WO2006134243A1

WO2006134243A1 - Device for presenting an image merged at different distances to a subject, said device comprising two optical systems centred on each eye of the subject

Info

Publication number: WO2006134243A1
Application number: PCT/FR2006/001037
Authority: WO
Inventors: Konogan Baranton
Original assignee: Essilor International (Compagnie General D'optique)
Priority date: 2005-06-14
Filing date: 2006-05-10
Publication date: 2006-12-21
Also published as: FR2886833B1; FR2886833A1

Abstract

The invention relates to a device for presenting a merged image (93) to a subject, said image being perceived by the subject at different distances. The inventive device comprises two pupillary openings (10, 11) in front of which the eyes (8, 9) of the subject are to be positioned, a front lens (12, 13) which is located behind each pupillary opening, is fixed in relation to the device, and comprises an optical axis (30, 31), and an optical imaging system (4, 5) for a test object (19, 20), comprising at least one optical element including at least one support (17, 18) for presenting the test object. According to the invention, each optical imaging system of a test object comprises a mobile optical element (14, 15) which follows a trajectory comprising at least one useful part having a displacement direction comprising a first component following the direction of the optionally propagated part of the optical axis of the front lens which is incident on the mobile optical element, and a second component which is transversal to the first component.

Description

DEVICE FOR PRESENTING A SUBJECT OF A FUSIONED IMAGE AT DIFFERENT DISTANCES COMPRISING TWO OPTICAL CENTER SYSTEMS

ON EACH EYE OF THE SUBJECT

TECHNICAL FIELD TO WHICH THE INVENTION RELATES The present invention relates generally to ophthalmic devices.

The invention relates more particularly to a device for presenting to a subject an image fused at different distances, comprising, for each eye of the subject, a support for presenting a test object and an optical imaging system for the subject. test object presented by the presentation medium.

The invention finds a particularly advantageous application for visual screening devices. TECHNOLOGICAL BACKGROUND

For each typology of carriers (classified by trade, type of activity, ...) and for each country, visual screening includes a visual acuity test that requires three different vision tests: a vision test of away, an intermediate vision exam and a near vision exam. Each vision examination is associated with an inclination of the gaze, also called a line of sight, and a distance of presentation of the image fused to the subject. Thus, each vision examination to be performed corresponds to a pair of values consisting of the presentation distance of the image fused to the subject and the angle of view. It sometimes happens that a pair of values used for a vision examination according to a country and a trade body corresponds, according to a given tolerance range of these values, to another pair of values used for the same vision examination for a other trades and / or for another country. However, most of the time these pairs of values do not overlap. Moreover, during the visual acuity examination, it is also desired to examine the phoria of the eyes, that is to say the alignment of the axes of aim of the subject's two eyes, and / or the fusion capacity of the two eyes. eyes. For this purpose, an image is presented on each eye and it is then necessary to have two independent optical paths, or made independent, for both eyes of the subject so that the image perceived by an eye is not perceived by the eye. other eye. There are visual screening devices for performing such a visual acuity test. However, for this type of device, each of these three vision examinations corresponds to an arrangement of fixed optical elements in the apparatus. It is then necessary to perform the visual acuity examination to have three fixed optical circuits in this device.

These optical circuits are made using optical elements such as reflecting mirrors and ophthalmic lenses to make an image on each eye of the subject forming the fused image positioned at the desired presentation distance. This solution involves the use of a large number of optical elements and complicates the realization of the visual screening apparatus since it must incorporate the optical circuits corresponding to the vision examinations in the same apparatus, that is to say say in a reduced environment. In addition, as explained above, this type of visual screening device is then dedicated to a single country and a single trade. Finally, it is not possible to adjust the device to correct a possible positioning error of the different optical elements during assembly of the device. As a result, the use of this type of apparatus is restricted and the investment expensive.

US Pat. No. 6,335,0032 to Titmus discloses a visual screening apparatus for varying the distance of presentation of the continuously fused image. There is provided a vision examination apparatus having a light-shielding housing and a viewer connected to the housing which has front and left lenses. A right mirror and a left mirror are each mounted pivoting inside the case behind the corresponding right and left front lenses. An image display on the right and an image display on the left are movably mounted inside the housing where the displays face each other, each display being generally perpendicular to a line between the front lens and the corresponding mirror. Finally, there are two auxiliary lenses, left and right, mounted movably inside the housing and aligned between the right and left display screens and the corresponding left and right mirrors.

This apparatus thus comprises for each eye an optical imaging system constituting an optical channel centered on each eye.

The respective images seen by the right eye and the left eye must be centered on each other regardless of the viewing distance examined. This device converts the center of the displayed images forming the merged image seen by the subject at the same place during the variation of the presentation distance of the images seen by the subject by introducing a deviation of the convergence point of these images seen by the subject. subject using the movable mirror. If the rotatably mounted mirror is held fixed, the images seen by the subject are off-center with respect to each other. Thus, the mirror which pivots is used to correct the defect of convergence in one place of the two images seen by the subject when the presentation distance of the merged image changes by displacement of an optical element such as the screen or the auxiliary lens following the propagated portion of the optical axis of the front lens incident on the optical element. This solution requires the mobility of several optical elements for each optical channel.

Mobile elements are dependent on each other. The more the number of moving elements increases the more complex the design of the apparatus, especially as regards the arrangement of the movable elements relative to each other. This results in a complex motorization. The cost of the device is thus high and the risk of major failure.

OBJECT OF THE INVENTION The object of the present invention is to reduce the number of moving optical elements necessary to vary the presentation distance of the image fused to the subject and to ensure the convergence of the two images forming the merged image seen by the subject.

Another object of the present invention is to simplify the motorization within said presentation device. For this purpose, according to the invention, a device is proposed for presenting to a subject a fused image perceived by this subject at different distances, comprising two pupillary openings in front of which the subject's eyes are intended to be positioned and behind each opening pupillary lens, a front lens having an optical axis, and an optical imaging system of a test object comprising one or more optical elements including at least one display medium for the test object, wherein each optical system method of imaging a test object comprises an optical element mounted movable with respect to the lens along a path having at least one useful portion having, at any point, a direction of movement comprising, on the one hand, a first component along the direction of the possibly propagated portion of the optical axis of the front lens incident on the movable mounted optical element and secondly, a second component transverse to the first component. The mobile mounted optical element is then movable in a plane passing through the optionally propagated portions of the optical axes of the two frontal lenses, incident on the corresponding mobile mounted optical elements.

By "optionally propagated" is meant that the optical axis is directly incident on an optical element or that it undergoes one or more referrals before reaching this optical element. Each optical imaging system of the test object presented by the presentation medium and the associated front lens generate an image of the corresponding test object seen by the subject. Each imaging optical system and the associated front lens then constitute an independent optical path for each eye, allowing the presentation on each of the two eyes of the image of the test object of the corresponding optical path independently of the image of the image. the test object of the other optical channel.

Such a trajectory of the auxiliary lens induces a misalignment of the movably mounted optical element relative to the portion of the possibly propagated axis of the front lens incident on the movable mounted optical element. This misalignment makes it possible to control the place of convergence of the two images of the two test objects seen by the subject together with the variation of the presentation distance of these two images forming the merged image seen by the subject. Thus, the presentation device according to the invention uses a single optically movable element to simultaneously control the place of convergence of the images of the test objects seen by the subject and the distance of presentation of these images forming the merged image.

According to another advantageous characteristic of the presentation device, each front lens having a focal distance, each imaging optical system giving a first image of the test object, the trajectory of each mobile mounted optical element is such that, given the composition of the optical system, the first image by the optical system of the test object moves in translation in a direction making with the optionally propagated portion of the optical axis of the front lens, incident on the movable mounted optical element, a first non-zero angle defined by the formula:

TAN (A1) = P / (2. F'2), A1 denoting the first angle, P denoting the distance in meters between the possibly propagated portions of the optical axes of the front lenses, incident on the two pupillary openings, and F'2 designating the focal length of the front lens in meters.

According to another advantageous characteristic of the presentation device, each front lens gives a second image of the first image of the test object, each second image being presented on the corresponding eye of the subject. For all the positions taken by the two mobile mounted optical elements, the first images of the two test objects by the optical imaging systems are arranged so that the second two images by the front lenses of the first two images of the two objects of test are located substantially in the same plane and centered on one another to form the merged image presented to the subject.

