Ophthalmic observation device

Abstract

The ophthalmic observation device (1) of the exemplary embodiment includes an illumination system (30), an imaging system (40), and a focusing processing unit (200, 210). The illumination system includes a light source (32a) that emits illumination light and a marker member (35) provided with a plurality of markers (36a, 36b), and projects the illumination light onto the eye to be examined (E) by means of the marker member. The imaging system includes an imaging element (62) and images the eye to be examined. The focusing processing unit detects a plurality of marker images from the image obtained by the imaging system, and performs focusing control of the imaging system based on the detected plurality of marker images.

Description

Technical Field

[0001] (Cross - reference to Related Applications)

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 106,087, filed on October 27, 2020, with the title "APPARATUS AND METHOD FOR OPHTHALMIC OBSERVATION", which is incorporated herein by reference in its entirety.

[0003] The present disclosure relates to an ophthalmic observation device. Background Art

[0004] An ophthalmic observation device is a device for observing a patient's eye (referred to as the eye to be examined). Ophthalmic observation is performed to grasp the state of the eye to be examined in various situations such as examinations, surgeries, and treatments.

[0005] Conventional ophthalmic observation devices provide an enlarged image obtained by an objective lens and a zoom optical system to a user via an eyepiece lens. However, in recent years, there are ophthalmic observation devices having the following structure: using an imaging element to capture the enlarged image obtained by the objective lens and the zoom optical system, and displaying the obtained captured image (referred to as a digital ophthalmic observation device). The types of digital ophthalmic observation devices include operating microscopes, slit - lamp microscopes, fundus cameras, etc. In addition, functions as digital ophthalmic observation devices are also provided in various ophthalmic examination devices such as refractometers, corneal astigmatometers, tonometers, corneal endothelial microscopes, wavefront aberrometers, and microperimeters. A surgical microscope that functions as a digital ophthalmic observation device is disclosed in Comparative Document 1.

[0006] Generally, an ophthalmic observation device provides an image of the eye to be examined to a user (such as a doctor or other medical staff). Typically, a digital ophthalmic observation device is configured to perform dynamic image capture using infrared light and / or visible light as illumination light and real - time dynamic image display of the obtained image. The real - time dynamic image (video) thus provided is referred to as an observation image or a live image.

[0007] Ophthalmic observation devices are used to observe various parts of the eye to be examined. For example, anterior eye observation can be performed by a standard optical system structure. On the other hand, posterior eye observation requires the illumination light to reach the posterior eye through the pupil while taking out the return light through the pupil and guiding it to the optical system, so different optical elements are required from anterior eye observation. A surgical microscope having the following structure is disclosed in Comparative Document 2 and Comparative Document 3: switching between anterior eye observation and posterior eye observation by not using or using a front lens.

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019 - 162336

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-013803

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2019-092844 Summary of the Invention

[0011] Generally, a digital ophthalmic observation device is configured such that when the optical system structure is changed from anterior eye observation to posterior eye observation and the refractive power of the eye to be examined is emmetropic, the fundus and the imaging element have an optically conjugate relationship. However, most eyes are ametropic (myopia, hyperopia, etc.), and there are individual differences in refractive power. Therefore, when applying the optical system structure for posterior eye observation, the fundus and the imaging element do not have a conjugate relationship, and the digital ophthalmic observation device cannot focus on the fundus. Therefore, in a conventional digital ophthalmic observation device, after switching to the optical system structure for posterior eye observation, it is necessary to perform focus adjustment again. However, currently, this re-focus adjustment is omitted by using a concave lens and / or a convex lens alone. Even in this case, it is necessary to finally perform fine adjustment of the focus. In addition, in this technical field, it is well known that the situation where the same focus adjustment and fine adjustment are required is not limited to the moment of switching from anterior eye observation to posterior eye observation.

[0012] One object of the present disclosure is to provide a new method for focus adjustment in a digital ophthalmic observation device.

[0013] The ophthalmic observation device according to several exemplary embodiments includes: an illumination system including a light source that emits illumination light and a marking member provided with a plurality of marks, and projecting the illumination light onto the eye to be examined by means of the marking member; an imaging system including an imaging element, and imaging the eye to be examined; and a focus processing unit that detects a plurality of mark images from an image obtained by the imaging system, and performs focus control of the imaging system based on the plurality of mark images.

[0014] In the ophthalmic observation device according to several exemplary embodiments, the plurality of marks may include two marks arranged at positions having different optical distances from the observation surface.

[0015] In the ophthalmic observation device according to several exemplary embodiments, one of the two marks may be arranged on the side closer to the light source than the position optically conjugate to the observation surface, and the other may be arranged on the side closer to the eye to be examined than the position optically conjugate to the observation surface.

[0016] In the ophthalmic observation device according to several exemplary embodiments, at least one of the plurality of marks may be arranged at a position separated from the optical axis of the illumination system.

[0017] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the plurality of markers include at least two markers having the same distance from the optical axis.

[0018] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the at least two markers include two markers symmetrically arranged about the optical axis in a direction orthogonal to the optical axis.

[0019] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that at least two of the plurality of markers are provided on a single component.

[0020] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the single component is a parallel plane plate that transmits the illumination light.

[0021] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the plurality of markers include a first marker provided on a first surface of the parallel plane plate and a second marker provided on a second surface of the parallel plane plate parallel to the first surface.

[0022] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that a position optically conjugate to the observation surface is disposed between the first surface and the second surface.

[0023] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the position optically conjugate to the observation surface is disposed at a position where the distance from the first surface is the same as the distance from the second surface.

[0024] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the focusing processing unit performs the focusing control based on the sizes of the plurality of marker images.

[0025] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the focusing processing unit compares the sizes of the plurality of marker images and performs the focusing control based on the result of the comparison.

[0026] The ophthalmic observation device according to several exemplary embodiments may further include: an objective lens; and a first moving mechanism that moves the illumination system and the imaging system in a direction along the optical axis of the objective lens. And, it is also possible that the focusing processing unit obtains movement control information including at least one of a movement direction and a movement distance based on the result of the comparison, and controls the first moving mechanism based on the movement control information.

[0027] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the plurality of markers include a pair of markers having the same size, and the pair of markers are respectively arranged at two positions that are separated by the same optical distance in opposite directions along the optical axis of the illumination system from positions that are optically conjugate with respect to the observation surface. Further, it is also possible that the focusing processing unit performs the focusing control in such a manner that the sizes of the two marker images corresponding to the pair of markers are the same.

[0028] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the focusing processing unit performs the focusing control based on the blurring of the plurality of marker images.

[0029] The ophthalmic observation device according to several exemplary embodiments may further include: an objective lens; a second moving mechanism that moves the illumination system and the imaging system in a direction orthogonal to the optical axis of the objective lens; an abnormal image detection unit that performs image analysis for detecting an abnormal image from the image obtained by the imaging system; and a movement processing unit that controls the second moving mechanism based on the abnormal image when the abnormal image detection unit detects the abnormal image.

[0030] The ophthalmic observation device according to several exemplary embodiments may further include: a cropping processing unit that crops a region of a predetermined size from the image obtained by the imaging system; and an abnormal image detection unit that performs image analysis for detecting an abnormal image from the partial image cropped from the image. Further, it is also possible that when the abnormal image detection unit detects the abnormal image, the cropping processing unit moves the region of the predetermined size to a region of the image that does not include the detected abnormal image.

[0031] The ophthalmic observation device according to several exemplary embodiments may further include a mode switching unit that switches between a first observation mode for observing a first part of the eye to be examined and a second observation mode for observing a second part of the eye to be examined that is different from the first part. Further, it is also possible that the focusing processing unit performs the detection of the plurality of marker images and the focusing control in response to the observation mode being switched by the mode switching unit.

[0032] In the ophthalmic observation device according to several exemplary embodiments, it is also possible that the first observation mode is an anterior eye part observation mode for observing the anterior eye part of the eye to be examined, and the second observation mode is a posterior eye part observation mode for observing the posterior eye part of the eye to be examined. Further, it is also possible that the mode switching unit includes a lens inserted into the optical path for switching from the anterior eye part observation mode to the posterior eye part observation mode.

[0033] According to the exemplary embodiment, a new method for focus adjustment in a digital ophthalmic observation device can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 FIG. is a schematic diagram showing an example of the structure of an ophthalmic observation device (surgical microscope system) according to an exemplary embodiment.

[0035] Figure 2 FIG. is a schematic diagram showing an example of the structure of an ophthalmic observation device according to an exemplary embodiment.

[0036] Figure 3 FIG. is a schematic diagram showing an example of the structure of an ophthalmic observation device according to an exemplary embodiment.

[0037] Figure 4 FIG. is a schematic diagram showing an example of the structure of an ophthalmic observation device according to an exemplary embodiment.

[0038] Figure 5 FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment.

[0039] Figure 6A FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment.

[0040] Figure 6B FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment.

[0041] Figure 6C FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment.

[0042] Figure 7 FIG. is a schematic diagram showing an example of the structure of an ophthalmic observation device according to an exemplary embodiment.

