Slit lamp

Abstract

To provide a slit lamp that can readily execute rotation of an illumination system even when a movement mechanism enables the illumination system and an observation system to be movable.SOLUTION: A slit lamp includes: an illumination system 30 including an illumination light source 33 and a deflection optical element 38; a rotation mechanism 24 for rotating the illumination system 30 about a rotation axis C in parallel with a Y direction when the Y direction of an X direction, the Y direction and a Z direction orthogonal to one another is in parallel with a vertical direction; an observation system 40 including an imaging device (camera 50, stereo camera 54) for imaging an eye to be examined E; a movement mechanism (XZ movement mechanism 18, Y movement mechanism 20) for moving the illumination system 30, the rotation mechanism 24 and the observation system 40 in the X direction, the Y direction and the Z direction; and an alignment control part 74 for executing alignment of the observation system 40 relative to the eye to be examined E by driving the movement mechanism on the basis of a filmed image D of the eye to be examined E that is filmed by the imaging device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a slit lamp used for observing a subject's eye. [Background technology]

[0002] A slit lamp (also called a slit lamp microscope, a slit lamp microscope, or a slit lamp microscope) is known as an ophthalmic device used for observing a subject's eye. The slit lamp uses slit light (also called slit light) to cut out a light slice of a target area of ​​the subject's eye, thereby observing a cross section of the target area and obtaining an image of the cross section.

[0003] The slit lamp described in Patent Document 1 includes an illumination system and an observation system that are held rotatably and independently of each other about one rotation axis. The illumination system irradiates the subject's eye with slit light of an adjusted width. The observation system guides return light from the subject's eye irradiated with the slit light from the objective lens through a pair of left and right observation optical paths to a pair of left and right eyepieces or a camera. This allows the examiner to observe the subject's eye through the eyepieces, or through a display unit that displays images continuously captured by the camera.

[0004] The ophthalmic apparatus described in Patent Document 2 includes an illumination system that irradiates illumination light onto the test eye, an observation system that photographs the test eye, an alignment optical system that irradiates alignment index light onto the test eye, a head unit that houses the illumination system, the observation system, and the alignment optical system, and a moving mechanism that moves the head unit in three axial directions (X, Y, and Z directions).

[0005] The illumination system described in Patent Document 2 selectively irradiates the subject's eye with multiple types of illumination light from a fixed angle in an oblique direction. By irradiating the subject's eye with slit light as illumination light from this illumination system, the subject's eye can be observed using the ophthalmic apparatus described in Patent Document 2 in the same way as with the slit lamp of Patent Document 1.

[0006] In addition, the ophthalmologic apparatus described in Patent Document 2 can perform auto-alignment of the head unit with respect to the corneal apex of the subject's eye by driving a moving mechanism based on an image of the subject's eye captured by an observation system. This allows automatic adjustment of the position of the head unit with respect to the subject's eye. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2012 / 172907 [Patent Document 2] Patent Publication No. 2021-153775 Summary of the Invention [Problem to be solved by the invention]

[0008] The ophthalmic apparatus described in Patent Document 2 can perform automatic alignment of the head part with respect to the subject's eye, but cannot rotate the illumination system around a rotation axis like the slit lamp described in Patent Document 1. For this reason, in the ophthalmic apparatus described in Patent Document 2, when viewed from one side in the Y direction (up and down direction), the illumination angle, which is the angle of incidence of the illumination light (slit light) with respect to the subject's eye, is fixed at a certain angle. Here, the appropriate illumination angle differs depending on the observation part of the subject's eye (cornea, iris, crystalline lens, etc.), so in the ophthalmic apparatus described in Patent Document 2 in which the illumination angle of the illumination system is fixed, it is difficult to observe some observation parts of the subject's eye.

[0009] Therefore, it is conceivable to provide the illumination system of the slit lamp of Patent Document 1 in the space between the head unit and the face support unit of the ophthalmic device described in Patent Document 2, so that the examiner can manually rotate the illumination system, i.e., change the illumination angle. However, when the illumination system and the observation system, etc. are movable in the XYZ directions by a movement mechanism as in the ophthalmic device of Patent Document 2, the distance between the examiner and the illumination system increases, making it difficult for the examiner to manually rotate the illumination system.

[0010] The present invention has been made in consideration of the above circumstances, and has an object to provide a slit lamp that allows easy rotation of the illumination system, even when the illumination system and observation system are movable by a movement mechanism. [Means for solving the problem]

[0011] A slit lamp for achieving the objects of the present invention includes an illumination system having an illumination light source that emits illumination light and a deflection optical element that deflects the illumination light emitted from the illumination light source toward a test eye, a rotation mechanism that rotates the illumination system about a rotation axis parallel to the Y direction when the Y direction is parallel to the up-down direction among mutually perpendicular X, Y, and Z directions, an observation system having an imaging device that images the test eye, a movement mechanism that moves the illumination system, the rotation mechanism, and the observation system in the X, Y, and Z directions, and an alignment control unit that drives the movement mechanism based on an image of the test eye captured by the imaging device to align the observation system with the test eye.

[0012] According to this slit lamp, the illumination system can be rotated around the rotation axis by driving the rotation mechanism.

[0013] A slit lamp according to another aspect of the present invention includes a plurality of observation modes for observing an eye to be examined, an information acquisition unit that acquires correspondence information between an angular position around an axis of rotation of an illumination system that is determined for each observation mode, an operation unit that accepts an operation to select an observation mode, and an illumination system rotation control unit that drives a rotation mechanism to rotate the illumination system to an angular position corresponding to the observation mode, based on the observation mode selected by the selection operation on the operation unit and the correspondence information acquired by the information acquisition unit. As a result, the illumination system can be automatically rotated to the angular position corresponding to the observation mode simply by performing an operation to select an observation mode, so that even an examiner who is inexperienced can easily adjust the illumination angle of the illumination system in a short time.

[0014] In a slit lamp according to another aspect of the present invention, the photographing device includes a plurality of first cameras that simultaneously photograph the subject's eye from a plurality of directions, and the alignment control unit drives the moving mechanism based on the photographed images of each of the plurality of first cameras to perform alignment of the observation system with respect to the pupil of the subject's eye. This makes it possible to automatically perform alignment of the observation system with respect to the pupil (iris) of the subject's eye.

