Phoropter and optometric apparatus for testing an individual's eye

Abstract

The invention relates to a phoropter (100) for testing the eyes of an individual when the individual observes a target, the phoropter comprising: - two optical units (110, 120) for both eyes of the individual, each optical unit having an entrance on the target side, an exit aperture on the individual side, and an optical system for providing different visual correction powers to the corresponding eye of the individual, - moving means adapted to adjust the relative position of the two optical units, - a partial mirror (27) located between the optical units and the target, - image acquisition means directed towards the partial mirror for acquiring images of the eyes of the individual looking towards the target through the two optical units, and - image display means adapted to display the acquired images.

Description

Technical Field

[0001] The present invention relates to a phoropter and optometrist device for testing the eye of an individual. Background Art

[0002] In the context of measuring the visual acuity of a patient, it has already been proposed to simulate the visual compensation to be provided, for example by means of a refractometer (also called a phoropter).

[0003] The phoropter includes a support element designed to receive the head of an individual and hold it in a predetermined position relative to the refractive head of the phoropter.

[0004] This refractive head houses trial lenses offering different corrections, which can be placed successively in front of the individual's eye until the right correction is found.

[0005] In this refractive head, the trial lenses are located on two discs that are mounted so they can rotate freely. This rotation is manually controlled. Each disc must be positioned relative to each of the patient's eyes so that when one of the discs rotates, the trial lens on that disc can be positioned in front of the corresponding eye.

[0006] Since patients do not all have identical morphologies, it is necessary to adjust the position of each disk relative to each of the patient's eyes before attempting to simulate the visual compensation to be provided.

[0007] For this purpose, the position of the disc can be manually adjustable. Furthermore, one of the trial lenses for each disc comprises a marking which helps the optometrist to place this lens on the axis of the respective patient's eye, thereby ensuring that the position of the disc is well adjusted relative to the position of the patient's eye.

[0008] The main disadvantage of this device is that the optometrist needs to observe the patient face to face, which is not always possible. Moreover, once the simulation of the visual compensation to be provided has been started, the optometrist cannot check whether the adjustment is still correct. Summary of the Invention

[0009] In this context, the present invention provides a phoropter for testing an eye of an individual while the individual views a target along an optical path, the phoropter comprising:

[0010] - two optical units for both eyes of the individual, each optical unit having an entrance on the target side, an exit aperture on the individual side, and an optical system for providing a different vision correction power to the respective eye of the individual,

[0011] - movement means suitable for adjusting the relative position of the two optical units,

[0012] - a partially reflecting mirror arranged along the optical path (between the optical unit and the target),

[0013] - image acquisition means (e.g. one or two cameras) directed towards the partially reflective mirror for acquiring an image of the individual's eye looking at the object through the two optical units, and preferably

[0014] - Image display means adapted to display the acquired images.

[0015] Thanks to the invention, the camera(s) can acquire images of the individual's eyes before or during the simulation of the visual compensation to be provided.Thus, the two optical units in front of the individual's eyes can be adjusted at any time.

[0016] Furthermore, the optometrist does not need to observe the patient face-to-face to make this adjustment, thereby enabling the patient to look at the target during this adjustment, which provides better accuracy when positioning the optical units.

[0017] Further non-limiting features of the device according to the invention:

[0018] - the image acquisition device comprises two cameras,

[0019] - each camera is directed towards the partially reflecting mirror for acquiring an image of one eye of the individual looking at a target through one of the optical units,

[0020] - The movement means comprise a joystick for manually adjusting the relative position of the two optical units.

[0021] - the phoropter further comprises a support element designed to receive the head of the individual and hold it in position,

[0022] - the movement means comprise two joysticks for manually adjusting the position of the two optical units relative to the support element,

[0023] - the movement means comprises at least one motor adapted to adjust the relative position of the two optical units, and a controller programmed to control the motor based on a plurality of images acquired by the image acquisition means and processed to detect the position of the pupil of the individual,

[0024] - the movement means comprise two motors, and the controller is programmed to automatically control these motors so as to adjust the position of the two optical units relative to the support element on the axis of the individual's pupils,

[0025] - the optical system is designed to produce variable spherical power and variable cylindrical power,

[0026] The partially reflecting mirror rests along its entire edge on a rim of the frame of the mirror support, said frame comprising three or four tongues which hold the partially reflecting mirror against said rim.

