Optometry device and associated method for testing an individual's eyes

Abstract

The invention relates to an optometry device for testing an individual's eye, the optometry device comprising a refractive test unit (10) having an optical system for providing different vision correction powers close to the individual's eye, and a display unit (20), the refractive test unit being adapted to produce a visual test image for the individual's eye, the visual test image being visible through an exit aperture (10A) of the test unit of the optometry device, the display unit comprising: a screen (21) adapted to display a test picture for producing the visual test image; and at least one optical element (30) having an optical power. According to the invention, the optical element exhibits an active state and an inactive state, in which the optical element exhibits a non-zero refractive power placed on the optical path of light emitted by the screen and leaving the device through the exit aperture, and in which the optical element introduces no refractive power on the optical path, in order to produce the visual test image at a variable distance from the exit aperture.

Description

Technical Field

[0001] The present invention relates to an optometry device and an associated method for testing the eyes of an individual. Background Art

[0002] Document EP 3298952 describes such a device. In this device, the screen is fixed. A fixed lens is positioned in the optical path of the picture displayed by the screen. The position of the individual's eye is in the focal plane of the lens.

[0003] The area of ​​the resulting vision test display that can be seen by an individual eye is quite narrow. Therefore, alignment between the vision test display and the eye is critical.

[0004] The optical distance between the device's screen and the aperture exit can be changed by moving the mirror closer to or further away from the screen.

[0005] This arrangement allows the optical distance to be varied only within a reduced range and only allows visual test displays of narrow angular width to be produced. Summary of the invention

[0006] It is therefore an object of the present invention to provide a device with a wider measurement range, thereby providing a more realistic refractive measurement adapted to the wearer.

[0007] According to the present invention, the above objects are achieved by providing an optometry device for testing an individual's eyes, the optometry device comprising a refractive test unit having an optical system for providing different vision correction powers close to the individual's eyes, and a display unit adapted to generate a visual test image for the individual's eyes, the visual test image being visible through an exit aperture of the test unit of the optometry device, the display unit comprising:

[0008] - a screen adapted to display a test picture used to generate said visual test image; and

[0009] - at least one optical element having an optical power,

[0010] The optical element assumes an active state in which it exhibits a non-zero optical power placed on an optical path of light emitted by the screen and exiting the device through the exit aperture and an inactive state in which the optical element introduces no optical power on the optical path so as to produce the visual test image at a variable distance from the exit aperture.

[0011] In particular, in an embodiment of the invention, the optical element is movable between an active position in which it is placed in the optical path of light emitted by the screen and leaving the device through the exit aperture, and a retracted position in which the optical element remains out of the optical path so as to produce the visual test image at a variable distance from the exit aperture.

[0012] In this embodiment of the invention, the optical element is movable between an active position corresponding to an active state and a retracted position corresponding to an inactive state by physical displacement of the optical element.

[0013] In another embodiment of the present invention, the optical element is preferably fixed and immovable. The optical element remains placed in the optical path of the light and has a variable refractive power that can be adjusted between a non-zero value corresponding to the active state and a zero value corresponding to the inactive state.

[0014] In other embodiments, a power change of the optical element is performed between an active state, in which a non-zero optical power is provided by the optical element placed in the optical path of light emitted by the screen and leaving the device through the exit aperture, and an inactive state, in which the power of the optical element is set to zero. Thus, in the inactive state, the optical element acts as if it remains out of the optical path. However, the optical element remains placed in the optical path of the light in both the active and inactive states of this optical element.

[0015] Thus, the distance between the generated visual test image and the exit aperture of the device can be modified by moving the lens between these two positions or by modifying its refractive power and thus test the individual's vision under different visual conditions, for example under distance conditions at infinity or under intermediate or near vision conditions.

[0016] Furthermore, the optical element can thus be physically removed from the optical path of the light by being displaced to a retracted position, or optically removed from the optical path by setting its refractive power to zero, for displaying the vision test image at a near viewing distance from the individual's eye. This allows the display of a vision test image with a larger image size under near viewing conditions. The larger size image makes it possible to display text for reading, and the image can be more easily aligned to the center of the exit aperture of the device.

[0017] Thanks to the optometry device according to the invention, it is thus possible to provide a visual test image at at least two different optical distances from the exit aperture, thereby providing a visual test image for testing the visual acuity of a subject under at least two different visual conditions, while reducing the overall size of the optometry device. The different visual conditions here correspond to two different viewing distances of the visual test image.

[0018] In embodiments where the optical element can be physically removed from the optical path, the fact that the optical element can be moved in and out of the optical path allows for a reduction in the overall size of the optometry device required to provide visual test images for testing a subject's vision under at least two different vision conditions, such as near and distance vision conditions.

[0019] The reduction in size of optometry devices makes them easier to store and use by eye care professionals.

[0020] Furthermore, the field of view angle remains wide enough under all visual conditions to enable display of realistic visual test images, or at least more realistic visual test images than in the prior art. More realistic means that the viewing conditions of the images (such as optical distance and field of view angle) are close to the viewing conditions in real life.

[0021] In embodiments where the optical element is optically removable from the optical path, by using an optical element with a variable power, the variable power of the optical element can preferably be continuously tuned or adjusted within a range of optical power values. Thus, an image displayed at a variable distance can be presented to the subject, the distance being continuously adjustable within a corresponding range of distances with a seamless transition between different distances.

[0022] Another advantage of the embodiment with a variable power optical element is that it allows the use of a fixed (non-movable) screen positioned as close as possible to the optical element, with or without one or several reflecting surfaces for bending the optical path, to define an optometry device that is as compact as possible.

[0023] Further non-limiting features of the device according to the invention:

[0024] - the variable distance is between the distance for far vision and the distance for near or intermediate vision;

[0025] - the optical element is an optical lens;

[0026] - the optical element is movable in rotation and / or translation between the active position and the retracted position;

[0027] - the screen is movable in translation along a reference axis between two positions corresponding to different distances between the generated visual test image and the exit aperture;

[0028] - the screen is movable in translation in two perpendicular directions in order to center the screen relative to the optical axis of the optical element;

[0029] - the optical element is an optical lens in its active position, the relative position of the screen and the optical lens being adjustable so as to position the screen at a distance from the optical element equal to the back focal length of the optical lens measured along the optical axis of the optical lens;

[0030] - the visual test image comprises a test picture displayed by the screen when not affected by the optical element, with or without reflection from the reflective surface of the device, or an image of the test picture projected by the optical element, with or without reflection from the reflective surface of the device;

[0031] - the relative positions of the screen, the optical element and the exit aperture are adapted to be varied so as to cause the distance between the visual test image and the exit aperture to vary continuously within a range of one or several optical distances between infinity and near visual distance;

[0032] - at least one reflective surface is arranged in said device so as to direct said optical path of light emitted by said screen towards said exit aperture;

[0033] - the at least one reflective surface is capable of translation and / or rotation between at least two positions;

[0034] - the at least one reflecting surface is moved in translation and / or rotation to a position in which, when the optical element is in the inactive state, i.e. when it remains out of the optical path or when its optical power is set to zero, the at least one reflecting surface directs the light emitted by the screen towards the exit aperture;

[0035] - the angular size of the visual test image measured as seen from the exit aperture is between 5° and 25°;

[0036] - the optometry device comprises a further screen suitable for displaying a further picture, the image of which is superimposed on the vision test image;

[0037] - the screen is one of the following: LCD screen, TFT screen, LED or OLED screen, serigraphy with backlight screen, display light projection screen with micro video projector.

[0038] More precisely, the angular size of the measured visual test image as seen from the exit aperture along the horizontal axis is preferably between 5° and 15°.

