock the rotational mobility of said rod in the support by compressing said holding base against at least part of the support ;

- The second operating means is screwed onto a thread provided at a first end of said rod;

- The second operating means comprises a nut and a lever which extends projecting from the nut, radially with respect to the screwing axis of the nut;

- A spring washer is provided which is threaded onto said rod and which is adapted to be interposed between, on one side, the support, and, on the other, a base for holding said blade or one of the two maneuvering means;

- The first operating means has a form of lever which extends over the second end of the rod, projecting radially from the longitudinal axis of the rod;

- The first operating means is molded onto said rod;

- The first operating means is made of plastic;

- the rod has at least one rib which projects radially from the longitudinal axis of the rod; and

- the rod is made of a single piece of metallic material.

The invention also relates to a head-up display comprising an image generation unit and an image projection device as mentioned above, arranged so as to receive the light beam emitted by the image generation unit.

Preferably, this head-up display includes a support on which the rod of the image projection device is mounted to rotate freely.

Detailed description of an exemplary embodiment

The description which follows with reference to the accompanying drawings, given by way of nonlimiting examples, will make it clear what the invention consists of and how it can be carried out.

In the accompanying drawings:

- Figure 1 is a schematic view of a first embodiment of a head-up display according to the invention;

- Figure 2 is a schematic view of a second embodiment of a head-up display according to the invention;

- Figure 3 is a schematic perspective view of an image projection device fitted to each of the head-up displays shown in Figures 1 and 2; and

- Figure 4 is a schematic perspective view of the adjustment and locking means fitted to the image projection device shown in Figure 3.

In Figures 1 and 2, there is shown schematically two embodiments of a head-up display 10 intended to equip a vehicle, for example a motor vehicle.

In these two embodiments, the head-up display 10 comprises an image generation unit 11 controlled by a computer (not shown), and an optical assembly 12 for projecting images.

In the first embodiment illustrated in FIG. 1, the image generation unit 11 comprises a screen, here a liquid crystal screen (or LCD for Liquid Crystal Display) with thin film transistors (or TFT for Thin- Film Transistor). It also includes here a backlight device located at the rear of the screen to generate a light beam passing through the screen.

In the second embodiment illustrated in FIG. 2, the image generation unit 11 comprises a diffuser 16 and a scanning unit which generates a light beam of variable direction so as to be able to scan the rear face of the diffuser 16. The scanning unit more precisely comprises a beam forming module 14 and a movable mirror 15, for example produced in the form of an electromechanical microsystem (or MEMS for MicroElectroMechanical System). The beam forming module 14 typically comprises three monochromatic light sources, such as laser sources, the respective light beams of which (monochromatic) are combined (for example using dichroic mirrors) in order to form the polychromatic light beam ( here laser) emitted at the output of the beam forming module 14. This light beam generated by the beam forming module 14 is directed towards the movable mirror 15, the orientation of which is controlled by a control module so that the reflected light beam (by the movable mirror 15) scans the rear face of the diffuser 16.

In these two embodiments, the image generation unit 11 makes it possible, under the control of the computer, to generate an image that the optical projection assembly 12 will be able to project into the driver's field of vision when the gaze of the latter faces the road.

In the two embodiments shown in FIGS. 1 and 2, the projection optical assembly 12 is more precisely designed to project a virtual image Img into the field of vision of the driver of the vehicle, at a distance from the driver which is greater than that separating the driver from the windshield 1 (so that the driver's eyes do not have to do any accommodation work to perceive the projected information).

The projection optical assembly 12 comprises for this purpose an optical deflection system 13 and an image projection device 20 placed in the field of vision of the driver of the vehicle.

The optical return system 13, which here only includes a folding mirror, makes it possible to return the image generated by the image generation unit 11 to the image projection device 20.

The image projection device 20 makes it possible to reflect this image in such a way that it appears to the driver as if it were displayed at a great distance from the latter.

This image projection device 20 is arranged in the passenger compartment of the motor vehicle, for example on the dashboard, between the windshield 1 of the vehicle and the driver's eyes.