[0027] The present invention also provides an optometry device for testing an individual's eye, the optometry device comprising a phoropter as described above and a display unit adapted to produce a target visible through the exit apertures of the two optical units of the phoropter, the display unit comprising:

[0028] - a first screen adapted to display a test picture for producing said visual target, and

[0029] - at least one optical element having optical power,

[0030] The optical element is movable between an active position in which it is placed in the optical path of light emitted by the first screen and exiting 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 target at a variable distance from the exit aperture.

[0031] Further non-limiting features of the optometry device according to the invention:

[0032] - the device comprises a second screen suitable for displaying a second picture, the image of this second picture being superimposed with said target at the exit aperture by means of a main partially reflecting mirror,

[0033] a single mirror support holding the main partially reflecting mirror and the partially reflecting mirror of the phoropter,

[0034] - the main partially reflecting mirror rests on a frame edge of the frame of the mirror support,

[0035] The main partial reflector rests along its entire edge against the frame rim, with a compressible material being sandwiched between the main partial reflector and the frame rim.

[0036] - the main partial reflector rests directly on three or four areas protruding from the frame edge,

[0037] - the edges of the main partial reflector are blocked by three or four pins which clamp it in place,

[0038] - the frame comprises at least two flexible strips which hold the main partially reflective mirror against the frame edge,

[0039] The frame is located on a first portion of a housing of the mirror support, the housing comprising a second portion fixed to the first portion and having an abutment located at a distance from the frame, with a gap or compressible material provided between the abutment and the frame.

[0040] The invention further relates to a mirror support (also called beam splitting box) comprising a housing supporting the main partially reflecting mirror and the partially reflecting mirror. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The following description, given by way of non-limiting examples with reference to the accompanying drawings, makes clear what the invention consists of and the manner in which it can be put into practice.

[0042] In the attached figure:

[0043] - Figure 1 and Figure 2 An optometry device according to the present invention is presented,

[0044] - Figure 3 yes Figure 1 and Figure 2 A side view of a phoropter of an optometry device is shown,

[0045] - Figure 4 is Figure 3 The image captured by the camera of the phoropter is shown,

[0046] - Figure 5 yes Figure 1 and Figure 2 A perspective view of the beam separation box of the optometry device is shown,

[0047] - Figure 6 yes Figure 5 Exploded view of the box,

[0048] - Figure 7 yes Figure 5 A cross-sectional view of the box,

[0049] - Figure 8 yes Figure 5 An exploded view of one of the mirrors in the box.

[0050] - Figure 9 According to the first embodiment Figure 5 An exploded view of another mirror of the box,

[0051] - Figure 10 According to the second embodiment Figure 5 An exploded view of another mirror of the box,

[0052] - Figure 11 yes Figure 2A perspective view of the internal components of a phoropter is shown. DETAILED DESCRIPTION

[0053] The present invention primarily relates to a phoropter (also known as a "refractor") designed to provide different powers of vision correction near an individual's eye. The phoropter can be used with an eye chart placed up to six meters from the phoropter. However, in the described embodiment, the phoropter is an optometry device having a display unit 20 adapted to display a test image as would be viewed through the phoropter 100. The display unit 20 is described in the first section of this report. The phoropter 100 will be described later.

[0054] exist Figure 1 and Figure 2 In the figure, the light path is represented by a dotted line and the propagation direction is represented by an arrow.

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

[0056] The purpose of the optometry device 10 is to test the eyes of an individual.

[0057] Interposed between the display unit 20 and the individual's eye is a phoropter 100. The phoropter is adapted to provide a variable optical correction to the individual's eye for viewing therethrough.

[0058] The light beam exiting the display unit 20 passes through the phoropter 100 and is directed toward the eye of the individual.

[0059] In the embodiment shown, the display unit 20 comprises:

[0060] - a screen 21 suitable for displaying a test picture ("target") for generating a visual test image, and

[0061] - At least one optical element 30 having optical power.

[0062] 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 exiting the device through the exit aperture, and a retracted position in which it remains out of the optical path so as to produce the visual test image at a variable distance from the exit aperture 120B.

[0063] The optical path is the path followed by a light beam emitted by the screen 21 at the center of the image displayed on the screen 21 , through the display unit 20 , to the exit aperture 120B of the phoropter 100 facing the patient.

[0064] When the optical element 30 is in its retracted position ( Figure 2 ), the visual test image comprises the test image displayed by the screen 21. The distance between the visual test image and the exit aperture of the phoropter 100 is the distance measured between the exit aperture and the screen 21 along the optical path.

[0065] When the optical element is in its active position ( Figure 1 ), the visual test image includes 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. The virtual image is located at an optical position. This optical position can be, for example, at infinity.