The mobility of the optical element mounted movably along the component of its trajectory oriented along the portion propagated by the optical axis of the front lens incident on the movable mounted optical element makes it possible to adjust the position of the first image of the object. by the optical element mounted movably relative to the axis of the front lens, in the direction of this axis. The transverse component, with respect to the propagated portion of this axis, of the path of the movably mounted optical element makes it possible to transversely adjust the position of the first image of the test object by the optical element mounted mobile with respect to said axis of the frontal lens. This transverse adjustment makes it possible to induce a prism effect on the place of convergence of the second image of the test object by the mobile mounted optical element. This effect of prism introduced on the second images, acting on the place of convergence, is called prismatic convergence. It is thus possible to control the convergence location for each optical path of each second image of the corresponding test object seen by each eye of the subject.

According to another advantageous characteristic of the presentation device, for all the positions taken by the two mobile mounted optical elements, there is a plane of symmetry between the two optical systems. The displacements of the two mobile mounted optical elements of the two optical systems are symmetrically symmetrical with respect to the plane of symmetry so that, for each vision examination, the arrangement of the optical elements of each optical channel is symmetrical to that of the other optical channel. . As a result, for the two optical paths, the second images seen by the subject are substantially in the same plane.

According to another advantageous characteristic of the presentation device, the two optical systems are arranged so that, for all the positions taken by the two mobile mounted optical elements, the center of the merged image presented to the subject is located on an axis parallel to the possibly propagated portion of the optical axis of the front lens incident on the eye and in the plane of symmetry existing between the two optical systems.

Thus, it is possible for an apparatus using an optical system centered on each eye to continuously vary the presentation distance of the image fused to the subject through the continuous variation in the distance at which the subject sees the images. second images forming the merged image, while having the two second images in the same plane and centered on each other, regardless of the presentation distance of the merged image to the desired subject. Finally, when the presentation distance is set, the merged image moves closer to or away from the subject without shifting laterally.

According to another advantageous characteristic of the presentation device, the presentation supports of the two optical systems are controlled by an electronic and / or computer system for selectively displaying two identical, partially different or totally different images. When the visual acuity examination requires a phoria examination or a stereoscopic test, each of the images of the two different or partially different test objects must be presented to the corresponding eye of the subject, independently of the other eye , at the same distance from the subject and the two images must be centered on each other. On the other hand, when the test objects used are optotypes, the two test objects are identical for the two optical paths. The merged image seen by the subject is then a unique optotype resulting from the precise superimposition of the test objects of each channel. According to another advantageous characteristic of the presentation device, the mobile mounted optical element is movable in translation along a direction making, with the possibly propagated portion of the optical axis of the front lens, incident on the mobile mounted optical element, a angle equal to the first angle.

When moving the movable optical element along the component of its trajectory directed along the optical axis of the front lens, the second image of the test object of each optical channel seen by the subject does not converge in the same place as the second image of the other optical channel. The second images are well displaced relative to the subject, but the centering of these second images relative to each other to form the merged image seen by the subject is not assured. The defect of convergence in the same place of the two second images of the test objects is then compensated by the introduction of the transverse component, at this portion of the axis, of the path of the movable mounted optical element.

Thus, this rectilinear trajectory is simple to implement and makes it possible to vary the presentation distance while ensuring the good superposition in their center of the two second images of the two test objects seen by the subject. According to another advantageous characteristic of the presentation device, the two mobile mounted optical elements are mounted and / or controlled to move together in translation.

The two mobile mounted optical elements must be moved symmetrically relative to each other and at the same speed to ensure accurate positioning of these mounted mobile optical elements. Thus, the electronic and / or computer and / or mechanical processing system makes it possible to control the movement of the two mobile mounted optical elements by means of a common motor to ensure a good accuracy of displacement.

According to another advantageous characteristic of the presentation device, the two mobile mounted optical elements are mounted and / or driven to move in the same direction.

When the portions of the propagated axes of the incident front lenses on the mobile mounted optical elements are parallel to each other, the trajectories of the mobile mounted optical elements being at an angle to these propagated portions of the axes of the front lenses, the trajectories of said movable mounted optical elements form a non-zero angle between them. This complicates the motorization of the device. To simplify this motorization, we add, for each optical path, reflecting mirrors between the auxiliary lens and the front lens. At least one of them is inclined so that the portion propagated by the mirror, incident on the movably mounted optical element, makes, with the direction of movement of the mobile mounted optical element, the first angle not bad. Thus, the mobile mounted optical elements can follow parallel paths with each other. A very simple motorization, generating a simple translation, then makes it possible to ensure the joint movement of the two mobile mounted optical elements along parallel paths.

According to another advantageous characteristic of the presentation device, the device comprises, between the pupillary openings and the frontal lenses, a mirror movable in translation and in rotation so that the optical axis of each frontal lens propagated by said movable mirror passes through the mirror. pupillary aperture corresponding substantially at its center.

For the subject to see the merged image presented optimally, the line of sight of an eye must be, at the front lens, coincident with the optical axis of the front lens. To do this, it suffices to add a mobile mirror in rotation and in translation to achieve this alignment of the optical axis and the line of sight. This solution involves an arrangement of the optical elements of the three-dimensional screening device to ensure the convergence of the second images of the test objects in one place, together with the variation of their presentation distance. In addition, this three-dimensional arrangement of the optical elements of the apparatus requires, due to space constraints, the addition of additional deflection mirrors and the reorganization of the deflection mirrors and the front lenses.

Thus, at each position and orientation of the moving mirror corresponds a gaze direction (or line of sight) according to which the subject must look. In other words, regardless of the direction of the line of sight from each of the two eyes, the arrangement of the optical elements and the introduction of the movable mirror can fold this axis of sight with the help of this mobile mirror so that the propagated portion of the line of sight remains merged with the propagated portion of the optical axis of the front lens. This makes it possible not to have to adapt the position of the set of optical elements of each of the two optical channels at each variation of the inclination of the line of sight.

According to another advantageous characteristic of the presentation device, the mobile mounted optical element comprises an auxiliary lens having an optical axis, positioned between the front lens and the presentation support of the test object.

According to another advantageous characteristic of the presentation device, the mobile mounted optical element comprises said support for presenting the test object. According to another advantageous characteristic of the presentation device, the optical imaging system is constituted by said presentation medium.

According to another advantageous characteristic of the presentation device, the movable mounted optical element comprises a dihedron open at 90 °, positioned between the front lens and the presentation support of the test object.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT The following description with reference to the accompanying drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be implemented. In the accompanying drawings:

FIG. 1 is a schematic view from above of the essential optical elements of a device for presentation to a subject of an image fused at a certain viewing distance according to a first embodiment according to the invention;

FIG. 2 is a schematic view from above of the essential optical elements of the device for presentation to a subject of an image fused at a close vision distance according to the first embodiment according to the invention;

FIG. 3 is a schematic view from above of the essential optical elements of the device for presentation to a subject of an image fused at a distance of far vision according to the first embodiment according to the invention; FIG. 4 is a schematic view from above of the essential optical elements of the device for presentation to a subject of an image fused at a mean viewing distance according to a second embodiment according to the invention; FIG. 5 is a schematic view from above of the essential optical elements of the device for presenting to a subject an image fused at a close vision distance according to the second embodiment according to the invention;

FIG. 6 is a diagrammatic view from above of the essential optical elements of the device for presentation to a subject of an image fused at a far vision distance according to the second embodiment according to the invention;

FIG. 7 is a three-dimensional and perspective schematic diagram of the essential optical elements of the device for presenting to a subject an image fused at three different distances and in a certain viewing direction according to a third embodiment according to FIG. 'invention;

FIG. 8 is a three-dimensional and perspective schematic diagram of the essential optical elements of the device for presentation to a subject of an image fused at three different distances and in a certain viewing direction according to a fourth embodiment according to FIG. 'invention; FIG. 9 is a schematic view from above of the essential optical elements of the device for presentation to a subject of a fused image at three different viewing distances according to a fifth embodiment according to the invention;

FIG. 10 is a schematic view from above of the essential optical elements of the device for presenting to a subject an image fused at three different viewing distances according to a sixth embodiment according to the invention.