[0015] In a slit lamp according to another aspect of the present invention, the photographing device includes a plurality of first cameras that simultaneously photograph the subject's eye from a plurality of directions, and a second camera that photographs the subject's eye through an objective lens having an optical axis parallel to the Z direction, and is equipped with an illumination system that irradiates the subject's eye with two light beams at two different angles centered on the optical axis, and the alignment control unit includes a first photographing control unit that causes the plurality of first cameras to simultaneously photograph the subject's eye irradiated with the two light beams, a first detection control unit that detects two Purkinje images generated in the subject's eye by the irradiation of the two light beams from the photographed images of each of the plurality of first cameras, and a moving mechanism that adjusts the position of the observation system in the X direction and the Y direction and adjusts the distance in the Z direction between the objective lens and the two Purkinje images to a predetermined working distance based on the detection result of the first detection control unit. and adjusting the position of the observation system in the Z direction, a second imaging control unit which, when the pre-alignment is completed, causes the second camera to capture an image of the test eye illuminated with the two light beams, a second detection control unit which detects two Purkinje images from the image captured by the second camera, a first XY alignment control unit which drives a moving mechanism based on the detection result of the second detection control unit to adjust the positions of the observation system in the X and Y directions, a positional deviation amount calculation unit which calculates the amount of positional deviation of the two Purkinje images in the Z direction with respect to the corneal apex of the test eye based on the detection result of the second detection control unit, and a first Z alignment control unit which drives the moving mechanism based on the calculation result of the positional deviation amount calculation unit to adjust the distance in the Z direction between the objective lens and the corneal apex to the working distance. This makes it possible to automatically perform alignment of the observation system with respect to the corneal apex of the test eye.

[0016] In the slit lamp according to another aspect of the present invention, the positional deviation amount calculation section determines the corneal curvature of the subject's eye based on the detection result of the second detection control section, and calculates the amount of positional deviation based on the corneal curvature.

[0017] A slit lamp according to another aspect of the present invention includes an iris position calculation unit that calculates the position of the iris of the subject's eye in the Z direction based on images captured by each of a plurality of first cameras, an anterior chamber position calculation unit that calculates the position of the anterior chamber of the subject's eye in the Z direction based on a calculation result of the iris position calculation unit and a calculation result of the position deviation amount calculation unit, a second XY alignment control unit that drives a movement mechanism based on a detection result of the second detection control unit to adjust the position of the observation system in the X direction and the Y direction, and a second Z alignment control unit that drives the movement mechanism based on the calculation result of the anterior chamber position calculation unit to adjust the distance in the Z direction between the objective lens and the anterior chamber to the working distance. This makes it possible to automatically align the observation system with the anterior chamber of the subject's eye.

[0018] In a slit lamp according to another aspect of the present invention, the rotation mechanism includes a shaft portion to which the illumination system is fixed and which rotates about a rotation axis, and a rotation drive portion which rotates the shaft portion.

[0019] In a slit lamp according to another aspect of the present invention, the rotation mechanism comprises a rail formed in an arc shape along a circumferential direction centered on the rotation axis, and a movable body to which the illumination system is fixed and which moves along the rail.

[0020] In a slit lamp according to another aspect of the present invention, the photographing device includes a plurality of first cameras that simultaneously photograph the subject's eye from a plurality of directions, and is equipped with a plurality of background illumination light sources arranged at the same height position in the Y direction as the plurality of first cameras.

[0021] In a slit lamp according to another aspect of the present invention, a plurality of background illumination light sources are arranged in an arc shape along the locus of an illumination system rotating around a rotation axis at a position closer to the observation system side than the locus of the illumination system when viewed from one side in the Y direction. This makes it possible to sufficiently irradiate the subject's eye with background illumination light regardless of the position to which the angular position of the illumination system is changed. Effect of the Invention

[0022] According to the present invention, even when the illumination system and the observation system are movable by a moving mechanism, the illumination system can be easily rotated. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a side view of a slit lamp according to a first embodiment. [Diagram 2] FIG. 2 is a side view of the slit lamp in a state where the stereo camera holding portion in FIG. 1 is omitted. [Diagram 3] FIG. 13 is a schematic diagram of the microscope and camera as viewed from above in the Y direction. [Figure 4] 11 is a schematic diagram of the stereo camera and the stereo camera holder as viewed from above in the Y direction. FIG. [Diagram 5] FIG. 13 is a front view of the stereo camera and the stereo camera holder as viewed from the front side (subject side) in the Z direction. [Figure 6] FIG. 2 is a functional block diagram of a control device. [Figure 7] 11 is a table showing an example of correspondence information. [Figure 8] 1 is an explanatory diagram for explaining the illumination angle (angular position) of the illumination system for each observation mode and the alignment target in the Z direction of the observation system. FIG. [Figure 9] FIG. 4 is a functional block diagram of a second alignment control unit. [Figure 10] FIG. 11 is an explanatory diagram for explaining a second alignment. [Figure 11] FIG. 2 is an explanatory diagram for explaining a captured image of a test eye in which two Purkinje images are produced. [Figure 12] 11 is an explanatory diagram for explaining the relationship between the corneal curvature of the test eye and the amount of positional deviation in the Z direction of two Purkinje images with respect to the corneal apex of the test eye. FIG. [Figure 13] FIG. 2 is an explanatory diagram for explaining the relationship between the distance in the X direction between two Purkinje images and the corneal curvature of the test eye. [Figure 14] 4 is a flowchart showing a flow of a process of observing an eye to be examined by using the slit lamp according to the first embodiment. [Figure 15] 15 is a flowchart showing the process flow of the first alignment (step S4) in FIG. 14. [Figure 16] 15 is a flowchart showing the process flow of the second alignment (step S6) in FIG. 14. [Figure 17] FIG. 11 is a functional block diagram of a control device for a slit lamp according to a second embodiment. [Figure 18] 13 is a table illustrating an example of correspondence information according to the second embodiment. [Figure 19] 1 is an explanatory diagram for explaining the illumination angle (angular position) of the illumination system corresponding to the observation mode "anterior chamber" and the alignment target in the Z direction of the observation system. FIG. [Figure 20] 13 is a flowchart showing the flow of a third alignment process. [Figure 21] FIG. 13 is a top view of an illumination system and a rotation mechanism of the slit lamp of the third embodiment. [Figure 22] FIG. 13 is a top view of an illumination system and a rotation mechanism of the slit lamp of the third embodiment. [Figure 23] FIG. 13 is a top view of the observation system of the slit lamp of the fourth embodiment, as viewed from above in the Y direction. [Figure 24] FIG. 13 is a front view of the observation system of the slit lamp of the fourth embodiment, as viewed from the front side in the Z direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [First embodiment] Fig. 1 is a side view of the slit lamp 10 of the first embodiment. Fig. 2 is a side view of the slit lamp 10 without the stereo camera holder 56 in Fig. 1. The X direction in the figure is the left-right direction (pupillary width direction of the subject's eye E) based on the subject (patient), and the Y direction is the up-down direction. The Z direction, which is perpendicular to both the X and Y directions, is the front-back direction (working distance direction) parallel to the front direction approaching the subject and the rear direction away from the subject.

