WO2020161427A1

WO2020161427A1 - Device for projecting an image such as a safety sign and/or a message onto a surface

Info

Publication number: WO2020161427A1
Application number: PCT/FR2020/050179
Authority: WO
Inventors: Sylvain DELEPLANQUE; Michel Desjardins; Nicolas AZAIS; Marc FIALEK; Sylvain EGRON
Original assignee: Lama Prg
Priority date: 2019-02-06
Filing date: 2020-02-04
Publication date: 2020-08-13
Also published as: FR3092406A1; FR3092406B1; EP3921699A1

Abstract

The present invention relates to a device for projecting an image such as a safety sign and/or a message onto a surface such as the ground or a wall, said device comprising at least one light source and an optical system comprising at least one optical lens; said device is noteworthy in that it comprises at least means for producing an image and/or a message from a collimated light source, and at least one convergent lens that focuses the collimated beams of the image on the entrance pupil of a fisheye lens or wide-angle objective.

Description

Title of the invention: Device for projecting an image such as a safety sign and / or a message on a surface!

Technical area

The present invention relates to a device for projecting an image such as a safety sign, of the zebra type for example, and / or a message on a surface such as the ground for example, and a manufacturing process an optical mask for producing the device according to the invention.

State of the art

In the field of safety signage, in particular for industrial buildings or residential buildings for example, it is well known that the regulations in force, particularly in France, provide for signage on the ground commonly called zebra in the law of garage doors, a zebra consisting of alternating yellow and black bands at an angle, or an arrow or a stop sign or a particular sign near a hazardous product storage area, etc.

Usually, these safety signs on the ground are produced by means of special paints of white color or colored using a stencil or not. However, these safety signs painted on the ground have the drawback that they have to be redone after a relatively short time, because they disappear from the ground. In addition, these safety signs get dirty very quickly, so that after a short time they are no longer sufficiently visible. In the event that these safety signs are affixed to the ground outside the building, they are subjected to bad weather, so that the arrangement of the color after a certain time makes it necessary to restore them. Incidentally, the installation of these painted safety signs requires preliminary cleaning of the floor as well as a drying time, which increases the cost of producing these signs.

[0004] In order to limit the exposure time of these safety signs on the ground, we have already imagined safety signs in the form of stickers. This is notably the case with document FR 1 073 093 for example.

[0005] Document FR 1 073 093 describes safety signaling devices consisting of sheets or strips of a mixture of thermoplastic synthetic materials based on suitably softened polyvinyls and esters of a polyacrylic acid with the addition of white pigments or colored, these sheets or strips being provided with an adhesive layer, and being fixed to the support by means of an adhesive of the same nature placed on this support. This mixture of plastics has a very high resistance to abrasion, equal to about two and a half times that of leather; it is weather-resistant and, by a suitable choice of plasticizer, it can be made insensitive to temperature variations in a range from about -15 to + 100 ° C.

Although this type of safety sign has the advantages of being installed quickly, the roadway on which the signage is applied can be used 5 to 10 minutes after installation, and of not slipping in bad weather, these safety signs nevertheless have the drawback of becoming dirty and deteriorating rapidly so that it is necessary to replace them regularly. In addition, it is necessary to produce signs of different sizes depending on the dimensions of the area of application of these signs. In order to remedy these drawbacks, we have already imagined safety signs consisting in projecting an image or a luminous message on the ground. This is the case in particular with American patent application US 2014/0204347.

[0008] Document US 2014/0204347 describes a device projecting an image onto a surface such as a wall or a floor. Said device comprises a source of bright light, preferably comprising a set of light-emitting diodes called LEDs, said light from this light source passing through one or more lenses called condenser in order to make it more uniform. These condenser lenses consist of aspherical or spherical lenses. The light then passes through a so-called mask image plate containing a small version of the image to be displayed. Once the light passes through the mask, it then passes through a focus assembly which includes a focusing lens, a compensating lens, a variation lens, a rear lens, and a front lens, with all lenses centered. on the projection axis. The focusing assembly creates a desired projected image on a target surface such as a wall or floor, the projected image being a representation of the image contained on the image plate.