In the figures, the images of the test objects by the optical elements are marked by their center. In addition, the angles and positions of the objects have been exaggerated for a better understanding of the operation of the device. In general, the distances along the Y axis have been multiplied by five with respect to the X axis. When reference is made to a portion of an axis or beam incident on an optical element, it is is the portion of the axis or the beam passing through the plane of the optical element, if it has one, or the portion of the axis or beam passing close to said optical element. When describing the position of optical elements relative to others, the registration axis corresponds to the path of an optical beam through said optical elements. In Figures 1, 2, and 3 there is shown a device for presentation to a subject of a merged image 93, 94, 95 at different distances. From right to left, this device, integral with a frame 1, comprises, for each eye 8, 9 of the subject, an optical system 4, 5 for imaging a test object 19, 20 presented by a presentation medium 17, 18, and a front lens 12, 13. Each presentation support 17, 18 and each front lens 12, 13 is fixed relative to the frame 1 of the device. Each front lens 12, 13 is convergent and has an optical axis 30, 31. These front lenses 12, 13 have a focal length F'2 of 149.05 mm and an index of 1.52. Downstream of the two front lenses 12 , 13 of the two optical systems 4, 5 are arranged two pupillary openings 10, 11. These two openings 10, 11 are located in the same plane, parallel to that of the front lenses 12, 13. The centers of these openings 10, 11 are separated by a distance P of 60 mm and are each on the optical axis 30, 31 of the corresponding front lens 12, 13. The eyes 8, 9 of the subject are intended to be positioned in front of these two pupil openings 10, 11. The geometrical arrangement of the optical elements with respect to each other is available for an optical system in tables of values at the end of the description of the invention. this first embodiment. The geometric coordinates are given in the XYZ frame, the origin being taken on the left eye 8 of the subject and the center of each of the optical elements being located at the same altitude Z = 0.

Each presentation medium 17, 18 of the test object 19, 20 is a screen on which the test object 19, 20 is displayed. The screens 17, 18 of the two optical systems 4, 5 are controlled by an electronic system. and / or computer and / or mechanical to selectively display two identical images, partially different or two totally different images.

Each optical system 4, 5 for imaging the test object 19, 20 corresponding also comprises a movable mounted optical element. This mobile mounted optical element is here an auxiliary lens 14, 15 positioned in front of the test object 19, 20. This auxiliary lens 14, 15 has an optical axis 32, 33. The two auxiliary lenses 14, 15 are convergent and have a F'1 focal length of 156, 84 mm and an index of 1, 52. Here, the optical axes 30, 31, 32, 33 of the front and auxiliary lenses are all parallel to each other, or, in other words, the lenses are all arranged in planes parallel to each other (that is to say parallel to the plane YZ in Figures 1, 2 and 3). Each test object imaging system 4, 5, 20 for each eye and the front lens 12, 13 centered on each associated eye 8, 9 define an optical path centered on each eye 8, 9. Optical generates an image 60, 61, 62, 63, 64, 65, also called second image, of the test object 19, 20 seen by the eye 8, 9 of the corresponding subject.

The auxiliary lens 14, 15 is mounted movably along a path in the plane passing through the axis 32, 33 of each auxiliary lens 14, 15, that is to say in the plane XY in FIGS. 1, 2 and 3 The trajectory of the auxiliary lens makes it possible to adjust the place of convergence of the images 60, 61, 62, 63, 64, 65 of the test objects by the auxiliary and front lenses forming the fused image 93, 94, 95 presented to the subject. . The mobility of the auxiliary lens thus makes it possible to adjust the distance of presentation of the fused image 93, 94, 95 to the subject and to ensure the fusion of said merged image 93, 94, 95.

Indeed, the trajectory has a direction of displacement comprising, on the one hand, a first component in the direction of the propagated portion of the optical axis 30, 31 of the front lens 12, 13 which passes through the auxiliary lens 14, 15 to varying the display distance of the images 60, 61, 62, 63, 64, 65 of the test objects 19, 20 participating in the formation of the fused image 93, 94, 95 seen by the subject. The useful portion of the trajectory of the auxiliary lens 14, 15 comprises, on the other hand, a second component transverse to the first component. This second transverse component makes it possible to superimpose and center the images 60, 61, 62, 63, 64, 65 to generate the merged image 93, 94, 95 seen by the subject.

Although in this example described, the auxiliary lens is constantly moving in translation at a bias relative to the propagated portion of the optical axis of the front lens incident on the auxiliary lens, it would also be possible to predict that the lens is moving. on the one hand, on a part of its trajectory, at an angle and, beyond a certain distance of presentation, for example, that the auxiliary lens moves along a portion parallel to the portion propagated by the optical axis of the front lens incident on the auxiliary lens.

Here, in particular, the auxiliary lens 14, 15 is movable in a direction 35, 36 making, with the propagated portion of the optical axis 30, 31 incident on the mounted mobile optical element 14, 15, a non-zero angle A1 defined by the formula:

TAN (A1) = P / (2. F'2), A1 denoting the first angle, P denoting the distance between the two apertures in meters and F'2 denoting the focal length of the front lens in meters.

Thus, the auxiliary lens 14, 15 has a useful travel segment between two extreme positions. The first extreme position makes it possible to perform a near vision examination and the second extreme position allows for a far vision examination. For each optical channel, the first extreme position of the auxiliary lens 14, 15 is a position in which the auxiliary lens 14,

15 is the closest to the other optical channel and farthest from the screen 17,

18 The second end position of the auxiliary lens 14, 15 is a position in which the auxiliary lens 14, 15 is farthest from the other optical path and closest to it. of the screen 17, 18 for displaying the test object 19, 20.

The optical elements of the two optical paths are arranged symmetrically with respect to one another. The presentation device thus has a plane of symmetry. For all the positions taken by the auxiliary lenses 14, 15, the center of the fused image 93, 94, 95 presented to the subject is located on a fixed axis 34. This axis is parallel to the propagated portion of the optical axis 30, 31 of the front lens 12, 13 incident on the eye 8, 9 and in the plane of symmetry of the optical system 4, 5.

Finally, an electronic and / or computer processing system (not shown) controls the displacement of the two auxiliary lenses 14, 15 at the same time and at the same speed. This displacement of the two auxiliary lenses 14, 15 at the same time and at the same speed makes it possible to ensure a good accuracy of the displacement of each lens 14, 15 and to ensure the symmetry of the geometrical configuration of the optical elements of each optical channel.

The operation of the presentation device is described below by following for an optical system 4, 5 for imaging the test object 19, the optical path of a light beam 80, 81 coming from the test object. 19, 20 displayed on the screen 17, 18.

The beam 80, 81 passes through the auxiliary lens 14, 15. The auxiliary lens 14, 15 being convergent, the beam 80, 81 is deflected into a beam 82, 83 folded towards the optical axis 32, 33 of the auxiliary lens 14, 15. The beam 82, 83 emerging from the auxiliary lens 14, 15 participates in the formation of a real image 51, 52, 53, 54, 55, 56, also called the first image, of the test object 19, 20. This real image 51, 52, 53, 54, 55, 56 is formed between the auxiliary lens 14, 15 and the front lens 12, 13.

The trajectory of the auxiliary lens 14, 15 is such that, given the arrangement of the optical elements of the optical system 4, 5, the actual image 51, 52, 53, 54, 55, 56 by the auxiliary lens 14, 15 of the test object 19, 20 moves in translation in a direction making the non-zero angle A1 with the optical axis 30, 31 of the front lens 12, 13.

A beam 86, 87 from this real image 51, 52, 53, 54, 55, 56 passes through the front lens 12, 13 and emerges into a beam 84, 85 folded down on the optical axis 30, 31 of the front lens 12 13. Finally, this beam 84, 85 passes through the opening 10, 11 in front of which is disposed the eye 8, 9 of the subject. The front lens 12, 13, the auxiliary lens 14, 15 and the screen 17, 18 are arranged (see tables of values in fine) so that the image 51, 52, 53, 54, 55, 56 is located between the optical focus of the front lens 12, 13 and the front lens 12, 13. The beam 84, 85 and all other beams from the actual image 51, 52, 53, 54, 55, 56 of the object of test 19, 20 then seem to come from the subject of the image 60, 61, 62, 63, 64, 65. This image 60, 61, 62, 63, 64, 65 seen by the subject is the virtual image, by the front lens 12, 13, of the actual image 51, 52, 53, 54, 55, 56, by the auxiliary lens 14, 15, of the test object 19, 20.

The actual images 51, 52, 53, 54, 55, 56 of the two test objects 19, 20 by the auxiliary lenses 14, 15 of the two optical systems 4, 5 are positioned on the one hand with respect to the X axis ( see the tables of values in fine) so that the two virtual images 60, 61, 62, 63, 64, 65 by the front lenses 12, 13 of the two actual images 51, 52, 53, 54, 55, 56 two test objects 19, 20 of the two optical systems 4, 5 are substantially in the same plane substantially perpendicular to the plane of symmetry of the presentation device. On the other hand, the real images 51, 52, 53, 54, 55, 56 are positioned relative to the Y axis (see the tables of values in fine) so that the two virtual images 60, 61, 62 , 63, 64, 65 are centered on each other to form the fused image 93, 94, 95 presented to the subject. For performing the various vision examinations, via a computer and / or electronic processing system (not shown), the desired vision test (far, intermediate, or near vision examination) is specified. you can set yourself the desired presentation distance of the image fused to the subject.