[0025] As shown in Figures 1 and 2, the slit lamp 10 includes a base 12, a face support unit 14, a stand 16 (also called a moving stage or moving table), an XZ movement mechanism 18 and a Y movement mechanism 20, a mounting unit 22, a rotation mechanism 24, an illumination system 30, an observation system 40, a control device 60, a display unit 62, and an operation unit 64.

[0026] The base 12 is placed on an optometry table (not shown). A face support part 14 is provided on the upper surface of the base 12 at the end on the front side in the Z direction, which is on the subject (subject's eye E) side. In addition, a stand 16 is provided on the upper surface of the base 12.

[0027] The face support part 14 has a pair of pillars 14a fixed to the base 12 and extending in the Y direction, a chin rest part 14b provided in the middle part of the pair of pillars 14a in the Y direction, and a forehead rest part 14c provided at the upper end part of the pair of pillars 14a in the Y direction. The chin rest part 14b can be raised and lowered in the Y direction by an electric actuator (not shown). The subject places his / her chin on the chin rest part 14b and places his / her forehead on the forehead rest part 14c, whereby the subject's face is supported by the face support part 14. This fixes the position of the subject's eye E.

[0028] An attachment section 22 is provided on the upper surface of the base 16 via a Y movement mechanism 20. The base 16 is moved in the XZ directions by an XZ movement mechanism 18, which is an electric actuator. The attachment section 22 is moved in the Y direction by the Y movement mechanism 20. The XZ movement mechanism 18 and the Y movement mechanism 20 are, for example, electric actuators equipped with a motor or the like, and correspond to the movement mechanism of the present invention.

[0029] An illumination system 30 is provided via a rotation mechanism 24 at an end portion on the front side in the Z direction of the mounting unit 22. An observation system 40 is provided at an end portion on the rear side (examiner side) in the Z direction of the mounting unit 22. The mounting unit 22 may be integrated with a vertical arm 41 of the observation system 40. By driving the XZ movement mechanism 18 and the Y movement mechanism 20, the rotation mechanism 24, illumination system 30, and observation system 40 move integrally in the X, Y, and Z directions via the stand 16 and the mounting unit 22.

[0030] The rotation mechanism 24 is provided on the mounting portion 22, and includes a shaft portion 25 that rotates about a rotation axis C parallel to the Y direction, and a rotation drive portion 26 that is an electric actuator such as a motor that rotates the shaft portion 25. An illumination system 30 is fixed (or may be connected or coupled) to a side surface of the shaft portion 25. Thus, by driving the rotation mechanism 24, the illumination system 30 rotates about the rotation axis C. After auto-alignment, which will be described later, is completed, the position of the rotation axis C in the XZ directions coincides with the observation site of the subject's eye E when viewed from one side in the Y direction.

[0031] The illumination system 30 includes an illumination unit 32 (also called a slit lamp) and a deflection optical element 38 (see FIG. 2), and irradiates the subject's eye E with slit light, which is slit-shaped illumination light. The illumination system 30 rotates about a rotation axis C by driving the rotation mechanism 24, and thereby changes its angular position in the circumferential direction about the rotation axis C. As a result, when the incidence angle of the slit light with respect to the subject's eye E when viewed from one side in the Y direction is defined as the illumination angle, the illumination angle of the illumination system 30 can be arbitrarily adjusted by driving the rotation mechanism 24.

[0032] As shown in FIG. 6 described later, the illumination unit 32 includes a known illumination light source 33, a slit width adjustment section 34 (also called a slit forming section), a slit length adjustment section (not shown), and a filter switching mechanism 35.

[0033] The illumination light source 33 (see FIG. 6) emits illumination light, which is white light. The slit width adjustment unit 34 (see FIG. 6) is provided on the optical path of the illumination light emitted from the illumination light source 33. The slit width adjustment unit 34 has, for example, a pair of slit blades, and adjusts the width of the slit light irradiated to the subject's eye E by changing the slit width, which is the distance between the pair of slit blades. The slit length adjustment unit (not shown) adjusts the length of the slit light. The filter switching mechanism 35 (see FIG. 6) selectively inserts and removes various optical filters, such as a blue filter, a red-free filter, an ND (Neutral Density) filter, a color temperature change filter, an IR (infrared) cut filter, and an exciter filter, on the optical path of the illumination unit 32.

[0034] The deflection optical element 38 is fixed to the upper side in the Y direction of the illumination unit 32. The deflection optical element 38 is, for example, a prism or a mirror, and deflects (including reflects) the illumination light (slit light) emitted from the illumination unit 32 toward the subject's eye E. This causes the slit light to be irradiated onto the subject's eye E. Then, return light from the subject's eye E irradiated with the slit light passes through both sides of the deflection optical element 38 and enters the observation system 40. The deflection optical element 38 is formed in a shape that prevents the return light from being vignetted.

[0035] The observation system 40 includes a vertical arm 41, a microscope 42, a camera 50, a stereo camera 54 (see FIG. 4), and a stereo camera holder 56 (see FIG. 4).

[0036] The vertical arm 41 has a shape extending in the Y direction, and its lower end in the Y direction is fixed to the rear end in the Z direction of the mounting part 22. A microscope 42 is fixed to the upper end of the vertical arm 41 in the Y direction.

[0037] The microscope 42 includes a known objective lens 43 (see FIG. 2) and a camera connector 44 to which a camera 50 is connected, and guides return light from the subject's eye E from the objective lens 43 to the camera 50. Note that the symbol O1 in FIG. 2 denotes the optical axis of the objective lens 43.

[0038] Fig. 3 is a schematic diagram of the microscope 42 and the camera 50 as viewed from above in the Y direction. Note that the stereo camera 54 and the stereo camera holder 56 are omitted from Fig. 3.

[0039] As shown in FIG. 3, the microscope 42 is provided with various optical systems between the objective lens 43 and the camera connector 44. The various optical systems include a half mirror 45 and an alignment light source 46 that constitute the illumination system of the present invention. The half mirror 45 is disposed on the optical path between the objective lens 43 and the camera connector 44. The half mirror 45 transmits a part of the return light from the subject's eye E and emits it toward the camera 50 (camera connector 44). The half mirror 45 also reflects a part of the alignment index light Li incident from the alignment light source 46 toward the objective lens 43. Instead of the half mirror 45, a beam splitter whose transmittance and reflectance are adjusted according to the output light amount of the alignment light source 46 and the received light amount at the camera 50 may be used.