[0009] Document EP 0 677 160 is also known, which describes a lamppost delivering light in a desired pattern on the ground. Said lamppost comprises a pole forming a light conduit having a proximal end and a distal end, an extended source of near-collimated light emitted near the distal end of said conduit and a light distribution member more distal from said source an array of light, wherein reflected light from said light distribution element illuminates a surface near said lamppost in a precise and predetermined pattern. Said light distribution element includes a light mask. light which is adapted to block a specified portion of the light emanating from the extended light source.

However, these devices have the drawback of providing a low contrast of the image projected on the ground so that they can only be used in the absence of sun, ie when it is dark, or in the absence of another exterior light source such as interior lighting.

[0011] There is therefore a need for a device for projecting safety signage on the ground which can be used both outdoors and indoors and providing a projected image of which the contrast is sufficient to be visible in all conditions. lighting.

Presentation of the invention

[0012] One of the aims of the invention is therefore to remedy at least one of these drawbacks by proposing a device for projecting safety signs on the ground of simple and inexpensive design and providing a projected image of which the contrast is sufficient to be visible in all lighting conditions.

For this purpose and in accordance with the invention, there is provided a device for projecting an image such as safety signage and / or a message on a surface such as the floor or a wall, said device comprising at least a light source and an optical system comprising at least one optical lens; said device is remarkable in that it comprises at least means for producing an image and / or a message from a light source, at least one converging lens which focuses the collimated beams of the image on the entrance pupil of a hypergonic lens, also called a fisheye lens, or a wide-angle lens. It will be observed that the hypergonic or wide angle lens of the device according to the invention allows the projection of a safety sign whose contrast is sufficient to be visible in all lighting conditions thus allowing use as well in outdoors, day and night, and indoors.

According to a first variant embodiment of the device according to the invention, the means for producing the image comprise a light source consisting of a plurality of light-emitting diodes called LEDS extending in pairs on either side. means capable of collimating the beams of the light emitted by said LEDS towards at least one converging lens which focuses the collimated beams of the image on the entrance pupil of the hypergonic lens or of the wide angle lens, said mask extending along the optical axis between the converging lens and the hypergonic or wide angle lens.

Preferably, said means capable of collimating the beams of light emitted by said LEDS consist of at least one condensing mirror.

[0017] Said condenser mirror is made up of two pairs of parabolic mirrors extending on either side of a plane of symmetry, said plane of symmetry extending parallel to the optical axis of the device.

[0018] Furthermore, the light source consists of four light-emitting diodes called LEDS extending respectively to the right of each parabolic mirror of the condenser mirror.

[0019] According to a second variant embodiment of the device according to the invention, the means for producing the image consist of a scanning laser forming an image on a fluorescent membrane, said fluorescent membrane emitting light at the impact zones of the laser beams on said membrane.

[0020] Said fluorescent membrane is reflective or transparent.

[0021] Said scanning laser consists of a laser emitting a ray on a polygonal mirror driven in rotation about its axis and of a reflecting mirror capable of reflecting the laser beams parallel to the optical axis of the device.

[0022] Furthermore, another object of the invention relates to a method of manufacturing an optical mask for producing a device for projecting an image onto a surface according to the invention, said method is remarkable in that it comprises at least the following steps of:

- measurement of the length and width of a so-called marking area on the projection surface, the marking area corresponding to the area in which the image is to be projected, and the optical axis of the device passing through the center of said marking area;

- measurement of the distance between three of the four corners of the marking area with the center of the lens of the device;

- determination of a digital model of the mask based on previous measurements, the selection of the mask thickness and the technical characteristics of the hypergonic or wide angle lens of the device;

printing of said mask by a rapid prototyping process from said digital model.

[0023] Preferably, said mask is printed by stereolithography from said digital model. [0024] In addition, the mask has a thickness of between 0.1 and 5 mm as well as the shape of an equiangular quadrilateral.

Brief description of the drawings

[0025] Other advantages and characteristics will emerge better from the description which follows of several variant embodiments, given by way of non-limiting examples, of the device for projecting an image on a surface according to the invention, with reference to to the accompanying drawings in which:

[Fig. 1] Figure 1 is a schematic perspective representation of the device according to the invention;

[Fig. 2] Figure 2 is a schematic perspective representation of the light source and a condenser mirror of the device according to the invention;

[Fig. 3] FIG. 3 is a representation of the spatial distribution and of the angular distribution of the light flux at the output of the condenser mirror;

[Fig. 4] FIG. 4 is a schematic representation of a zebra-type safety signaling image produced by the device according to the invention;

[Fig. 5] Figure 5 is a schematic representation of the measurements for the manufacture of an optical mask for the device according to the invention;

[Fig. 6] FIG. 6 is a schematic representation of an alternative embodiment of the device according to the invention.

detailed description For the sake of clarity, in the remainder of the description, the same elements have been designated by the same references in the various figures. In addition, the various views are not necessarily drawn to scale.