[0039] The invention also proposes a method for testing an individual's eyes using an optometry device for testing an individual's eyes, the optometry device comprising a refractive test unit having an optical system for providing different vision correction powers close to the individual's eyes, and a display unit adapted to generate a visual test image for the individual's eyes, the visual test image being visible through an exit aperture of the test unit of the optometry device, the display unit comprising:

[0040] - a screen adapted to display a test picture used to generate said visual test image; and

[0041] - at least one optical element having an optical power,

[0042] the optical element assuming an active state in which the optical element exhibits a non-zero optical power placed in the optical path of light emitted by the screen and exiting the device through the exit aperture and an inactive state in which the optical element introduces no optical power in the optical path so as to produce the visual test image at a variable distance from the exit aperture;

[0043] This method includes:

[0044] - generating the visual test image for the individual's eye based on the test picture, the visual test image being visible through the exit aperture of the optometry device, the individual's eye being able to view the test visual image through the exit aperture,

[0045] - varying the variable distance between the visual test image and the exit aperture by varying the state of the optical element between the active state and the inactive state,

[0046] - evaluating the visual perception of at least one eye of the individual of the vision test image at different distances between the vision test image and the exit aperture. DETAILED DESCRIPTION

[0047] The following description with reference to the accompanying drawings will make clear what the invention comprises and how it is implemented. The invention is not limited to the (multiple) embodiments shown in the accompanying drawings. Accordingly, it should be understood that where features mentioned in the claims are followed by reference numerals, these reference numerals are included only for the purpose of enhancing the intelligibility of the claims and are in no way limiting the scope of the claims.

[0048] In the attached picture:

[0049] - Figures 1 to 3 Concerning the first embodiment of the present invention,

[0050] - Figures 4 to 6 Concerning the second embodiment of the present invention,

[0051] - Figure 7 and Figure 8 Concerning the third embodiment of the present invention,

[0052] - Fig. 9 This invention relates to a fourth embodiment.

[0053] In the following description, the same or corresponding elements in each embodiment will be denoted by the same reference numerals and will not be described in detail each time.

[0054] The optical path of light is represented by a dotted line, and the direction of propagation is represented by an arrow.

[0055] The mobility of the optical components is indicated by the double arrow placed alongside.

[0056] The invention relates to an optometry device 100; 200; 300; 400 for testing the eyes of an individual. Four embodiments of the optometry device 100; 200; 300; 400 according to the invention are shown in the drawings.

[0057] This optometry device 100; 200; 300; 400 according to the invention comprises a refractive test unit 10 having an optical system for providing different vision correction powers close to an individual's eyes and a display unit 20 adapted to produce a visual test image for the individual's eyes, the visual test image being visible through an exit aperture 10A of the test unit 10 of the optometry device 100; 200; 300; 400.

[0058] Here, the refraction testing unit 10 is separated from the display unit 20 .

[0059] The refractive test unit 10 is interposed between the display unit 20 and the individual's eye. The refractive test unit is movable so that its position can be adjusted in front of the individual's eye. The display unit 20 is generally fixed. The refractive test unit 10 is movable relative to the display unit 20 so that their relative positions can be adjusted.

[0060] The refractive testing unit 10 may be of any type known to the person skilled in the art. Such a refractive testing unit 10 is generally referred to as a "phoropter". It is adapted to provide a variable optical correction for the eye of an individual looking through it.

[0061] In particular, it may comprise a classic optical system for presenting in front of one or each eye of an individual different lenses with different optical powers, or no lens or a blank lens with no optical power.

[0062] The lenses with different powers are interchanged manually or preferably by motorized command (not shown). These different powers are the vision correction powers for the individual eyes placed nearby.

[0063] The refractive testing unit 10 preferably comprises an optical system having one or more lenses with adjustable focal power (such as liquid lenses).

[0064] The refractive testing unit 10 is, for example, a vision compensation system as described in document WO 2015 / 155 458.

[0065] The refraction testing unit 10 includes, for example, a lens with variable spherical power.

[0066] The variable spherical power lens has, for example, a deformable surface. The shape of this surface (particularly the radius of curvature of this surface, and therefore the spherical power provided by the lens) can be controlled by moving a mechanical part (e.g. a ring), which can be driven by a motor of the refraction test unit 10.

[0067] The refractive testing unit may also include a pair of independently rotatable lenses, each lens having a cylindrical power.

[0068] Each of them can be rotated by the action of other motors of the refractive testing unit 10 .

[0069] As explained in document WO 2015 / 107 303, the motor is controlled by a control unit such that the combination of the variable spherical power lens and the two cylindrical power lenses provides the desired spherical correction and the desired cylindrical correction for the individual eye.

[0070] The various components of the refractive testing unit 10 (such as the variable spherical lens, cylindrical lens, motor and control unit) are enclosed in Figure 7 and Figure 8 The housing 12 is shown. This housing 12 is different from the housing 2 which encloses the display unit 20. The refraction test unit 10 and the display unit 20 are accommodated in separate housings.

[0071] As a variant, the refraction test unit and the display test unit can be accommodated in a common housing. However, generally speaking, they are located in different spatial areas of the vision measurement device. These different spatial areas do not overlap.

[0072] In this embodiment, the optometry device comprises two vision compensation systems as described above, each of which is located in front of one eye of the individual. The adjustable focal power of these vision compensation systems is the vision correction focal power for the eye of the individual placed nearby.

[0073] The exit aperture 10A of the optometry device 100; 200; 300; 400 corresponds to the opening of the refractive test unit where an individual can position their eye to see through the optical system (i.e., phoropter or vision compensation system) of the refractive test unit 10. This exit aperture is centered on the optical axis of the lens or lenses of the refractive test unit.

[0074] However, the exit aperture is typically off-center relative to the optical axis of the optical elements of the display unit, as will be described in more detail later.

[0075] The refractive testing unit 10 optionally includes one or more elements designed to receive the head of an individual and hold it in a predetermined position relative to the refractive testing unit 10. This element may, for example, receive the forehead of an individual, such as the element 11 shown in the figure. Alternatively or in addition, the refractive testing unit may include an element for receiving the chin of an individual.

[0076] Such a refractive testing unit 10 is well known and will not be described in detail here.

[0077] The light beam leaving the display unit 20 is directed towards the individual's eye by one or more lenses of the test unit 10. The individual's eye is placed against the exit aperture 10A of the test unit through which the light beam emitted by the screen 21 leaves the optometry device 100;200;300;400.

[0078] The display unit 20 includes:

[0079] - a screen 21 suitable for displaying a test picture used to generate said visual test image; and

[0080] - At least one optical element 30 having optical power.

[0081] According to the present invention, the optical element 30 presents an active state and an inactive state, in which the optical element exhibits a non-zero refractive power placed on the optical path of light emitted by the screen 21 and leaving the device 100; 200; 300; 400 through the exit aperture 10, and in which the optical element does not introduce a refractive power on the optical path so as to produce a visual test image at a variable distance from the exit aperture 10A.

[0082] In the embodiment shown in the figures, the optical element 30 is movable between an active position in which it is placed in the optical path of light emitted by the screen and leaving the device through the exit aperture, and a retracted position in which the optical element remains outside the optical path so as to produce a visual test image at a variable distance from the exit aperture 10A.

[0083] The optical path is the path taken by a light beam emitted by the screen 21 at the center of the image displayed by the screen 21 when traversing the display unit 20 to the exit aperture 10A of the refractive testing unit 10 .

[0084] The visual test image includes a test picture displayed by the screen 21 when it is not affected by the optical element 30, and reflected or not reflected by the reflective surface of the device 100; 200; 300; 400, or an image of the test picture projected by the optical element 30, and reflected or not reflected by the reflective surface of the device.

[0085] Projection means that the image of the test picture is formed by an optical element (such as a lens). The image of the test picture formed by the lens is a virtual image of the test picture.

[0086] When the optical element is in its retracted position, the vision test image comprises a test picture displayed by the screen 21. The distance between the vision test image and the exit aperture of the refractive test unit 10 is the distance measured between the exit aperture and the screen 21 along the optical path.

[0087] When the optical element is in its active position, the visual test image comprises an image (or projection) of the test picture displayed by the screen 21 as seen through the optical element 30. This image is usually a virtual image. It is located at a certain optical position. This optical position can be, for example, at infinity.

[0088] The distance between the vision test image and the exit aperture of the refractive test unit 10 is then the distance between the exit aperture and the optical position of the vision test image. The optical element 30 may comprise, for example, an optical lens 31, as in the example described here.