[0040] When aligning the observation system 40 with the subject's eye E, the alignment light source 46 emits two alignment index lights Li (corresponding to two light beams of the present invention), which are parallel lights irradiated at two different angles in the infrared wavelength range, toward the half mirror 45. As a result, the alignment index light Li reflected by the half mirror 45 is irradiated onto the subject's eye E via the objective lens 43.

[0041] At this time, the alignment light source 46 emits two alignment index lights Li from the objective lens 43 toward the half mirror 45 so as to be irradiated onto the subject's eye E at two different angles (for example, a lower limit of 5° to an upper limit of 10°) centered on the optical axis O1. The height positions of the two alignment index lights Li in the Y direction are the same (including approximately the same). By irradiating the subject's eye E with the two alignment index lights Li, two Purkinje images Pi are generated in the subject's eye E. In order to project the two alignment index lights Li onto the subject's eye E at two different angles, two alignment light sources 46 may be provided, two half mirrors 45 may be used, or an opening having two holes may be provided in front of the emission direction of the alignment light source 46.

[0042] The various optical systems described above include a known optical magnification switching mechanism 47 and a filter switching mechanism 48 shown in FIG. 6, which will be described later, in addition to the half mirror 45 and the alignment light source 46. The optical magnification switching mechanism 47 switches the optical magnification of the microscope 42. The filter switching mechanism 48 selectively inserts and removes various optical filters, such as a barrier filter, on the optical path of the microscope 42. Although not shown, the microscope 42 may be provided with a known autofocus optical system. Note that left and right eyepieces (eyepiece lenses) may be provided at the position of the camera connection unit 44 of the microscope 42, and the camera connection unit 44 may be connected to the optical path of the microscope 42 via a light branching element.

[0043] The camera 50 corresponds to the second camera and the photographing device of the present invention, and is used for auto-alignment of the observation system 40 with respect to the subject's eye E, and for observing the subject's eye E after the auto-alignment is completed. The camera 50 includes an image sensor 51 of a complementary metal oxide semiconductor (CMOS) type or a charge coupled device (CCD) type. The camera 50 captures the return light from the subject's eye E, which is incident from the microscope 42, by the image sensor 51, and outputs a photographed image D (image data, see FIG. 6) of the subject's eye E to a control device 60 described later. Note that the camera 50 may have a conjugate position at a position in the Z direction substantially the same as the rotation axis C.

[0044] Fig. 4 is a schematic diagram of the stereo camera 54 and the stereo camera holder 56 as viewed from above in the Y direction. Fig. 5 is a front view of the stereo camera 54 and the stereo camera holder 56 as viewed from the front side (subject side) in the Z direction.

[0045] As shown in Fig. 4 and Fig. 5, the stereo camera 54 is used for auto-alignment of the observation system 40 with respect to the subject's eye E, and simultaneously captures the subject's eye E from a plurality of different directions. Specifically, the stereo camera 54 is composed of two cameras 54a (corresponding to a plurality of first cameras and a photographing device of the present invention) spaced apart in the X direction centered on the optical axis O1 when viewed from above in the Y direction, and simultaneously captures the subject's eye E from two directions. The stereo camera 54 outputs two simultaneously captured images D (image data, see Fig. 6) to a control device 60 described later. The number of cameras 54a constituting the stereo camera 54 may be three or more.

[0046] The stereo camera holding part 56 is detachably attached to the front end of the microscope 42 in the Z direction, or is fixed non-detachably. The stereo camera holding part 56 holds two cameras 54a constituting the stereo camera 54. The stereo camera holding part 56 and the microscope 42 may be integrated, that is, the stereo camera 54 may be provided on the front end surface of the microscope 42 in the Z direction. The stereo camera holding part 56 is also provided with two BG illumination light sources 57 that emit background (BG) illumination light.

[0047] The two BG illumination light sources 57 are provided at the same height position (including approximately the same height position) as the stereo camera 54 in the Y direction, and irradiate the subject's eye E with BG illumination light. The BG illumination light is used as necessary when observing the subject's eye E, for example, to illuminate the background of the slit light irradiated to the subject's eye E or to observe opacity of the crystalline lens of the subject's eye E. The number and arrangement positions of the BG illumination light sources 57 are not particularly limited.

[0048] 1 and 2, the control device 60 is a computing device that executes various types of arithmetic processing and control processing, and in this embodiment, for example, a PC (Personal Computer) is used. The control device 60 may be provided in, for example, the base 12.

[0049] The control device 60 centrally controls the operation of each part of the slit lamp 10. For example, the control device 60 controls auto-alignment of the observation system 40 (microscope 42) with respect to the subject's eye E, for each of a plurality of observation modes for observing the subject's eye E, corresponding to the observation mode. The control device 60 also automatically adjusts the illumination angle of the illumination system 30 according to the observation mode, and automatically adjusts the slit width of the slit width adjustment unit 34 according to the observation mode. Furthermore, the control device 60 causes the display unit 62 to display a captured image D (observation image) of the subject's eye E captured by the camera 50.

[0050] The display unit 62 is connected to the control device 60, and is, for example, a known monitor such as an LCD (Liquid Crystal Display). The display unit 62 displays various setting screens of the slit lamp 10, a captured image D of the subject's eye E captured by the camera 50, and the like.

[0051] The operation unit 64 is, for example, a keyboard and a mouse. The operation unit 64 accepts input of various operations of the slit lamp 10, including an operation for selecting an observation mode, an operation for the illumination system 30 (manual adjustment of the slit width, filter switching, etc.), an operation for the observation system 40 (optical magnification switching, filter switching, etc.), a manual rotation operation for the illumination system 30, and a manual alignment operation for the observation system 40. At least a part of the operation unit 64 may be provided on the base 12, the stand 16, etc.

[0052] Fig. 6 is a functional block diagram of the control device 60. As shown in Fig. 6, the functions of the control device 60 are realized by using various processors. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), and a programmable logic device (e.g., simple programmable logic devices (SPLD), complex programmable logic devices (CPLD), and field programmable gate arrays (FPGA)). The various functions of the control device 60 may be realized by one processor, or may be realized by multiple processors of the same type or different types.

[0053] In addition to the chin rest 14b, XZ movement mechanism 18, Y movement mechanism 20, rotation mechanism 24, illumination system 30, observation system 40, display unit 62, and operation unit 64, a memory unit 66 is connected to the control device 60.

[0054] The storage unit 66 stores correspondence information 68 in addition to a control program (not shown) for the slit lamp 10. This correspondence information 68 is information indicating the correspondence between a plurality of observation modes for the subject's eye E and the illumination angle of the illumination system 30, the slit width of the slit width adjustment unit 34, and setting information for auto-alignment, which are determined for each observation mode. This correspondence information 68 is stored in the storage unit 66 by, for example, the manufacturer of the slit lamp 10.