A device for projecting a safety sign of the zebra type, i.e. a sign in the form of white or yellow hatching, will be described below; however, it is obvious that the device according to the invention will be able to project an image such as a safety sign and / or a message on a surface such as the floor or a wall without departing from the scope of the invention.

Referring to Figure 1, the device for projecting an image such as safety signage and / or a message on a surface such as the floor or a wall, according to the invention comprises means of production of an image and / or message 1, collimating means 2 towards at least one converging lens 3 which focuses the collimated beams on the entrance pupil of a hypergonic lens 4, also called a fisheye lens.

Said means for producing the image 1 comprise a light source 5 consisting of a plurality of light-emitting diodes called LEDS 6 extending in pairs on either side of means 2 capable of collimating the beams of light emitted by said LEDS 6 towards at least one converging lens 7 which focuses the collimated beams on the entrance pupil of the hypergonic lens 4, a mask 8 extending on the optical axis between the converging lens 7, said mask comprising an image of a zebra, and the hypergone lens 4. Said LEDs 6 consist, for example, of LEDS marketed by the company CREE under the reference HXP35.

Referring to Figures 1 and 2, said means 2 adapted to collimate the beams of light emitted by said LEDS 6 consist of a condenser mirror 9. Said condenser mirror 9 consists of two pairs of Off-axis parabolic mirrors 10 extending on either side of a plane of symmetry, said plane of symmetry extending parallel to the optical axis of the device. An LED 6 extends to the right of each parabolic mirror 10. In this particular embodiment, each parabolic mirror 10 has a conicity of -1, a lateral shift of 10 mm, an angular shift of 90 ° and a RoC of 10. mm. However, it is obvious that each parabolic mirror 10 may have a shift of between 5 and 15 mm and an angular shift of between 60 and 120 °, depending on the position and orientation of the LEDs 6, without going out. within the scope of the invention.

In this particular embodiment, the light source 5 consists of four light-emitting diodes called LEDS 6 extending respectively to the right of each parabolic mirror 10 of the condenser mirror 9, FIG. 3 showing the spatial distribution of the output flux mirrors 10 and the angular distribution of the flux at the outlet from mirrors 10 respectively, the beam being collimated as can be seen.

It is obvious that the light source can include any number of LEDS 6 and that the condenser mirror 9 will then include as many parabolic mirrors 10 as LEDS 6 without departing from the scope of the invention.

The device according to the invention, with reference to Figure 4, allows to project an image of a zebra on the ground with great sharpness and great contrast so that it can be visible in all conditions lighting thus allowing use both outdoors, day and night, as well as indoors.

It will be noted that the zebra thus obtained present comprises a succession of white and black bands. However, in order to obtain a zebra consisting of yellow bands, or any other color, and black, the hypergone lens 4 may be provided at the outlet of the housing with a yellow filter or a filter of any other color respectively, not shown in the figures. Moreover, it is obvious that the device also comprises a casing receiving the various optical elements of the invention as well as an electronic card controlling the light source, not shown in the figures.

[0035] In addition, the so-called fisheye hypergone 4 lens may be substituted by a wide angle lens without departing from the scope of the invention.

So that the zebra is clean and well sized regardless of the configuration of the place where the device according to the invention is installed, in particular regardless of the distance from the ground of the device and the angle of projection, it is necessary to place a suitable mask in the device described above. Thus, another object of the invention relates to a method of manufacturing an optical mask for the production of a device for projecting an image on a surface according to the invention.

[0037] Referring to Figure 5, said method according to the invention which can be implemented by means of a computer program comprises the following steps of:

- determination of a digital model of the mask according to the previous measurements, the selection of the thickness of the mask and the technical characteristics of the device's hypergone or wide-angle lens;

printing of said mask by a rapid prototyping process from said digital model.

