Improved ophthalmic apparatus

Abstract

Ophthalmic apparatus comprising: - an ocular inspection device for acquiring images of a subject's eye, wherein said ocular inspection device includes a first optical path, along which said ocular inspection device projects light towards the subject's eye and receives reflected light from the subject's eye, wherein said ocular inspection device has an eyepiece arranged along said first optical path and including at least a lens; - a detection arrangement of the position of the eye pupil operatively coupled to said ocular inspection device, wherein said detection arrangement comprises a camera assembly including at least a camera capable of acquiring images of the eye pupil and data processing means configured to calculate the position of the eye pupil by processing images of the pupil acquired by said at least a camera. Said at least a camera is able to acquire images of the pupil of the eye though at least a second optical acquisition path that passes through the at least a lens of said eyepiece. Said detection arrangement has no physical components intercepting light travelling along the first optical path of said ocular inspection device.

Description

[0001] IMPROVED OPHTHALMIC APPARATUS

[0002] DESCRIPTION

[0003] The present invention relates to the field of ophthalmic apparatus. In particular, the present invention relates to an ophthalmic apparatus provided with an ocular inspection device and an alignment system for aligning said ocular inspection device with the pupil of the eye of a subject being examined.

[0004] As is known, an ophthalmic apparatus may include an ocular inspection device, such as a fundus camera, intended to examine specific portions of the subject’s eye, such as the retina.

[0005] In many ophthalmic apparatuses, for a correct ocular examination, the aforementioned ocular inspection device must be aligned with the pupil of the eye being examined.

[0006] These devices are therefore provided with a system for measuring the position of the pupil in a three-dimensional space so as to allow automatic or manual centring of the ocular inspection device with the pupil.

[0007] Figure 1 illustrates a known type of ophthalmic apparatus 1.

[0008] The ophthalmic apparatus 1 includes an ocular inspection device 2 comprising an eyepiece 3 facing a subject’s eye E, during the ocular examination.

[0009] The ophthalmic apparatus 1 includes a detection arrangement of the position of the eye pupil. Such a detection arrangement comprises a camera assembly 4 including a pair of cameras 41, 42 arranged to acquire images of the pupil from different viewing points. The cameras have optical axes 51, 52 oriented substantially towards the nominal position of the eye pupil P and passing next to the eyepiece 3 of the ocular inspection device.

[0010] The detection arrangement includes data processing means capable of calculating the position of the eye pupil P by processing the images acquired by cameras 41, 42 using appropriate stereoscopic image analysis algorithms.

[0011] Solutions of the type illustrated in Figure 1 are normally used in ophthalmic apparatuses including ocular inspection devices with a relatively narrow field, for example up to approximately 60°. However, they are difficult, if not impossible, to employ in ophthalmic apparatuses including ocular inspection devices with ultra-wide angular acquisition fields, for example greater than 60°.

[0012] In ophthalmic apparatuses of this type, in fact, the eyepiece of the ocular inspection device has normally relatively large dimensions and is positioned in the immediate vicinity of the eye of the subject being observed, during the ocular examination.

[0013] This implies that the cameras of the detection arrangement must necessarily have optical axes that are very inclined with respect to the optical axis of the eyepiece of the ocular inspection device in order to be able to image the eye pupil. Therefore, during an ocular examination, the acquisition of images of the pupil of the eye can be easily prevented or hindered by the subject's cheekbones or nose. This circumstance may obviously compromise the ongoing ocular examination.

[0014] Furthermore, being exposed to the surrounding environment, the above-mentioned cameras may easily get dirty with fingerprints or dust and consequently require frequent cleaning. Installing a protective window for the cameras would not solve the problem because it would require frequent cleaning as well. Evidently, all these problems lead to an increase in the time and costs of maintenance of the ophthalmic apparatus.

[0015] US2023 / 0397810A1 discloses an apparatus for observing a subject’s eye, which comprises illuminating means adapted to emit light towards the eye, acquisition means comprising suitable cameras capable of acquiring images of the eye, with both the illumination means and acquisition means optically coupled to the eye by means of a lens.

[0016] The observation apparatus also comprises measuring means of the position of the eye, which are configured to process the images acquired by said cameras.

[0017] The observation apparatus is a self-standing system, which cannot be mounted on an eye inspection device as there is no useful space for a dedicated optical path, along which an ocular inspection device could project light towards the subject’s eye and receive reflected light from the latter in order to acquire images of an eye portion, for example the retina.

[0018] JP2008161406A discloses an ophthalmic apparatus including an ocular inspection device of a subject’s eye and a detection arrangement of the position of the eye pupil, which is operatively coupled to said ocular inspection device. Such a detection arrangement comprises illuminating means adapted to emit light towards the eye, acquisition means comprising cameras capable of acquiring images of the eye and measuring means of the position of the eye pupil based on the images acquired by said cameras. The detection arrangement is optically coupled to the optical path of the ocular inspection device by means of a beam splitter (the so-called dichroic mirror).