[0055] Fig. 7 is a table showing an example of the correspondence information 68. Fig. 8 is an explanatory diagram for explaining the illumination angle (angular position) of the illumination system 30 for each observation mode and the alignment target (reference) in the Z direction of the observation system 40.

[0056] 7, the correspondence information 68 has a plurality of observation modes set therein, such as "cornea" for observing the cornea, "crystalline lens (IOL)" for observing the crystalline lens or intraocular lens (IOL), "crystalline lens (cataract)" for observing the crystalline lens of a cataract, and "iris" for observing the iris. The correspondence information 68 also stores "illumination angle," "slit width," and "working distance" for each observation mode.

[0057] The "illumination angle" of the correspondence information 68 is the illumination angle of the illumination system 30, i.e., the angular position around the axis of rotation C of the illumination system 30. Here, the angular position at which the illumination optical axis O2 of the illumination system 30 coincides (including approximately coincides) with the optical axis O1 when viewed from one side in the Y direction is represented as "0°". Note that the "illumination angle" of the correspondence information 68 may be set to match the rotation directions (clockwise, counterclockwise) of the illumination system 30 corresponding to the left eye and right eye of the subject's eye E, respectively.

[0058] The "slit width" in the correspondence information 68 is the slit width of the slit width adjustment unit 34, and the size is set in multiple stages ("wide", "medium", "thin", and "extra thin"). The "slit width" may be set as a specific numerical value.

[0059] In the "working distance" of the correspondence information 68, the setting information of the auto-alignment, more specifically, the alignment target in the Z direction of the observation system 40, is set. In the auto-alignment in the Z direction, the distance between the objective lens 43 and the observation part of the subject's eye E corresponding to the observation mode is adjusted to a predetermined working distance. Therefore, in the "working distance" of the correspondence information 68, the observation part of the subject's eye E corresponding to the observation mode ("corneal apex", "iris") is set for each observation mode. Note that when the "working distance" is "iris", the distance between the objective lens 43 and the pupil of the subject's eye E is adjusted to be the working distance.

[0060] Note that the alignment target in the XY directions of the observation system 40 may also be added for each observation mode as setting information for auto-alignment in the correspondence information 68. For example, when the "working distance" is "iris", the target of the XY alignment is the pupil center of the subject's eye E. Also, when the "working distance" is "corneal apex", the alignment target of the XY alignment is the central position in the X direction of the two Purkinje images Pi described above.

[0061] As shown by symbol XVIIIA in Figures 7 and 8, in the observation mode "cornea", the illumination angle is set to a value selected from the range of 10° to 20°, the slit width is set to "wide", and the working distance is set to "corneal apex".

[0062] As shown by symbol XVIIIB in Figures 7 and 8, in the observation mode "Crystal Lens (IOL)", the illumination angle is set to a value selected from the range of 10° to 20°, the slit width is set to "wide", and the working distance is set to "iris" (pupil).

[0063] As shown by reference symbol XVIIIC in Figures 7 and 8, in the observation mode "Crystal Lens (Cataract)", the illumination angle is set to a value selected from the range of 30° to 60°, the slit width is set to "Very Fine", and the working distance is set to "Iris" (pupil).

[0064] As shown in Fig. 7, in the observation mode "iris", the illumination angle is set to a value selected from the range of 30° to 90°, the slit width is set to "medium", and the working distance is set to "iris" (pupil). Note that the arrangement of the illumination system 30 and the observation system 40 in the observation mode "iris" is basically the same as in the observation mode "crystalline lens (cataract)", and is therefore omitted from Fig. 8.

[0065] The types and number of observation modes, the setting items for each observation mode (illumination angle, slit width, working distance), and the setting values ​​for each setting item are not limited to the examples shown in Figures 7 and 8, and can be changed as appropriate. In addition, the setting values ​​for each setting item for each observation mode (for example, illumination angle, slit width, etc.) may be changeable by the operation unit 64.

[0066] Returning to Fig. 6, the functions of the control device 60 are realized by using various processors. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), and a programmable logic device (e.g., simple programmable logic devices (SPLD), complex programmable logic devices (CPLD), and field programmable gate arrays (FPGA)). The various functions of the control device 60 may be realized by one processor, or may be realized by multiple processors of the same type or different types.

[0067] The control device 60 executes a control program read from the memory unit 66, and thereby functions as an illumination system control unit 71, an observation system control unit 72, an information acquisition unit 73, an alignment control unit 74, an illumination system rotation control unit 75, and a display control unit 76.

[0068] The illumination system control unit 71 controls the operation of the illumination system 30. When the power of the slit lamp 10 is turned on, or when auto-alignment of the observation system 40 and adjustment of the illumination angle of the illumination system 30 are completed, the illumination system control unit 71 starts emission of illumination light from the illumination light source 33. In addition, the illumination system control unit 71 drives the filter switching mechanism 35 in response to a filter switching operation input to the operation unit 64, and inserts or removes an optical filter into or from the optical path of the illumination unit 32.

[0069] Furthermore, the illumination system control unit 71 determines a slit width corresponding to the selected observation mode based on the type of observation mode selected by the operation unit 64 and corresponding information 68 input from an information acquisition unit 73 described below. Then, the illumination system control unit 71 drives the slit width adjustment unit 34 to adjust the slit width of the slit width adjustment unit 34 to a slit width corresponding to the observation mode.

[0070] The observation system control unit 72 controls the operation of the observation system 40. When the power of the slit lamp 10 is turned on, or when the auto-alignment of the observation system 40 and the automatic adjustment of the illumination angle of the illumination system 30 are completed, the observation system control unit 72 acquires a photographed image D (observation image) of the subject's eye E from the camera 50. In addition, the observation system control unit 72 drives the optical magnification switching mechanism 47 in response to an optical magnification switching operation input to the operation unit 64 to change the optical magnification of the microscope 42. Furthermore, the observation system control unit 72 drives the filter switching mechanism 48 in response to a filter switching operation input to the operation unit 64 to insert or remove an optical filter into or from the optical path of the microscope 42.

[0071] For example, when the slit lamp 10 is turned on or an observation mode is selected using the operation unit 64, the information acquisition unit 73 acquires the correspondence information 68 from the storage unit 66 and outputs the correspondence information 68 to the illumination system control unit 71, the alignment control unit 74, and the illumination system rotation control unit 75. Instead of acquiring the correspondence information 68 from the storage unit 66, the information acquisition unit 73 may acquire the correspondence information 68 from a predetermined server or the like via the Internet.