[0043] Figure 8 FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment.

[0044] Figure 9 FIG. is a schematic diagram showing an example of the structure of an ophthalmic observation device according to an exemplary embodiment.

[0045] Figure 10A FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment.

[0046] Figure 10B FIG. is a schematic diagram for explaining an example of the operation of an ophthalmic observation device according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0047] With reference to the accompanying drawings, several exemplary embodiments of the ophthalmic observation device of the embodiments will be described in detail. In addition, matters described in the documents cited in this specification and any publicly known techniques can be combined with the exemplary embodiments.

[0048] The ophthalmic observation device of the exemplary embodiment is used to grasp the state of the eye to be examined in medical procedures such as surgery, examination, and treatment. The ophthalmic observation device of the exemplary embodiment described below is a surgical microscope system, but the ophthalmic observation device is not limited to a surgical microscope system. For example, the ophthalmic observation device can be any one of a slit lamp microscope, a fundus camera, a refractometer, a corneal astigmatometer, a tonometer, a corneal endothelial microscope, a wavefront aberrometer, and a microperimeter, and can also be a system including any one or more of them. More generally, the ophthalmic observation device can be any ophthalmic device having an observation function.

[0049] The target site for observation using the ophthalmic observation device can be any site of the eye to be examined, or any site of the anterior eye part and / or any site of the posterior eye part. The target sites for observation of the anterior eye part include, for example, the cornea, iris, anterior chamber, anterior chamber angle, lens, ciliary body, zonular fibers, etc. The target sites for observation of the posterior eye part include, for example, the retina, choroid, sclera, vitreous body, etc. The target site for observation is not limited to eye tissues, and can also be any site that is an observation target in ophthalmology (and / or other departments), such as the eyelid, meibomian gland, and eye socket.

[0050] At least a part of the functions of the elements disclosed in this specification is implemented using circuitry or processing circuitry. The circuitry or processing circuitry includes a general-purpose processor, a dedicated processor, an integrated circuit, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), a programmable logic device (e.g., SPLD (Simple Programmable Logic Device), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array)), legacy circuitry, or any combination thereof configured and / or programmed to perform at least a part of the disclosed functions. A processor is considered to be processing circuitry or circuitry including transistors and / or other circuitry. In the present disclosure, circuitry, unit, component, or terms similar thereto are hardware that performs at least a part of the disclosed functions or hardware programmed to perform at least a part of the disclosed functions. The hardware may be the hardware disclosed in this specification or known hardware configured and / or programmed to perform at least a part of the recited functions. In the case where the hardware is a processor regarded as a certain type of circuitry, circuitry, unit, component, or terms similar thereto are a combination of hardware and software for configuring the hardware and / or the processor.

[0051] <Ophthalmic observation device>

[0052] Figure 1 The structure of the ophthalmic observation device is shown in an exemplary manner.

[0053] The ophthalmic observation device 1 (surgical microscope system) according to the embodiment includes an operation device 2, a display device 3, and a surgical microscope 10. In some embodiments, the surgical microscope 10 may include at least one of the operation device 2 and the display device 3. Additionally, in some embodiments, the display device 3 may not be included in the ophthalmic observation device 1. That is, the display device 3 may be a peripheral device of the ophthalmic observation device 1.

[0054] <Operation device 2>

[0055] The operating device 2 includes operating equipment and / or input equipment. For example, the operating device 2 may also include buttons, switches, mice, keyboards, trackballs, operating panels, dials, etc. Typically, the operating device 2 includes a foot switch in the same way as a general ophthalmic surgical microscope. Additionally, it may be configured to perform operations using voice recognition, eye gaze input, etc.

[0056] <Display device 3>

[0057] The display device 3 displays an image of the eye to be examined obtained by the surgical microscope 10. The display device 3 includes a display device such as a flat panel display. Additionally, the display device 3 may also include various display devices such as a touch panel. A typical display device 3 includes a large-screen display device. The display device 3 includes one or more display devices. In the case where the display device 3 includes two or more display devices, for example, one is a display device with a larger screen and the other is a display device with a smaller screen. Additionally, a structure may also be adopted in which multiple display areas are set on one display device to display multiple pieces of information.

[0058] The operating device 2 and the display device 3 do not need to be separate devices. For example, a device in which the operating function and the display function are integrated, such as a touch panel, may also be used as the display device 3. In this case, the operating device 2 includes the touch panel and a computer program. The operation content of the operating device 2 is input as an electrical signal to a processor (not shown). Additionally, the graphical user interface (GUI) displayed by the display device 3 and the operating device 2 may also be used for operations and information input. In several ways, the functions of the operating device 2 and the display device 3 may also be implemented through a touch screen.

[0059] <Surgical microscope 10>

[0060] The surgical microscope 10 is used to observe the eye (eye to be examined) of a supine patient. The surgical microscope 10 captures the eye to be examined and generates digital image data (video data). In particular, the surgical microscope 10 generates a dynamic image (video) of the eye to be examined. The dynamic image generated by the surgical microscope 10 is sent to the display device 3 through a wired and / or wireless signal line for display. The user (surgical operator) can perform surgery while observing the eye to be examined through the displayed video. In several ways, in addition to observing such a video, the surgical microscope 10 can also be observed through a conventional eyepiece lens.

[0061] In several ways, the surgical microscope 10 includes a communication device for sending and receiving electrical signals to and from the operating device 2. The operating device 2 receives the operation of the user and generates a corresponding electrical signal (operation signal). The operation signal is sent to the surgical microscope 10 through a wired and / or wireless signal line. The surgical microscope 10 performs processing corresponding to the received operation signal.

[0062] The observation modes of the surgical microscope 10 using this method include an anterior eye observation mode and a posterior eye observation mode. The anterior eye observation mode is used to observe magnified images of various parts of the anterior eye (such as the cornea Ec, etc.). The posterior eye observation mode is used to observe magnified images of various parts of the posterior eye (such as the fundus Ef, etc.). The posterior eye observation mode uses the front lens 21 described later. When the front lens 21 is disposed in the optical path, the objective lens 20 and the front lens 21 can be regarded as the objective lens together.

[0063] An example of the structure of the optical system of the surgical microscope 10 will be described. Hereinafter, for ease of explanation, the optical axis direction of the objective lens is set as the Z direction (for example, the vertical direction during surgery, the up and down direction), a predetermined direction orthogonal to the Z direction is set as the X direction (for example, the horizontal direction during surgery, the left and right direction for the surgeon and the patient), and a direction orthogonal to both the Z direction and the X direction is set as the Y direction (for example, the horizontal direction during surgery, the front and back direction for the surgeon, the body axis direction for the patient).

[0064] The observation optical system of the surgical microscope 10 has a pair of optical systems. One optical system acquires image data presented to the left eye of the user, and the other optical system acquires image data presented to the right eye of the user. Thus, the user can observe through both eyes (binocular observation), and in particular, can perform stereoscopic observation.

[0065] Figure 2 and Figure 3 Fig. shows a structural example of the optical system of the surgical microscope 10. Figure 2 is a schematic diagram of the optical system observed from the side of the eye to be examined E, Figure 3 is a schematic diagram of the optical system observed from the side. For simplicity of illustration, in Figure 2 the illustration of the illumination optical system 30 disposed above the objective lens 20 is omitted.

[0066] The surgical microscope 10 includes an objective lens 20, a reflecting mirror RM, a dichroic mirror DM, an illumination optical system 30, and an observation optical system 40. And the surgical microscope 10 includes a front lens 21 used in the posterior eye observation mode. The observation optical system 40 includes a zoom extender 50 and a camera 60. In several embodiments, the illumination optical system 30 (the first illumination optical systems 31L and 31R) and / or the observation optical system 40 includes a reflecting mirror RM. Additionally, in several embodiments, the illumination optical system 30 (the first illumination optical systems 31L and 31R) and / or the observation optical system 40 includes a dichroic mirror DM.

[0067] The objective lens 20 is disposed facing the eye to be examined E. The optical axis OA of the objective lens 20 is arranged parallel to the Z direction. The objective lens 20 may include two or more lenses.

[0068] The dichroic mirror DM couples the optical path of the illumination optical system 30 (the first illumination optical systems 31L and 31R) with the optical path of the observation optical system 40. The dichroic mirror DM is disposed between the zoom extender 50 and the mirror RM. The dichroic mirror DM reflects the illumination light from the illumination optical system 30 (the first illumination optical systems 31L and 31R) and guides it to the eye E to be examined via the mirror RM and the objective lens 20 (and the front lens 21), and transmits the return light from the eye E to be examined guided by the (front lens 21 and) objective lens 20 and the mirror RM and guides it to the imaging camera 60 via the zoom extender 50.