[0019] The beam splitter has the disadvantage of disturbing both the illumination light radiation travelling from the ocular inspection device to the subject’s eye and the reflected light travelling from the eye to the ocular inspection device. It may also cause undesired reflections overlapped to the light returning from the eye to the ocular inspection device which may reduce contrast or create artifacts. Therefore, the arrangement of the beam splitter in the optical path of the ocular inspection device causes an overall loss of quality of the images acquired by the ocular inspection device during eye examination.

[0020] The main task of the present invention is to provide an ophthalmic apparatus which allows the drawbacks of the prior art, highlighted above, to be overcome.

[0021] Within this scope, an object of the present invention is to provide an ophthalmic apparatus including an ocular inspection device operatively coupled to a detection arrangement, which is capable of detecting the position of the pupil by means of cameras even if such an ocular inspection device has an ultra-wide field.

[0022] A further object of the present invention is to provide an ophthalmic apparatus that does not require periodic cleaning of lenses or windows of cameras used to detect the position of the pupil.

[0023] A further object of the present invention is to provide an ophthalmic apparatus having a cleaner and more essential aesthetic appearance, with an eyepiece as the only optic in view and without additional lenses or camera windows used to detect the position of the pupil.

[0024] A further object of the present invention is to provide an ophthalmic apparatus that is relatively simple to manufacture on an industrial level, at competitive costs.

[0025] This task and these objects, as well as other objects which will be apparent from the following description and the accompanying drawings, are achieved, according to the invention, by an ophthalmic apparatus, according to claim 1, proposed below, and the related dependent claims.

[0026] The ophthalmic apparatus, according to the invention, comprises an ocular inspection device for acquiring images of a subject’s eye.

[0027] The ocular inspection device includes a first optical path, through which said ocular inspection device projects light towards the subject’s eye and receives light reflected by the subject’s eye, during an ocular examination.

[0028] The ocular inspection device has an eyepiece arranged along said first optical path and including at least a lens.

[0029] Preferably, the ocular inspection device has an ultra-wide optical field, for example an optical field wider than 60°. In principle, however, the ocular inspection device could have a narrower field.

[0030] The ophthalmic apparatus, according to the invention, comprises a detection arrangement of the position of the eye pupil, which is operatively coupled to the ocular inspection device.

[0031] The detection arrangement comprises a camera assembly including at least a camera capable of acquiring images of the eye pupil of a subject under observation.

[0032] The detection arrangement further comprises data processing means configured to calculate the position of the eye pupil of a subject under observation by processing images of the eye pupil acquired by said at least a camera.

[0033] Preferably, said ocular inspection device is movable in a three-dimensional space.

[0034] Preferably, the ophthalmic apparatus also comprises actuation means operatively coupled to the ocular inspection device. Said actuation means are structured to move said ocular inspection device in a three-dimensional space.

[0035] According to the invention, the aforementioned detection arrangement is structured in such a way that at least a camera of the camera assembly is capable of acquiring images of the pupil of the eye using at least a corresponding second optical path passing through the at least a lens of the eyepiece of the ocular inspection device.

[0036] Additionally, the aforementioned detection arrangement is structured in such a way that no physical components of said detection arrangement intercept the light radiation travelling along the first optical path of the ocular inspection device. In practice, according to the invention, the physical components of the detection arrangement are positioned outside the space volume occupied by the light radiation travelling along the first optical path of the ocular inspection device in such a way not to intercept the light radiation used by said ocular inspection device to acquire images of the eye, during an ocular examination.

[0037] Preferably, the aforementioned camera assembly comprises a pair of cameras. In this case, the cameras are preferably mounted symmetrically with respect to a vertical plane passing through the optical axis of the eyepiece of the ocular inspection device.

[0038] Preferably, the at least a camera of the camera assembly comprises a pinhole objective.

[0039] According to some embodiments of the invention, the aforementioned camera assembly comprises at least a mirror arranged along the at least a second optical path of said at least a camera so as to reflect light radiation, coming from the pupil of the eye and passing through the at least a lens of the eyepiece, towards the aforementioned at least a camera.

[0040] According to some embodiments of the invention, the aforementioned camera assembly comprises at least a camera having a useful acquisition field of the light radiation coming from the pupil that is narrower than the total field of an objective of said at least a camera. In this case, the useful acquisition field of an objective of said at least a camera has an acquisition axis inclined with respect to an optical axis of said objective.

[0041] Preferably, in the operation of said apparatus, during an ocular examination, said ocular inspection device is positioned with respect to the eye pupil of a subject under observation such that the eye pupil is located at or in proximity to a focal point of at least a lens of the eyepiece of the ocular inspection device, through which the light radiation used by said at least a camera to acquire images of the eye pupil passes.