[0089] In the case where the optical element 30 includes an optical lens 31 , the image of the test picture is the image of the test picture viewed through the lens 31 .

[0090] In the example described here, the optical element 30 comprises a single lens 31. This lens 31 can be a lens with fixed or variable focal power. Here, this lens is the only optical lens included in the display unit 20. Therefore, this lens is the only optical lens enclosed in the housing 2.

[0091] According to the invention, the distance between the visual test image and the exit aperture varies at least between a far distance and different near or intermediate distances. The far distance is typically between infinity and 65-70 cm. The intermediate distance is typically between 65-70 cm and 40 cm. The near distance is typically between 40 cm and 33 cm.

[0092] Preferably, the relative positions of the screen 21, the optical element 30 and the exit aperture 10A are adapted to be varied so that the distance between the generated vision test image and the exit aperture varies continuously over a range of one or several optical distances between infinity and near viewing distance.

[0093] In another embodiment of the optometry device according to the invention, not shown in the figures, said optical element remains placed in said optical path of the light and has a variable refractive power which is variable between a non-zero value corresponding to said active state and a zero value corresponding to said inactive state.

[0094] In other embodiments, the optical element is preferably fixed and non-movable.

[0095] Apart from these differences, the optometry apparatus according to this embodiment is the same as the embodiment described in detail below.

[0096] Of course, embodiments of the optometry device that can be used in two different ways are contemplated if the optical element has a variable power and is still movable between an active position in which the optical path of light passes through the optical element and a retracted position in which the optical element is outside the optical path of light. In this case, the active state and the inactive state of the optical element can be obtained by physically moving the optical element or optically changing the power of the optical element.

[0097] Minimum configuration of vision measurement device:

[0098] In a minimal configuration, the visual test images can be generated at only two different distances:

[0099] 1) The visual test image may be generated at a first and smallest optical distance corresponding to the optical distance between the exit aperture and the screen, defined when the optical element adopts its retracted position or inactive state, the screen 21 being directly viewed by the individual. In this configuration, no optical components or only one or several reflective surfaces are placed in the optical path between the exit aperture and the screen. The screen is directly viewed by the subject, unaffected by the optical element being in its retracted position or inactive state. This first distance preferably corresponds to the near or intermediate vision distance ( Figure 8 ).

[0100] 2) When the optical element is placed in an active state in the optical path between the exit aperture and the screen, the visual test image can also be generated at a second and maximum optical distance corresponding to the optical distance between the exit aperture and the virtual image of the screen. The subject observes the screen indirectly through the optical element, and the subject observes the virtual image of the screen. This second distance preferably corresponds to the telescopic distance. The optical element is, for example, positioned in an active state in the optical path so that the exit aperture is optically conjugate with the screen.

[0101] In this minimal configuration, it is conceivable that the optometry device according to the invention comprises only a fixed screen and that the optical element is movable between a retracted position and an active position in order to produce a visual test image at two different optical distances. The optical element may have a fixed focal power. It is also conceivable that the optometry device according to the invention comprises only a fixed screen and that the optical element is of the tunable type, i.e. has a tunable optical power that varies between a zero value (inactive state) and a non-zero value (active state). In this case, the optical element may have a variable focal power and always remain along the optical path, only its optical power varying in the different states.

[0102] Minimum configuration for bending the optical axis using a reflective surface

[0103] The need to give the optometry device a compact configuration can be raised. However, the screen 21 and the optical element 30 (when it is a lens) need to be separated by an optical distance close to the focal length of the lens to be able to provide distance vision of the screen 21, which, as is known, can be set to several tens of centimeters (80-100 cm in the example).

[0104] One or several reflecting surfaces may be used in order to bend the path of the light and to limit the size of the display unit.

[0105] Such reflective surfaces may be arranged such that both the screen 21 and the optical element 30 may be positioned closest to each other (eg less than 20 cm or preferably less than 10 cm from each other).

[0106] In this way, the optical distance between the screen 21 and the optical element 30 can be set to the focal length closest to the optical element 30, and the virtual image given from the screen can be observed under the condition of close to infinity (4 meters or 6 meters, or even farther). The two observation distances are obtained when the optical element is along the optical path (the farthest observation distance) and outside the optical path (the shortest observation distance), respectively.

[0107] Enhanced configuration with more than 2 distances

[0108] In the above configurations, to also provide a minimum near viewing distance, at least one reflective surface may be used to short-circuit a portion of the optical path, thereby allowing long distance viewing when the optical element is in an inactive or retracted position.

[0109] To this end, in the embodiment shown in the drawings, the screen 21 and the optical element 30 are arranged so that their optical axes and the screen axis are perpendicular to each other (considering that the screen 21 generates a light beam along the screen axis S which is perpendicular to the mid-plane of the screen 21). In addition, the first reflecting surface is movably mounted between a far / intermediate vision position, in which the first reflecting surface directs the light coming from the screen 21 to the continuous reflecting surface, and a near vision position, in which the first reflecting surface directs the light coming from the screen 21 towards the exit aperture instead of the optical element in its first active position.

[0110] Preferably, the distance between the generated visual test image and the exit aperture can adopt more than 2, preferably more than 3, more than 4, more than 5 values ​​between infinity and near distance. To this end, the optical element can have a variable focus and / or the screen can be continuously or stepwise translationally movable along the optical path of the light emitted by it. These different distances can also be provided by providing one or more movable reflective surfaces. Each reflective surface can be translationally or rotationally movable. Each reflective surface can be movable into and out of the optical path of the light, or can be movable along the optical path of the light.

[0111] In such an embodiment, the optometry device may not include reflective surfaces 41, 42, 43 intended to bend the optical path between the screen and the optical element, the screen axis and the optical axis of the lens are aligned, and the screen 21 is defined to move in translation along this common axis to define several far / intermediate distances when the optical element is active and several near distances when the optical element is inactive.

[0112] Preferably, the distance between the generated visual test image and the exit aperture may take any value between infinity and the near distance. To this end, the optical element may have a variable focal power, and / or the screen and / or one or more reflective surfaces may be movable, in particular translationally movable along the optical path of the light emitted thereby.

[0113] In the different embodiments shown in the figures, the optometry device 100; 200; 300; 400 according to the invention comprises a housing 2 adapted to be placed, for example, on a table or to be mounted on a stand for placement on a table or on the floor.

[0114] Here, the housing 2 encloses a display unit 20. The test unit 10 is placed outside this housing 2 and is preferably mounted on the housing 2.

[0115] Here, the display unit 20 includes an acuity module 20A and a scene module 20B.

[0116] Acuity module 20A includes screen 21 and optical element 30 .

[0117] The screen 21 is, for example, one of the following: an LED or OLED screen, a screen with a screen backlight, a display light projection screen with a micro video projector, an LCD screen or a TFT screen. The screen 21 generates a light beam along a screen axis S perpendicular to its plane. This light beam is intended to generate an image of an object, such as an optotype, for an individual using an optometry device.

[0118] In the example described here, the screen 21 is flat.

[0119] The test picture displayed by the screen 21 is, for example, an optotype. As known to those skilled in the art, other types of pictures suitable for testing the vision of an individual may be used. Therefore, the acuity module 10 is designed to generate a visual test image (representing an object, such as an optotype) for an individual's eyes.

[0120] Here, the optical element 30 comprises an optical lens 31. Here, the lens 31 is an achromatic lens, for example, with an effective focal length between 70 centimeters and one meter, preferably about 80 centimeters. The lens comprises, for example, an achromatic doublet lens. It can also be, for example, a simple lens. In the case of using a simple lens, this simple lens preferably has an effective focal length of more than 80 centimeters, for example 82 centimeters, to limit chromatic aberrations.

[0121] In the example described here, the lens 31 can be convex. In this case, the focal length of the lens and its relative position to the screen 21 and the exit aperture can be determined so that the screen 21 is located at a distance lower than or at most equal to the focal length of the lens. In this way, when the lens 31 is in an active state, that is, along the optical path and with a non-zero optical power, it provides a virtual image of a larger size from the screen to the subject viewing the exit aperture (magnifying glass effect). Likewise, when the lens is in an inactive state, for example in a retracted position, this virtual image is observed at a virtual distance from the exit aperture that is greater than the optical distance existing between the exit aperture and the screen 21.