[0069] The dichroic mirror DM coaxially couples the optical path of the illumination optical system 30 (the first illumination optical systems 31L and 31R) with the optical path of the observation optical system 40. That is, the optical axis of the illumination optical system 30 intersects with the optical axis of the observation optical system 40 in the dichroic mirror DM. In this mode, the illumination optical system 30 includes a left-eye illumination optical system (31L) and a right-eye illumination optical system (31R), and the observation optical system 40 includes a left-eye observation optical system 40L and a right-eye observation optical system 40R. The dichroic mirror DM coaxially couples the optical path of the left-eye illumination optical system (the first illumination optical system 31L) with the optical path of the left-eye observation optical system 40L, and coaxially couples the optical path of the right-eye illumination optical system (the first illumination optical system 31R) with the optical path of the right-eye observation optical system 40R. That is, the optical axis OL of the left-eye illumination optical system (the first illumination optical system 31L) intersects with the optical axis OB of the left-eye observation optical system 40L in the dichroic mirror DM, and the optical axis OR of the right-eye illumination optical system (the first illumination optical system 31R) intersects with the optical axis OB of the right-eye observation optical system 40R in the dichroic mirror DM.

[0070] The mirror RM is disposed above the objective lens 20. The upper end of the optical axis OA of the objective lens 20 extending in the Z direction is located at the mirror RM. In addition, the mirror RM deflects the optical axes OB of the observation optical systems 40L and 40R extending in the Y direction so as to be parallel to the optical axis OA of the objective lens 20 (in the Z direction). In the mirror RM, the optical axis OA of the objective lens 20 is located in the middle of the optical axis OB of the observation optical system 40L and the optical axis OB of the observation optical axis 40R. The first illumination optical systems 31L and 31R are disposed above the dichroic mirror DM. The second illumination optical system 32 is disposed above the objective lens 20. The second illumination optical system 32 is disposed at a position offset toward the dichroic mirror DM side with respect to the mirror RM. That is, the optical axis OS of the second illumination optical system 32 is located on the side closer to the dichroic mirror DM than the optical axis OA of the objective lens 20.

[0071] The illumination optical system 30 is an optical system for illuminating the eye E to be examined via the objective lens 20 (and the front lens 21). The illumination optical system 30 can be configured to illuminate the eye E to be examined with any one of two or more illumination lights having different color temperatures. The illumination optical system 30 projects illumination light of a specified color temperature onto the eye E to be examined under the control of a control unit (200) described later.

[0072] As described above, the illumination optical system 30 includes first illumination optical systems 31L and 31R and a second illumination optical system 32.

[0073] The illumination method using the first illumination optical systems 31L and 31R is so-called "coaxial illumination", whereby a transillumination image using diffuse reflection of the fundus can be obtained. In this mode, the user can observe the transillumination image of the eye E to be examined with both eyes. That is, in this mode, it is possible to use both the left-eye observation optical system 40L and the right-eye observation optical system 40R to capture the transillumination image of the eye E to be examined and display the obtained pair of transillumination images.

[0074] The optical axis OS of the second illumination optical system 32 is arranged at a position deviated from the optical axis OA of the objective lens 20 in the Y direction. The first illumination optical systems 31L and 31R and the second illumination optical system 32 are arranged such that the deviation of the optical axis OS from the optical axis OA of the objective lens 20 is greater than the deviation of the optical axes OL and OR from the optical axis OA of the objective lens 20. Thereby, so-called "angled illumination (oblique illumination, tilted illumination)" can be achieved, and while being able to prevent the mixing of ghosts caused by corneal reflection and the like, the eye E to be examined can be observed with both eyes. Also, the parts and unevenness of the tissue of the eye E to be examined can be observed in detail.

[0075] The first illumination optical system 31L includes a light source 31a and a condenser lens 31b. The light source 31a outputs illumination light having a wavelength in the visible region corresponding to a color temperature of, for example, 3000 K (Kelvin). The illumination light output from the light source 31a passes through the condenser lens 31b, is reflected by the dichroic mirror DM, is reflected by the reflecting mirror RM, passes through the objective lens 20 (and the front lens 21), and is incident on the eye E to be examined. The first illumination optical system 31R is the same.

[0076] The second illumination optical system 32 includes a light source 32a, a lens 32b, and an identification member 35. The identification member 35 is arranged between the light source 32a and the lens 32b. The light source 32a may include a condenser lens (not shown). The light source 32a outputs illumination light having a wavelength in the visible region corresponding to a color temperature of 4000 K to 6000 K. Although described in detail later, a plurality of identifications are provided on the identification member 35. The lens 32b serves to project the plurality of identifications provided on the identification member 35 onto the eye E to be examined.

[0077] The identification component 35 provides a plurality of identifications for observing the focusing adjustment (focus control) of the optical system 40 on the eye E to be examined. The identification component 35 can have any structure and can also include any device and any element. For example, the identification component 35 can be one or more optical elements (such as a plate-like component with light transmissibility, typically a parallel plane plate) provided with a mask (such as a cross identification, a pinhole identification) as an identification, can also be one or more aperture components that can use the opening as an identification, can also be a plurality of light sources (such as light-emitting elements like LEDs), or can be a transmissive display (such as a transmissive LCD, a transmissive OLED).

[0078] The illumination light output from the light source 32a passes through the identification component 35 and the lens 32b, and is refracted by the objective lens 20 (and the front lens 21) and incident on the eye E to be examined without passing through the mirror RM.

[0079] The configurations and manners of the plurality of identifications provided on the identification component 35 can be arbitrary. In addition, the plurality of identification configurations and / or manners can also be changed. The plurality of identification manners (shape, size, color, etc.) can be the same or different. Several examples of the plurality of identification configurations are described below. In addition, at least two of these examples can be locally combined.

[0080] A first example of the plurality of identification configurations is described. In this example, the optical distance from the observation surface is concerned. The plurality of identifications in this example at least include two identifications with different optical distances from the observation surface. The observation surface is the position where the user most expects to focus (the position (part, depth) that the user pays attention to in the observation of the eye E to be examined), and is the position (observation position) that has an optically conjugate relationship with respect to the imaging element 62 of the observation optical system 40.

[0081] When the eye E to be examined is emmetropic, when the optical conjugate relationship is achieved in the anterior eye observation mode, even if the front lens 21 is inserted into the optical path and then transferred to the eye observation mode, it is focused on the desired observation surface of the posterior eye (typically the fundus Ef (retina)), so almost no focusing adjustment is required as the observation part is transferred.

[0082] In contrast, when the eye E to be examined is ametropic, even if the preferred optical conjugate relationship is achieved in the anterior eye observation mode, when transferred to the posterior eye observation mode, the focus deviates from the desired observation surface of the posterior eye. Therefore, by projecting and photographing the two identifications in this specific example, two identification images with different focusing states are depicted in the captured image, and the current focusing state of the observation optical system 40 is grasped based on the parameters (size, blur, etc.) related to these identification images, so that focusing adjustment can be performed (detailed later).

[0083] Describe a specific example of the first example. In this specific example, a surface conjugate to the observation surface is disposed between two markers. In other words, with respect to the surface optically conjugate to the observation surface (the surface that intersects the optical path of the second illumination optical system 32), one marker is disposed on the light source 32a side, and another marker is disposed on the lens 32b side (the side of the eye E to be examined) with respect to this surface. By referring to two marker images based on such two markers, it is possible to grasp the focusing state and perform focusing adjustment.

[0084] Describe a second example of the arrangement of a plurality of markers. At least one of the plurality of markers in this example is not disposed on the optical axis OS of the second illumination optical system 32. That is, at least one of the plurality of markers in this example is disposed at a position separated from the optical axis OS of the second illumination optical system 32. When two or more markers are both disposed on the optical axis OS, these images overlap in the captured image and cannot be distinguished, losing the meaning as markers. The purpose of this example is to avoid such a problem, and two or more markers are disposed at mutually different positions in the direction (XY direction) orthogonal to the optical axis OS.

[0085] Describe a specific example of the second example. In this specific example, the plurality of markers include at least two markers having the same distance from the optical axis OS of the second illumination optical system 32. In other words, when the three-dimensional coordinates (XYZ coordinates) of each of the at least two markers are projected onto the XY plane orthogonal to the optical axis OS, at least two projection positions (XY coordinates) corresponding to the at least two markers are disposed on the same circle centered on the XY coordinates of the optical axis OS.

[0086] For example, at least two markers having the same distance from the optical axis OS include two markers symmetrically disposed with respect to the optical axis OS in the direction (XY direction) orthogonal to the optical axis OS. In other words, when the XYZ coordinates of each of the two markers are projected onto the XY plane, two XY coordinate points corresponding to the two markers are symmetrically disposed with respect to the XY coordinates of the optical axis OS.

[0087] By arranging the plurality of markers regularly in this way, compared with the case where the plurality of markers are arranged irregularly, the analysis range can be reduced in the detection of marker images (described later), so that the processing can be made easier and faster. In addition, when manually performing fine adjustment of focusing while referring to the display image depicting the marker images, the user can easily find the marker images and can easily compare a plurality of marker images.