[0066] The distance between the visual test image and the exit aperture of the phoropter 100 is then the distance between the exit aperture and the optical position of the visual test image. The optical element 30 may comprise, for example, an optical lens 31 , as in the example described here.

[0067] In the case where the optical element 30 includes the optical lens 31 , the image of the test picture is the image of the test picture viewed through the lens 31 .

[0068] The distance between the visual test image and the exit aperture varies between at least a far distance and different near or intermediate distances. The far distance is typically comprised between infinity and 65-70 cm. The intermediate distance is typically comprised between 65-70 cm and 40 cm. The near distance is typically comprised between 40 cm and 33 cm.

[0069] Preferably, the relative positions of the screen 21, optical element 30 and exit aperture 120B 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 more optical distances between infinity and near distance.

[0070] The optometry device 10 comprises a main housing 2 which is placed, for example, on a table or mounted on a stand so as to be placed on a table or on the floor.

[0071] Here, the main housing 2 surrounds the display unit 20. The phoropter 100 is mounted on the main housing 2.

[0072] Here, the display unit 20 includes an acuity module 20A and a scene module 20B.

[0073] Acuity module 20A includes screen 21 and optical element 30 .

[0074] The screen 21 generates a light beam along a screen axis S which is perpendicular to the mean plane of the screen 21. This light beam is intended to generate an image of an object, such as an optotype, for an individual using an optometry device.

[0075] In the example described here, the screen 21 is flat.

[0076] Here, the optical element 30 comprises an achromatic lens having an effective focal length between 70 centimeters and one meter, for example preferably about 80 centimeters.

[0077] Preferably, the optical element 30 and the screen 21 are arranged relative to each other so that there is at least one relative position between the optical lens 31 and the screen 21, at which time the screen 21 is placed at a distance from the optical lens 31 equal to the back focal length of the lens 31.

[0078] Therefore, in the telescopic configuration, when the lens 31 is placed in the optical path of light, the relative positions of the screen 21 and the lens 31 can be adjusted so that the screen 21 is located at a back focal length from the lens 31.

[0079] In this way, the vision test image generated by the display module 20 can be placed at infinity relative to the exit aperture, and therefore relative to the individual's eye.The distance between the generated vision test image and the exit aperture is then set to infinity.

[0080] The optical element 30 comprises a lens 31 and is fixed to a support 32 which is pivotally mounted on a portion of the housing 2 .

[0081] like Figure 1 As shown, when the support 32 of the lens 31 is in a first angular position, the support 32 is parallel to the optical path of the light and causes the lens 31 to traverse this optical path: the light emitted by the screen passes through the lens 31. The optical path of the light follows at least partially the optical axis L of the lens 31.

[0082] like Figure 2 As shown, when the support 32 of the lens 31 is in the second angular position, the support 32 is tilted 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 avoids the lens 31.

[0083] The screen 21 is movable in translation along two perpendicular directions in order to center it relative to the other optical components of the ophthalmic device 10 , in particular relative to the optical axis L of the lens 31 in its active position.

[0084] This centering step ensures that light emitted at the center of the screen leaves the optometry device at the center of the exit aperture.

[0085] 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.

[0086] The acuity module 20A of the display unit 20 also includes at least one reflective surface to direct the light path toward the exit aperture 120B.

[0087] Said reflective surface allows folding the optical path of the light beam emitted by the screen so as to limit the size of the display module.

[0088] In practice, the reflective surface comprises three mirrors 41, 42, 43, of which the first mirror is movable in order to further vary the distance between the visual test image and the exit aperture.

[0089] This 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 alternately placed at an angle of 45° or 135° relative to the screen axis S.

[0090] 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.

[0091] Due to this arrangement, when the first mirror 41 is in its first position, the light beam generated by the screen 21 can be continuously reflected by the first mirror 41 toward the second mirror 42. The light beam is then reflected by the second mirror 42 toward the third mirror 43, and then reflected by the third mirror 43, so that the light beam is directed toward the lens 31 along the optical axis L of the lens 31. Here, the main directions of the screen axis S and the optical axis L are perpendicular to each other.

[0092] The light beam passes through the lens 31 (when the optical element 30 is in the first active position), then reaches the first beam splitter 26 and is reflected towards the individual's eye.

[0093] exist Figure 2 In the configuration shown, the optical element 30 is in its second, retracted position and the first mirror is rotated so that the light beam passes directly from the screen 21 to the first beam splitter 26 .