[0122] In the example described here, when the lens 31 is in an inactive state, i.e., out of the optical path or having an optical power equal to zero, the minimum optical distance between the exit aperture and the screen 21 can be set to the near distance, for example, 40 cm or 33 cm (see Figure 8 ).

[0123] The effective focal length of the lens 31 corresponds to the optical power of the lens itself. It is measured between the focal plane of the lens and a theoretical plane placed inside the lens. Since it is not easy to position the optical element relative to the lens using the effective focal length, and the position of the theoretical plane is difficult to determine accurately, the back focal length can be used.

[0124] The back focal length of the lens 31 is measured along the optical axis L of the lens 31 between the last diopter vertex of the lens and the focal plane of the lens, that is, from the back surface of the lens to the focal plane of the lens 31 .

[0125] As explained later, the optical axis L is bent here by using a reflecting surface such as a mirror.

[0126] Alternatively, in the case of small screens, such as 1" micro screens with high resolution HD or full HD, lenses with a small effective focal length (e.g. 20 cm) can be used. This can be used to obtain smaller devices.

[0127] Preferably, the optical element 30 and the screen 21 are arranged relative to each other so that there is at least one relative position of the optical lens 31 and the screen 21, wherein the screen 21 is placed at a distance from the optical lens 31 equal to the back focal length of the lens 31.

[0128] Therefore, in the telescopic configuration, when the lens 31 is placed on the optical path of the light, the relative position of the screen 21 and the lens 31 can be adjusted so that the screen 21 is located at the back focal length from the lens 31.

[0129] In this way, the vision test image generated by the display module 20 can be placed at infinity relative to the exit aperture and thus relative to the individual's eye. The distance between the generated vision test image and the exit aperture is then set to infinity.

[0130] According to an embodiment of the present invention, the optical element 30 is movable between at least the first active position, in which the optical path of the light beam emitted by the screen 21 and propagating to the individual's eye passes through the optical element 30, and the second retracted position, in which the optical path of the light beam avoids the optical element 30. In the case where the optical element 30 is a lens 31, the light beam passes through the lens 31 when it is in the active position but does not pass through the optical lens 31 when it is in the retracted position.

[0131] Thus, the acuity module is adapted to generate images of objects at variable distances for an individual eye.

[0132] In fact, here, in all the embodiments described, the optical element 30 comprises a lens 31. The lens is fixed on a support 32 pivotally mounted on a part of the housing 2 of the device 100;200;300;400.

[0133] In a first angular position of the support 32 of the lens 31, for example Figure 1 , Figure 4 , Figure 7 and Fig. 9 As shown in FIG. 3 , the support 32 is parallel to the optical path of the light and makes the lens 31 straddle this optical path: the light emitted by the screen then passes through the lens 31. The optical path of the light follows the optical axis L of the lens 31 at least partially.

[0134] In the second angular position of the support 32 of the lens 31, for example Figure 2 , Figure 3 , Figure 5 , Figure 6 and Figure 8 As shown in FIG. 3 , the support 32 is inclined relative to the optical path of the light and places the lens 31 outside this optical path: the light beam emitted by the screen 21 then avoids passing through the lens 31 .

[0135] Of course, the geometry of the support 32 allows this support 32 to remain out of the optical path in all its angular positions.

[0136] The support 32 is pivotally mounted so as to be able to pivot about a rotation axis X1 perpendicular to the optical path of the light beam at the location of the lens 31 when it is placed in the first angular position. In other words, the rotation axis of the lens 31 is perpendicular to the optical axis L of the lens 31 .

[0137] In the example described here, the lens 31 has a rectangular shape. The lens is inserted inside a frame around its edge. Two triangular branches link the frame to the pivot axis of the lens 31. A rectangular ring holds the lens 31 in place in the frame. This ring is mounted thanks to screws on the side of the frame facing the pivot axis.

[0138] In all the embodiments described here, the screen 21 is movable in translation in two perpendicular directions in order to center the screen 21 relative to the other optical components of the optometric device 100; 200; 300; 400, in particular relative to the optical axis L of the lens 31 in its active position or state.

[0139] To this end, adjustment means are provided for centering the screen 21 relative to the optical axis L or the optical center of the lens 31 when it is in its active position or state. In other words, the adjustment means allow the screen 21 to be optically centered on the optical axis L of the lens 31. These adjustment means comprise an adjustable support 23 for the screen 21. This adjustable support 23 can be moved in a plane parallel to the screen 21. In practice, this plane is perpendicular to the screen axis S. This adjustment is made during manufacture. Optionally, this adjustment can be repeated during the life of the device. The movement of the screen in this plane can be achieved manually, for example with a micrometer screw, or automatically by a motorized system controlled by an electronic unit (not shown in the figures).

[0140] A motorized active re-centering of the screen 21 may be achieved. Alternatively, the screen may be centered only for a predetermined fixed position.

[0141] Thanks to the adjustment means, the screen 21 is accurately centered relative to the optical center of the lens 31. This centering step ensures that the light emitted in the center of the screen leaves the optometry device at the center of the exit aperture.

[0142] The size of the mirror and lens is chosen to be wide enough to enable easy centering of the visual test image. The minimum distance between the screen, mirror and lens may also be enlarged to facilitate this centering.

[0143] Furthermore, in addition to this physical centering of the screen, a digital centering correction may be applied to the test picture displayed by the screen 21 in order to compensate for predetermined deviations of the screen or other optical components, in particular reflective surfaces in a predetermined configuration of the device. Such a digital centering correction consists in moving the test picture on the screen so that it appears centered relative to the exit aperture. The electronic unit may be programmed to implement this correction of the test picture.

[0144] Physical and digital centering adjustments are intended to keep the visual test image visible to the individual eye through the device's exit aperture, centered with respect to all relative positions of the device's optical components.

[0145] Thanks to the adjustment device, the image displayed by the screen can be centered exactly with respect to the optical axis L of the lens 31 .

[0146] When the screen 31 and / or the image displayed by the screen is exactly centered on the optical axis L of the lens 31, the screen axis considered to be at the center of the displayed image, the optical axis L of the lens 31 and the optical path of the light coincide inside the display unit.

[0147] Between the display unit 20 and the test unit 10 , the optical path of the light may deviate from the optical axis L of the lens 31 , because the test unit 10 and thus the exit aperture 10A is placed in front of the individual's eye and may therefore be moved relative to the optical axis L of the lens 31 .

[0148] As described in more detail later, in some embodiments the screen 21 may also be movable, in particular along the screen axis S, in order to further vary the distance between the visual test image and the exit aperture.

[0149] In such an embodiment (see the first and second embodiments), the screen 21 of the acuity module 20A is movable in translation along a reference axis between two positions corresponding to different distances between the visual test image and the exit aperture. This reference axis here coincides with or is parallel to the screen axis S.

[0150] In an embodiment described in more detail below, the acuity module 20A of the display unit 20 further comprises at least one reflective surface. Said reflective surface is arranged in said device 100; 200; 300; 400 so as to direct the light path towards the exit aperture 10A.

[0151] Said reflective surface allows bending the optical path of the light beam emitted by the screen so as to limit the size of the display module.

[0152] In practice, the at least one reflecting surface comprises at least one mirror, preferably between two and four mirrors.

[0153] Alternatively, the reflective surface may comprise any kind of beam splitter.

[0154] Alternatively, in a simplified embodiment, the optometry device may not comprise a reflective surface. As in the embodiment described here, the screen is then placed on the optical axis of the lens and is preferably movable in translation along the optical axis of the lens. The optical axis of the lens is then straight, since it is not bent by a mirror.

[0155] Furthermore, the at least one reflecting surface may be translationally and / or rotationally movable between at least two positions.

[0156] The reflective surface may be movable in order to further vary the distance between the visual test image and the exit aperture, as will be described in more detail later.