To perform a far vision examination, the auxiliary lens 14, 15 is moved to its useful travel segment at its end closest to the display 17, 18 of the test object 19, 20, to the favor of a mobile device type motorized carriage in active connection with the electrical processing system and / or computer.

The optical axis 32, 33 of the auxiliary lens 14, 15 is then offset along the Y axis (see FIG. 3 and tables of values in fine) with respect to the center of the test object 19, 20 displayed and relative to to the optical axis 30, 31 of the front lens 12, 13. The actual image 55, 56 by the auxiliary lens 14, 15 is then located near the focus of the front lens 12, 13. The optical axes 30, 31 of the two frontal lenses 12, 13 being parallel and the actual images 55, 56 of the test objects 19, 20 found on this axis 30, 31 and the focus of each of the front lenses 12, 13, the images 64, 65 of these real images 55, 56 of the test objects 19, 20 by the frontal lenses 12, 13 are virtually rejected in two parallel directions which meet at infinity. Here, an infinite distance corresponds to a distance of about 6000mm. These two virtual images 64, 65 presented to the subject at infinity appear to him to be centered and located on the axis 34 belonging to the plane of symmetry of the presentation device, thus forming the fused image 95.

For an intermediate vision examination, the auxiliary lens 14, 15 is moved along its useful travel segment. The auxiliary lens 14, 15 is then positioned between its two extreme positions, at a position corresponding to the desired intermediate presentation distance of the fused image 93.

The actual image 51, 52 of the test object 19, 20 is displaced with respect to the previous position in a direction making with the optical axis 30, 31 of the front lens 12, 13 the non-zero angle Al L the actual image 51, 52 is thus shifted along and with respect to the axis 30, 31 of the lens 12, 13 so that the virtual image 60, 61 by 12, 13 of the actual image 51, 52 of the test object 19, 20 is on the axis 34 and thus forms, with the virtual image 60, 61 corresponding to the other optical channel, the merged image 93 seen by the subject. This merged image 93 is view on the axis 34 by the subject at the desired distance parameterized in the computer and / or electronic processing system.

For close vision examination, the auxiliary lens 14, 15 is further removed from the screen 17, 18. The auxiliary lens 14, 15 is moved in the same direction 35, 36 as previously on its useful stroke segment, in its position at the end of the useful stroke, the furthest away from the screen 17, 18 of display.

Thus, the virtual image 62, 63 of the test object 19, forming the merged image 94 is located on the axis 34 at the distance of the desired subject for near vision examination. Alternatively, the auxiliary lens may be replaced by an optical system equivalent to an objective and the front lens by an optical system equivalent to an eyepiece.

The following three tables provide an example of a geometric arrangement of the optical elements relative to one another, as explained above.

Near-vision examination X (mm) Y (mm)

Eye 0.00 0.00

Front lens 119, 06 0.00

Screen 1304, 50, 209, 32

Auxiliary lens 377, 55 22, 15

Intermediate real picture 188, 77 -15, 97

Merged image 250 -30

Intermediate vision test X (mm) Y (mm)

Eye 0.00 0.00

Front lens 119, 06 0.00

Screen 1304, 50, 209, 32

Auxiliary lens 423, 27, 31, 44

Real intermediate image 232, 85 -7, 10

Merged Image 600 -30

Far Vision Exam X (mm) Y (mm)

Eye 0.00 0.00 Front lens 119, 06 0.00

Screen 1304, 50, 209, 32

Auxiliary lens 456, 88 38, 13

Intermediate Actual Image 264, 43 -0, 74 Merged Image 6000 -30

Figures 4, 5 and 6 illustrate a second embodiment of the invention which is a variant of the previous embodiment of the invention. As in the previous embodiment, it is provided from left to right in Figures 4, 5 and 6, two optical systems 4A, 5A constituting two optical channels each centered on an eye 8, 9 of the subject to be positioned in front of the camera. pupil aperture 10, 11. It is also provided the computer and / or electronic processing unit (not shown).

For each optical channel, there is thus the auxiliary lens 14, 15 of optical axis 32, 33 serving as an objective for the test object 19, 20 displayed on the screen 17, 18. Then upstream of this auxiliary lens 14, there is also the front lens 12, 13. The front lens 12, 13 has an optical axis which, when propagated, is an axis 30A, 31A in several parts. The pupil aperture 10, 11 is centered on the optical axis 30A, 31A of the front lens 12, 13. The two optical paths are always arranged symmetrically with respect to each other. As previously, the auxiliary lens 14, 15 forms a real image 51 A, 52A, 53A, 54A, 55A, 56A, also called the first image, of the test object 19, displayed on the screen 17, 18. Similarly, , the front lens forms a virtual image, 60A, 61A, 62A, 63A, 64A, 65A, also called second image, of the actual image 51 A, 52A, 53A, 54A, 55A, 56A of the test object 19 , 20, participating in the formation of the fused image 93A, 94A, 95A seen by the subject. The fused image 93A, 94A, 95A moves on the axis 34.

In this embodiment, two mirrors 71, 72, 73, 74 have been added in addition to the aforementioned elements, for each optical channel. The two mirrors 71, 72, 73, 74 are arranged between the front lens 12, 13 and the auxiliary lens 14, 15. The first mirror 71, 73 is arranged, in FIGS. 4, 5 and 6, opposite the front lens 12, 13. This mirror is arranged in a plane corresponding to the YZ plane. rotated 45 degrees about the Z axis. Above this first mirror 71, 73, in Figures 4, 5 and 6, a second mirror 72, 74 is provided. disposed in a plane corresponding to the YZ plane rotated by an angle A2 with A2 = 45 + A1 / 2 in degrees about the Z axis so that a beam directed in the Y direction incident on the mirror 72, 74 is returned in a beam approximating the plane of symmetry of the device by making the angle A1 with the optical axis 32, 33 of the auxiliary lens 14, 15.

These mirrors 71, 72, 73, 74 make it possible to modify the path of the optical beams. The optical axis 30A, 31A of the front lens 12, 13 is then propagated by these two mirrors. The propagated optical axis 30A, 31A thus consists of several axis portions. It is also said that the optical axis is "folded". In FIGS. 4, 5 and 6 starting from the front lens 12, 13 and moving towards the auxiliary lens 14, 15, the first portion 47A, 37A of the optical axis 30A, 31A of the front lens 12, 13 is perpendicular to the general plane of the front lens 12, 13, that is to say oriented along the axis X. At the first mirror 71, 73 this optical axis 30A, 31A is returned in a second portion 44A, 34A with an axis perpendicular to the first axis portion 47A, 37A, along the Y axis. Then, at the second mirror 72, 74, this axis 30A, 31A is returned along a portion of axis 48A, 38A in XY plane, the portion making the angle A1 with the optical axis 32, 33 oriented along the X axis, the auxiliary lens 14, 15. Similarly, an optical beam 8OA, 81 A from the test object 19, 20 passes through the auxiliary lens 14, is folded (or returned) by the mirrors 71, 72, 73, 74, and participates in the formation of the actual image 51A, 52A, 53A, 54A, 5A, 56A of the test object 19, 20. As shown in Figure 4 in intermediate vision, the actual image 51 A, 52A is formed between the two mirrors 71, 72, 73, 74. The same is true in near vision for the actual image 53A, 54A of the test object 19, 20 by the auxiliary lens 14, 15 (see Figure 5). In far vision, as shown in Figure 6, the actual image 55A, 56A of the test object 19, 20 by the auxiliary lens 14, 15 is formed substantially at the focus of the propagated portion of the optical axis 3OA , 31A of the front lens 12, 13, between the mirror 72, 74 and the auxiliary lens 14, 15. A beam 82A, 83A from this real image 51A, 52A, 53A, 54A,

55A, 56A of the test object 19, crosses, after returning, the front lens 12, 13 and is folded over the optical axis 30A, 31A of the front lens 12, 13 into a beam 84A, 85A then participating in forming the virtual image 60A, 61A, 62A, 63A, 64A, 65A. As in the previous embodiment, the auxiliary lens 14, 15 is movable between two extreme positions. Here, the auxiliary lens 14, 15 is movable in a direction parallel to its optical axis 32, 33. As previously, the two extreme positions correspond to a position for a close vision examination (see FIG. 5) and a position for a far vision examination (see Figure 6). As shown in FIG. 4 for an intermediate vision examination, the auxiliary lens 14, 15 takes an intermediate position between these two extreme positions.