[0094] Scene module 20B includes an additional screen 22 and an additional mirror 24. Additional screen 22 is used to display a background image. This background image is preferably an environment familiar to the individual, such as a natural environment, either exterior or interior, such as a city, landscape, or room. Additional mirror 24 is a concave mirror. The optical axis of the concave mirror passes through its vertex and, at the exit of the display unit, overlaps with the optical axis L of lens 31 of acuity module 20A.

[0095] A first beam splitter 26 is positioned between the acuity module 20A and the scene module 20B to superimpose the light emitted by the screen 21 of the acuity module 20A and the light emitted by the additional screen 22 of the scene module 20B. The beam splitter 26 is positioned to reflect light from the screen 21 of the acuity module 20A toward the phoropter 100 and, ultimately, toward the individual's eye. The beam splitter also reflects light emitted by the additional screen 22 toward the additional mirror 24, directing the light reflected by the first beam splitter 26 through the additional mirror toward the individual's eye. The two light beams from the acuity module and the scene module exit the display module housing 2 through an opening closed by a second beam splitter 27.

[0096] The beam splitters 26, 27 both belong to the beam splitting box 200 described below.

[0097] At this point in the description, we can describe the phoropter 100 in more detail.

[0098] exist Figure 3 Such a phoropter 100 is shown in FIG.

[0099] The phoropter comprises two optical units (or "phoropter head halves") 110, 120 for use with both eyes of an individual (at Figure 3 Only one optical unit 120 is visible).

[0100] Here, the two optical units 110 , 120 are identical.

[0101] Each optical unit 110, 120 has a housing 121 comprising two openings, an inlet 120A on the side of the scene module 20B and an outlet aperture 120B on the patient side. These openings are centered on the optical axis Y (an optical axis with the same reference numeral Y is defined for each optical unit 110, 120).

[0102] The exit aperture 120B of each optical unit 110, 120 is designed to be placed on axis of the patient's respective eye.

[0103] Housing 121 houses an optical system or module (not shown) for providing different powers of vision correction to the respective eyes of the patient.

[0104] This optical system can be of any type. In particular, it can include different lenses with different optical powers to be presented to each eye of the individual. In this embodiment, the lenses with different powers are interchanged manually or, preferably, electronically. These different powers are vision-correcting powers for the eyes of the individuals located nearby.

[0105] In the illustrated embodiment, the optical system preferably includes two lenses with adjustable power, such as liquid lenses with variable spherical power.

[0106] The variable spherical power lens has, for example, a deformable surface. The shape of this surface (in particular the radius of curvature of this surface, and therefore the spherical power provided by the lens) can be controlled mechanically (for example by a ring attached to a mechanical part driven by a motor) or in a different way.

[0107] The phoropter 100 may also include a pair of independently rotatable lenses, each lens having a cylindrical power, which can be rotated by other motors of the phoropter 100.

[0108] 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 patient's eye with a desired spherical correction and a desired cylindrical correction, as described in document WO 2015 / 1007 303.

[0109] The phoropter 100 also includes one or more support elements 122 designed to receive the individual's head and hold it in a predetermined position relative to the phoropter 100. This support element 122 can, for example, receive the individual's forehead. Alternatively or additionally, the phoropter can include an element for receiving the individual's chin.

[0110] In this embodiment, the forehead support element 122 is slidably mounted on a frame of the phoropter 100 (the frame 140 being screwed to the main housing 2) along an axis parallel to the optical axis Y, so that the distance between the patient's eye and the liquid lens of the optical units 110, 120 can be manually adjusted. To assist the optometrist in adjusting the position of the support element 122 along this sliding axis, at least one of the optical units 110, 120 includes an image sensor 180 located on one side of the housing 121, capable of acquiring side images showing both the patient's eye and the liquid lens. The computing unit is programmed to measure the distance between the patient's eye and the liquid lens on this image and to display the result of this measurement on a screen 151 visible to the optometrist.

[0111] According to the present invention, the phoropter 100 further comprises:

[0112] - movement means suitable for adjusting the position of the two optical units 110 , 120 relative to each other,

[0113] a partially reflecting mirror (second beam splitter 27 ) located along the optical path between the optical units 110 , 120 and the screen 21 ,

[0114] - image acquisition means directed towards the second beam splitter 27 for acquiring an image of the eye of an individual looking at the optotype through the two optical units 110 , 120 , and

[0115] - Image display means adapted to display the acquired images.

[0116] like Figure 1 and Figure 2 As shown, the second beam splitter 27 is placed between the first beam splitter 26, the image acquisition device and the optical units 110, 120 so that the light beams emitted by the screens 21, 22 of the acuity module 20A and the scene module 20B reach the patient's eyes and enable the image acquisition device to observe these eyes.