As shown in FIG. 3, this image projection device 20 is mounted on a support 40, which is equipped with means for fixing to the board of the vehicle edge.

Here, the support 40 has two uprights 41, 42 whose upper ends end in flanges 43, 44. The two flanges 43, 44 are in the form of two parallel plates, the upper edges of which each have a notch in the form of U. The two notches are here located opposite one another (on the same axis, called the longitudinal axis A1) and they therefore form a "welcome cradle".

This support 40 is here made in one piece, here in plastic (alternatively, a metallic material could be used).

As shown in FIG. 3, the image projection device 20 comprises an at least partially reflecting blade 22 which is articulated on the support 40 around the longitudinal axis A1, and means for adjusting and blocking 30 of the orientation of the blade 22 relative to the support 40 around the longitudinal axis A1.

The blade 22 is for its part in the form of a partially transparent plate, of generally rectangular shape and elongated along the longitudinal axis A1.

The blade 22 is made of polycarbonate by injection. It is treated to present a partially reflective coating on the front and to present an anti-reflection coating on the rear.

The blade 22 could be flat. However, it is curved here so as to enlarge the size of the virtual image Img seen by the driver.

This blade 22 is fixed immovably by its lower edge in a holding base 21 which is made in one piece of plastic and which is articulated on the support 40.

The blade 22 makes it possible to reflect the image formed by the image generation unit 11 so as to project the virtual images Img in the field of vision of the driver.

So that the driver can see the virtual images whatever the height of his face relative to the dashboard, it is necessary that he manually adjust the orientation of the blade 22 relative to the support 40 by means of adjustment and blocking 30 above.

Here, according to a particularly advantageous characteristic of the invention, these adjustment and blocking means 30 comprise:

- a rod 31 by which the blade 22 is articulated on the support 40,

a first operating means 32 accessible to the user for pivoting the blade 22 relative to the support 40, and

- a second operating means 33 accessible to the user for locking this pivoting mobility of the blade 22 relative to the support 40.

As FIGS. 3 and 4 clearly show, the rod 31 here has a cylindrical shape of revolution around the longitudinal axis A1. It is made of a single piece of metallic material. It projects on either side of the holding base 21 and it has a first end 31A on which is mounted the first operating means 32, and a second end 31B which is threaded and on which the second operating means is screwed 33.

For the articulation of the blade 22 relative to the support 40 around the longitudinal axis A1, this rod 31 passes through the notches of the support 40: the rod 31 is thus placed in the receiving cradle defined above.

The rod 31 is mounted to rotate freely in the flanges 43, 44 of the support.

40.

On the other hand, stop means are provided for blocking the blade 22 in rotation relative to the rod 31. In the present case, these stop means are in the form of two pins 31C which extend radially in projecting from the external face of the rod 31 and which are engaged in two ribs provided in correspondence in one of the flanges of the holding base 21 of the blade 22. The cooperation of the pins 31C with these ribs then ensures the coupling of the rod 31 to the blade 22.

We can now describe in more detail the form and function of each of the two maneuvering means 32, 33.

These maneuvering means could have forms of knurling wheels or any other form suited to their functions.

However, here, as shown in FIGS. 3 and 4, the first operating means 32 (which it is recalled that it allows the blade 22 to be pivoted manually relative to the support 40) comprises a ring 32A which is located at the first end 31A of the rod 31, and a first lever 32B which extends projecting from the ring 32A, radially with respect to the longitudinal axis A1.

This first operating means 32 is made of plastic and is here molded onto the rod 31 so as to be immobile with respect thereto. Consequently, the conductor can pivot the rod 31 and the blade 22 by manipulating this single first lever 32B.

The second operating means 33 is for its part screwed onto the thread provided at the second end 31B of the rod 31.

To this end, it comprises a nut 33A screwed onto this thread and a second lever 33B which extends projecting from the nut 33A, radially with respect to the longitudinal axis A1.

This second operating means 33 is produced by overmolding the second plastic lever 33B around the nut 33A.