The displacement of the auxiliary lenses 14, 15 relative to the screen 17, 18, in a direction parallel to their optical axis 32, 33 making the angle A1 with the propagated optical axis 30A, 31A of the front lens 12, 13 , then makes it possible to ensure the centering of the virtual images 6OA, 61A, 62A, 63A, 64A, 65A forming the fused image 93A, 94A, 95A. and varying the position of the fused image 93A, 94A, 95A on the axis 34. In this embodiment, the axis 30A, 31A propagated from the front lens 12, 13 by the two mirrors 71, 72, 73, 74 corresponds when unfolded, that is to say when the two mirrors 71, 72, 73, 74 are not present, to the optical axis 30, 31 in the first embodiment shown in FIGS. FIGS. 1, 2 and 3. Thus, in this second embodiment shown in FIGS. 4, 5, 6, the two mirrors 71, 72, 73, 74, the auxiliary lens 14, 15 and the screen 17, 18 are arranged so that the actual image 51A, 52A, 53A, 54A, 55A, 56A of the test object 19, 20 by the auxiliary lens 14, 15 is positioned along the optical axis 30A, 31A with respect to optical focus of the front lens 12, 13 and transverse to this optical axis 30A, 31A, at the same level as the actual image 51, 52, 53, 54, 55, 56 with respect to the axis 30, 31 in the first embodiment . In particular, the actual image 55A, 56A of the test object 19, 20 during a distance vision examination is as previously positioned substantially at the front lens optical focus 12, 13 and during the near-vision and intermediate vision, the actual images 51A, 52A, 53A, 54A are positioned between the optical focus of the front lens 12, 13 and the front lens 12, 13 and offset with respect to this axis 30A, 31A.

The displacement of the auxiliary lenses 14, 15 can be effected by means of a common motorized carriage (not shown) to the two auxiliary lenses 14, 15, and in active connection with the computer processing system and / or electronic. A very simple motorization, generating a simple translation, then makes it possible to ensure the common displacement of the two auxiliary lenses 14, 15, arranged symmetrically with respect to each other, along parallel paths. FIG. 7 shows a third embodiment of the presentation device according to the invention which is a variant of the second embodiment shown in FIGS. 4, 5 and 6. As in the second embodiment, it is provided an optical system 4B, 5B per eye 8, 9 constituting an optical channel centered for each of the two eyes 8, 9 positioned behind the two pupil openings 10, 11.

Compared to the previous embodiment and for each of the two optical channels, there is the screen 17, 18 displaying the test object 19, 20, the auxiliary lens 14, 15 of optical axis 32, 33, the front lens 12, 13. There is also the computer and / or electronic processing unit (not shown). For the sake of clarity, FIG. 7 shows three positions of the auxiliary lens. A first position corresponds to the position of the auxiliary lens 14, 15, in solid lines, for an intermediate vision examination. A second position corresponds to the position of the auxiliary lens 14 ", 15", in dotted lines, for a distance vision examination. A third position corresponds to the position of the auxiliary lens 14 ', 15', in dotted lines, for near vision examination. The optical axes 32, 33, 30B, 31B of the auxiliary lenses 14, 15, 14 ', 15', 14 ", 15" and the front faces 12, 13 have been represented, the positions of the actual images 51 B, 52B, 53B, 54B, 55B, 56B test objects 19, 20 by the auxiliary lenses 14, 15, 14 ', 15', 14 ", 15" and the positions of virtual images 6OB, 61 B, 62B, 63B, 64B, 65B actual images 51B, 52B, 53B, 54B, 55B, 56B of the test objects 19, 20 through the front lenses 12, 13 forming the fused image 93B, 94B, 95B seen by the subject. However, the optical beams forming these images have not been represented for the sake of clarity.

For each optical channel, the two reflecting mirrors 71, 72, 73, 74 of the second embodiment shown in FIGS. 4, 5 and 6 are here configured differently in view of the three-dimensional organization of the optical systems 4B, 5B. Thus two mirrors 71B, 72B, 73B, 74B are provided on either side of the front lens 12, 13. In addition, a third deflection mirror 75, 76 is also provided. The subject's eye looks in a certain direction. This direction defines from the center of the eye 8, 9 a line of sight 6, 7. For the subject to see the merged image presented optimally, the line of sight 6, 7 of an eye 8, 9 must be, at the level of the front lens 12, 13, coincides with the optical axis 30B, 31B of this front lens 12, 13.

It is then provided a movable mirror 77 in translation along the Z axis and in rotation about the Y axis so that the portion propagated from the sighting axis 6, 7 through the front lens 12, 13 is substantially merged with the optical axis of this front lens 12, 13 regardless of the inclination of the line of sight 6, 7. Thus, at each position and orientation of the movable mirror 77 corresponds a direction of gaze (the line of sight) following which the subject must look. In addition, the variation in angular size induced by the displacement of the auxiliary lens 14, 15 is compensated for by the variation in the opposite angular dimension induced by the displacement of the moving mirror 77. In FIG. 7, the presentation device is described as follows. the line of sight 6, 7 propagated from an eye 8, 9 to the screen 17, 18 for displaying the test object 19, 20 corresponding. The eyes 8, 9 of the subject, as well as the two pupil openings 10, 11 are positioned in a mean plane YZ.

The movable mirror 77 is positioned vis-à-vis the eyes 8, 9 as explained above. The propagating axis 6, 7 propagated is then coincident with the optical axis 30B, 31B of the front lens 12, 13. It is therefore equivalent here to speak of the optical axis 30B, 31B propagated from the front lens 12, 13 or the line of sight 6, 7 propagated.

The propagated axis of view 6, 7 is returned by the mirror 77 in a portion 46B, 36B parallel to the axis Z. The mirror 71B, 73B is positioned opposite the mirror 77 in a plane corresponding to the XZ plane rotated 45 degrees so that the propagated axis of view 6, 7 is returned by the mirror 71 B, 73B in a portion 44B, 34B parallel to the Y axis. The front lens 12, 13 is positioned opposite the mirror 71 B, 73B in the XZ plane. The propagated portion 44B, 34B of the line of sight 6, 7 is parallel to the Y axis and coincides with the optical axis 30B, 31B of the front lens 12, 13 as explained above. The deflection mirror 72B, 74B is positioned on the other side of the front lens 12, 13 with respect to the mirror 71B, 73B in a plane corresponding to the XY plane having undergone a rotation of angle A2 with A2 = (45 - A1 / 2) degrees, around the X axis so the mirror 72B, 74B returns the incident portion 44B, 34B of the propagated sighting axis in a portion 48B, 38B which moves away from the plane of symmetry of the device. The propagated portion 48B, 38B of the sighting axis 6, 7 is located in the plane YZ and is the angle A1 with the axis Z. The mirror 75, 76 is positioned above and in front of it. of the mirror 72B,

74B in a plane corresponding to the XY plane which has been rotated 45 degrees about the Y axis so that the portion 48B, 38B is returned along a portion 49B, 39B which moves away from the plane of symmetry of the device. The portion 49B, 39B is in the XY plane and makes an angle A1 with the optical axis 32, 33 of the auxiliary lens 14, 15, 14 ', 15', 14 ", 15" placed opposite the mirror 75, 76 and substantially at the same altitude Z as said mirror 75, 76.

The operation of the device according to this embodiment is similar to that of the second embodiment. Thus, in this third embodiment shown in FIG. 7, the two mirrors 71B, 72B, 73B, 74B, the auxiliary lens 14, 15, 14 ', 15', 14 ", 15" and the screen 17, 18 are arranged so that when the optical system 4B, 5B is "unfolded", the actual image 51B, 52B, 53B, 54B, 55B, 56B of the test object 19, 20 by the auxiliary lens 14, 15, 14 ', 15', 14 ", 15" is positioned along the optical axis 30B, 31B with respect to the optical focus of the front lens 12, 13 and transverse to this optical axis 30B, 31B, at same level as the actual image 51A, 52A, 53A, 54A, 55A, 56A with respect to the optical axis 30A, 31A of the second embodiment (FIGS. 4, 5, 6). In particular, the actual image 55B, 56B of the test object 19, 20 during a far vision examination is positioned substantially at the front lens optics focus 12, 13 and during the intermediate vision and vision vision examinations. Nearly, the actual images 51B, 52B, 53B, 54B are positioned between the optical focus of the front lens 12, 13 and the front lens 12, 13 and offset with respect to this axis 30B, 31B.

The displacement of the auxiliary lenses 14, 15, 14 ', 15', 14 ", 15" can be effected by means of a common motorized carriage (not shown) to the two auxiliary lenses 14, 15, and in active connection with the computer and / or electronic processing system. A very simple motorization, generating a simple translation, then makes it possible to ensure the joint displacement of the two auxiliary lenses 14, 15, 14 ', 15', 14 ", 15" along parallel paths.

The virtual images 6OB, 61B, 62B, 63B, 64B, 65B and merged 93B, 94B, 95B are located on the axis 34. As previously, this axis 34 is in the plane in the plane of symmetry of the device and in the plane passing through the portions of the sighting axes 6, 7 starting from the eye 8, 9.