[0072] The alignment control unit 74 operates in response to an observation mode selection operation on the operation unit 64, and controls auto-alignment of the observation system 40 with respect to the subject's eye E, based on the type of observation mode selected by this selection operation and the corresponding information 68 input from the information acquisition unit 73. This alignment control unit 74 functions as a first alignment control unit 74A or a second alignment control unit 74B, depending on the type of observation mode.

[0073] The first alignment control unit 74A operates when an observation mode in which "iris" is set as the "working distance" in the above-mentioned correspondence information 68, that is, an observation mode in which the pupil (iris) of the subject's eye E is the target of Z alignment, is selected. This first alignment control unit 74A controls the first alignment, which is the alignment of the observation system 40 with the pupil of the subject's eye E.

[0074] The first alignment control unit 74A simultaneously captures the subject's eye E (anterior eye portion) using each camera 54a of the stereo camera 54, and acquires a captured image D of the subject's eye E from each camera 54a. Then, the first alignment control unit 74A detects the three-dimensional position of the pupil center of the subject's eye E by a known method (see, for example, JP 2013-248376 A) based on the captured image D acquired from each camera 54a. Next, the first alignment control unit 74A drives the XZ movement mechanism 18 and the Y movement mechanism 20 based on the detection result of the three-dimensional position of the pupil center to perform XY alignment for aligning the optical axis O1 of the observation system 40 with the pupil center in the XY direction, and Z alignment for adjusting the distance between the objective lens 43 and the pupil to the working distance in the Z direction.

[0075] The second alignment control unit 74B operates when an observation mode in which "corneal apex" is set as the "working distance" in the correspondence information 68 described above, that is, an observation mode in which the corneal apex of the subject's eye E is the alignment target of the Z alignment, is selected. This second alignment control unit 74B controls the second alignment, which is the alignment of the observation system 40 with respect to the corneal apex of the subject's eye E. The second alignment is performed in a state in which two Purkinje images Pi are generated in the subject's eye E by irradiating the subject's eye E with two alignment index lights Li from the alignment light source 46. This second alignment includes pre-alignment and main alignment.

[0076] In the pre-alignment, alignment (position adjustment) of the observation system 40 in the XYZ directions with respect to the two Purkinje images Pi is performed based on a photographed image D obtained by photographing the subject's eye E in which two Purkinje images Pi are generated, using a stereo camera 54. This pre-alignment is performed to place the two Purkinje images Pi within the depth of field of the camera 50, that is, to enable the main alignment. In the main alignment, alignment of the observation system 40 with respect to the corneal apex position of the subject's eye E is performed based on a photographed image D obtained by photographing the subject's eye E in which two Purkinje images Pi are generated, using the camera 50.

[0077] Fig. 9 is a functional block diagram of the second alignment control unit 74B. Fig. 10 is an explanatory diagram for explaining the second alignment (pre-alignment, main alignment). Fig. 11 is an explanatory diagram for explaining a captured image D of the subject's eye E in which two Purkinje images Pi are generated.

[0078] 9, the second alignment control unit 74B functions as a first photographing control unit 80, a first detection control unit 82, a pre-alignment control unit 84, a second photographing control unit 86, a second detection control unit 88, a positional deviation amount calculation unit 90, an XY alignment control unit 92, and a Z alignment control unit 94. The first photographing control unit 80, the first detection control unit 82, and the pre-alignment control unit 84 are used for pre-alignment. On the other hand, the second photographing control unit 86, the second detection control unit 88, the positional deviation amount calculation unit 90, the XY alignment control unit 92, and the Z alignment control unit 94 are used for main alignment.

[0079] 10 and 11, when performing pre-alignment, the first photography control unit 80 operates to emit two alignment index lights Li from the alignment light source 46. As a result, two alignment index lights Li are irradiated from the alignment light source 46 to the subject's eye E, and two Purkinje images Pi spaced apart in the X direction with respect to the optical axis O1 are generated in the subject's eye E.

[0080] The first imaging control unit 80 also controls the stereo camera 54 (two cameras 54a) to simultaneously capture images of the subject's eye E in which two Purkinje images Pi are generated. As a result, a captured image D of the subject's eye E is output to the first detection control unit 82 by each of the cameras 54a.

[0081] The first detection control unit 82 detects two Purkinje images Pi from each captured image D simultaneously captured by the stereo camera 54 using a known method, and outputs the detection result to the pre-alignment control unit 84. If the first detection control unit 82 fails to detect the two Purkinje images Pi, it performs the above-mentioned first alignment to adjust (coarsely adjust) the position of the observation system 40 with respect to the subject's eye E, and then performs simultaneous imaging by the stereo camera 54 and detection of the two Purkinje images Pi.

[0082] The pre-alignment control unit 84 drives the XZ movement mechanism 18 and the Y movement mechanism 20 based on the detection results of the two Purkinje images Pi for each of the two captured images D input from the first detection control unit 82, and performs pre-alignment of the observation system 40 with respect to the subject's eye E.

[0083] Specifically, the pre-alignment control unit 84 performs XY alignment of the observation system 40 by driving the XZ movement mechanism 18 and the Y movement mechanism 20 in the XY directions so that the positions (center positions, etc.) of the two Purkinje images Pi with respect to the objective lens 43 are adjusted to specified positions, for example, based on the XY positions of the two Purkinje images Pi for each of the two photographed images D. The pre-alignment control unit 84 also performs Z alignment of the observation system 40 by driving the XZ movement mechanism 18 in the Z direction so that the distance between the objective lens 43 and the two Purkinje images Pi is adjusted to a predetermined working distance, based on the Z positions of the two Purkinje images Pi for each of the two photographed images D. This pre-alignment makes it possible to place the two Purkinje images Pi within the depth of field of the camera 50.

[0084] The second photography control unit 86 operates after the completion of the pre-alignment to emit the two alignment index lights Li from the alignment light source 46, or to continue emitting the two alignment index lights Li from the alignment light source 46 from the pre-alignment. As a result, two Purkinje images Pi are continuously generated in the test eye E.

[0085] Further, the second imaging control unit 86 controls the camera 50 to capture an image of the subject's eye E in which two Purkinje images Pi are generated. As a result, a captured image D of the subject's eye E is output from the camera 50 to the second detection control unit 88.

[0086] The second detection control unit 88 detects two Purkinje images Pi from the image D captured by the camera 50 by a known method, and outputs the detection result to the positional deviation amount calculation unit 90 and the XY alignment control unit 92.

[0087] The positional deviation calculation unit 90 calculates information indicating the Z position of the corneal apex of the test eye E, specifically, the positional deviation amount Δz (see FIG. 12 ) of the two Purkinje images Pi in the Z direction relative to the corneal apex of the test eye E, based on the detection results of the two Purkinje images Pi in the captured image D input from the second detection control unit 88.