[0042] Preferably, said camera assembly is positioned internally to a casing portion, which surrounds at least partially the eyepiece of the ocular inspection device.

[0043] Further features and advantages of the ophthalmic apparatus, according to the invention, will be better understood with reference to the description given below and to the accompanying figures, provided for merely illustrative and non-limiting purposes, in which:

[0044] - Figure 1 schematically illustrates a known type of ophthalmic apparatus; and

[0045] - Figure 2 schematically illustrates a block diagram of an ophthalmic apparatus, according to the invention; and

[0046] - Figure 3 schematically illustrates a perspective view of the ophthalmic apparatus, according to the invention; and

[0047] - Figure 3 A schematically illustrates a portion of an ocular inspection device included in the ophthalmic apparatus, according to the invention; and

[0048] - Figures 4-7 schematically illustrate an embodiment of the ophthalmic apparatus, according to the invention; and

[0049] - Figures 8-12 schematically illustrate a further embodiment of the ophthalmic apparatus, according to the invention.

[0050] With reference to the aforementioned figures, the present invention relates to an ophthalmic apparatus 100.

[0051] The ophthalmic apparatus 100 includes an ocular inspection device 120 for acquiring images of a subject’s eye E during an ocular examination.

[0052] The ocular inspection device 120 may be, for example, a fundus camera, an ophthalmoscope, an OCT (Optical Coherence Tomography) ocular inspection device, a microperimeter, or a similar device.

[0053] The ocular inspection device 120 includes a first optical path OP, along which the light radiation L used to examine a subject's eye E can travel (figure 3 A).

[0054] In operation, the ocular inspection device 120 projects light towards a suitable eye portion and receives the light reflected by said eye portion to acquire suitable images of said eye portion. As an example, the ocular inspection device 120 may include illuminating means (not shown) projecting light along the first optical path OP to illuminate the eye retina R and suitable acquisition means (not shown) adapted to receive the reflected light along the first optical path OP and acquire images of the retina R. The ocular inspection device 120 has an eyepiece 110 arranged along the first optical path OP having an optical axis A.

[0055] For the sake of clarity, it is specified that, in the context of the present invention, the eyepiece 110 identifies a group of lenses of the ocular inspection device that faces the subject's eye E during an ocular examination.

[0056] The eyepiece 110 includes one or more lenses 111. Evidently, the eyepiece 110 can contain any number of lenses. For example, it could comprise a single lens or a group of lenses bonded together, such as a doublet composed of two bonded lenses, or any combination of single lenses and / or bonded lens groups.

[0057] As it evident in figure 3 A, the light radiation L travelling along the first optical path OP of the ocular inspection device 120 occupies a certain space volume. Therefore, the light radiation L passes through a section lens Al of the eyepiece 100, which is preferably centred on the optical axis A of the latter (figure 7).

[0058] Preferably, the ocular inspection device 120 has an ultra-wide field, e.g., wider than 60°. In principle, however, the ophthalmic apparatus 100 could have a narrower field, for example less than or equal to 60°.

[0059] For the sake of clarity, it is specified that, in the context of the present invention, the field of the ocular inspection device identifies the maximum angle a that can be defined, on a certain reference plane, by two beams of light projected from the ocular inspection device towards the retina of the eye through the pupil and / or defined by two beams of light coming from the retina of the eye, passing through the pupil, and received by the ocular inspection device (figure 3A).

[0060] For example, in the case of a fundus camera, the definition of field is detailed in the ISO 10940 standard. For other types of ocular inspection devices, the field may be defined similarly to that for a fundus camera.

[0061] The extent of the field may be different if measured along different reference planes. Typically, the field measured along a horizontal reference plane is greater than or equal to the field measured along a vertical reference plane.

[0062] For the sake of clarity, it should be noted that, in the context of the present invention, the terms horizontal and vertical refer to a normal position of use of the ophthalmic apparatus, as illustrated in the aforementioned Figures 1-3.

[0063] The ophthalmic apparatus 100 comprises a detection arrangement 500 for detecting the position of the pupil P of the eye E, during an ocular examination.

[0064] The detection arrangement 500 is operatively coupled to the ocular inspection device 120 and it is adapted to measure the position occupied by the eye pupil P of a subject under observation with respect to the ocular inspection device 120.

[0065] The detection arrangement 500 comprises a camera assembly 200, which includes one or more cameras 210, 220 capable of acquiring images of the eye pupil P, and data processing means 250 (for example a computerized unit), which are capable of processing the images provided by the camera assembly 200 and calculating the position of the eye pupil P, at a certain instant, in a reference system that is preferably integral with the ocular inspection device 120.

[0066] Preferably, the calculated position data are indicative of the relative positioning between the pupil P and the ocular inspection device 120, during the ocular examination. Such a position data can be simply made available to the user or can be further processed according to the needs.