[0117] In other words, this second beam splitter 27 is positioned to reflect the light coming from the optical units 110 , 120 towards the image acquisition device and to allow the light beams emitted by the screens 21 , 22 of the acuity module 20A and the scene module 20B to pass through it.

[0118] The movement mechanism is designed to allow the two optical units 110, 120 to move closer to or further away from each other along an axis X, parallel to the plane of the second beam splitter 27, to accommodate different eye distances. The two optical units 110, 120 can be moved between two extreme positions: a closest position, in which the two optical elements touch each other along the X axis; and a furthest position, in which the two optical elements are separated by a maximum distance along this X axis; through intermediate positions. In these intermediate positions, the "average position" is set so that the two cameras of the optical units 110, 120 are spaced apart from the average interpupillary distance of an adult, for example, between 64 and 66 mm. Here, this axis X is orthogonal to the optical axis Y of the liquid lens.

[0119] like Figure 11 As shown, the moving device comprises a slider fixed to a frame 140 of the phoropter 100 on which each optical unit 110, 120 can slide along a single axis (X axis).

[0120] This slider comprises a cylindrical rod 141 which is fixed to a frame 140. The slider also comprises two sleeves 142 which are free to slide along the cylindrical rod 141 along the X axis.

[0121] In a first embodiment not shown in the drawings, the movement device is designed to be actuated manually.

[0122] In this embodiment, the housings 121 of the optical units 110, 120 are respectively mounted on two sleeves 142 (preferably with the ability to rotate around the Z axis). The moving device further includes at least one handle that enables the optometrist to manually adjust the relative position of one optical unit 110, 120 relative to the other.

[0123] More specifically, the moving device may comprise two handles to manually adjust the position of the two optical units relative to the support element 122. The handles may be formed by the housings 121 of the optical units 110, 120 if their shape facilitates gripping of the units.

[0124] exist Figure 11 In the preferred embodiment shown, the movement means is electric.

[0125] For this purpose, a bracket 143 is mounted on each sleeve 142 , which bracket holds one of the optical units 110 , 120 .

[0126] The moving means comprises at least one motor adapted to adjust the relative position of the two optical units 110, 102, and a controller (here a computer 150) programmed to control the motor according to images as they are acquired and processed to detect the position of the patient's pupil.

[0127] More specifically, in this preferred embodiment, the moving device includes four motors 144 that are capable of sliding the two brackets 143 along the X-axis.

[0128] A worm gear is provided between each motor 144 and one of the carriages 143. In other words, each carriage 143 is driven by a pair of motors 144 for the following reason.

[0129] Each pair of motors allows the corresponding carriage 143 to slide along the rod (along the X-axis) when the rotation of the two motors is synchronized.

[0130] When the rotation of the two motors is not synchronized, the pair of motors allows the carriage 143 to pivot about the Z axis (an axis with the same label Z is defined for each optical unit 110, 120). More specifically, in order for the carriage 143 to pivot about the Z axis without sliding along the X axis, the two motors must be controlled to have the same speed but in opposite directions.

[0131] To this end, each bracket comprises a first upper portion fixed to the corresponding sleeve 142 and a second lower portion mounted on the first portion and having mobility in rotation about the Z axis.

[0132] This second part is screwed onto the housing 121 of the respective optical unit 110 , 120 and is provided with a gear that engages with the motor screw.

[0133] Due to the mobility of rotation around the Z axis, the optical axes Y of the liquid lenses can be tilted relative to each other to be oriented in the direction of gaze of each eye of the patient. This mobility is very useful when testing the patient's near vision (which requires the patient to squint while looking at an optotype).

[0134] Thanks to their mobility along the X-axis, the liquid lenses can be positioned on the axis of the patient's eyes, that is, at a distance from each other that depends on the patient's interpupillary distance. We note that the distance between the optical axes Y of the liquid lenses is equal to the interpupillary distance only when these axes are parallel.

[0135] In order to automatically or manually adjust the distance between the two optical units 110 , 120 , an image acquisition device and an image display device are used.

[0136] In the embodiment shown, the image acquisition means comprise two cameras 132 , each directed towards the second beam splitter 27 to acquire an image of one eye of the patient looking at an optotype through one of the optical units 110 , 120 .