[0088] Describe a third example of a plurality of identification configurations. In this example, at least two of the plurality of identifications are provided on a single component. The single component is included in the identification component 35. Generally, the identification component 35 is composed of more than one component. According to this example, for example, compared with the case where two identifications are respectively provided on other components, the structure of the identification component 35 can be simplified. In addition, the identification component 35 can also be configured as two or more components in which a plurality of identifications are dispersedly arranged.

[0089] Describe a specific example of the third example. The single component in this specific example is a parallel plane plate that transmits the illumination light output from the light source 32a. The plurality of identifications may include a first identification provided on the first surface of the parallel plane plate and a second identification provided on the second surface parallel to the first surface. In other words, it can also be configured such that identifications are provided on two mutually parallel surfaces (referred to as two surfaces) of the parallel plane plate. And the position conjugate to the observation surface can also be arranged between the two surfaces of the parallel plane plate. That is to say, the position conjugate to the observation surface can also be arranged inside the parallel plane plate. In addition to this, the position conjugate to the observation surface can also be arranged on the central plane of the parallel plane plate. In other words, the position optically conjugate to the observation surface can also be arranged at positions at the same distance from the two surfaces of the parallel plane plate respectively. According to such a specific example, a structural example of the first example is provided. Generally, when the identification component 35 includes a plate-like component such as a parallel plane plate, the arrangement state of the plate-like component with respect to the optical axis OS of the second illumination optical system 32 can be arbitrary. For example, the parallel plane plate can also be arranged such that its two optical surfaces are orthogonal or oblique to the optical axis OS.

[0090] The color temperature of the illumination light from the first illumination optical systems 31L and 31R is lower than the color temperature of the illumination light from the second illumination optical system 32. By adopting such a structure, the examined eye E can be observed in a warm color system using the first illumination optical systems 31L and 31R, and the structure and manner of the examined eye E can be observed in detail.

[0091] In several ways, the optical axes OL and OR can be relatively moved with respect to the optical axis OA of the objective lens 20, respectively. The direction of this relative movement is a direction intersecting the optical axis OA of the objective lens 20, and this relative movement is represented by a displacement vector in which at least one of the X component and the Y component is not zero. In several ways, the optical axes OL and OR can be moved independently, respectively. On the other hand, in several ways, the optical axes OL and OR can be moved integrally. For example, the surgical microscope 10 is provided with a moving mechanism (31d) for moving the first illumination optical systems 31L and 31R independently or integrally, and the first illumination optical systems 31L and 31R are moved independently or integrally in a direction intersecting the optical axis OA of the objective lens 20 by this moving mechanism. Thereby, the visual effect of the eye E to be examined can be adjusted. In several ways, the moving mechanism operates under the control of a control unit (200) described later.

[0092] In several ways, the optical axis OS can be relatively moved with respect to the optical axis OA of the objective lens 20. The direction of this relative movement is a direction intersecting the optical axis OA of the objective lens 20, and this relative movement is represented by a displacement vector in which at least one of the X component and the Y component is not zero. For example, the surgical microscope 10 is provided with a moving mechanism (32d) for moving the second illumination optical system 32, and the second illumination optical system 32 is moved in a direction intersecting the optical axis OA of the objective lens 20 by this moving mechanism. Thereby, the visual effect of the unevenness of the part and tissue of the eye E to be examined can be adjusted. In several ways, the moving mechanism operates under the control of a control unit (200) described later.

[0093] As described above, in this mode, illumination light is projected from a position directly above the objective lens 20 to the eye E to be examined, and the optical axis OB of the observation optical system 40 is arranged horizontally (along the Y direction), but the arrangement of the optical system is not limited thereto. For example, the observation optical system 40 can be arranged such that the angle formed by the optical axis OB of the observation optical system 40 and the plane (XY plane) orthogonal to the optical axis OA of the objective lens 20 is 20 degrees or less.

[0094] According to the structure of this mode, generally, the observation optical system 40 having an optical path length longer than that of the illumination optical system 30 is arranged substantially parallel to the XY plane, so that it does not obstruct the field of view of the surgical operator as in the case of a conventional surgical microscope in which the observation optical system is arranged vertically in front of the surgical operator's eyes. Therefore, the surgical operator can easily observe the screen of the display device 3 provided in the front. That is, the visibility of display information (image, video, various other reference information of the eye E to be examined) during surgery is improved. In addition, since the housing is not arranged in front of the surgical operator's eyes, a sense of oppression is not given to the surgical operator, thereby reducing the burden on the surgical operator.

[0095] The observation optical system 40 is an optical system for observing an image formed based on the return light of the illumination light incident from the eye E to be examined via the (front lens 21 and) objective lens 20. In this embodiment, the observation optical system 40 guides the image to the imaging element of the imaging camera 60. The observation optical system 40 functions as an imaging system.

[0096] As described above, the observation optical system 40 includes a left-eye observation optical system 40L and a right-eye observation optical system 40R. The structure of the left-eye observation optical system 40L is the same as that of the right-eye observation optical system 40R. In several embodiments, the left-eye observation optical system 40L and the right-eye observation optical system 40R can independently change their optical configurations.

[0097] The zoom expander 50 is also referred to as a beam expander, a variable beam expander, etc. The zoom expander 50 includes a left-eye zoom expander 50L and a right-eye zoom expander 50R. The structure of the left-eye zoom expander 50L is the same as that of the right-eye zoom expander 50R. In several embodiments, the left-eye zoom expander 50L and the right-eye zoom expander 50R can independently change their optical configurations.

[0098] The left-eye zoom expander 50L includes a plurality of zoom lenses 51, 52, and 53. At least one of the plurality of zoom lenses 51, 52, and 53 can be moved in the optical axis direction by a zoom mechanism (the zoom mechanism 50Ld described later).

[0099] Similarly, the right-eye zoom expander 50R includes a plurality of zoom lenses 51, 52, and 53, and at least one of the plurality of zoom lenses 51, 52, and 53 can be moved in the optical axis direction by a zoom mechanism (the zoom mechanism 50Rd described later).

[0100] The zoom mechanism can be configured to move each zoom lens of the left-eye zoom expander 50L and each zoom lens of the right-eye zoom expander 50R independently or integrally in the optical axis direction. Thereby, the magnification when photographing the eye E to be examined is changed. In several embodiments, the zoom mechanism moves under the control of the control unit (200) described later.

[0101] The imaging camera 60 is a device that photographs the image formed by the observation optical system 40 and generates digital image data, typically a digital camera (digital video camera). The imaging camera 60 includes a left-eye imaging camera 60L and a right-eye imaging camera 60R. The structure of the left-eye imaging camera 60L is the same as that of the right-eye imaging camera 60R. In several embodiments, the left-eye imaging camera 60L and the right-eye imaging camera 60R can independently change their optical configurations.

[0102] The left-eye imaging camera 60L includes an imaging lens 61 and an imaging element 62. The imaging lens 61 forms an image based on the return light that has passed through the left-eye zoom extender 50L on the imaging surface of the imaging element 62. The imaging element 62 is an area sensor and can typically be a charge-coupled device (CCD) image sensor or a complementary metal-oxide semiconductor (CMOS) image sensor. The imaging element 62 operates under the control of a control unit (200) described later.

[0103] The right-eye imaging camera 60R includes an imaging lens 61 and an imaging element 62. The imaging lens 61 forms an image based on the return light that has passed through the right-eye zoom extender 50R on the imaging surface of the imaging element 62. The imaging element 62 is an area sensor and can typically be a CCD image sensor or a CMOS image sensor. The imaging element 62 operates under the control of a control unit (200) described later.

[0104] <Processing System>

[0105] Refer to Figure 4 Describe several examples of the processing system of the ophthalmic observation device 1. Any two or more of the various structural examples described below can be at least partially combined.

[0106] The control unit 200 controls each part of the ophthalmic observation device 1. The control unit 200 includes a main control unit 201 and a storage unit 202. The main control unit 201 includes a processor and controls each part of the ophthalmic observation device 1. For example, in order to implement the functions of this embodiment, the processor can read and execute a program stored in the storage unit 202 or other storage devices, and can utilize (refer to, process, calculate, etc.) data and information stored in the storage unit 202 or other storage devices.

[0107] The main control unit 201 can execute the control of each of the two light sources 31a of the illumination optical system 30, the control of the light source 32a of the illumination optical system 30, the control of each of the two imaging elements 62 of the observation optical system 40, the control of the moving mechanisms 31d and 32d respectively, the control of the zoom mechanisms 50Ld and 50Rd respectively, the control of the operation device 2, and the control of the display device 3, etc.

[0108] The control of the light source 31a includes the lighting, extinguishing, light quantity adjustment, illumination aperture adjustment, etc. of the light source. The control of the light source 32a includes the lighting, extinguishing, light quantity adjustment, illumination aperture adjustment, etc. of the light source. When the illumination optical system 30 includes a light source capable of changing the color temperature, the main control unit 201 can change the color temperature of the output illumination light by controlling this light source.