[0067] Preferably, each camera 210, 220 of the camera assembly 200 comprises an objective 211, 221 (having a corresponding optical axis OA - Figure 9) and a sensor 212, 222 (for example a C-MOS sensor) optically coupled to each other.

[0068] According to the embodiments of the invention illustrated in Figures 3-12, the camera assembly 200 comprises a pair of cameras 210, 220, which can be mounted (preferably side by side) symmetrically with respect to a vertical plane passing through the optical axis A of the eyepiece 110, advantageously under the optical axis A of the eyepiece 110.

[0069] For reasons of simplicity of exposition, the ophthalmic apparatus according to the invention will be described below with specific reference to these preferred embodiments. This is not intended to limit the scope of this invention in any way. In principle, in fact, the camera assembly 200 could comprise a single camera, or a pair of cameras mounted in diametrically opposed positions with respect to the optical axis A of the eyepiece 110, or a greater number of cameras mounted on one side or on opposite sides of the eyepiece 100.

[0070] As a further alternative, the camera assembly 200 could comprise a stereo camera that includes a pair of side-by-side objectives and a pair of sensors mounted on a common electronic board.

[0071] Preferably, the camera assembly 200 is housed in an internal volume defined by a casing 125 of the ocular inspection device 120. More specifically, the camera assembly 200 is housed in a chamber 1251 defined in a casing portion 1250 that surrounds, at least partially, the eyepiece 110 (Figures 3, 6, 7, 11, 12).

[0072] As will be better seen later, the mounting of the cameras in the chamber 1251, close to the eyepiece 110, is greatly facilitated by the special arrangement of the cameras 210, 220. Preferably the detection arrangement 500 comprises also illuminating means 260 that include, for example, one or more LED devices mounted on a dedicated electronic board (Figure 2). The illuminating means 260 are adapted to emit light towards the eye E in order to illuminate an area surrounding the pupil P.

[0073] Preferably, the illuminating means 260 are mounted together with the camera assembly 200. In case the camera assembly 200 includes two cameras 210, 220, the illuminating means 260 can be mounted between the aforementioned cameras, in the same chamber 1251 housing said cameras.

[0074] Preferably the illuminating means 260 are capable of emitting infrared light.

[0075] Normally, the ocular inspection device 120 is movable with respect to a support base (not shown) and a support structure (not shown) for resting the subject's face, both of which are in a fixed position.

[0076] Preferably, with reference to Figure 2, the ophthalmic apparatus 100 comprises an alignment system suitable for positioning the ocular inspection device 120 in a position of alignment with respect to the pupil P of an eye E of the subject being examined.

[0077] For clarity, it is specified that an alignment position of the ocular inspection device 110 is a position at which the following operating conditions occur:

[0078] - the optical axis A of the eyepiece 110 of the ocular inspection device 120 passes through a predefined area of the eye pupil P, e.g. through the centre of the eye pupil P; and

[0079] - the eyepiece 110 is at a predefined optimal distance from the eye pupil P.

[0080] The above-mentioned alignment system of the ophthalmic apparatus comprises the detection arrangement 500 and actuation means 300 adapted to move the ocular inspection device 120 into an alignment position with respect to the pupil P of the eye E.

[0081] The actuation means 300 are operatively coupled to the ocular inspection device 120 and are capable of moving the latter in space along three degrees of freedom of a reference system integral with the support base and the support structure of the subject’s face.

[0082] The actuation means 300 may comprise a motorized mechanism that can be automatically controlled by the control unit 250, which is preferably provided with an appropriate user interface. Alternatively, they may include a mechanism that can be manually operated by a user.

[0083] According to some embodiments of the invention, the actuation means 300 are operatively coupled to the detection arrangement 500. In this case, the data processing means 250 process the images provided by the camera assembly 200, calculate the position of the eye pupil P and provide, based on the calculated position data, command signals to the actuation means 300 in order to automatically move the ocular inspection device 120 in a predefined (working) position relative to the pupil P.

[0084] According to alternative embodiments, however, the detection arrangement 500 makes available the calculated position data directly to the user in order to allow the actuation means 300 to be operated manually.

[0085] In general, the ocular inspection device 120, the ocular 110, the data processing means 250, the actuation means 300 and the illuminating means 260 can be manufactured on an industrial level according to known type solutions. Hereinafter, all these parts or components of the ophthalmic apparatus 100 will not be described in further detail but only with reference to the aspects of interest for the invention, for obvious reasons of brevity of exposition. Of course, the ophthalmic apparatus 100 could include further parts or components (for example, a head rest, a chin rest, a joystick, and the like), which are not described herein as they are of little interest for the purposes of the invention.