In Figure 8, there is shown a fourth embodiment of the presentation device according to the invention which is a variant of the third embodiment. As in the previous embodiment, there is provided an optical system 4C, 5C per eye 8, 9 constituting an optical channel centered for each of the two eyes 8, 9 positioned behind the two pupil openings 10, 11. previous embodiment and for each of the two optical channels, there is the screen 17, 18 displaying the test object 19, 20, the auxiliary lens 14, 15, 14 ', 15', 14 ", 15" optical axis 32, 33, in three positions, the front lens 12, 13, the reflecting mirror 71 B, 73B, the mirror 77, the sighting axis 6, 7, the portions 49B, 39B, 44B, 34B, 46B, 36B 6, 7 or optical axis of the front lens 12, 13. There is also the computer and / or electronic processing unit (not shown). In this embodiment, two mirrors 72C, 75C, 74C, 76C equivalent to the mirrors 72B, 75, 74B, 76 of the third embodiment but oriented differently are provided for each optical channel.

The front lens 12, 13 has an optical axis 30C, 31C which is propagated differently from the optical axis 30B, 31B of the third embodiment. The angle A1 between the optical axis 30C, 31C propagated from the front lens 12, 13 and the optical axis 32, 33 of the auxiliary lens 14, 15, 14 ', 15', 14 ", 15", of which the direction is that of the displacement of this auxiliary lens, is introduced by the reflecting mirror 75C, 76C located vis-à-vis the auxiliary lens 14, 15, 14 ', 15', 14 ", 15". On the one hand, the mirror 72C is in a plane corresponding to the XY plane which has been rotated 45 degrees about the X axis. On the other hand, the mirror 75C, 76C is positioned in the plane corresponding to the XY plane after a rotation around the Y axis by 45 degrees followed by an angle rotation A1 / 2 around Z, transforming the X axis into an X axis and the Y axis into a Y axis (see Figure 8) , so that the portion 49B, 39B of the optical axis 3OC, 31C moves away from the plane of symmetry of the device by making the angle A1 with the optical axis 32, 33 of the lens 14, 15, 14 ' , 15 ', 14 ", 15". Thus, this optical axis 30C, 31C comprises between the mirror 72C, 74C and the mirror 75C, 76C a portion of axis 48C, 38C parallel to the axis Z.

As in the embodiment shown in FIG. 7, FIG. 8 shows the optical axes 32, 33, 3OC, 31 C of the lenses 14, 15, 14 ', 15', 14 ", 15" and front end positions 12, 13, the positions of the actual images 51 C, 52 C, 53 C, 54 C, 55 C, 56 C of the test objects 19, 20 through the auxiliary lenses 14, 15, 14 ', 15', 14 ", 15", and the positions of the virtual images 6OC, 61C, 62C, 63C, 64C, 65C of the actual images 51C, 52C, 53C, 54C, 55C, 56C test objects 19, 20 by the front lenses 12, 13 forming the fused image 93C, 94C, 95C seen by the subject. However, the optical beams forming these images have not been represented for the sake of clarity.

The actual image 51 C, 52 C, 53 C, 54 C, 55 C, 56 C of the test object 19, 20 through the auxiliary lens 14, 15, 14 ', 15', 14 ", 15" is positioned along the optical axis 3OC, 31 C with respect to the optical focus of the front lens 12, 13 and transversely to this optical axis 3OC, 31 C, at the same level as the actual image 51 B, 52B, 53B, 54B, 55B, 56B with respect to the optical axis 30B, 31B of the third embodiment. In particular, the actual image 55C, 56C of the test object 19, 20 during a distance vision examination is positioned substantially at the front lens optics focus 12, 13 and during the intermediate vision and near vision examinations. , the real images 51 C 52C 53C _1, 54C are positioned between the optical focus of the front lens 12, 13 and the front lens 12, 13 and offset relative to this axis 3OC, 31 C. the operation of the device according to this embodiment is identical to that of the third embodiment. FIG. 9 represents a fifth embodiment of the invention which is a variant of the first embodiment shown in FIGS. 1, 2 and 3. As in the first embodiment, there are two eyes 8, 9 of the subject positioned in front of the two pupil apertures 10, 11 and behind each pupil aperture 10, 11, on the one hand, the front lens 12, 13 fixed with respect to the frame 1 of the presentation device and centered on the corresponding pupil aperture 10, 11 and, on the other hand, a 4D, 5D imaging optical system. Here the optical system 4D, 5D, presenting, by means of the front lens 12, 13 corresponding, for each corresponding eye 8, 9 of the subject image 60, 61, 62, 63, 64, 65 of the test object 19, 20 linked to its presentation support 17, 18 fixed relative to the frame 1, is different from that of the first embodiment. As in the first embodiment, each optical system 4D, 5D and each front lens 12, 13 associated define an optical path for each eye independently of the other eye, that is to say that the image of the test object perceived by one eye is not perceived by the other eye and vice versa. Here, the element The moving optics of each imaging optical system is a dihedron 114, 115, 114 ', 115', 114 ", 115" open at an angle of 90 °. Thus, each imaging optical system 4D, 5D comprises the presentation medium 17, 18 of the test object 19, 20 corresponding and the dihedron 114, 115, 114 ', 115', 114 ", 115" associated. (For each optical channel, this open dihedron at 90 ° has a first face 114B, 115B ₁ 114B ', 115B ^1, 114B ", 115B" oriented Ia front lens 12, 13 and a second 114A face 115A ₁ 114A' 115A ', 114A ", 115A" oriented towards the presentation support 17, 18 of the test object 19, 20.

As for the auxiliary lens of the first embodiment constituting the movably mounted optical element of the corresponding imaging optical system (FIG. 1), the dihedron 114, 115, 114 ', 115', 114 ", 115" is mounted movably on a stroke segment 135, 136 whose direction makes the angle A1 with the optical axis 30, 31 of the front lens 12, 13. The two dihedrons 114, 115, 114 ', 115', 114 ", 115" are mounted mobile jointly. FIG. 9 shows, for each optical channel, three positions available for the dihedron on its stroke segment 135, 136 during a visual acuity test. A first position corresponds to the position of the dihedron 114, 115, for an intermediate vision examination. A second position corresponds to the position of the dihedron 114 ", 115", for a distance vision examination. A third position corresponds to the position of the dihedron 114 ', 115', for a near vision examination. The segment 135, 136 of the dihedral stroke is thus defined between two extreme positions provided for the dihedron, the position of the dihedron 114 ", 115 'for a near vision examination and the position of the dihedron 114", 115 "for an examination In particular, as in the first embodiment with the corresponding movable mounted optical element, when the dihedron is moved into position for far vision examination, the dihedron 114 ", 115" gives a first image. 55, 56 of the test object 19, which is positioned substantially at the optical focus of the corresponding front lens 12, 13. Similarly, when the dihedron, previously positioned for a far vision examination, is moved for examination of intermediate vision or near vision examination, it is moved on its segment 135, 136 of useful stroke making the angle A1 with the optical axis 30, 31 of the front lens 12, 13 being brought closer to this front lens 12, 13 and s 4D, 5D optical imaging system of the other optical channel. During this displacement of the dihedron, the first image 51, 52, 53, 54, 55, 56 of the test object 19, 20 by the dihedral is moved on a segment also making an angle A1 with the optical axis 30 , 31 of the front lens 12, 13, this segment being located outside the optical axis 30, 31, on the side of the optical imaging system 4D, 5D of the other optical channel. The length of the displacement segment of the first image 51, 52, 53, 54, 55, 56 of the test object 19, 20 by the dihedron 114, 115, 114 ', 115 ", 114", 115 "is the twice the length of the segment 135, 136 useful stroke of the dihedron 114, 115, 114 ', 115', 114 ", 115". Indeed, a displacement of the dihedron 114, 115, 114 ', 115', 114 ", 115 "causes a double displacement of the first image 51, 52, 53, 54, 55, 56 of the test object 19, 20 by this dihedron 114, 115, 114 ', 115', 114", 115 ".

As for the first embodiment, there is shown for each of the first images 51, 52, 53, 54, 55, 56 test objects 19, 20 by the dihedron associated with each of the three dihedral positions represented 114, 115, 114 ', 115', 114 ", 115", the three positions of each of the second images 60, 61, 62, 63, 64, 65, these second images being as in the first embodiment the conjugated images of the first images 51 , 52, 53, 54, 55, 56 test objects 19, 20 by the front lenses 12, 13. As in the first embodiment, each of these second images 60, 61, 62, 63, 64, 65 forms with the second image 60, 61, 62, 63, 64, 65 associated with the other optical channel the fused image 93, 94, 95 seen by the subject.