[0157] The scene module 20B here comprises an additional screen 22 and an additional mirror 24. The additional screen 22 is used to display a background picture. This background picture is preferably an environment familiar to the individual, such as a natural environment, an exterior or interior, such as a city, a landscape or a room. Here, the additional mirror 24 is a concave mirror. The optical axis of the additional mirror passes through the vertex of the concave mirror and here overlaps with the optical axis L of the lens 31 of the acuity module 20A at the exit from the display unit.

[0158] The additional screen 22 may be a video display, such as an LCD display, or any adapted screen of the type previously described with reference to the screen 21 of the acuity module 20A.

[0159] In a variant, the additional screen may include an LED matrix and a light diffusion device. The LED matrix is ​​placed behind the light diffusion device to produce a soft ambient light that will surround the visual test image produced by the acuity module.

[0160] The beam splitter 26 is placed between the acuity module 20A and the scene module 20B in order to superimpose the light emitted by the screen 21 of the acuity module 20A with the light emitted by the additional screen 22 of the scene module 20B. The beam splitter 26 is positioned so that it reflects the light from the screen 21 of the acuity module 20A towards the refraction test unit 10 and finally towards the individual's eye. The beam splitter also reflects the light emitted by the additional screen 22 towards the additional mirror 24 and lets the light reflected by this additional mirror 26 pass directly through the beam splitter towards the individual's eye. The two light beams from the acuity module and the scene module leave the housing 2 of the display module through the opening 3.

[0161] The exemplary embodiments shown in the figures will now be described in more detail.

[0162] Figures 1 to 3 The first embodiment shown is a complex embodiment.

[0163] In this first embodiment, the acuity module 20A comprises three mirrors 41, 42, 43. The screen axis S is horizontal here. The main direction of the optical axis L of the lens 31 in its active position or state is vertical here outside the portion of the optical axis L bent by the mirrors.

[0164] The first mirror 41 is placed on the screen axis S. The first mirror is movable to pivot about a rotation axis X2 perpendicular to the screen axis S. In a first position, the first mirror 41 is oriented at 45° to the screen axis S and directs the light beam emitted by the screen 21 toward the second mirror 42 ( Figure 1 and Figure 2 ) and in the second position, the first mirror is oriented at 135° to the screen axis S and directs the beam toward the beam splitter 26 ( Figure 3 The second position of the first mirror 41 can be reached only when the optical element 30 is in its retracted second position.

[0165] The second mirror 42 and the third mirror 43 are arranged at right angles to each other. In addition, they are arranged at angles of 45° and 135° relative to the screen axis S.

[0166] Thanks to this arrangement, when the first mirror 41 is in its first position, the light beam generated by the screen 21 can be reflected by the first mirror 41 successively towards the second mirror 42. The light beam is then reflected by the second mirror 42 towards the third mirror 43 and then passes through the third mirror 43 so that the light beam is directed towards the lens 31 along the optical axis L of the lens 31. The main directions of the screen axis S and the optical axis L are perpendicular to each other here.

[0167] The light beam passes through the lens 31 (when the optical element 30 is in the first active position) and then reaches the beam splitter 26 and is reflected towards the individual's eye.

[0168] In this first embodiment, the support 23 of the screen 21 is movable along the screen axis S. The support is in fact adapted to slide parallel to the screen axis S on a first track 51 mounted on the housing 2, for example. The distance between the visual test image and the exit aperture can thus be modified by moving the screen 21. The movement of the screen 21 can be modified by comparing Figure 2 and Figure 3 Visualize on the graph. Figure 2 On the screen, 21 is more Figure 3 The optical element 30 is located further away from the first mirror 41 .

[0169] Furthermore, the second mirror 42 and the third mirror 43 are held together on a base 48 mounted on a track 52 of the acuity module 20A so that the mirrors 42 , 43 are slidably movable parallel to the main direction of the optical axis L of the lens 31 .

[0170] By moving the mount 48 carrying the mirrors 42, 43 (for example thanks to an electric motor and associated mechanisms not shown in the figures), the distance between the generated visual test image and the exit aperture can be further modified.

[0171] The movement of mirrors 42 and 43 can be compared Figure 1 and Figure 2 Visualize in the figure. Figure 1 On the mirror 42, 43 than in Figure 2 is further away from the optical element 30.

[0172] Due to this, the acuity module 20A is adapted to generate vision test images for an individual eye E at variable distances.

[0173] The lens 31 has here, for example, an effective focal length of 823 millimeters with an accuracy of 10%. The back focal length is here 813 millimeters.

[0174] exist Figure 1, the lens 31 is in the first active position. The first mirror 41 is in the first position, and the second mirror and the third mirror are in their extreme positions farthest from the lens 31. The screen 21 is also in an extreme position, in which it is placed farthest from the first mirror 41 in its first position.

[0175] The different elements of the device are arranged so that Figure 1 In the configuration shown in , the screen 21 is placed in the focal plane of the lens. Therefore, the test picture displayed on the screen appears to be at an infinite distance from the individual's eye. The distance between the visual test image and the exit aperture is therefore infinite. Therefore, the visual acuity of the individual's eye can be tested under far vision conditions by evaluating the visual performance of the individual observing the visual test image.

[0176] Then the second mirror 42 and the third mirror 43 can be Figure 1 The optical element 30 is slidable from the extreme position shown in FIG.

[0177] By keeping the screen 21 Figure 1 By moving the second mirror 42 and the third mirror 43 along the second track 52 when the lens 31 is in the extreme position of the telescope, and moving the lens 31 from its active position to its retracted position, the distance between the generated visual test image and the exit aperture 10A can be changed from infinity to about 68 cm. Therefore, the visual acuity of an individual's eye can be tested for any distance between infinity and 68 cm under telescopic conditions.

[0178] Since the mirrors 42, 43 can slide continuously on the second track 52 here, the distance between the visual test image and the exit aperture can also be continuously changed within the range between infinity and 68 centimeters.

[0179] The viewing angle along the horizontal axis of the screen 21 is approximately 8°. According to norms PR NF EN ISO 10938 and NF EN ISO 8596, the maximum acuity determined is 20 / 10, based on the fact that a standard optotype requires a minimum of two pixels to form the inner shape of the optotype.

[0180] Alternatively, the screen 21 may also be Figure 1 to an intermediate position (not shown in the figure) in which the screen is closest to the first mirror 41 which is in its first position.

[0181] The corresponding distance between the visual test image and the exit aperture may then vary between 5.6 meters to infinity when only the screen is moved, and between 1 meter to infinity when only the second mirror 42 and the third mirror 43 are moved between their two extreme positions.

[0182] Alternatively, the screen and mirror may be positioned so as to produce a visual test image located 6 meters from the exit aperture 10A, and the visual performance of the individual's eye may be assessed at 6 meters. This measurement may allow the visual performance to be calculated for an optotype placed at infinity, for example by adding a spherical offset to the measured spherical correction. More precisely, the acuity measured at 6 meters may be converted to the acuity measured at infinity by adding a +0.16 diopter offset, as is well known in the art.

[0183] In the first embodiment Figure 2 In the configuration shown in FIG. 3 , the optical element 30 including the lens 31 is in its second, retracted position. The distance between the visual test image and the exit aperture is approximately 67 cm.

[0184] The screen 21 can then also be Figure 1 to an intermediate position (not shown in the figure) in which the screen is closest to the first mirror 41 which is in its first position.

[0185] The second mirror 42 and the third mirror 43 can also be Figure 1 and the other extreme position closest to the optical element 30 .

[0186] The distance between the visual test image and the exit aperture can be varied from about one meter to about 50 centimeters by moving the screen 21 along the first track 51 and moving the second mirror 42 and the third mirror 43 along the second track 52. Thus, the visual acuity of an individual's eye can be tested for any distance between one meter and 50 centimeters under visual conditions.

[0187] Since the screen 21 and the mirrors 42, 43 can slide continuously on the first track 51 and the second track 52 respectively, the distance between the visual test image and the exit aperture can also be continuously changed in the range between one meter and 50 centimeters.

[0188] The viewing angle of the screen 21 is then approximately 8°. Based on the fact that a standard optotype requires a minimum of two pixels to form the inner shape of the optotype, the maximum acuity determined is 10 / 10.

