FR2768822A1 - DEVICE FOR OPTICALLY PROJECTING IMAGES WITH 2 DIMENSIONS OR 3 DIMENSIONS "FLOATING" IN FRONT OF A SCREEN, VISIBLE WITHOUT SPECIAL GLASSES OR PROSTHESES - Google Patents

Abstract

Device for the optical projection of 2-dimensional or 3-dimensional images "floating" in front of a screen, visible without special glasses or prostheses. The invention relates to a device for forming real 3-dimensional images, for direct natural vision. It comprises a screen (1) consisting of a fresnel lens, a mixer (2) and several projectors (7) consisting of an image source (6) as well as an objective formed by the lenses (3, 4 The screen (1) is the only element visible to the observing public. Each projector (7) forms an image (11, 12) across the screen. The plane of the image (11, 12) is detached from the screen (t), hence the effect of the images "floating" in space. By varying the distance (A) by moving the projector (7) or the distance (B) by moving the image source (6), we act on the magnification and the spatial position of the image. 10, 11) can be placed at an adjustable distance from the screen (1), at the front or at the rear of it. The device according to the invention is particularly intended for the fields of leisure, exhibitions and advertising.

Description

The present invention relates to an optical image projection device
2-dimensional or 3-dimensional "floating" in front of a screen, visible without
special glasses or prostheses.

Technical area
Optical processes allowing the formation of real 3-dimensional images; for direct natural vision.

State of the art
The public is enthusiastic about relief images or holograms in the fields of leisure, exhibitions or advertising. Beyond holography and "lenticular array images", optical processes exist based on mirrors or lenses to form images "in space
These are methods of restoring wave fronts allowing the volume vision of the image, or methods of obtaining image planes outside of the optical apparatus.

 Here are some current problems: - In these devices, all or part of the systems are visible to the public, which limits the effect of surprise when producing effects in space.

- Current devices result in heavy and bulky equipment.

- Current devices do not allow the adjustment of the spatial localization of images.

- Current devices do not always allow the association or composition of multiple images.

Description of the device
The device according to the invention overcomes these drawbacks.

 Figure 1 shows the device according to the invention.

According to a first characteristic, it indeed comprises a screen (1) consisting of a fresnel lens. It is the only component perceived by the observing public. This screen has a conventional appearance and obscures all the equipment located at the rear.

 A mixer (2) made up of a semi-reflecting mirror allows the association of several images and thus authorizes the effect of composition of multiple images.

 The lenses (3,4,5) form a target.

The image source (6) consists of a cathode ray tube, or a process
with "LCD" type optical valves for example, or any other means of
generate the image.

The housing (7) incorporates the image source (6) and the objective (3,4,5), constituting
thus an image projector.

 Each projector (7) forms an image (11,12) across the screen (1).

 The plane of the image (11,12) is detached from the screen (1), hence the effect of the images "floating" in space for an observing audience.

By varying the distance (A) by displacement of the projector (7) or the distance (B) by displacement of the image source (6), one acts on the magnification and the spatial position of the image. The variation of the distances (A, B) by displacement is obtained by a system of slides, by way of nonlimiting example.

The image plane (11,12) can be placed at an adjustable distance from the screen,
at the front or at the rear thereof.

The projectors (7), the mixer (2), and the screen (1) are detached elements and free of physical links between them, which facilitates the handling and transport of the apparatus.

This detachment principle also reduces the overall size and weight of the assembly. The projectors (7) and the mixer (2) are placed and wedged on a support
or a chassis, not shown in Figures 1 and 2.

 This principle allows assembly and disassembly at will.

The support or chassis can be fitted with rollers to facilitate the adjustment of
distance between the screen (1) and the rest of the equipment.

 Figure 2 shows a variant of this device.

The device according to the variant mixes a 2-dimensional video image (13)
with a 3-dimensional object image (14).

 A housing (8) receives the object (9) intended to form an image.

Lighting (10) consisting of projectors providing uniform light,
illuminates the object.

The device according to the invention and its variant, is particularly intended
in the fields of leisure, exhibitions and advertising.

Claims (4)

 1) Device for the optical projection of 2-dimensional or 3-dimensional "floating" images at the front of a screen, visible without special glasses or prostheses, characterized in that it comprises a screen (1) consisting of a lens fresnel, a mixer (2) and several projectors (7) consisting of an image source (6) and an objective formed by lenses (3,4,5).  2) Device according to claim 1 characterized in that the screen (1) is the  only visible element of the observing public, from the situation of the rest  the switchgear at the back of this same screen (1).  3) Device according to claim 1 characterized in that the screen (1), the  mixer (2) and the projectors (7) are separate elements free of  physical links between them, which can be assembled and disassembled at will, on  a support or chassis.  4) Device according to claim 1 or claim 3 characterized in  by varying the distances (A) and (B), each of the image planes (11,12,  13,14) can be independently placed at an adjustable distance from the front  or at the back of the screen (1).