By screwing the second operating means 33, the driver can lock any movement of the rod 31 relative to the support 40. Indeed, by screwing this second operating means 33, the first and second operating means 32, 33 are sandwiched the stack of flanges 43, 44 of the support 40 and the holding base 21, which frictionally locks the movement of these elements relative to each other.

When the second operating means 33 is unscrewed, this friction locking ceases, which allows the driver to adjust the inclination of the blade relative to the support 40.

Here, to prevent the unscrewing of the second operating means 33 from completely releasing the rotation of the rod 31 relative to the support 40 and from causing the blade 22 to tip over, a spring 34 is provided which is threaded onto the rod 31 and which is interposed between, on one side, one of the flanges 43, 44, and, on the other, one of the two maneuvering means 32, 33 or the holding base 21.

This spring 34 is here in the form of a spring washer. It is located on the side of the first operating means 32 and it allows, when the lever 33B is unscrewed, to maintain a sufficient friction force to prevent the blade

22 to switch. This friction force is however low enough to allow the driver to adjust the inclination of the blade 22 relative to the support 40 using the first operating means 32.

The present invention is in no way limited to the embodiment described and shown.

In particular, provision may be made for the second operating means to be mounted other than by a screwing system on the rod. As an example, a bayonet mount could be used.

Claims (11)

1. Image projection device (20) for a head-up display (10), comprising: - an at least partially reflecting strip (22), and - means for adjusting and blocking (30) the orientation of said blade (22) relative to a support (40), characterized in that said means for adjusting and blocking (30) comprise: - a rod (31) which extends along a longitudinal axis (A1), with respect to which said blade (22) is locked in rotation about said longitudinal axis (A1), and which is adapted to be mounted free to rotate in the support (40) around said longitudinal axis (A1), and - two maneuvering means (32, 33) accessible to the user, which are mounted respectively on the two ends (31 A, 31 B) of said rod (31), of which a first maneuvering means (32) is blocked in rotation relative to the rod (31) about said longitudinal axis (A1) and a second operating means (33) of which is adapted to lock the rotational mobility of said rod (31) relative to the support (40) around said axis longitudinal (A1). 2. Image projection device (20) according to the preceding claim, in which the blade (22) is equipped with a holding base (21) which is engaged on the rod (31) and in which the second means of maneuver (33) is adapted to lock the rotational mobility of said rod (31) in the support (40) by compressing said holding base (21) against at least part of the support (40). 3. Image projection device (20) according to one of the preceding claims, in which the second operating means (33) is screwed onto a thread provided at one of the ends (31 B) of said rod (31 ). 4. Image projection device (20) according to one of the preceding claims, in which the second operating means (33) comprises a nut (33A) and a lever (33B) which projects from the nut (33A), radially with respect to the screwing axis of the nut (33A). 5. Image projection device (20) according to one of the preceding claims, in which a spring washer (34) is provided which is threaded on said rod (31) and which is adapted to be interposed between, d 'On one side, the support (40), and, on the other, a holding base (21) of said blade (22) or one of the two maneuvering means (32, 33). 6. Image projection device (20) according to one of the preceding claims, in which the first operating means (32) comprises a lever (32B) which projects radially from the longitudinal axis ( A1) of the rod (31). 7. Image projection device (20) according to one of the preceding claims, in which the first operating means (32) is made of plastic and is molded onto said rod (31). 8. Image projection device (20) according to one of the preceding claims, in which the rod (31) comprises at least one rib (31 C) which projects radially from the longitudinal axis ( A1) of the rod (31). 9. Image projection device (20) according to one of the preceding claims, in which the rod (31) is made in one piece from metallic material. 10. Head-up display (10) comprising an image generation unit (11), characterized in that it further comprises an image projection device (20) according to one of the preceding claims, arranged so as to receive the light beam emitted by the image generation unit (11). 11. Head-up display (10) according to the preceding claim, comprising a support (40) on which the rod (31) of the image projection device (20) is mounted to rotate freely. 1/2 212 A1 34 ^31A 31B National registration number FA 838881 FR 1753788