[0088] 12 is an explanatory diagram for explaining the relationship between the corneal curvature R of the test eye E and the positional deviation Δz of two Purkinje images Pi in the Z direction relative to the corneal apex of the test eye E. As shown in Fig. 12, when the corneal curvature of the test eye E is "R", the two Purkinje images Pi are generated at a position shifted by about R / 2 forward in the Z direction from the corneal apex. Therefore, the positional deviation Δz of the two Purkinje images Pi in the Z direction relative to the corneal apex of the test eye E is expressed by the following [Mathematical Expression 1].

[0089]

number

[0090] FIG. 13 is an explanatory diagram for explaining the relationship between the distance ΔX in the X direction between two Purkinje images Pi and the corneal curvature R of the test eye E. As shown in FIG. 13, since the two alignment index lights Li irradiated to the test eye E are parallel lights, the distance ΔX in the X direction between the two Purkinje images Pi depends only on the corneal curvature R. For this reason, for example, the two alignment index lights Li are irradiated to a model eye (not shown) with a known corneal curvature R, and the distance ΔX of the two Purkinje images Pi generated on the model eye is measured. Thereafter, in the same manner, irradiation of the two alignment index lights Li to a plurality of model eyes with different corneal curvatures R and measurement of the distance ΔX for each model eye are repeatedly performed. As a result, corneal curvature information (data table, calculation formula, etc.) (not shown) showing the relationship between the distance ΔX of the two Purkinje images Pi and the corneal curvature R of the test eye E is obtained.

[0091] The positional deviation amount calculation unit 90 first calculates the distance ΔX between the two Purkinje images Pi based on the detection results of the two Purkinje images Pi input from the second detection control unit 88. Next, the positional deviation amount calculation unit 90 determines the corneal curvature R of the subject's eye E based on the calculation result of the distance ΔX and the above-mentioned corneal curvature information. Then, the positional deviation amount calculation unit 90 calculates the positional deviation amount Δz with reference to the above-mentioned [Mathematical Expression 1] based on the corneal curvature R, and outputs the calculation result to the Z alignment control unit 94.

[0092] Note that, since the Z positions of the two Purkinje images Pi at the time of completion of pre-alignment have been obtained, the second alignment control unit 74B may be provided with a corneal vertex position calculation unit that calculates the Z position of the corneal vertex based on the Z positions of the two Purkinje images Pi and the positional deviation amount Δz.

[0093] 9, the XY alignment control unit 92 corresponds to the first XY alignment control unit of the present invention. The XY alignment control unit 92 performs XY alignment (main alignment) of the observation system 40 by driving the XZ movement mechanism 18 and the Y movement mechanism 20 so that the positions (center positions, etc.) of the two Purkinje images Pi are adjusted to specified positions with respect to the objective lens 43, for example, based on the XY positions of the two Purkinje images Pi detected by the second detection control unit 88.

[0094] The Z alignment control unit 94 corresponds to the first Z alignment control unit of the present invention. Based on the calculation result of the positional deviation amount Δz input from the positional deviation amount calculation unit 90, the Z alignment control unit 94 drives the XZ movement mechanism 18 to execute Z alignment (main alignment) of the observation system 40 so that the distance between the objective lens 43 and the corneal apex is adjusted to the working distance. Specifically, the observation system 40 after the completion of the pre-alignment is moved backward in the Z direction by the positional deviation amount Δz. When the main alignment (XYZ alignment) is completed, the rotation axis C and the XZ position of the observation site of the subject's eye E coincide (including approximately coincide) when viewed from one side in the Y direction.

[0095] The illumination-system rotation control unit 75 determines the illumination angle (angular position around the rotation axis C) of the illumination system 30 based on the type of observation mode selected by the operation unit 64 and the corresponding information 68 input from the information acquisition unit 73. After the first alignment or the second alignment is completed, the illumination-system rotation control unit 75 drives the rotation mechanism 24 to rotate the illumination system 30 to an angular position corresponding to the observation mode based on the illumination angle of the illumination system 30 previously determined. Note that the illumination-system rotation control unit 75 may rotate the illumination system 30 clockwise or counterclockwise around the rotation axis C based on the selection result of the left or right eye by the operation unit 64.

[0096] The display control unit 76 operates when the slit lamp 10 is powered on, after the alignment of the observation system 40 is completed, or after the illumination angle of the illumination system 30 is adjusted, and continuously acquires the photographed images D from the camera 50 and continuously outputs them to the display unit 62. As a result, the photographed images D (observation images) of the subject's eye E are displayed on the display unit 62.

[0097] [Operation of the first embodiment] FIG. 14 is a flow chart showing the flow of a process for observing the eye E by the slit lamp 10 of the first embodiment having the above-mentioned configuration.

[0098] As shown in FIG. 14, when the slit lamp 10 is powered on, the information acquisition unit 73 of the control device 60 acquires the correspondence information 68 from the memory unit 66 and outputs the correspondence information 68 to the illumination system control unit 71, the alignment control unit 74, and the illumination system rotation control unit 75 (step S1).

[0099] Next, after the subject's face is supported by the face support part 14 and the height adjustment of the chin rest part 14b is completed, the examiner inputs a selection operation of an observation mode for the subject's eye E to the operation part 64 (step S2). As a result, the alignment control part 74 starts auto-alignment of the observation system 40 with respect to the subject's eye E based on the type of observation mode selected by the selection operation and the corresponding information 68 input from the information acquisition part 73.

[0100] When an observation mode in which the pupil (iris) of the subject's eye E is the alignment target of the Z alignment is selected, the alignment control unit 74 functions as a first alignment control unit 74A to execute the first alignment (YES in step S3, NO in steps S4 and S5). When an observation mode in which the corneal apex of the subject's eye E is the alignment target of the Z alignment is selected, the alignment control unit 74 functions as a second alignment control unit 74B to execute the second alignment (NO in step S3, YES in step S5, step S6).

[0101] When the second alignment is performed, the first alignment may be performed before that (YES in step S3, YES in step S4 and step S5, step S6). This allows the two Purkinje images Pi generated in the subject's eye E to be reliably photographed by the stereo camera 54.

[0102] FIG. 15 is a flowchart showing the process flow of the first alignment (step S4) in FIG.