[0086] An important aspect of the invention consists in that the (one or more) cameras 210, 220 of the camera assembly 200 are capable of acquiring images of the pupil P of the eye using (one or more) corresponding second optical paths 213, 223 passing through at least a lens 111 of the eyepiece 110. In other words, during operation of the ophthalmic apparatus, each camera 210, 220 of the camera assembly is capable of acquiring light radiation coming from the pupil P of the eye through a corresponding second optical path 213, 223 which passes through at least a lens 111 of the eyepiece 110.

[0087] For the sake of clarity, it is specified that, within the scope of the present invention, each second optical path 213, 223 of a camera 210, 220 is an acquisition path followed by the light radiation coming from the pupil P, captured by the camera and used by the aforementioned camera to acquire an image of the pupil.

[0088] A further important aspect of the invention consists in that the detection arrangement 500 does not include physical components positioned in such a way to intercept the light radiation L travelling along the first optical path OP of the ocular inspection device.

[0089] In practice, differently from the solutions of the state of the art, all the physical components of the detection arrangement 500 are positioned outside the space volume occupied by the light radiation travelling along the first optical path OP.

[0090] In the following, for reasons of simplicity of exposition, the ophthalmic apparatus 100 will be described in more details with specific reference to embodiments, in which the (one or more) second optical paths of the (one or more) cameras 210, 220 pass through a single lens 111 of the eyepiece 110. This is not intended to limit the scope of this invention in any way. In principle, in fact, the second optical paths of the aforementioned cameras could pass through a group of lenses or all of the lenses of the eyepiece 110 provided that no physical components of the detection arrangement 500 intercept the light radiation L travelling along the first optical path OP of the ocular inspection device.

[0091] According to the present invention, the lens 111 of the eyepiece 110, crossed by the acquisition paths 213, 223 of the cameras 210, 220, cooperates with the objectives 211, 221 of the cameras 210, 220 to form the image of the pupil P on the sensors 212, 222 of the cameras themselves. In practice, the lens 111 of the eyepiece 110 helps to conjugate optically the pupil P with the sensors 212, 222 of the cameras 210, 220.

[0092] This allows the cameras 210, 220 to be arranged with optical axes oriented according to desired directions along second optical paths 213, 223 which are bent by refraction by the lens 111 so as to be oriented towards the pupil P of the eye being examined.

[0093] The optical axes of the cameras 210, 220 do not therefore necessarily have to be oriented towards the pupil P of the eye being examined as in the prior art solutions.

[0094] As it can be noted in Figures 3 to 8, the second optical paths 213, 223 of the cameras 210, 220 are not too inclined with respect to the axis A of the eyepiece 110, not even in the case of an ultra-wide field of the ophthalmic apparatus.

[0095] This advantageous aspect of the invention is essentially due to the fact that the acquisition paths 213, 223 of the cameras 210, 220 extend from the pupil P of the eye E to the cameras passing through the lens 111 of the eyepiece 110 instead of passing outside the eyepiece itself, as occurs in the prior art solutions.

[0096] Consequently, unlike known solutions, the pupil of the eye being examined can be easily imaged by the cameras 210, 220 of the camera assembly 200, even in the case in which the ophthalmic apparatus 100 has an ultra- wide field (greater than 60°) and is provided with an eyepiece 110 of relatively large dimensions and positioned close to the eye to be examined.

[0097] A further advantage of the present invention arises from the fact that the lens 111 of the eyepiece 110 crossed by the acquisition paths 213, 223 of the cameras 210, 220 is interposed between the cameras 210, 220 and the eye E of the subject during the ocular examination, along the acquisition paths 213, 223.

[0098] The lens 111 of eyepiece 110 is thus able to protect the cameras 210, 220 from dirt and fingerprints. Of course, the outer surface of the eyepiece lens I l l is cleaned periodically to ensure proper functioning of the ocular inspection device 120. However, an important advantage of the invention lies precisely in that the cleaning operations to be carried out are limited to the lens 111 of the eyepiece 110 since, unlike prior art solutions, it is no longer necessary to provide for any periodic cleaning of the camera lenses or of any protective optical window for the cameras themselves. Evidently, all this allows to reduce the maintenance time and costs of the ophthalmic apparatus 100.

[0099] The solution proposed by the present invention offers some advantages even if used in an ophthalmic apparatus with a narrower field (less than or equal to 60°). For example, it allows avoiding or reduce maintenance interventions for cleaning the lenses of the cameras 210, 220 or any optical windows protecting the cameras themselves. Additionally, it allows the cameras 210, 220 to be arranged inside the casing 125 of the ophthalmic apparatus, which can thus have a more aesthetically pleasing appearance, with the eyepiece 110 as the only optic in view and without additional windows for the cameras used to detect the position of the pupil, as occurs in known prior art solutions.