[0137] In an embodiment not shown, each camera 132 can be fixed to the bracket 143 of the corresponding optical unit 110, 120 and thus be integral with the corresponding optical unit 110, 120 during translation. In this variation, regardless of the distance between the two optical units 110, 120 along the X axis, the optical axis of each camera will remain perpendicular to the Y optical axis of the liquid lens of the corresponding optical unit 110, 120 on the beam splitter 27 (the two axes intersect each other in the beam splitter 27). Perpendicular means that the two axes are orthogonal and intersect each other.

[0138] However, in the embodiment shown (see Figure 3 ), the two cameras are fixed to the main housing 2 so that they are not integral with the corresponding optical units 11 and 120 when translated along the X-axis, and their optical axes are stationary. In this configuration, the optical units 110 and 120 have only one position so that the optical axis of each camera remains perpendicular to the optical axis Y of the liquid lens of the optical units 110 and 120 on the beam splitter 27. This single position of the optical units along the X-axis can be set to the above-mentioned average value.

[0139] In this embodiment, when the optical axes of the liquid lenses of the two optical units 110, 120 are in an average position, the cameras are well centered on these axes (in other words, the optical axis Y of each liquid lens intersects the optical axis of the corresponding camera). However, when the distance between these optical axes Y changes due to movement of the optical units 110, 120 away from the average position along the X axis, the optical axis Y of each liquid lens no longer intersects the optical axis of the corresponding camera, and parallax phenomena occur. As described below, these phenomena must be counteracted.

[0140] In another embodiment, the two cameras are held by the two optical units 110, 120, respectively, and are therefore integral with the respective optical units 110, 120 in translation and rotation. In this embodiment, the optical axis of each camera remains perpendicular to the optical axis Y of the liquid lens of the respective optical unit 110, 120 on the beam splitter 27 (the two axes intersect each other on the beam splitter 27), regardless of the distance separating the two optical units 110, 120 along the X axis and the angle between the optical units 110, 120 (this is useful when testing a patient's near vision, which requires the patient to squint when looking at an optotype).

[0141] Preferably, each camera 132 is housed in a small protective black box so that it is not visible to the patient.

[0142] An image display device suitable for displaying the image acquired by the camera 132 is for example an LED or OLED or LCD or TFT screen 151. It is positioned so that it can be seen by the optometrist.

[0143] exist Figure 3 In the embodiment shown, this screen 151 belongs to a computer 150 having a further human-machine interface 152 (keyboard and / or mouse).

[0144] The computer 150 is connected to the cameras 132 so as to be able to display in real time an image combination Img comprising the images acquired by these cameras (see Figure 4 ).

[0145] The computer is programmed to assist the optometrist in adjusting the distance between the optical units 110 , 120 .

[0146] If the moving device is of manual type, the computer 150 is programmed to display a sight 153 centered on each acquired image at the location of the Z optical axis of each liquid lens. This sight 153 can have a cross shape, a circular shape, or a square shape with a transparent inner surface.

[0147] As mentioned above, in the embodiment where the camera 123 is fixed to the main housing 2, the position of these sights 153 must be calculated to compensate for the parallax phenomenon that occurs when the position of the optical units 110, 120 differs from the average position. This calculation is based on the position of the optical units 110, 120 along the X axis, due to the predetermined setting that associates each position of the optical unit with the position of the sight to be displayed.

[0148] To determine the position of the optical unit, the computer may acquire the angular position of the four motors (if present) and / or use position sensors coupled to the carriage.

[0149] Then, to position the optical units 110 , 120 in front of the patient's eyes, the optometrist can use the handle to force the units to slide along the rod 141 until the patient's pupil is centered within the sight 153 (center of the cross, circle, square).

[0150] If the movement means are of the electric type, the computer 150 is programmed to automatically control the four motors to adjust the position of the two optical units 110 , 120 on the axis of the patient's pupils.

[0151] To this end, the computer 150 is here programmed to:

[0152] - displaying a sight 153 superimposed on the acquired image,

[0153] - determining the position of the patient's pupil relative to the sight 153 from the acquired image Img (for this purpose, the computer 150 is equipped with image processing functions allowing the identification of a completely black circle in the image and its position along the X axis on this image), and

[0154] - driving instructions for each motor are deduced therefrom to position a detected solid black circle representing at least the pupil of the test subject (or the iris of a dark-eyed test subject) in the centre of the sight 153 .

[0155] At this stage we can describe in more detail Figures 5 to 7 The beam splitting box 200 is shown.

[0156] This box comprises a housing consisting of three parts: an upper part 210, a middle part 211 (also called "mirror support") and a lower part 212 (see Figure 6 ).