[0189] In the first embodiment Figure 3In the configuration of FIG. 1 , the optical element 30 is still in the retracted position and the first mirror 41 is in the second position pivoted towards the optical element. In this configuration, the light beam is reflected by the first mirror 41 directly from the screen 21 to the beam splitter 26 without being reflected by the second mirror 42 and the third mirror 43. Only the screen 21 can be moved to change the optical position of the visual test image and thus change the distance between the generated visual test image and the exit aperture. The second mirror 42 and the third mirror 43 are bypassed. Figure 3 The configuration here corresponds to a distance of 33 cm between the visual test image and the exit aperture.

[0190] The distance between the generated visual test image and the exit aperture can be varied from about 50 cm to about 33 cm by moving the screen 21 along the first track 51. Thus, the visual acuity of an individual's eye can be tested for any distance between 50 and 33 cm under near vision conditions.

[0191] Since the screen 21 can slide continuously on the first track 51, the distance between the generated visual test image and the exit aperture can also be continuously changed within the range of 50 cm to 33 cm. When the screen slides on the first track 51 between its two extreme positions, the field of view angle of the screen 21 changes between 12° and 15°.

[0192] The screen 21 and the three mirrors 41 , 42 , 43 are controlled in movement, for example thanks to a motor 19 and associated mechanisms not shown in the figures.

[0193] The set points for the positions of the screen and mirror may be automatically determined by the software taking into account the visual performance of the individual's eyes in recognizing the optotypes of the vision test images produced by the device.

[0194] Figures 4 to 6 The second embodiment shown is also a complex embodiment.

[0195] The screen axis S is vertical, like the main direction of the optical axis L of the lens 31 in its active position. Preferably, the optical axis L of the lens 31 and the screen axis S partially overlap. In this second embodiment, the support 23 of the screen 21 can also be moved along the screen axis S. The support is in fact adapted to slide parallel to the screen axis S on a first track 51 mounted on the housing 2. The distance between the generated visual test image and the exit aperture can thus be modified by moving the screen 21. The movement of the screen 21 can be modified by comparing Figure 5 and Figure 6 Visualize on the graph. Figure 5 On the screen, 21 is more Figure 6 is further away from the optical element 30.

[0196] In this second embodiment, the acuity module 20A comprises four mirrors 61 , 62 , 63 , 64 .

[0197] Here, they are held together in pairs of two mirrors oriented at right angles to each other. Each of the first and second pairs of mirrors is supported by a support element 65 , 66 slidably mounted on a second track 67 .

[0198] Each pair of mirrors can slide independently along the second track 67 .

[0199] In particular, the first pair of mirrors 61, 64 can slide in and out of the screen axis S.

[0200] When the first pair of mirrors 61, 64 is placed on the screen axis S, the first mirror 61 of the first pair of mirrors is placed on the screen axis S, in front of the screen 21. The first mirror 61 is oriented at 45° to the screen axis S and reflects the light beam emitted by the screen 21 towards a second mirror 62 of the second pair of mirrors, which is oriented parallel to the first mirror 61. This second mirror 62 reflects the light beam towards a third mirror 63 of the second pair of mirrors, which is oriented at 90° relative to the second mirror 62. The third mirror 63 reflects the light beam towards a fourth mirror 64 belonging to the first pair of mirrors, which is oriented parallel to the third mirror 63.

[0201] The fourth mirror 64 reflects the light beam in the main direction of the optical axis L of the lens 31 in the vertical direction toward the beam splitter 26 .

[0202] Thanks to this arrangement, when the first pair of mirrors 61, 64 is placed on the screen axis S, the light beam emitted by the screen 21 can be reflected successively by the first mirror 61 towards the second mirror 62. The light beam is then reflected by the second mirror 62 towards the third mirror 63, then by the third mirror 63 towards the fourth mirror 64, and by the fourth mirror 64 towards the lens 31 in the main direction of the optical axis L of the lens 31. The screen axis S and the optical axis L partially overlap here.

[0203] The light beam passes through the lens 31 (when the optical element 30 is in the first active position) and then reaches the beam splitter 26 and is reflected towards the individual's eye.

[0204] When the first pair of mirrors is placed in the optical path, the distance between the visual test image and the exit aperture 10A can be modified by moving the base 66 carrying the second pair of mirrors 62, 63 relative to the base 65 of the first pair of mirrors 61, 64 (for example thanks to an electric motor and associated mechanisms not shown in the figure).

[0205] The movement of the second pair of mirrors 62, 63 can be compared Figure 4 and Figure 5Visualize in the figure. Figure 4 In the second pair of mirrors, mirrors 62 and 63 are larger than those in Figure 5 It is further away from the mirrors 61 , 64 of the first pair of mirrors and from the optical element 30 .

[0206] exist Figure 4 , the lens 31 is in a first active position. For example, this lens has an effective focal length of 857 mm. The first pair of mirrors 61, 64 is placed in the optical path of the light emitted by the screen 21; the second pair of mirrors 62, 63 is in its extreme position farthest from the first pair of mirrors 61, 64. The screen 21 is also in an extreme position, in which it is placed farthest from the first mirror 61 of the first pair of mirrors.

[0207] The different elements of the device are arranged so that Figure 4 In the configuration shown in , the screen 21 is placed in the focal plane of the lens 31. Therefore, the image of the test picture displayed on the screen appears to be at an infinite distance from the individual's eye. The distance between the visual test image and the exit aperture 10A is therefore infinite. Therefore, the visual acuity of the individual's eye can be tested under far vision conditions by evaluating the visual performance of the individual observing the visual test image.

[0208] The viewing angle of the screen 21 is approximately 9°. Based on the fact that the standard optotype used requires a minimum of 2 pixels to form the internal shape of a letter, the maximum acuity determined is 16 / 10.

[0209] Screen 21 can then be viewed from Figure 4 5 . The screen slides from the extreme position shown in FIG. 5 to an intermediate position in which the screen is closer to the first mirror 61 of the first pair of mirrors when the first mirror 61 is placed in the optical path of the light beam.

[0210] The second pair of mirrors 62, 63 can also be Figure 4 The limit position shown in FIG. 6 is slid to another limit position closest to the first pair of mirrors 61 , 64 .

[0211] The distance between the visual test image and the exit aperture 10A can be varied from infinity to about 2 cm by moving the screen 21 along the first track and the second pair of mirrors 62, 63 along the second track 67. Thus, the visual acuity of an individual's eye can be tested for any distance between infinity and 2 cm under far vision conditions.

[0212] Since the screen 21 and the mirror can slide continuously on the first track and the second track 67 respectively, the distance between the generated visual test image and the exit aperture can also be continuously changed within the range between infinity and 1.5 cm.

[0213] exist Figure 5In the configuration shown in FIG. 3 , the optical element 30 including the lens 31 is in its second, retracted position.

[0214] Screen 21 can be viewed from Figure 4 The extreme position shown in FIG. 1 slides to a position (not shown in the figure) where it is closest to the first mirror 61 (in the optical path) in the first pair of mirrors.

[0215] The second pair of mirrors 62, 63 can also be Figure 4 The limit position shown in FIG. 1 is slid to the other limit position closest to the first pair of mirrors.

[0216] Thus, the distance between the visual test image and the exit aperture 10A may be varied continuously from about 70 centimeters to about one meter.

[0217] Therefore, the visual acuity of an individual's eye can be tested under visual conditions for any distance included in this range.

[0218] Figure 5 The configuration shown in corresponds to a distance of 67 cm between the visual test image and the exit aperture.

[0219] exist Figure 6 In the configuration, the optical element 30 is still in the retracted position, and the first and second pairs of mirrors 61 , 62 , 63 , 64 are slid to be placed outside the optical path of the light emitted by the screen 21 .

[0220] In this configuration, the light beam is directed from the screen 21 to the beam splitter 26 without being reflected by any mirrors. In this configuration, only the screen 21 can be moved to change the length of the light path. The first pair of mirrors and the second pair of mirrors are bypassed.

[0221] By moving the screen 21 along the first track, the distance between the visual test image and the exit aperture 10A can be varied from about 50 cm to about 25 cm. Thus, the visual acuity of an individual's eye can be tested for any distance between 50 and 25 cm under near vision conditions.