[0100] Preferably, in the operation of the ophthalmic apparatus, during an ocular examination, the ocular inspection device 120 is positioned with respect to the pupil P of the eye E of the subject under observation such that the said pupil is positioned at or near a focal point of the said at least a lens 111 of the eyepiece 110 crossed by the second optical paths 213, 223 of the cameras 210, 220. In this way, the light beams coming from points located in the plane of the pupil P diverge before passing through the lens 111 of the eyepiece 110 and become substantially parallel following passage through the aforementioned lens (Figures 4 and 8).

[0101] The cameras 210, 220 may thus include objectives 211, 221 conjugated at infinity, i.e. arranged so as to form images of very distant objects on a corresponding sensor 212, 222.

[0102] Objectives of this type are widely available commercially, at relatively low costs. This solution is particularly advantageous as it allows for a significant reduction in the costs of manufacturing the camera assembly 200.

[0103] In principle, however, during an ocular examination, the pupil P of eye E of a subject being observed could also be in a position relatively distant from the focal point of the lens 111 of the eyepiece 110. In this case, the cameras 210, 220 can still acquire images of the pupil through lens 111, but using objectives 211, 221 that are not conjugated at infinity.

[0104] As mentioned above, the physical components of the detection arrangement 500 (for example, all the parts and components of the camera assembly 200, the illuminating means 260, and the data processing means 250) are arranged in such a way not to intercept the light radiation L travelling along the first optical path OP of the ocular inspection device.

[0105] This solution allows remarkably improving the quality of the images acquired by the ocular inspection device as the presence of artefacts, reflections, or loss of optical power due to the presence of extraneous objects along the first optical path OP (such as beam splitters, as it occurs in the solutions of the state of the art) is prevented.

[0106] Figures 4-7 refer to a possible embodiment of the ophthalmic apparatus, according to the invention.

[0107] According to this embodiment, the camera assembly 200 comprises one or more mirrors 214, 224 arranged along the second optical paths 213, 223 of the cameras 210, 220 so as to be interposed between the lens 111 of the eyepiece 110 and the aforementioned cameras.

[0108] During the ocular examination, each mirror 214, 224 reflects the light radiation, which comes from the pupil P of the eye being examined and which passes through the lens 111 of the eyepiece 110, towards a corresponding camera 210, 220.

[0109] Preferably, the camera assembly 200 includes a mirror 214, 224 for each camera 210, 220.

[0110] According to alternative embodiments (not illustrated), however, the camera assembly 200 could comprise a single mirror sufficiently large to direct the light radiation coming from the pupil P towards a plurality of cameras or a stereo camera.

[0111] In Fig. 7, the section A0 of the lens 111 of the eyepiece 110 is shown, crossed by the second optical paths 213, 223 of the cameras 210, 220 during an ocular examination.

[0112] The lens section A0 includes a portion Al, through which it passes the light radiation L travelling along the first optical path P0 and used by the ocular inspection device 120 to examine the eye E (figure 3 A).

[0113] As can be observed, the shape of the section portion Al is similar to a disk from which two diametrically opposed portions A2 and A3 are missing with respect to the optical axis A of the eyepiece 110. This shape is typical for a fundus camera or other types of ophthalmic devices.

[0114] It can be noted how the cameras 210, 220 and the mirrors 214, 224 can be easily positioned so as to optimize the volume through which the light radiation useful for the ocular inspection device 120 passes.

[0115] To this end, the use of mirrors 214, 224 is particularly advantageous since it allows the body of cameras 210, 220 to be moved laterally to move it away from the optical axis A of eyepiece 110 so as to leave more available space for the volume occupied by the light radiation used by the ocular inspection device during eye examination.

[0116] The section portions A2, A3 of the lens 111 are not crossed by light radiation useful for the ocular inspection device 120.

[0117] Consequently, the section portions A2, A3 of the lens 111 are available and can be crossed by the second optical paths 213, 223 of the cameras 210, 220. For example, light beams coming from the pupil P of the eye under examination may pass through suitable areas A4, A5 of the section portion A2 of the lens 111 of the eyepiece 110, as illustrated in Figure 7.

[0118] In principle, however, the acquisition paths 213, 223 of the cameras 210, 220 could pass through the lens 111 of the eyepiece 110 even at the section portion Al without negatively affecting the performance of the ocular inspection device 120.

[0119] In this respect, it is in fact sufficient that the physical components of the ophthalmic apparatus, arranged in the vicinity of the eyepiece 110 (for example between the mirrors 214, 224 and cameras 210, 220), do not intercept the first optical path P0 of the light radiation used by the ocular inspection device 120 to examine the eye.

[0120] In this sense, the presence of the mirrors 214, 224 is useful for moving the cameras 210, 220 away from the optical axis A of the eyepiece 110 and consequently for increasing the useful volume for the passage of the light radiation used for the ocular inspection device.

[0121] According to the embodiment of Figures 4-7, the cameras 210, 220 of the camera assembly 200 may include pinhole type objectives 211, 221.