[0157] The lower part 212 is designed to be mounted and screwed onto the main housing 2. The lower part has a large opening 213 to allow the light emitted by the screen 21 to enter the beam splitting box 200.

[0158] The middle part 211 is mounted and screwed to the lower part 212. The middle part has the shape of a roof prism with a bottom face open towards said opening 213 and two main faces equipped with beam splitters 26, 27.

[0159] The upper part 210 is mounted and screwed onto the middle part 211. The upper part has a parallelepiped shape and houses the convex mirror 24 at one end. The other end of the upper part is open and shaped to be applied to the middle part 211 along the edge of the first beam splitter 26. The screen 22 is fixed to the upper surface of this upper part 210.

[0160] The convex mirror 24 has a great thickness so that its fixing to the upper part 210 can be done in many different ways, for example by gluing its edge to the inner face of the upper part 210 .

[0161] In contrast, the beam splitters 26, 27 have a small thickness, less than 5 mm.

[0162] In this embodiment, the first beam splitter 26 has a thickness of 1 mm, and the second beam splitter 27 has a thickness of 2 mm.

[0163] These beam splitters need to be fixed to avoid excessive stress on them, which would cause them to deform and distort the measurement results.

[0164] In order to avoid such deformations, each beam splitter 26 , 27 is blocked on the middle part 211 by means of a special frame.

[0165] like Figure 8 As shown, the second beam splitter 27 has a rectangular shape. Its frame 270 has a shape similar to the shape of the edge of this beam splitter.

[0166] This frame 270 comprises four edges and means for fixing this frame to the middle part 211 .

[0167] These fixing means comprise two tongues 271 projecting from the outer surface of the first rim. These tongues 271 are designed to engage with receiving cavities provided in the middle portion 211 .

[0168] These fixing means also comprise a small opening in a second edge opposite the first edge, which receives a screw 273 engaged in a washer 274 and screwed into the intermediate portion 211 .

[0169] The frame 270 can be made of any rigid material (plastic, steel, aluminum...). It is preferably molded in one piece.

[0170] To block the second beam splitter 27, the upper surface of the frame 270 is recessed along the entire contour of its inner face. Due to this recess, the frame 270 presents a support surface 275 that is planar and defined by the outer portion of the frame. The second beam splitter 27 is housed in this recess so that it rests on the support surface 275 along its entire edge.

[0171] In order to hold the second beam splitter 27 against the support surface 275, the frame 270 includes at least three tongues 276 protruding from the upper surface of the frame to clamp the second beam splitter 27 to the support surface 275. Here, the frame 270 includes four tongues 276 distributed along the first edge and the second edge.

[0172] exist Figure 9 and Figure 10 Two embodiments of the first beam splitter 26 and its frame 260; 280 are shown in FIG.

[0173] In both embodiments, the first beam splitter 26 has a rectangular shape with chamfered corners. The frames 260; 280 have a shape similar to the shape of the edges of this beam splitter.

[0174] In these embodiments, the frame is designed to be sandwiched between the upper and middle portions of the beam splitting box 200 .

[0175] For this reason, Figure 7 As shown, the frame 260 rests on a flange provided on the middle part 211, and four supports 214 in the form of pins are provided on the inner face of the upper part to be placed against or at a small distance from the frame 260. A compressible material may be sandwiched between the pins 214 and the frame 260. In a variant in which no compressible material is used, a small gap comprised between the pins 214 and the frame 260 is provided to ensure that the frame does not deform when the upper part 210 and the middle part 211 are screwed together.

[0176] In both embodiments, the upper surface of the frame 260; 280 is recessed along the entire contour of its inner face. Due to this recess, the frame 260; 280 presents an inner portion ("frame edge") having a flat support surface 265; 285 that is bounded by the outer portion of the frame. The first beam splitter 26 is housed in this recess so that it rests along its entire edge on the support surface 265; 285 and cannot move on this flat surface.

[0177] The means for blocking the first beam splitter 26 on the support surface 265; 285 are different in the first and second embodiment.

[0178] In the first embodiment, the first beam splitter 26 does not rest directly on the support surface 265 of the frame 260. Instead, a compressible material is sandwiched between the first beam splitter 26 and the support surface 265. The compressible material is an elastomeric foam strip having the shape of the support surface 265.

[0179] In order to hold the first beam splitter 26 against the foam strip, the frame 260 comprises at least two flexible strips 261. Each strip is profiled and comprises a first rib designed to be fixed (e.g. glued) to the edge of the frame 260 and a lip protruding from the inner face of the rib and pressing against the upper surface of the first beam splitter 26. Here, each strip 261 is made of an elastomer.