For each optical channel and each position of the dihedron 114, 115, 114 ', 115', 114 ", 115", the path of one of the optical beams 80, 81, 82, 83, 84, 85, resulting from the object 19, 20, participating in the formation of these images 51, 52, 53, 54, 55, 56, 60, 61, 62, 63, 64, 65 has also been shown.

As in the first embodiment, the second images 60, 61, 62, 63, 64, 65 and the resulting merged images 93, 94, 95 are located on the axis 34 in the plane of symmetry of the device.

Thus, when the dihedron 114, 115, 114 ', 115', 114 ", 115" travels all positions on its race segment 135, 136 between its position for a near vision examination and a distance vision examination, the merged image 93, 94, 95 corresponding to the two test objects 19, 20 is presented to the subject continuously at all presentation distances between the near vision distance and the far vision distance. FIG. 10 represents a sixth embodiment of the invention which is a variant of the first embodiment shown in FIGS. 1, 2 and 3. As in the first embodiment, there are two eyes 8, 9 of the subject positioned in front of the two pupil apertures 10, 11 and behind each pupil aperture 10, 11, on the one hand, the front lens 12, 13 fixed with respect to the frame 1 of the presentation device and centered on the corresponding pupil aperture 10, 11 and, on the other hand, an optical imaging system 4E, 5E. As in the first embodiment, each optical system 4E, 5E, that is to say each presentation support 17, 18, 17 ', 18', 17 ", 18" of the test object 19 , 20, and each front lens 12, 13 associated define an optical path for each eye independently of the other eye. Here, the optical system 4E, 5E presenting, for each corresponding eye 8, 9, the image 60, 61, 62, 63, 64, 65 of the test object 19, 20 linked to its presentation support 17, 18 , 17 ', 18', 17 ", 18", is different from that of the first embodiment in that it comprises only the presentation support 17, 18, 17 ', 18', 17 ", 18". Thus, here, the moving optical element of each imaging optical system 4E, 5E is the presentation medium 17, 18, 17 ', 18', 17 ", 18".

As for the auxiliary lens 14, 15 of the first embodiment constituting the movably mounted optical element of the corresponding imaging optical system (FIG. 1), the presentation support 17, 18, 17 ', 18', 17 ", 18 "is movably mounted on a race segment 235, 236 whose direction is the angle A1 with the optical axis of the front lens. The two presentation supports 17, 18, 17 ', 18', 17 ", 18" are movably mounted together.

In Figure 10, there is shown, for each optical channel, three positions available for the presentation medium on its race segment 235, 236 during a visual acuity test. A first position corresponds to the position of the presentation support 17, 18, for an intermediate vision examination. A second position corresponds to the position of the presentation support 17 ", 18", for a distance vision examination. A third position corresponds to the position of the presentation support 17 ', 18', for a close vision examination. In particular, the position of the presentation medium for a distance vision examination is substantially coincidental with the optical focus of the corresponding front lens 12, 13. Unlike the first embodiment, here the movably mounted optical element of the imaging optical system 4E, 5E, which is the presentation medium 17, 18, 17 ', 18', 17 ", 18" itself. same, generates directly, for example by backlighting the test object 19, 20, a first image of the test object, here confused with the test object 19, 20 linked to its presentation support 17, 18 , 17 ', 18', 17 ", 18" which then equates to the first image of the test object by the moving optical element of the first embodiment. In particular, as in the first embodiment with the corresponding movably mounted optical element, when the presentation medium is moved in position for far vision examination substantially at the focus of the front lens 12, 13, the presentation medium 17 ", 18" via the test object 19, 20 directly generates a first image of the test object 19, which is positioned substantially at the optical focus of the corresponding front lens 12, 13. Similarly, when the presentation medium, previously positioned for a far vision examination, is moved for an intermediate vision examination or near vision examination, the presentation medium is moved to its useful race segment 135, 136. making the angle A1 with the optical axis of the front lens 12, 13 being brought closer to this front lens 12, 13 and the optical imaging system 4E, 5E of the other optical channel. The first image generated directly by the test object 19, 20 linked to its presentation medium 17, 18, 17 ', 18', 17 ", 18" and thus spatially merged with the test object 19, 20 itself. same is imaged by the front lens 12, 13 corresponding to give the second image 60, 61, 62, 63, 64, 65 of this test object 19, 20 corresponding perceived by the eye 8, 9 corresponding. For each optical channel and each position of the presentation medium 17, 18, 17 ', 18', 17 ", 18", the path of one of the optical beams 80, 81, 82, 83, 84, 85, resulting from the Test object 19, 20, participating in the formation of these second images 60, 61, 62, 63, 64, 65 by means of the corresponding front lens 12, 13, has also been shown. Each of these second images 60, 61, 62, 63, 64, 65 is located on the axis 34 in the plane of symmetry of the device and, for each of the positions of the presentation medium 17, 18, 17 ', 18', 17 ", 18" forms with the second image 60, 61, 62, 63, 64, 65 of the optical system 4E, 5E of the other optical channel the fused image 93, 94, 95 presented to the subject at the desired distance . Thus, when the presentation medium 17, 18, 17 ', 18', 17 ", 18" travels all positions on its race segment 235, 236 between its position for a near vision examination and a vision test of away, the corresponding merged image 93, 94, 95 of the two test objects 19, 20 is presented to the subject continuously at all presentation distances between the near vision distance and the far vision distance.

As a variant for this sixth embodiment, it is also possible to provide that it is the image of the presentation medium by a fixed optical element, such as a 90 ° open dihedron or a lens, which moves on the segment moving the first image, not directly the presentation medium of the test object, as described above. The presentation medium is then located upstream of the fixed optical element (the fixed optical element is located between the front lens and the mobile presentation medium) and moves on a segment between a near vision position a position of distance vision, obliquely, angle A1, with respect to the portion of the optical axis possibly propagated from the front lens incident on the fixed optical element.

With regard to the fifth and sixth embodiments of FIGS. 9 and 10, it is provided to position each eye 8, 9 at the focal point of the corresponding front lens 12, 13 so that the fused image 93, 94, 95 presented to the subject has a constant angular dimension regardless of its presentation distance. Finally, to take into account the direction of the axis of view of the subject, the device, integral with its frame 1, can be rotatably mounted about an axis passing through the centers of the two pupil openings 10, 11.

Concerning the fifth and sixth embodiments which are variants of the first embodiment, it is possible to adapt them to produce from each a variant of the second, third and fourth embodiments. For this purpose, two folding mirrors are used between each pupil aperture and the corresponding mobile optical element by introducing the bias between the direction of movement of the optical element and the portion of the propagated optical axis of the front lens incident on the lens. movable optical element, inclining one of the mirrors relative to the other of the angle of the desired bias A1. The movable optical element, i.e. the dihedron for the fifth embodiment and the carrier for the sixth embodiment (in its variant using a fixed optical element to form a first image of the test object mobile presentation support) is then moved in a direction parallel to the portion, possibly propagated (for a variant of the third and fourth embodiment), the optical axis of the front lens, incident on the corresponding pupillary aperture. Alternatively, for all the embodiments of the invention described above, it is possible to use, instead of two separate screens, a single polarized screen for simultaneously displaying two identical or different test objects. According to another variant, the optical elements of each of the channels may be arranged so that the axis of movement of the merged images is always parallel to the optical axes (unfolded) of the front lenses or to the line of sight and off-center with respect to eyes. Finally, it is always possible to add folding mirrors in the path of the optical beams to adapt the different embodiments of the invention to the congestion constraints encountered.

Claims

1. A device for presentation to a subject a merged image (93, 94, 95; 93A, 94A, 95A; 93B, 94B ₁ 95B; 93C, 94C, 95C) perceived by the subject at various distances, comprising two pupillary apertures (10, 11) before which the eyes (8, 9) of the subject are intended to be positioned and, behind each pupillary aperture (10, 11):

a front lens (12, 13) having an optical axis (30, 31; 30A, 31A, 30B, 31B, 30C, 31C),

an optical system (4, 5, 4A, 5A, 4B, 5B, 4C, 5C, 4D, 5D, 4E, 5E, 4D, 5D, 4E, 5E) for imaging a test object (19, 20 ) comprising one or more optical elements including at least one presentation medium (17, 18) of the test object (19, 20), characterized in that each optical system (4, 5; 4A, 5A, 4B, 5B 4C, 5C, 4D, 5D, 4E, 5E) of a test object (19, 20) comprises a movably mounted optical element (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115") relative to the front lens (12, 13) in a path having at least one useful portion having, at any point, a direction of movement comprising firstly a first component in the direction of the optionally propagated portion (48A, 38A, 49B, 39B) of the optical axis (30, 31; 31A, 30B, 31B, 30C, 31C) of the front lens (12, 13) incident on the movably mounted optical element (14, 15, 14 ', 15', 14 ", 15"; 8, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115") and secondly, a second component transverse to the first component.