[0038] Preferably, said mask is printed by stereolithography from said digital model thus obtained and the mask has a thickness of between 0.1 and 5 mm as well as a shape of an equiangular quadrilateral. It goes without saying that said mask can be obtained by laser cutting from the digital model or by any other method well known to those skilled in the art and that said mask can have any quadrilateral shape, in particular when the projection axis of the device is not normal to the marking surface, without departing from the scope of the invention.

[0039] According to a second variant embodiment of the device according to the invention, with reference to FIG. 6, the device for projecting an image such as safety signage and / or a message on a surface such as the ground or a wall according to the invention comprises, in the same way as above, means for producing an image and / or a message 1, at least one converging lens 3 which focuses the collimated beams on the entrance pupil of a hypergone 4 lens, also called a fisheye lens.

This variant embodiment differs from that previously described by the fact that the means for producing the image 1 consist of a scanning laser 11 forming an image on a fluorescent membrane 12, said fluorescent membrane 12 emitting light at the impact zones of the laser beams on said membrane 12. Said scanning laser 11 consists of a laser 13 emitting a ray on a polygonal mirror 14 driven in rotation around its axis and of a reflecting mirror 15 able to reflect the laser beams parallel to the axis optical device. In this particular example of embodiment, the fluorescent membrane 12 is transparent; however, it is quite obvious that said fluorescent membrane 12 could be reflective without however departing from the scope of the invention.

Finally, it is obvious that the examples which have just been given are only specific illustrations in no way limiting as to the fields of application of the invention.

Claims

1. Device for projecting an image such as safety signage and / or a message on a surface such as the ground or a wall, said device comprising at least one light source and an optical system comprising at least one optical lens, characterized in that it comprises at least means for producing an image and / or a message from a collimated light source, at least one converging lens which focuses the collimated beams of the image on the pupil of input of a hypergonic lens, also called a fisheye lens, or a wide angle lens.

2. Device according to claim 1 characterized in that the means for producing the image comprise a light source consisting of a plurality of light-emitting diodes called LEDS extending in pairs on either side of means capable of collimating them. beams of the light emitted by said LEDS to at least one converging lens which focuses the collimated beams of the image onto the entrance pupil of the hypergonic lens or the wide angle lens, a mask extending over the optical axis between the converging lens and the hypergonic or wide-angle lens

3. Device according to claim 2 characterized in that said means capable of collimating the beams of light emitted by said LEDS consist of at least one condenser mirror.

4. Device according to claim 3 characterized in that said condenser mirror consists of two pairs of parabolic mirrors extending on either side of a plane of symmetry, said plane of symmetry extending parallel to the axis optical device.

5. Device according to claim 4 characterized in that the light source consists of four light-emitting diodes called LEDS extending respectively to the right of each parabolic mirror of the condenser mirror.

6. Device according to claim 1 characterized in that the image production means consist of a scanning laser forming an image on a fluorescent membrane, said fluorescent membrane emitting light at the impact areas of the beams of the laser on said membrane.

7. Device according to claim 6 characterized in that the fluorescent membrane is reflective.

8. Device according to claim 6 characterized in that the fluorescent membrane is transparent.

9. Device according to any one of claims 6 to 8 characterized in that the scanning laser consists of a laser emitting a ray on a polygonal mirror driven in rotation about its axis and of a reflecting mirror capable of reflecting the laser beams parallel to the optical axis of the device.

10. A method of manufacturing an optical mask for producing a device for projecting an image onto a surface according to any one of claims 1 to 5, characterized in that it comprises at least the following steps of:

i) Measurement of the length and width of a so-called marking area on the projection surface, the marking area corresponding to the area in which the image is to be projected, and the optical axis of the device passing through the center of said marking area;

ii) Measure the distance between three of the four corners of the marking area with the center of the lens of the device;

iii) Determination of a digital model of the mask as a function of the previous measurements, the selection of the thickness of the mask and the technical characteristics of the hypergone or wide angle lens of the device; iv) Printing of said mask by a rapid prototyping process from said digital model.

11. A method of manufacturing an optical mask according to claim 10 characterized in that said mask is printed by stereolithography from said digital model.

12. A method of manufacturing an optical mask according to claim 10 characterized in that said mask is obtained by laser cutting from the digital model.

13. A method of manufacturing an optical mask according to any one of claims 10 to 12 characterized in that the mask has a thickness between 0.1 and 5 mm.

14. A method of manufacturing an optical mask according to any one of claims 10 to 13 characterized in that the mask has the shape of an equiangular quadrilateral. |