[0109] The control of the imaging elements 62 includes exposure adjustment, gain adjustment, imaging rate adjustment, etc. The main control unit 201 can control the two imaging elements 62 so that the imaging timings of the two imaging elements 62 are the same or control the two imaging elements 62 so that the difference in the imaging timings of the two imaging elements 62 is within a predetermined time. Further, the main control unit 201 can perform read control on the digital data obtained by each imaging element 62.

[0110] The moving mechanism 31d moves the two light sources 31a independently or integrally in a direction intersecting the optical axis of the objective lens 20. By controlling the moving mechanism 31d, the main control unit 201 can move the optical axes OL and OR of the illumination optical system 30 independently or integrally with respect to the optical axis OA of the objective lens 20.

[0111] The moving mechanism 32d moves the light source 32a in a direction intersecting the optical axis of the objective lens 20. By controlling the moving mechanism 32d, the main control unit 201 can move the optical axis OS with respect to the optical axis OA of the objective lens 20.

[0112] The moving mechanism 70 moves the surgical microscope 10. For example, the moving mechanism 70 is configured such that at least a part of the illumination optical system 30 and the observation optical system 40 are integrated. Thereby, while maintaining the relative positional relationship between at least a part of the illumination optical system 30 and the observation optical system 40, the relative positions of at least a part of the illumination optical system 30 and the observation optical system 40 with respect to the eye E to be examined can be changed. In several modes, the moving mechanism 70 is configured such that the first illumination optical systems 31L and 31R and the observation optical system 40 move integrally. Thereby, while maintaining the coaxial illumination state, the relative positions of the first illumination optical systems 31L and 31R and the observation optical system 40 with respect to the eye E to be examined can be changed. In several modes, the moving mechanism 70 is configured such that the second illumination optical system 32 and the observation optical system 40 move integrally. Thereby, while maintaining the illumination angle of the oblique illumination, the relative positions of the second illumination optical system 32 and the observation optical system 40 with respect to the eye E to be examined can be changed. In several modes, the moving mechanism 70 is configured such that the first illumination optical systems 31L and 31R and the second illumination optical system 32 and the observation optical system 40 move integrally. Thereby, while maintaining both the coaxial illumination state and the illumination angle of the oblique illumination, the relative positions of the illumination optical system 30 and the observation optical system 40 with respect to the eye E to be examined can be changed.

[0113] The moving mechanism 70 can move the surgical microscope 10 in any direction. For example, the moving mechanism 70 can move the surgical microscope 10 three-dimensionally. That is, the moving mechanism 70 can move the surgical microscope 10 in the X direction, Y direction, and Z direction respectively, and can also move the surgical microscope 10 in any direction formed by combining at least two of the X direction, Y direction, and Z direction.

[0114] The movement in the XY direction (movement in the X direction, movement in the Y direction, movement in the combined direction of the X direction and the Y direction) is performed during various integrated movements of the illumination optical system 30 and the observation optical system 40. The component group of the moving mechanism 70 for moving the surgical microscope 10 in the XY direction corresponds to the second moving mechanism.

[0115] The movement in the Z direction is performed for the focusing adjustment of the observation optical system 40. By moving the observation optical system 40 in the Z direction, the focus of the observation optical system 40 moves in the Z direction. The component group of the moving mechanism 70 for moving the surgical microscope 10 in the Z direction corresponds to the first moving mechanism. In addition, the method of focusing adjustment of the observation optical system 40 is not limited to this. For example, as in a fundus camera, a focusing lens and a mechanism for moving it may be provided in the observation optical system (imaging system).

[0116] In addition, it may be configured that when the front lens 21 is disposed in the optical path, the focusing adjustment is performed by the movement of the front lens 21, and when the front lens 21 is not disposed in the optical path, the focusing adjustment is performed by the movement of the objective lens 20.

[0117] More commonly, the ophthalmic observation device 1 may also be configured to perform focusing adjustment by at least one or a combination of at least two of the movement of at least a part of the illumination optical system 30, the movement of at least a part of the observation optical system 40, the movement of the objective lens 20, and the movement of the front lens 21.

[0118] The moving mechanism 70 operates under the control of the control unit 200.

[0119] In several modes, the main control unit 201 can controllably link at least two of the moving mechanisms 31d, 32d, and 70.

[0120] The zooming mechanism 50Ld moves at least one of the plurality of zoom lenses 51 to 53 of the left-eye zoom extender 50L in the optical axis direction. The main control unit 201 can change the magnification of the left-eye observation optical system 40L by controlling the zooming mechanism 50Ld.

[0121] Similarly, the zoom mechanism 50Rd moves at least one of the plurality of zoom lenses 51 to 53 of the right-eye zoom expander 50R in the optical axis direction. The main control unit 201 can change the magnification of the right-eye observation optical system 40R by controlling the zoom mechanism 50Rd.

[0122] The control of the operation device 2 includes operation permission control, operation prohibition control, transmission control and / or reception control of operation signals from the operation device 2, etc. The main control unit 201 receives the operation signals generated by the operation device 2 and executes the control corresponding to the received signals.

[0123] The control of the display device 3 includes information display control, etc. The main control unit 201, as a display control unit, can cause the display device 3 to display an image based on the digital image data generated by the imaging element 62. Typically, according to a pair of video data (video signals) generated in parallel by the imaging element 62 respectively, the display device 3 can display a pair of videos (a pair of moving images) in parallel. In addition, the main control unit 201 can cause the display device 3 to display a still image (frame) included in any one of the pair of videos. And, the main control unit 201 can cause the display device 3 to display an image (moving image, still image, etc.) obtained by processing the digital image data generated by the imaging element 62. In addition, the main control unit 201 can cause the display device 3 to display any information generated by the ophthalmic observation device 1 and any information obtained by the ophthalmic observation device 1 from the outside.

[0124] The main control unit 201 can cause the display device 3 to sequentially display the digital image data (frames) sequentially generated by the imaging element 62 of the left-eye observation optical system 40L as left-eye video data to display the left-eye video, and at the same time, can cause the display device 3 to sequentially display the digital image data (frames) sequentially generated by the imaging element 62 of the right-eye observation optical system 40R as right-eye video data to display the right-eye video. Here, the left and right imaging elements 62 can be synchronized with each other, and the display of the left-eye video and the display of the right-eye video can also be synchronized with each other. Thus, the ophthalmic observation device 1 can substantially cause the display device 3 to display the left and right frames substantially simultaneously obtained by the left and right imaging elements 62, so as to enable the display update to be synchronized.

[0125] Alternatively, after the image data obtained by the observation optical system 40 is processed by the data processing unit 210, the main control unit 201 causes the display device 3 to display. The data processing unit 210 can sequentially apply predetermined processing (image processing) to the digital image data (frames) sequentially generated as left-eye image data by the imaging element 62 of the left-eye observation optical system 40L, and can also sequentially apply predetermined processing (image processing) to the digital image data (frames) sequentially generated as right-eye image data by the imaging element 62 of the right-eye observation optical system 40R. Here, the left and right imaging elements 62 can be synchronized with each other, and the processing of the left-eye image data and the processing of the right-eye image data can also be synchronized with each other. That is, the data processing unit 210 can process the left and right frames substantially simultaneously obtained by the left and right imaging elements 62 in parallel. The left and right frames processed in parallel are, for example, sent to the main control unit 201 as a pair of frames (i.e., related to each other). The main control unit 201 can receive a pair of frames (left-eye frame and right-eye frame) sequentially input from the data processing unit 210 and cause the display device 3 to sequentially display the sequentially input left-eye frames to display the left-eye image, and can also cause the display device 3 to sequentially display the sequentially input right-eye frames to display the right-eye image. Here, the display of the left-eye image and the display of the right-eye image can also be synchronized with each other. Thus, the ophthalmic observation device 1 can process the frames substantially simultaneously obtained by the left and right imaging elements 62 in parallel and can substantially simultaneously cause the display device 3 to display, enabling the display update to be synchronized.

[0126] The main control unit 201 can cause the display device 3 to display the left-eye image and the right-eye image in a stereoscopic observation manner. For example, the main control unit 201 creates a pair of left and right parallax images based on the left-eye frame and the right-eye frame substantially simultaneously obtained, and can cause the display device 3 to display the pair of parallax images. A user (such as a surgical operator) can recognize the pair of parallax images as a stereoscopic image using a known stereoscopic observation method. The stereoscopic observation method applicable to this mode can be arbitrary. For example, it can also be a stereoscopic observation method with the naked eye, a stereoscopic observation method using auxiliary equipment (such as polarized glasses), a stereoscopic observation method using image processing (image synthesis, rendering, etc.) of the left-eye frame and the right-eye frame, a stereoscopic observation method of simultaneously displaying a pair of parallax images, a stereoscopic observation method of switching and displaying a pair of parallax images, or any one of a combination of two or more of them.

[0127] The data processing unit 210 performs various data processing. Several examples of the processing that the data processing unit 210 can perform are described below. The data processing unit 210 (each of its elements) includes a processor that operates according to a predetermined software (program) and is realized through the cooperation of hardware and software. The data processing unit 210 functions as a focusing processing unit together with the control unit 200 (main control unit 201).