[0222] Figure 6 The configuration shown in corresponds to a distance of 33 cm between the visual test image and the exit aperture.

[0223] Since the screen 21 can slide continuously on the first track, the distance between the generated visual test image and the exit aperture can also be continuously changed within the range of 50 cm to 33 cm.

[0224] The screen 21, the mirrors 61, 62, 63, 64 and the optical element 30 are controlled in movement, for example thanks to motors and associated mechanisms not shown in the figures.

[0225] Figure 7 and Figure 8 The third embodiment shown in FIG. 1 is a simplified variation of the first embodiment described previously.

[0226] In this third embodiment, the acuity module comprises similar optical components to those of the first embodiment, except that the screen 21 and the second and third mirrors 42, 43 are fixed rather than movable.

[0227] As in the first embodiment, the first mirror 41 is placed in the optical path and is mounted to pivot about an axis of rotation perpendicular to the optical path of the light beam so as to be alternatively placed at an angle of 45° or 135° relative to the screen axis S.

[0228] In this embodiment, light emitted by the screen can follow one of three optical paths, depending on the angular position of the first mirror 41 .

[0229] When the first mirror 41 is in the first position (45° to the screen axis S) and the optical element 30 is in its active position ( Figure 7 ), the light is reflected by the first mirror 41 towards the second mirror 42, and by the second mirror 42 towards the third mirror 43, and by the third mirror towards the optical element 30 and the beam splitter 26. The distance between the generated visual test image and the exit aperture is about 6 meters: the test picture displayed by the screen 21 is then seen by the individual's eye at a distance of about 6 meters.

[0230] Without further modifications, the optical element 30 can be pivoted to its retracted position.The distance between the visual test image and the exit aperture 10A is then about one meter.

[0231] The first mirror 41 can then be pivoted to its second position (135° to the screen axis S). The light beam emitted by the screen 21 is then reflected by the first mirror 41 directly towards the beam splitter 26 and then by the beam splitter 26 towards the individual's eye. The distance between the visual test image and the exit aperture 10A is then about 40 cm (at Figure 8 config).

[0232] Thus, a visual test image may be displayed at three fixed distances from the exit aperture of the device.

[0233] With the third embodiment of the optometry device 300, an individual may view a vision test image at three different optical distances.

[0234] The fourth embodiment is another simplified variation of the first embodiment. Fig. 9In this fourth embodiment shown in , the screen is fixed. The screen axis S is vertical, and the first mirror 41 is removed. Similar to the first embodiment, the second mirror 42 and the third mirror 43 are mounted to be vertically slidable along the second track 52.

[0235] The light beam emitted by the screen 21 is directed toward the second mirror 42, reflected by the second mirror 42 toward the third mirror 43, and reflected by the third mirror 43 toward the optical element 30 in its active position, or toward the beam splitter 26 when the optical element 30 is in the retracted position.

[0236] The lens 31 has here an effective focal length of, for example, 686 millimeters. The viewing angle of the screen 21 is then approximately 11° along the horizontal axis. The maximum acuity determined is 16 / 10 at 2 pixels. The size of a pixel is, for example, approximately 63 micrometers.

[0237] When the lens is in the active position, the distance between the visual test image and the exit aperture 10A can be varied within the range of 80 cm to infinity.

[0238] When the lens is in the retracted position, the distance between the visual test image and the exit aperture 10A may vary within the range of 40 cm to 95 cm.

[0239] With the fourth embodiment of the optometry device 400, an individual may view a vision test image at two different distance ranges.

[0240] In practice, whatever embodiment is considered, the translational movement of the screen along the optical path of the light emitted by the screen, and / or the rotational or translational movement of the mirror, and / or the movement of the optical elements of the acuity module are preferably achieved automatically by a motorized system controlled by said electronic unit (not shown in the figures).

[0241] The electronic unit is programmed to command these movements based on predetermined refractive procedure steps and parameters entered by the operator.

[0242] The acuity module is adapted to generate an image of an object at a variable distance for the individual eye E. The image of the object is a real or virtual image of a test picture displayed by the screen 21 .

[0243] The individual's field of view is large enough to observe the entire screen 21.

[0244] The light beam emitted from the acuity module 20A is finally reflected by the beam splitter 26 toward the test unit 10 and through this test unit 10 toward the individual's eye.

[0245] In the scene module 20B, the light beam generated by the additional screen 22 is reflected by the beam splitter 26 toward the additional mirror 24 (eg Figure 1), is reflected on the additional mirror 24 toward the beam splitter 26 (light ray R2) and is transmitted by the beam splitter 26 to ultimately head toward the individual eye E (light ray R3).

[0246] The focal length of the additional mirror 24 is such that a person using an optometry device can view the image produced by the additional screen 22 at a distance greater than 5 meters or greater than 6 meters.

[0247] Thus, in the present embodiment, the elements of the scene module 20B are positioned so that the virtual image produced by the additional screen 22 of the scene module 20B is within the distance of the individual's eyes, that is to say corresponds to the individual's visual distance.

[0248] Thus, the beam splitter 26 makes it possible not only to reflect the beam generated by the acuity module 20A, but also to add in the same direction the beam originally generated by the additional screen 22 of the scene module 20B, i.e. to combine the image generated by the acuity module 20A with another image generated by the screen of the scene module 20B. Finally, the overall image generated by the display unit and seen by the individual comprises the superimposed visual test image generated by the acuity module and the scene image generated by the scene module.

[0249] In the variant described, in which the additional screen comprises an LED matrix and light diffusing means, a soft ambient light generated by the scene module surrounds the vision test image generated by the acuity module.

[0250] The width of the additional screen 22 of the scene module 20B makes it possible to produce a light beam extending substantially along the entire length of the beam splitter 26 and which is therefore visible to the individual eye E over a relatively wide angle (generally 10° or more, preferably 30° or more).

[0251] Thanks to the invention, the light beam emitted by the screen 21 of the acuity module 20A is also visible over a fairly wide angle, typically an angle of 5° or more, by the individual eye E. In other words, the angular size of the measured visual test image seen from the exit aperture 10A is greater than 5°, for example between 5° and 25°, more preferably between 8° and 15° for a screen used for acuity testing, the image of which is surrounded by the image of the additional screen 22 having a wider field angle of 33° on the horizontal axis.

[0252] The novel optometry device 100; 200; 300; 400 according to the invention allows easy assessment of an individual's visual performance at different distances from a visual test image.

[0253] In addition, optical elements can be removed from the optical path of the light to display the vision test image at a near distance from the individual's eye. This allows the display of a vision test image with a larger image size under near conditions. The larger size image makes it possible to display text for reading and to more easily align the image to the center of the device's exit aperture. For example, when the lens 31 is in the retracted position, the angular size of the vision test image along the horizontal axis when displayed at 33 centimeters is 15°.

[0254] Subjective refraction testing using the refraction testing unit 10 may thus be performed with optometry marks placed at a selected set of different distances from an individual's eyes.

[0255] This results in more accurate refractive measurements, which may include measurements at infinity using embodiments in which continuous variation of the distance between the generated visual test image and the exit aperture is possible.

[0256] Although the distance between the vision test image and the exit aperture 10A is variable, the size of the sight mark or any other object displayed by this screen 21 can be adjusted depending on this distance. This adjustment is controlled by the electronic unit.

[0257] The above-described optometry device, although compact, can simulate real situations thanks to the images produced by the scene module with a wide field of view. This allows performing vision tests with vision test images that are close to realistic vision conditions.

[0258] By using the acuity module 20A and the scene module 20B simultaneously, a high-resolution optotype can be displayed in the center of an image with a wide field of view.

[0259] When the additional screen 22 of the scenario module 20B is a video display, the tests performed using the optometry device can even simulate a mobile environment, as in a real situation.

[0260] In the example described here, the optical element 30 comprises an optical lens 31 .