[0122] For the sake of clarity, it is specified that, in the context of the present invention, a pinhole objective is an objective provided with an external diaphragm, with all its lenses arranged between the external diaphragm and the sensor that acquires the image (e.g., shown in figures 8-9).

[0123] This solution is advantageous because it allows for a reduction in the size of the mirrors 214, 224 intended to reflect the light radiation coming from the pupil P of the eye. Obviously, a reduction in the size of the mirrors 214, 224 further facilitates the arrangement of the latter so as to increase the volume occupied by the light radiation useful for the ocular inspection device 120.

[0124] Figures 8-12 refer to a further embodiment of the ophthalmic apparatus, according to the invention.

[0125] According to this embodiment, the cameras 210, 220 of the camera assembly 200 have a useful acquisition field UF narrow compared to the total field TF of the objectives 211, 212 of the aforementioned cameras (Figure 9).

[0126] For the sake of clarity, it should be noted that, in the context of the present invention, the total field TF of an objective is the angular field (typically conical in shape) in which the objective is able to receive light radiation useful for generating an image (Figure 9).

[0127] Instead, the useful acquisition field UF of the cameras 210, 220 is the portion (typically pyramidal in shape) of the total field TF, through which the light radiation passes which is capable of producing an image on the surface of the sensor 212, 222 (Figure 9). In practice, according to this embodiment, the cameras 210, 220 of the camera assembly 200 have a useful acquisition field UF of the light radiation coming from the pupil P which constitutes only a portion of the total field TF of their objectives 211, 221.

[0128] The useful acquisition field UF of the cameras 210, 220 has an acquisition axis FA inclined with respect to the optical axis OA of the objectives 211, 221 of the aforementioned cameras. This implies that the useful acquisition field UF of the cameras 210, 220 is in an eccentric position with respect to the total field TF of the objectives 211, 221.

[0129] The position of the useful acquisition field eccentric with respect to the objective axis offers the important advantage of allowing the body of each camera 210, 220 to be tilted so as to increase the volume available for the passage of the light radiation used for the ocular inspection device 120 (Figure 12).

[0130] Preferably, the sensor 212, 224 of each camera 210, 220 is off-centre with respect to the OA axis of the objective of said camera.

[0131] Even in the absence of this decentration, the acquisition of images corresponding to the useful acquisition field UF would be possible but each camera 210, 220 would have to be provided with a sensor 212, 224 with a relatively large active surface and use an acquisition window that is off-centre and corresponds only to a portion of the active surface of the sensor.

[0132] The off-centre positioning of the sensor 212, 224 of each camera 210, 220 with respect to the OA axis of the camera objective allows for a better match between the overall active surface of the sensor and the useful acquisition field UF of the camera.

[0133] The sensor 212, 224 of each camera 210, 220 is thus able to acquire images corresponding to the useful acquisition field UF even if it has a relatively small active surface. Obviously, this allows for the installation of cheaper cameras with smaller overall dimensions.

[0134] Preferably, the objectives 211, 221 of the cameras 210, 220 have a relatively large total field of view TF, e.g. greater than 60°.

[0135] Preferably, the cameras 210, 220 are provided with pinhole type objectives 211, 221. The use of these objectives allows to reduce the surface of the areas A4, A5 of the portion of section A2 crossed by the second optical paths 213, 223, along which it travels the light radiation used by the cameras 210, 220 to acquire images of the pupil P, as shown in figure 12.

[0136] This allows to place the cameras 210, 220 closer to the border of the lens 111, thus leading to a further increase of the volume crossed by the light radiation used by the ocular inspection device 120 to examine the eye E.

[0137] According to this embodiment of the invention, the cameras 210, 220 have the axis FA of their useful field UF inclined with respect to the optical axis OA of their objectives. This allows the body of the cameras 210, 220 to be inclined, so that it can be moved even more distant from the optical axis A of the eyepiece 110. Obviously, this allows to further increase of the volume through which the light radiation useful for the ocular inspection device 120 passes (Figure 12).

[0138] Furthermore, according to this embodiment of the invention, it is possible to avoid the provision of mirrors with a consequent reduction in the structural complexity of the camera assembly 200.

[0139] However, variations of the solution proposed in Figures 8-12 are possible in which cameras 210, 220 with “standard” objectives (i.e., not pinhole type) are used. Even in these cases, the cameras 210, 220 can be mounted inclined with respect to the optical axis OA of their objectives so as to distance their body from the optical axis A of the eyepiece 110.

[0140] Variants of the solution proposed in Figures 8-12 are also possible, in which mirrors are used in combination with cameras 210, 220. Even in these cases, the cameras 210, 220 can be mounted inclined with respect to the optical axis OA of their objectives, so as to reduce the dimensions of the aforementioned mirrors and increase the useful volume used for the passage of the light radiation used for the ocular inspection device 120 (Figure 12).