[0128] The ophthalmic observation device 1 of the present embodiment projects a plurality of markers onto the eye E to be examined by illumination light while performing imaging, detects a plurality of marker images from the obtained image (image data, frame), and performs focusing control of the observation optical system 40. The data processing unit 210 executes processing to detect a plurality of marker images corresponding to the plurality of markers from the image of the eye E to be examined. The moving mechanism 70 is controlled by the main control unit 201 to perform focusing control based on the detected plurality of marker images.

[0129] The data processing unit 210 is configured to detect a marker image from an image using an arbitrary region extraction method. At this time, the data processing unit 210 can perform marker image detection according to a processing procedure created in consideration of each marking method and / or configuration provided in the marker member 35.

[0130] Describe several examples of marker image detection in consideration of the marking method. Considering that the marker image is depicted darker when the marker is a mask and the marker image is depicted brighter when the marker is a light source, the data processing unit 210 can perform marker image detection using brightness threshold processing such as binarization. In addition, when the color of the marker is characteristic, the data processing unit 210 can perform marker image detection using color analysis processing such as characteristic color extraction. In addition, when the marker shape is characteristic, the data processing unit 210 can perform marker image detection using shape analysis processing such as pattern matching. In addition, the data processing unit 210 may be configured to perform marker image detection using arbitrary segmentation. Generally, segmentation is a process of determining a local region in an image. Segmentation may include any known image processing technique, for example, it may also include segmentation using image processing such as edge detection and / or segmentation using machine learning (e.g., deep learning).

[0131] In consideration of the marker configuration, for example, the data processing unit 210 can determine a search range in the image frame according to the marker configuration in the marker member 35. In addition, the search range may be determined in advance according to the configuration of the optical system. When the configuration of the optical system is variable, the data processing unit 210 can determine the search range in the current configuration of the optical system according to the search range determined in advance for the default configuration of the optical system and the current configuration of the optical system.

[0132] <Auto Focus>

[0133] Describe several examples of the operation (autofocus) of the ophthalmic observation device 1 of the present embodiment. In addition, hereinafter, an example of the operation when transferring from the anterior eye observation mode to the posterior eye observation mode will be described, and the same operation can be performed in other situations. As is known to those skilled in the art, for example, the same operation can be performed even when transferring from the posterior eye observation mode to the anterior eye observation mode or in any other situation.

[0134] Describe a first example of the operation of the ophthalmic observation device 1. Consider the case of transferring from the anterior eye observation mode in which the observation surface is disposed with respect to the cornea Ec (a state in which the cornea Ec and the imaging element 62 are in an optically conjugate relationship) to the posterior eye observation mode. As described above, the transfer from the anterior eye observation mode to the posterior eye observation mode is performed by inserting the front lens 21 between the objective lens 20 and the eye E to be examined.

[0135] In several ways, the ophthalmic observation device 1 can automatically detect the situation where the front lens 21 is inserted into the optical path. For example, when the user operates to insert the front lens 21 into the optical path, the ophthalmic observation device 1 can detect the movement of the component (such as an arm portion) for supporting the front lens 21 through an encoder or a microswitch (not shown), and thus start the process of focus control. As another example, when the front lens 21 is inserted into the optical path under the control of the main control unit 201, the ophthalmic observation device 1 can start the process of focus control after the main control unit 201 performs such control, for example. As yet another example, the ophthalmic observation device 1 can detect the situation of transferring from the anterior eye observation mode to the posterior eye observation mode based on the change in the image caused by the insertion of the front lens 21 into the optical path.

[0136] The process of focus control in this example starts with the identification component 35 providing a plurality of identifiers. In several ways, under the control of the main control unit 201, the identification component 35 is inserted into the optical path of the second illumination optical system 32 or a plurality of identifiers are displayed in the transmissive display serving as the identification component 35 under the control of the main control unit 201.

[0137] Next, the main control unit 201 turns on the light source 32a of the second illumination optical system 32. Thereby, the illumination light output from the light source 32a is projected onto the eye E to be examined via the identification component 35. The observation optical system 40 acquires an image (image) of a plurality of identification images depicted corresponding to the plurality of identifiers projected onto the eye E to be examined. The main control unit 201 sequentially transfers the frames (still images) sequentially acquired by the observation optical system 40 to the data processing unit 210.

[0138] The data processing unit 210 sequentially detects a plurality of identification images based on the sequentially input frames. The plurality of identifications include two identifications disposed at positions separated by different optical distances from the observation surface (e.g., the retina). In this case, the defocused states of the two identification images corresponding to the two identifications are different. For example, when one of the two identifications is disposed on the side of the light source 32a with respect to the position optically conjugate to the observation surface, and the other is disposed on the side of the eye to be examined E with respect to the position optically conjugate to the observation surface, when the focus of the observation optical system 40 is located on the near side of the observation surface (objective lens 20 side), the focusing degree on this one identification is improved (i.e., the defocus of the other identification becomes larger), and when the focus of the observation optical system 40 is located on the far side of the observation surface, the focusing degree on the other identification is improved (i.e., the defocus of the other identification becomes larger). In addition, when the focus is (substantially) coincident with the observation surface, the defocus degrees of the two identification images become the same. For example, when the two identifications have the same size, when the focus is (substantially) coincident with the observation surface, the sizes of the two identification images become the same. Thus, depending on the position of the focus relative to the observation surface, the focused identification becomes the opposite. By utilizing this situation, it is possible to determine whether the focus is on the near side or the far side relative to the observation surface. In addition, any known defocus quantification method can be applied to evaluate the magnitude of defocus.

[0139] Thus, the data processing unit 210 in this example can obtain the position of the focus relative to the observation surface based on the defocus of the plurality of identification images, and thus can obtain the moving direction of the surgical microscope 10 for making the focus coincide with the observation surface. In addition, the data processing unit 210 can obtain the moving amount (moving distance) of the surgical microscope 10 for making the focus coincide with the observation surface based on the degree of defocus (comparison thereof) of the plurality of identification images.

[0140] At least one of the moving direction and the moving amount obtained by the data processing unit 210 is provided to the main control unit 201 as moving control information. The main control unit 201 controls the moving mechanism 70 based on the moving control information, and thus can perform focusing adjustment (focus control) for making the focus of the observation optical system 40 coincide with the observation surface (e.g., the retina).

[0141] According to such a first example, it is possible to reduce the workload of the user, shorten the surgical time, and reduce the burden on the user and the patient.

[0142] A second example of the operation of the ophthalmic observation device 1 will be described. Similar to the first example, consider the case of switching from the anterior eye observation mode to the posterior eye observation mode. Refer to Figure 5 . Figure 5 The outline of the second illumination optical system 32 is shown.

[0143] The lens 32c is a condenser lens (described above) provided for the light source 32a. The lens 32c functions as a collimating lens that converts the illumination light output from the light source device 32a into a parallel light beam.

[0144] The identification member 35 in this example is a parallel flat plate. A first identification 36a is formed on the surface 35a on the light source 32a side of the parallel flat plate 35, and a second identification 36b is formed on the surface 35b (the surface on the side of the eye to be examined E) parallel to the surface 35a. The forms of the first identification 36a and the second identification 36b are arbitrary respectively. For example, the shape of the first identification 36a and the shape of the second identification 36b may be the same (for example, circular), and the size of the first identification 36a and the size of the second identification 36b may also be the same. In addition, Figure 5 In order to improve the recognizability of the first identification 36a and the second identification 36b, these are represented by mutually different figures.

[0145] The first identification 36a is arranged at a position separated by a first distance in a first direction (above in Figure 5 orthogonal to the optical axis OS of the second illumination optical system 32. The second identification 36b is arranged at a position separated by a second distance in a second direction (below in Figure 5 orthogonal to the optical axis OS and different from the first direction). The first distance and the second distance may be the same or different. The first direction and the second direction may be opposite directions with respect to the optical axis OS, or may not be opposite directions with respect to the optical axis OS. In this example, the first distance and the second distance are the same and the first direction and the second direction are opposite directions with respect to the optical axis OS. That is, in this example, the first identification 36a and the second identification 36b are arranged at positions symmetric (point-symmetric) with respect to the optical axis OS in a direction (XY direction) orthogonal to the optical axis OS.

[0146] The reference numeral 35c represents a surface that is equidistant from the first surface 35a and the second surface 35b respectively. That is, the surface 35 is the central surface of the parallel flat plate 35 that is parallel to both the first surface 35a and the second surface 35b and is equidistant from both. The surface 35 is in an optically conjugate relationship with the observation surface 81. The first identification image 82a formed by the second illumination optical system 32 is an image of the first identification 36a and is formed at a position optically conjugate to the first identification 36a. Similarly, the second identification image 82b formed by the second illumination optical system 32 is an image of the second identification 36b and is formed at a position optically conjugate to the second identification 36b.

[0147] The reference numeral 80 simply represents an optical element group arranged between the parallel flat plate 35 and the observation surface 81 (for example, the retina). When applicable Figure 2 and Figure 3In the case of the optical system shown, the optical element group 80 includes the lens 32 b and the objective lens 20 in the anterior ocular observation mode, and includes the lens 32 , the objective lens 20 , and the front lens 21 in the posterior ocular observation mode.