[0180] In the second embodiment, since four foam pieces are sandwiched between this first beam splitter 26 and the support surface 285 , the first beam splitter 26 does not rest directly on the support surface 285 of the frame 280 .

[0181] In this second embodiment, the frame 280 comprises three small rings protruding from the support surface 265, which are designed to receive a quantity of glue.

[0182] The frame further comprises: four openings 282 located on two opposite edges, the axes of the openings being parallel to the support surface 285 and perpendicular to the longitudinal axes of the two edges; and four pins 283 glued into the four openings 282. The end of each pin 283 is longitudinally divided into two parts for clamping the first beam splitter 26 and gluing it thereto.

[0183] Thanks to the glue, the first beam splitter 26 is well attached to its frame without excessive mechanical stress.

Claims

1. An optometry device (10) for testing an eye of an individual, the optometry device comprising: A phoropter (100) for testing an individual's eye while the individual observes a target along an optical path, the phoropter comprising: - two optical units (110, 120) for both eyes of the individual, each optical unit having an entrance (120A) on the target side, an exit aperture (120B) on the individual side, and an optical system for providing different vision correction powers to the respective eyes of the individual, and - movement means suitable for adjusting the relative position of the two optical units, - a partially reflecting mirror (27) arranged along the optical path, and - image acquisition means directed towards the partially reflecting mirror (27) for acquiring an image of the eye of the individual looking at the target through the two optical units (110, 120); - a display unit (20) adapted to produce a target visible through the exit apertures (120B) of the two optical units (110, 120) of the phoropter (100), said display unit (20) comprising: - a first screen (21) suitable for displaying a test picture used to generate said target, - a second screen (22) suitable for displaying a second picture, the image of which is superimposed on the target at the exit aperture (120B) by means of a main partially reflecting mirror (26), and - at least one optical element (30) having optical power, The optical element (30) is movable between an active position in which the optical element is placed in the optical path of light emitted by the first screen (21) and leaving the device through the exit aperture (120B), and a retracted position in which the optical element remains out of the optical path so as to produce the target at a variable distance from the exit aperture (120B). Wherein a single mirror support (200) holds the main partial reflector (26) and the partial reflector (27) of the phoropter (100).

2. The optometry device (10) according to claim 1, wherein: The image acquisition means comprise two cameras (132), each camera (132) being directed towards the partially reflective mirror (27) in order to acquire an image of one eye of the individual looking at the target through one of the optical units (110, 120).

3. The optometry device (10) according to claim 1, wherein: The moving device includes a joystick to manually adjust the relative positions of the two optical units.

4. The optometry device (10) according to claim 3, wherein: The phoropter further comprises a support element (122) designed to receive the head of the individual and hold it in position, and wherein the moving device comprises two joysticks for manually adjusting the position of the two optical units relative to the support element (122).

5. The optometry device (10) according to claim 1, wherein: The moving device includes at least one motor adapted to adjust the relative position of the two optical units (110, 120) and a controller programmed to process the image acquired by the image acquisition device (132) so as to detect the position of the individual's pupil on the image, and to control the motor according to the detected position of the individual's pupil.

6. The optometry device (10) according to claim 5, wherein: The mobile device further comprises a support element (122) designed to receive the head of the individual and hold it in position, wherein the mobile device comprises two motors, and wherein the controller is programmed to automatically control the motors to adjust the position of the two optical units (110, 120) relative to the support element (122) on the axis of the individual's pupils.

7. The optometry device (10) according to claim 1, wherein: The partially reflecting mirror (27) rests along its entire edge on a frame edge of the frame of the single mirror support (200), the frame comprising three or four tongues (276) which hold the partially reflecting mirror (27) against the frame edge.

8. The optometry device (10) according to claim 1, wherein: The main partially reflecting mirror (26) rests on a frame edge of the frame of the single mirror support (200).

9. The optometry device (10) according to claim 8, wherein: The main partial reflector (26) rests against the frame edge along its entire edge, with compressible material being sandwiched between the main partial reflector (26) and the frame edge.

10. The optometry device (10) according to claim 8, wherein: The main partial reflector (26) rests directly on three or four areas protruding from the frame edge.

11. The optometry device (10) according to claim 8, wherein: The edge of the main partial reflector (26) is blocked by three or four pins (283) which clamp it in place.

12. A single mirror support for an optometry device (10) according to any one of claims 1 to 11, comprising a housing supporting the main partially reflecting mirror (26) and the partially reflecting mirror (27).

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