2. Presentation device according to the preceding claim, characterized in that the front lens (12, 13) is fixed relative to the pupil openings (10, 11).

3. Presentation device according to one of the preceding claims, characterized in that the movable mounted optical element (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18' , 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115") is movable in a plane passing through the optionally propagated portions (48A, 38A; 49B, 39B) of the optical axes (30, 31); 30A, 31A, 30B, 31B, 30C, 31C) of the two front lenses (12, 13) incident on the movably mounted optical elements (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115").

4. Presentation device according to one of the preceding claims, characterized in that, each lens (12, 13) having a focal length, each optical system (4, 5; 4A, 5A; 4B, 5B; 4C, 5C 4D, 5D; 4E, 5E) imparting a first image (51, 52, 53, 54, 55, 56; 51A, 52A, 53A, 54A, 55A, 56A; 51B, 52B, 53B, 54B; 55B, 56B; 51C, 52C, 53C, 54C, 55C, 56C) of the test object (19, 20), the path of each movably mounted optical element (14, 15, 14 ', 15', 14 " , 15 "; 17, 18, 17 ', 18', 17", 18 "; 114, 115, 114 ', 115', 114", 115 ") is such that, given the composition of the optical system (4 5, 4A, 5A, 4B, 5B, 4C, 5C, 4D, 5D, 4E, 5E), the first image (51, 52, 53, 54, 55, 56; 51A, 52A, 53A, 54A, 55A, 56A; 51B, 52B, 53B, 54B, 55B, 56B; 51C, 52C, 53C, 54C, 55C, 56C) by the optical system of the test object (19, 20) moves in translation in a direction making with the portion possibly propagated (48A, 38A 49B, 39B) of the optical axis (30, 31; 3OA, 31A; 3OB, 31 B; 3OC, 31C) of the front lens (12, 13) incident on the movably mounted optical element (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115"), a first non-zero angle (A1) defined by the formula:

TAN (A1) = P / (2. F'2), A1 denoting the first angle, P denoting the distance in meters between the optionally propagated portions of the optical axes (30, 31; 30A, 31A, 30B, 31B; , 31C), frontal lenses (12, 13), incident on the two pupil apertures (10, 11), and F'2 denoting the focal length of the front lens (12, 13) in meters.

5. Presentation device according to the preceding claim, characterized in that each front lens (12, 13) gives a second image (60, 61, 62, 63, 64, 65, 60A, 61A, 62A, 63A, 64A, 65A, 60B, 61B, 62B, 63B, 64B, 65B, 6OC, 61C, 62C, 63C, 64C, 65C) of the first image (51, 52, 53, 54, 55, 56; 51A, 52A, 53A, 54A, 55A, 56A, 51B, 52B, 53B, 54B, 55B, 56B, 51C, 52C, 53C, 54C, 55C, 56C) of the test object (19, 20), each second image (60 , 61, 62, 63, 64, 65, 6OA, 61A, 62A, 63A, 64A ₁ 65A, 6OB, 61 B, 62B, 63B, 64B, 65B; 6oC, 61 C, 62C, 63C, 64C, 65C) being presented on the corresponding eye (8, 9) of the subject.

6. Presentation device according to the preceding claim, characterized in that, for all the positions taken by the two movable mounted optical elements (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ' , 18 ', 17 ", 18"; 114, 115, 114', 115 ', 114 ", 115"), the first images (51, 52, 53, 54, 55, 56; 51A, 52A, 53A, 54A; 55A, 56A, 51B, 52B, 53B, 54B, 55B, 56B, 51C, 52C, 53C, 54C, 55C, 56C) of the two test objects (19, 20) by the optical imaging systems (4, 5; 4A, 5A, 4B, 5B, 4C, 5C, 4D, 5D, 4E, 5E) are arranged such that so that the second two images (60, 61, 62, 63, 64, 65; 60A, 61A, 62A, 63A, 64A, 65A; 60B, 61B, 62B, 63B, 64B, 65B; 6OC, 61C, 62C; , 63C, 64C, 65C) by the front lenses (12, 13) of the first two images (51, 52, 53, 54, 55, 56; 51A, 52A, 53A, 54A, 55A, 56A, 51B, 52B). , 53B, 54B, 55B, 56B; 51C, 52C, 53C, 54C, 55C, 56C) of the two test objects (19, 20) are located substantially in the same plane and centered on one another to form the fused image (93, 94, 95, 93A, 94A, 95A, 93B, 94B, 95B, 93C, 94C, 95C) presented to the subject.

7. Presentation device according to the preceding claim, characterized in that for all the positions taken by the two movable mounted optical elements (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ' , 18 ', 17 ", 18"; 114, 115, 114', 115 ', 114 ", 115"), there is a plane of symmetry between the two optical systems (4, 5; 4A, 5A; 4B ₁ 5B ; ₁ 4C 5C, 4D, 5D, 4E, 5E).

8. Presentation device according to the preceding claim, characterized in that the two optical systems (4, 5; 4A, 5A; 4B, 5B; 4C, 5C; 4D, 5D; 4E, 5E) are arranged so that, for all positions taken by the two movably mounted optical elements (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 '; , 115 ', 114 ", 115"), the center of the fused image (93, 94, 95; 93A, 94A, 95A; 93B, 94B, 95B; 93C, 94C, 95C) presented to the subject is located on a axis (34) parallel to the optionally propagated portion (48A, 38A; 49B, 39B) of the optical axis (30, 31; 30A, 31A; 30B, 31B, 30C, 31C) of the front lens (12, 13) incident on the eye (8, 9) and in the plane of symmetry between the two optical systems (4, 5; 4A, 5A; 4B, 5B; 4C ₁ 5C; 4D, 5D; 4E, 5E).

9. Presentation device according to one of the preceding claims, characterized in that, the presentation supports (17, 18) of the two optical systems (4, 5; 4A, 5A; 4B, 5B; 4C, 5C; 4D, 5D; 4E, 5E) are driven by an electronic and / or computer system to selectively display two identical, partially different or totally different images.

10. Presentation device according to one of the preceding claims, characterized in that the movably mounted optical element (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115") is movable in translation in a direction (35, 36; 135, 136; 235, 236), with the optionally propagated portion ( 48A, 38A, 49B, 39B) of the optical axis (30, 31; 3OA, 31A; 3OB, 31 B; 30C, 31C) of the front lens incident on the movably mounted optical element (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115"), an angle equal to the first angle (A1).

11. Presentation device according to one of the preceding claims, characterized in that the two movable mounted optical elements (14, 15, 14 ',

15 ', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18"; 114, 115, 114 ', 115', 114 ", 115") are mounted and / or controlled to move together in translation.

12. Presentation device according to one of the preceding claims, characterized in that the two movable mounted optical elements (14, 15, 14 ', 15', 14 ", 15"; 17, 18, 17 ', 18', 17 ", 18", 114, 115, 114 ', 115', 114 ", 115") are mounted and / or controlled to move in the same direction.

13. Presentation device according to one of the preceding claims, characterized in that the device comprises, between the pupillary openings (10, 11) and the front lenses (12, 13), a mobile mirror (77) in translation and in translation. rotation so that the optical axis (30, 31; 30A, 31A, 30B, 31B, 30C, 31C) of each front lens (12, 13) propagated by said movable mirror (77) passes through the pupillary opening ( 10, 11) corresponding substantially at its center.

14. Presentation device according to one of claims 1 to 13, characterized in that the movably mounted optical element (14, 15, 14 ', 15', 14 ", 15") comprises an auxiliary lens (14, 15). , 14 ', 15', 14 ", 15") having an optical axis (32, 33) positioned between the front lens (12, 13) and the display medium of the test object (19, 20).

15. Presentation device according to one of claims 1 to 13, characterized in that the movably mounted optical element (17, 18, 17 ', 18', 17 ", 18") comprises said presentation support (17, 18, 17 ', 18', 17 ", 18") of the test object (19, 20).

16. Presentation device according to the preceding claim, characterized in that the optical imaging system (4E, 5E) is constituted by said presentation medium (17, 18, 17 ', 18', 17 ", 18").

17. Presentation device according to one of claims 1 to 13, characterized in that the movably mounted optical element (114, 115, 114 ', 115', 114 ", 115") comprises a dihedron open at 90 ° ( 114, 115, 114 ', 115', 114 ", 115"), positioned between the front lens (12, 13) and the display medium (17, 18) of the test object (19, 20).