[0148] The illumination light output from the light source 32a is converted into parallel light by the lens 32c, and is transmitted through the parallel plane plate 35 provided with the first mark 36a and the second mark 36b, and is projected to the subject's eye E via the optical element group 80. When the subject's eye E in the state of projecting such illumination light is photographed by the observation optical system 40, an image (image) depicting the first mark image 82a and the second mark image 82b is obtained. In this example, the positional relationship between the focus of the observation optical system 40 and the observation surface 81 is obtained by applying these two mark images 82a and 82b.

[0149] Figure 6A , Figure 6B as well as Figure 6C Several examples of the manner in which the first marker image 82a and the second marker image 82b are drawn in the image (frame) obtained in this example are shown.

[0150] Figure 6A The image 91 shown is a simplified representation of an image obtained when the focus of the observation optical system 40 is located on the side closer to the observation surface 81 (the side of the objective lens 20). In this case, the focal position of the observation optical system 40 is optically closer to the position where the first identification image 82a is formed (the position optically conjugate with the first identification image 36a) than the position where the second identification image 82b is formed (the position optically conjugate with the second identification image 36b). Therefore, the focusing state of the first identification image 82a of the image 91 is relatively good (less blur), and the focusing state of the second identification image 82b of the image 91 is relatively poor (more blur). That is, when the first identification image 82a detected by the data processing unit 210 is compared with the second identification image 82b, the size of the first identification image 82a is smaller than the size of the second identification image 82b.

[0151] Figure 6B The image 92 shown is simplified to represent the image obtained when the focus of the observation optical system 40 is located closer to the distal side (opposite to the objective lens 20) than the observation surface 81. In this case, the focal position of the observation optical system 40 is optically closer to the position where the second marker image 82b is formed than the position where the first marker image 82a is formed. Therefore, the focusing state of the first marker image 82a of the image 92 is relatively poor (large blur), and the focusing state of the second marker image 82b of the image 91 is relatively good (small blur). That is to say, when the first marker image 82a detected by the data processing unit 210 is compared with the second marker image 82b, the size of the first marker image 82a is larger than the size of the second marker image 82b.

[0152] Figure 6C The shown image 93 simply represents an image obtained when the focal point of the observation optical system 40 coincides (substantially) with the observation surface 81. In this case, the distance from the focal point position of the observation optical system 40 to the position where the first identification image 82a is formed is optically (substantially) the same as the distance from the focal point position of the observation optical system 40 to the position where the second identification image 82b is formed. Therefore, the focusing state of the first identification image 82a in the image 93 is the same as the focusing state of the second identification image 82b. That is, when the first identification image 82a detected by the data processing unit 210 is compared with the second identification image 82b, the size of the first identification image 82a is substantially the same as the size of the second identification image 82b.

[0153] From the above description, it can be seen that according to this example, the focusing state of the observation optical system 40 can be grasped based on the sizes of the two identification images. In addition, the number of identification images used is not limited to two, and may be three or more.

[0154] In the case where the sizes of the two identification images are different, the ophthalmic observation device 1 of this example can, through the data processing unit 210, determine that the focal point of the observation optical system 40 deviates from the observation surface (the focusing state is not good). And the ophthalmic observation device 1 of this example can control the moving mechanism 70 through the main control unit 201 to move the surgical microscope 10, thereby performing focusing adjustment. In addition, in the case where a focusing lens is provided in the observation optical system 40, its position can be adjusted. The data processing unit 210 can determine the moving direction of the surgical microscope 10 by obtaining the size relationship between the two identification images. In addition, the data processing unit 210 can determine the moving amount of the surgical microscope 10 based on the difference (difference, ratio, etc.) in the sizes of the two identification images. The main control unit 201 can control the moving mechanism 70 based on the moving control information obtained in this way. By repeating this series of processes, the focal point of the observation optical system 40 can be guided to the observation surface, and the preferred focusing state can be maintained.

[0155] In several ways, the ophthalmic observation device 1 can perform processing for analyzing an observation image obtained by the surgical microscope 10 and detecting a plurality of marker images, processing for calculating the sizes (e.g., diameter, perimeter) of the detected marker images, processing for comparing the sizes of the calculated plurality of marker images, processing for obtaining movement control information (movement direction, movement amount) based on the result of the size comparison, and processing for moving the surgical microscope 10 (or focusing lens) based on the obtained movement control information. In addition, in several ways, the ophthalmic observation device 1 can repeatedly perform this series of processing until the sizes of the detected plurality of marker images satisfy a predetermined condition. For example, the ophthalmic observation device 1 can repeatedly perform the above series of processing until the sizes of the plurality of marker images become the same (e.g., until the sizes become the same or until the size difference is below a predetermined threshold).

[0156] In several ways, focus control can be performed corresponding to the switching of the observation site. For example, the ophthalmic observation device 1 further includes a mode switching unit for switching between a first observation mode for observing a first site of the eye to be examined E and a second observation mode for observing a second site different from the first site. The control unit 200 and the data processing unit 210 (focus processing unit) are configured to perform detection of a plurality of marker images and focus control corresponding to the switching of the observation mode by the mode switching unit. According to such a method, the switching of the observation mode can be used as a trigger to start the autofocus in any of the above methods.

[0157] As described above, the first observation mode may be an anterior eye observation mode, and the second observation mode may be a posterior eye observation mode. In this case, the mode switching unit may include a front lens 21 inserted into the optical path to switch from the anterior eye observation mode to the posterior eye observation mode. The ophthalmic observation device 1 can start the autofocus in any of the above methods with the insertion of the front lens 21 into the optical path as a trigger. In addition, the ophthalmic observation device 1 can also start the autofocus in any of the above methods with the retraction of the front lens 21 from the optical path as a trigger.

[0158] Instead of performing autofocus or in addition to performing autofocus, the ophthalmic observation device 1 can display information indicating the focus state obtained by the data processing unit 210. Thus, the user can grasp the current focus state based on the displayed information.

[0159] Instead of performing autofocus or in addition to performing autofocus, the ophthalmic observation device 1 can display information indicating the movement control information (movement direction, movement amount) obtained by the data processing unit 210. Thus, the user can manually perform focus adjustment (fine adjustment, etc.) while referring to the displayed information. That is, according to such an ophthalmic observation device 1, manual focus adjustment can be assisted.

[0160] <Alignment>

[0161] The several autofocus methods described above are equivalent to the positioning (alignment) of the surgical microscope 10 in the Z direction. In addition to this, the ophthalmic observation device 1 can perform the alignment of the surgical microscope 10 in the XY direction.

[0162] In the past, while referring to the observation image (for example, while observing the display image or while peeping through the eyepiece lens to observe the eye to be examined), the surgical operator moved the surgical microscope so that unwanted light and dark areas entered the field of view. The operation performed in this way is carried out using a foot switch and a control lever provided on the surgical microscope.

[0163] Hereinafter, several examples of the alignment in the XY direction will be described. In addition, at least two of the several examples described below can be combined at least locally. In addition, in the following description, matters related to the ophthalmic observation device 1 will be referred to as appropriate.

[0164] In the alignment in the XY direction, the illumination optical system 30 and the observation optical system 40 are moved at least locally in the XY direction. This movement is carried out by controlling the movement mechanism 70 by the main control unit 201.

[0165] In addition, it may be configured to perform alignment by moving the front lens 21 when the front lens 21 is disposed in the optical path, and to perform alignment by moving the objective lens 20 when the front lens 21 is not disposed in the optical path.

[0166] More commonly, the ophthalmic observation device 1 may also be configured to perform alignment according to any one or any combination of two or more of the movement of at least a part of the illumination optical system 30, the movement of at least a part of the observation optical system 40, the movement of the objective lens 20, and the movement of the front lens 21.

[0167] Figure 7 A structural example showing a first method for realizing automatic alignment in the XY direction is shown. The data processing unit 210A in this example is an example of the data processing unit 210 and includes an abnormal image detection unit 211. The abnormal image detection unit 211 performs image analysis to detect abnormal images from the images obtained by the observation optical system 40. Abnormal images are, for example, image regions with abnormally high brightness (such as images of unwanted light such as light spots, etc.), image regions with abnormally low brightness (dark regions), and the like. The abnormal image detection unit 211 can be configured, for example, to detect abnormal images by performing brightness threshold processing.

[0168] The control unit 200 (main control unit 201) and the data processing unit 210 function as movement processing units, and control the movement mechanism 70 according to the abnormal images detected by the abnormal image detection unit 211 to move the surgical microscope 10 in the XY direction.