[0141] It has been seen in practice that the ophthalmic apparatus, according to the invention, allows the described drawbacks of the prior art to be solved, achieving the intended objects.

[0142] The ophthalmic apparatus, according to the invention, is able to detect the position of the pupil, by means of cameras, even if the ocular inspection device has an ultra-wide field.

[0143] The ophthalmic apparatus, according to the invention, ensures high operational reliability and does not require frequent maintenance and cleaning, especially with regard to the cameras of the camera assembly.

[0144] The ophthalmic apparatus, according to the invention, has a relatively simple structure. Unlike prior art solutions, the camera assembly can be easily integrated with the eyepiece of the ocular inspection device reducing weights and dimensions.

[0145] Since the detection arrangement 500 has no physical components intercepting light L travelling along the first optical path OP of the ocular inspection device 120, the ophthalmic apparatus, according to the invention, is able to perform a high-quality eye examination, which is generally more performant compared to the ophthalmic apparatuses using beam splitters, described in some of the prior art solutions.

[0146] The ophthalmic apparatus, according to the invention, has a more aesthetically pleasing appearance, with the eyepiece as the only optic in view and without additional lenses or windows for the cameras used to detect the position of the pupil, as occurs in prior art solutions.

[0147] The ophthalmic device, according to the invention, can be manufactured industrially at very competitive costs compared to prior art solutions. For example, the camera assembly may include cameras with low-cost objectives or micro cameras that are widely available on the market at relatively low costs.

Claims

CLAIMS1. Ophthalmic apparatus (100) comprising:- an ocular inspection device (120) for acquiring images of a subject’s eye (E), wherein said ocular inspection device includes a first optical path (OP), along which said ocular inspection device projects light towards the subject’s eye and receives reflected light from the subject’s eye, wherein said ocular inspection device has an eyepiece (110) arranged along said first optical path and including at least a lens (111);- a detection arrangement (500) of the position of the eye pupil (P) operatively coupled to said ocular inspection device (120), wherein said detection arrangement comprises a camera assembly (200) including at least a camera (210, 220) capable of acquiring images of the eye pupil (P) and data processing means (250) configured to calculate the position of the eye pupil by processing images acquired by said at least a camera (210, 220); characterized in that said at least a camera (210, 220) is able to acquire images of the pupil (P) of the eye though at least a second optical path (213, 223) that passes through the at least a lens of said eyepiece (110), wherein said detection arrangement (500) has no physical components intercepting light (L) travelling along the first optical path (OP) of said ocular inspection device.

2. Ophthalmic apparatus, according to claim 1, characterised in that said camera assembly (200) comprises a pair of cameras (210, 220).

3. Ophthalmic apparatus, according to claim 2, characterised in that said cameras (210, 220) are mounted symmetrically with respect to a vertical plane passing through an optical axis (A) of said eyepiece (110).

4. Ophthalmic apparatus, according to one of the preceding claims, characterised in that said at least a camera (210, 220) comprises a pinhole objective (211, 221).

5. Ophthalmic apparatus, according to one of the preceding claims, characterised in that said camera assembly (200) comprises at least a mirror (214, 224) arranged along the at least a second optical path (213, 223) of said at least a camera (210, 220) so as to reflect light radiation, which comes from the eye pupil (P) and passes through said at least a lens (111) of said eyepiece (110) towards said at least a camera (210, 220).

6. Ophthalmic apparatus, according to one of the preceding claims, characterised in that said camera assembly (200) comprises at least a camera (210, 220) having an useful acquisition field (UF) of light radiation coming from the eye pupil (P), which is formed by a portion of the overall field (TF) of an objective (211, 221) of said at least a camera,said useful acquisition field having an acquisition axis (FA) inclined with respect to an optical axis (OA) of the objective (211, 221) of said at least a camera.

7. Ophthalmic apparatus, according to one of the preceding claims, characterised in that said camera assembly (200) is positioned internally to a casing portion (1251) surrounding at least partially the eyepiece (110) of said ocular inspection device (120).

8. Ophthalmic apparatus, according to one of the preceding claims, characterised in that, during an ocular examination, said ocular inspection device (12) is positioned with respect to the eye pupil (P) so that the eye pupil is located at or in proximity of a focal point of the at least a lens (111) of said eyepiece (110).

9. Ophthalmic apparatus, according to one of the preceding claims, characterised in that said detection arrangement (500) includes illuminating means (260) structured to emit light towards the subject’s eye (E) and illuminate an area surrounding the eye pupil (P).

10. Ophthalmic apparatus, according to one of the previous claims, characterised in that it comprises actuation means (300) operatively coupled to said ocular inspection device and structured to move said ocular inspection device (120) in a three-dimensional space.

11. Ophthalmic apparatus, according to one of the previous claims, characterised in that said ocular inspection device (120) has a field wider than 60°.

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