[0261] In the example described here, the optical element 30 is rotationally movable between the active position and the retracted position. Alternatively, the optical element may be translationally movable between the active position and the retracted position. The example described above may be implemented, for example, by an optical lens that is translationally movable between a first position, in which the lens is placed across the optical path with its optical axis aligned with the main direction, and a second position, in which the lens is moved out of the optical path with its optical axis remaining parallel to the main direction.

[0262] In an alternative simplified embodiment of the invention, the acuity module of the display unit does not comprise any reflective surface, but only the screen and the optical elements.The screen may be translationally movable or non-translationally movable along a screen axis.

[0263] Furthermore, the relative position and orientation of the optical components of the device, in particular the reflective surfaces, may be modified to obtain the same distance between the visual test image and the exit aperture.

[0264] In an alternative simplified embodiment of the invention, there is no scene module.

[0265] The advantage of the embodiment using an optical element with variable focal power, and the embodiment with a movable screen 21 but without bending mirrors 41, 42, 43, in which the optical axis extends along a straight line between the optical element 30 and the screen 21, is that the image displayed at a variable distance is presented to the subject in a seamless transition. This is possible in the first case because the variation of the focal power of the tunable lens is continuous, and in the second case because the translational displacement of the screen 21 can also be continuous.

[0266] According to the present invention, the above described vision measuring device can be used to test an individual's eyes by the following steps:

[0267] -i) generating a visual test image for the individual's eye based on the test picture, the visual test image being visible through an exit aperture of an optometry device, such as a phoropter, through which the individual's eye can view the test visual image,

[0268] -ii) varying the variable distance between the visual test image and the exit aperture (10A) by changing the state of the optical element (30) between the active state and the inactive state,

[0269] -iii) evaluating the visual perception of at least one eye of an individual of the vision test image at different distances between the vision test image and the exit aperture.

[0270] In particular, step ii) may comprise varying the distance between the visual test image and the exit aperture by moving the optical element between an active position, in which the optical element is placed in the optical path of light emitted by the screen and leaving the device through the exit aperture, and a retracted position, in which the optical element remains out of the optical path.

[0271] Step ii) may alternatively comprise changing the variable refractive power of the optical element between a non-zero value corresponding to the active state and a zero value corresponding to the inactive state. In this case, the optical element does not move. It remains in the optical path of the light.

[0272] Visual perception of a visual test image is assessed by asking the individual to describe his perception of the visual test image, by saying whether the visual test image is seen, or by whether an optotype such as a letter is recognized. Visual perception may also be assessed, for example, by determining the delay required for the individual to recognize an optotype. The assessment of visual perception may be performed by any method known to those skilled in the art.

[0273] Further, while the screen and optics positions are fixed, the power of the lens and / or the visual test image in the optometry device is changed depending on the individual's responses during the assessment step.

Claims

1. An optometry device (100; 200; 300; 400) for testing an individual's eyes, comprising a refractive testing unit (10) and a display unit (20), wherein the refractive testing unit has an optical system for providing different vision correction powers at a position close to the individual's eyes, and the display unit is adapted to generate a visual test image for the individual's eyes, wherein the visual test image is displayed through the optometry device (100; 200; 300; 400) the exit aperture (10A) of the test unit is visible, and the display unit (20) comprises: - a screen (21), said screen being adapted to display a test picture for generating said visual test image; and - at least one optical element (30) having an optical power, The optical element (30) exhibits an active state, in which the optical element exhibits a non-zero optical power placed on the optical path of light emitted by the screen (21) and leaving the device (100; 200; 300; 400) through the exit aperture (10A), and an inactive state, in which the optical element introduces no optical power on the optical path, so as to produce the visual test image at a variable distance from the exit aperture (10A), wherein the optometry device comprises a plurality of reflective surfaces for bending the optical path of the light, The plurality of reflective surfaces include a second mirror (42) and a third mirror (43) arranged at right angles to each other.

2. The vision measuring device (100; 200; 300; 400) according to claim 1, wherein: The optical element (30) is movable between an active position corresponding to the active state, in which the optical element is placed in the optical path of light emitted by the screen (21) and leaving the device (100; 200; 300; 400) through the exit aperture (10A), and a retracted position corresponding to the inactive state, in which the optical element remains out of the optical path.

3. The visual acuity measuring device according to claim 1, wherein: The optical element remains placed in the optical path of the light and has a variable optical power that is variable between a non-zero value corresponding to the active state and a zero value corresponding to the inactive state.

4. The vision measuring device (100; 200; 300; 400) according to claim 1, wherein: The variable distance is between the distance for far vision and the distance for near vision or intermediate vision.

5. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The optical element (30) is an optical lens (31).

6. The vision measuring device (100; 200; 300; 400) according to claim 2, wherein: The optical element (30) is capable of rotational and / or translational movement between the active position and the retracted position.

7. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The screen (21) is movable in translation along a reference axis between two positions corresponding to different distances between the generated visual test image and the exit aperture (10A).

8. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The screen (21) is capable of translational movement in two perpendicular directions to center the screen (21) relative to the optical axis of the optical element (30).

9. The optometry device (100; 200; 300; 400) according to claim 7, wherein: The optical element (30) is an optical lens (31) in its active position, and the relative position of the screen (21) and the optical lens (31) is adjustable so as to position the screen (21) at a distance from the optical element (30) equal to the back focal length of the optical lens (31) measured along the optical axis (L) of the optical lens (31).

10. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The visual test image comprises a test picture displayed by the screen (21) when not affected by the optical element (30) and reflected or not reflected by a reflective surface of the device, or an image of the test picture projected by the optical element (30) and reflected or not reflected by a reflective surface of the device.

11. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The relative positions of the screen (21), the optical element (30) and the exit aperture (10A) are adapted to be changed so that the distance between the visual test image and the exit aperture (10A) varies continuously within one or several optical distances between infinity and near distance.

12. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The plurality of reflective surfaces are arranged in the device so as to direct the optical path of light emitted by the screen (21) towards the exit aperture (10A).

13. The optometry device (100; 200; 300; 400) according to claim 1, wherein: The measured angular size of the visual test image as seen from the exit aperture (10A) is between 5° and 25°.

14. The optometry device (100; 200; 300; 400) according to claim 1, comprising a second screen (21) adapted to display a second picture, the image of which is superimposed with the vision test image at the exit aperture (10A) of the device.

15. The optometry device (100; 200; 300; 400) according to claim 1, wherein the plurality of reflective surfaces comprises a first mirror (41) movable to pivot, the light emitted by the screen following one of a plurality of light paths depending on the angular position of the first mirror (41).

16. The optometry device (100; 200; 300; 400) according to claim 1, wherein the second mirror (42) and the third mirror (43) are slidably movable to produce the vision test image at a variable distance from the exit aperture (10A).

17. A method for testing an individual's eyes using an optometry device (100; 200; 300; 400) for testing an individual's eyes, the optometry device comprising a refractive test unit (10) having an optical system for providing different vision correction powers at a position close to the individual's eyes, and a display unit (20), the display unit being adapted to generate a visual test image for the individual's eyes, the visual test image being visible through an exit aperture (10A) of the test unit of the optometry device, the display unit (20) comprising: - a screen (21), said screen being adapted to display a test picture for generating said visual test image; and - at least one optical element (30) having an optical power, the optical element (30) exhibiting an active state, in which the optical element exhibits a non-zero optical power placed on an optical path of light emitted by the screen (21) and leaving the device (100; 200; 300; 400) through the exit aperture (10A), and an inactive state, in which the optical element introduces no optical power on the optical path, so as to produce the visual test image at a variable distance from the exit aperture (10A); wherein the optometry device comprises a plurality of reflective surfaces for bending the optical path of the light, wherein the plurality of reflective surfaces comprises a second mirror (42) and a third mirror (43) arranged at right angles to each other, This method includes: - generating the vision test image for the eye of the individual based on the test picture, the vision test image being visible through the exit aperture (10A) of the optometry device and being viewable by the eye of the individual through the exit aperture, - varying the variable distance between the visual test image and the exit aperture (10A) by changing the state of the optical element (30) between the active state and the inactive state, - evaluating the visual perception of the vision test image by at least one eye of the individual at different distances between the vision test image and the exit aperture (10A).

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