[0169] Figure 8 The image 300 shown schematically represents the image included in the abnormal image. Reference numeral 301 denotes an abnormal image (spot or dark area) detected by the abnormal image detection unit 211 from the image 300. The data processing unit 210 can determine the moving direction based on the position of the abnormal image 301 in the image 300 (image frame). For example, in Figure 8 the image 300, the abnormal image exists in the upper left corner area. In this case, the data processing unit 210 can set the lower right corner direction as the moving direction. Typically, the data processing unit 210 can set the direction opposite to the direction in which the abnormal image is present when viewed from the center of the image as the moving direction. For example, the data processing unit 210 performs a process of obtaining a representative point of the abnormal image and a vector starting from the representative point and ending at the center of the image, and can set the orientation of this vector as the moving direction. The representative point of the abnormal image can also be, for example, the position closest to the center of gravity position, the center of the image, etc.

[0170] The data processing unit 210 can determine the moving amount based on the size of the abnormal image 301 in the image 300. For example, the data processing unit 210 performs a process for determining the position of the abnormal image closest to the center of the image and a vector starting from the intersection point of the straight line passing through this specific position and the center of the image with the frame edge and ending at this specific position, and can set the magnitude (or larger) of this vector as the moving amount. In this case, the orientation of this vector can be set as the moving direction.

[0171] The main control unit 201 controls the moving mechanism 70 based on the movement control information (moving direction, moving amount) obtained by the data processing unit 210, thereby enabling alignment in the XY directions of the surgical microscope 10. In addition, by repeatedly acquiring the movement control information and moving the surgical microscope 10, the optimal position in the XY directions can be searched.

[0172] According to such automatic alignment, compared with the conventional manual alignment, the workload of the user can be reduced, the surgical time can be shortened, and the burden on the user and the patient can be alleviated.

[0173] Figure 9 Shows a structural example of a second method for achieving automatic alignment in the XY directions. The data processing unit 210B in this example is an example of the data processing unit 210 and includes a cropping processing unit 212 and an abnormal image detection unit 213.

[0174] The cropping processing unit 212 crops a region of a predetermined size (referred to as a cropping target region) from the image obtained by the observation optical system 40. The size of the cropping target region may be fixed or variable. In addition, the default position of the cropping target region may be fixed or variable. The main control unit 201 causes the display device 3 to display the image (partial image) cropped from the image obtained by the observation optical system 40.

[0175] The abnormal image detection unit 213 performs image analysis to detect an abnormal image from the partial image cropped from the image obtained by the observation optical system 40. The abnormal image detection unit 213 performs the same processing as the abnormal image detection unit 211 in the first example.

[0176] When the abnormal image detection unit 213 detects an abnormal image based on the partial image, the cropping processing unit 212 moves the region of the predetermined size to the region of the image (the image obtained by the observation optical system 40) that does not include the detected abnormal image. In addition, the cropping processing unit 212 may change the cropping target region (for example, size, shape) in such a way that it does not include the detected abnormal image.

[0177] Figure 10A The shown image 310 simply represents the image included in the abnormal image. The image 310 is the image obtained by the observation optical system 40 and represents the entire shooting region of the imaging element 62. Reference numeral 311 indicates the abnormal image mixed into the image 310. Reference numeral 312 indicates the cropping target region at the current stage. The cropping processing unit 212 crops the cropping target region 312 (referred to as the partial image 312) from the image 311. The abnormal image detection unit 213 performs image analysis for detecting an abnormal image based on the partial image 312. In Figure 10A In the shown example, the partial image 312 includes a part of the abnormal image 311. In this case, the cropping processing unit 212 moves the cropping target region to the region of the partial image 312 that does not include the detected abnormal image. The process of determining the moving direction and the moving amount can be performed in the same manner as in the first example. In addition, abnormal image detection may be applied to the entire image 311, and the result may be reflected in the movement of the cropping target region.

[0178] Figure 10B The cropping target region 313 shown by such auto-alignment movement is represented. The moved cropping target region 313 does not include the abnormal image. In addition, by repeatedly obtaining the movement control information (moving direction, moving amount) and moving the cropping target region, the optimal cropping target region can be searched for.

[0179] According to such auto-alignment, compared with the conventional manual alignment, the workload of the user can be reduced, the operation time can be shortened, and the burdens on the user and the patient can be alleviated.

[0180] The present disclosure only exemplifies embodiments, and any deformation, omission, addition, substitution, etc. can be implemented within the scope of the present disclosure and its equivalents.

[0181] (Description of reference numerals)

[0182] 1: Ophthalmic observation device; 2: Operating device 3: Display device; 10: Surgical microscope; 30: Illumination optical system; 35: Identification component; 40: Observation optical system; 62: Imaging element; 200: Control unit; 201: Main control unit; 210: Data processing unit; 211, 213: Abnormal image detection unit; 212: Cropping processing unit.

Claims

1. An ophthalmic observation device, comprising: A lighting system, including a light source that emits illumination light and an identification member provided with a plurality of identifications, and projecting the illumination light onto the eye to be examined by means of the identification member; A imaging system, including an imaging element, and imaging the eye to be examined; And A focusing processing unit that detects a plurality of identification images from the images obtained by the imaging system, and performs focusing control of the imaging system based on the plurality of identification images, The plurality of identifications include two identifications arranged at positions with different optical distances from the observation surface, The focusing processing unit performs the focusing control based on at least one of the sizes and blurs of the plurality of identification images.

2. The ophthalmic observation device according to claim 1, wherein One of the two identifications is arranged on the side of the light source with respect to the position optically conjugate to the observation surface, and the other is arranged on the side of the eye to be examined with respect to the position optically conjugate to the observation surface.

3. The ophthalmic observation device according to claim 1 or 2, wherein At least one of the plurality of identifications is arranged at a position separated from the optical axis of the lighting system.

4. The ophthalmic observation device according to claim 3, wherein The plurality of identifications include at least two identifications having the same distance from the optical axis.

5. The ophthalmic observation device according to claim 4, wherein The at least two identifications include two identifications symmetrically arranged about the optical axis in a direction orthogonal to the optical axis.

6. The ophthalmic observation device according to claim 1 or 2, wherein At least two of the plurality of identifications are provided on a single member.

7. The ophthalmic observation device according to claim 6, wherein The single member is a parallel plane plate that transmits the illumination light.

8. The ophthalmic observation device according to claim 7, wherein The plurality of identifications include a first identification provided on a first surface of the parallel plane plate and a second identification provided on a second surface of the parallel plane plate parallel to the first surface.

9. The ophthalmic observation device according to claim 8, wherein A position optically conjugate to the observation surface is arranged between the first surface and the second surface.

10. The ophthalmic observation device according to claim 9, wherein The position optically conjugate to the observation surface is arranged at a position where the distance from the first surface is the same as the distance from the second surface.

11. The ophthalmic observation device according to claim 1 or 2, wherein The focusing processing unit compares the sizes of the plurality of identification images, and performs the focusing control based on the result of the comparison.

12. The ophthalmic observation device according to claim 11, wherein The ophthalmic observation device further includes: An objective lens; and A first moving mechanism that moves the lighting system and the imaging system in a direction along the optical axis of the objective lens, The focusing processing unit obtains movement control information including at least one of a movement direction and a movement distance based on the result of the comparison, And controls the first moving mechanism according to the movement control information.

13. The ophthalmic observation device according to claim 11, wherein, the plurality of markers includes a pair of markers having the same size, and the pair of markers are respectively arranged at two positions separated by the same optical distance in opposite directions along the optical axis of the illumination system from positions that are optically conjugate with respect to the observation surface. The focusing processing unit performs the focusing control in such a manner that the sizes of the two marker images corresponding to the pair of markers are the same.

14. The ophthalmic observation device according to claim 1 or 2, wherein, the ophthalmic observation device further includes: an objective lens; a second moving mechanism that moves the illumination system and the imaging system in a direction orthogonal to the optical axis of the objective lens; an abnormal image detection unit that performs image analysis for detecting an abnormal image from the image obtained by the imaging system; and a moving processing unit that controls the second moving mechanism according to the abnormal image when the abnormal image detection unit detects the abnormal image.

15. The ophthalmic observation device according to claim 1 or 2, wherein, the ophthalmic observation device further includes: a cropping processing unit that crops a region of a predetermined size from the image obtained by the imaging system; and an abnormal image detection unit that performs image analysis for detecting an abnormal image from the partial image cropped from the image, when the abnormal image detection unit detects the abnormal image, the cropping processing unit moves the region of the predetermined size to a region of the image that does not include the detected abnormal image.

16. The ophthalmic observation device according to claim 1 or 2, wherein, the ophthalmic observation device further includes: a mode switching unit for switching between a first observation mode for observing a first part of the eye to be examined and a second observation mode for observing a second part of the eye to be examined that is different from the first part, the focusing processing unit performs the detection of the plurality of marker images and the focusing control in response to the switching of the observation mode by the mode switching unit.

17. The ophthalmic observation device according to claim 16, wherein, the first observation mode is an anterior eye part observation mode for observing the anterior eye part of the eye to be examined, the second observation mode is a posterior eye part observation mode for observing the posterior eye part of the eye to be examined, the mode switching unit includes a lens inserted into the optical path for switching from the anterior eye part observation mode to the posterior eye part observation mode.

Images