[0103] As shown in Fig. 15, first, the first alignment control unit 74A performs simultaneous photographing of the subject's eye E (anterior eye portion) by each camera 54a of the stereo camera 54 (step S4A) and obtains a photographed image D of the subject's eye E from each camera 54a. Next, the first alignment control unit 74A detects the three-dimensional position of the pupil center of the subject's eye E by a known method based on the photographed image D obtained from each camera 54a (step S4B). Then, based on the detection result of the three-dimensional position of the pupil center, the first alignment control unit 74A drives the XZ movement mechanism 18 and the Y movement mechanism 20 to perform XY alignment for aligning the optical axis O1 of the observation system 40 with the pupil center and Z alignment for adjusting the distance in the Z direction between the objective lens 43 and the pupil to the working distance (step S4C).

[0104] FIG. 16 is a flowchart showing the process flow of the second alignment (step S6) in FIG.

[0105] The second alignment control unit 74B first executes pre-alignment, and therefore functions as a first photography control unit 80, a first detection control unit 82, and a pre-alignment control unit 84. Then, the first photography control unit 80 causes the alignment light source 46 to emit two alignment index lights Li. As a result, the two alignment index lights Li are irradiated onto the subject's eye E, and two Purkinje images Pi spaced apart from each other in the X direction around the optical axis O1 are generated in the subject's eye E (step S6A).

[0106] The first photography control unit 80 also controls the stereo camera 54 to simultaneously photograph the subject's eye E in which two Purkinje images Pi are generated (step S6B). As a result, a photographed image D of the subject's eye E is output from each camera 54a to the first detection control unit 82. Then, the first detection control unit 82 detects two Purkinje images Pi for each of the two simultaneously photographed photographed images D and outputs the detection results to the pre-alignment control unit 84 (step S6C).

[0107] Next, the pre-alignment control unit 84 drives the XZ movement mechanism 18 and the Y movement mechanism 20 based on the detection result of the first detection control unit 82 to perform pre-alignment of the observation system 40 with respect to the subject's eye E (step S6D). This performs XY alignment of the observation system 40 to adjust the positions (center positions, etc.) of the two Purkinje images Pi to specified positions with respect to the objective lens 43, and Z alignment of the observation system 40 to adjust the distance in the Z direction between the objective lens 43 and the two Purkinje images Pi to the working distance. This ensures that the two Purkinje images Pi are contained within the depth of field of the camera 50, making main alignment possible.

[0108] When the pre-alignment is completed, the second alignment control unit 74B functions as a second shooting control unit 86, a second detection control unit 88, a positional deviation amount calculation unit 90, an XY alignment control unit 92, and a Z alignment control unit 94 to perform main alignment.

[0109] The second photography control unit 86 continues emitting the two alignment index lights Li from the alignment light source 46. Then, the second photography control unit 86 causes the camera 50 to photograph the subject's eye E in which two Purkinje images Pi are generated (step S6E). As a result, a photographed image D is output from the camera 50 to the second detection control unit 88. Then, the second detection control unit 88 detects the two Purkinje images Pi from the photographed image D and outputs the detection result to the positional deviation amount calculation unit 90 and the XY alignment control unit 92 (step S6F).

[0110] The misalignment amount calculation unit 90 calculates the distance ΔX between the two Purkinje images Pi based on the detection result of the second detection control unit 88, and determines the corneal curvature R of the subject's eye E based on the calculation result of the distance ΔX and the above-mentioned corneal curvature information (step S6G). Next, the misalignment amount calculation unit 90 calculates the misalignment amount Δz by referring to the above-mentioned [Equation 1] based on the corneal curvature R, and outputs the calculation result to the Z alignment control unit 94 (step S6H).

[0111] The XY alignment control unit 92 drives the XZ movement mechanism 18 and the Y movement mechanism 20 based on the detection result of the second detection control unit 88 to perform XY alignment (main alignment) of the observation system 40 (step S6I). As a result, for example, the positions (center positions, etc.) of the two Purkinje images Pi are adjusted to specified positions in the XY directions with respect to the objective lens 43.

[0112] On the other hand, the Z alignment control unit 94 drives the XZ movement mechanism 18 based on the calculation result of the positional deviation amount Δz input from the positional deviation amount calculation unit 90 to perform Z alignment (main alignment) of the observation system 40 (step S6J). As a result, the distance in the Z direction between the objective lens 43 and the corneal apex is adjusted to the working distance. Note that, before performing this Z alignment, the processes from the above-mentioned steps S6A to S6C may be repeatedly performed to detect the Z positions of the two Purkinje images Pi, and Z alignment may be performed based on the Z positions and the positional deviation amount Δz. This completes the second alignment. Also, when viewed from one side in the Y direction, the XZ positions of the rotation axis C and the observation site of the subject's eye E coincide with each other.

[0113] 14, when the first alignment or the second alignment is completed, the illumination system rotation control unit 75 determines the illumination angle (angular position) of the illumination system 30 based on the type of observation mode selected by the operation unit 64 and the corresponding information 68 input from the information acquisition unit 73 (step S7). Note that the timing of determining the illumination angle in step S7 is not particularly limited as long as it is between steps S2 and S8.

[0114] Next, the illumination system rotation control unit 75 drives the rotation mechanism 24 based on the determined illumination angle of the illumination system 30 to rotate the illumination system 30 to an angle position corresponding to the observation mode (step S8). This allows the examiner to automatically rotate the illumination system 30 to an illumination angle corresponding to the observation mode simply by operating the operation unit 64 to select the observation mode.

[0115] In addition, the illumination system control unit 71 drives the slit width adjustment unit 34 based on the type of observation mode selected by the operation unit 64 and the corresponding information 68 input from the information acquisition unit 73, and adjusts the slit width of the slit width adjustment unit 34 to a slit width corresponding to the observation mode.

[0116] Furthermore, the observation system control unit 72 starts continuous photographing (video shooting) of the subject's eye E by the camera 50 at a predetermined timing (step S9). At this time, autofocus of the microscope 42 or the like may be performed by a known method as necessary. Then, the display control unit 76 continuously obtains the photographed images D from the camera 50 and continuously outputs them to the display unit 62. As a result, the photographed images D of the subject's eye E are displayed as a video on the display unit 62 (step S10).

[0117] As described above, in the first embodiment, the illumination system 30 can be rotated around the rotation axis C by the rotation mechanism 24, so that even if the distance in the Z direction between the illumination system 30 and the examiner is increased by the XZ movement mechanism 18 or the like, the examiner does not need to manually rotate the illumination system 30. As a result, the illumination system 30 can be easily rotated. In addition, the illumination system 30 can be automatically rotated to an illumination angle corresponding to the observation mode simply by the examiner selecting an observation mode on the operation unit 64, so that even an inexperienced examiner can easily adjust the illumination angle of the illumination system 30 in a short time.

[0118] Furthermore, in the first embodiment, the examiner can automatically perform auto-alignment of the observation system 40 corresponding to the observation mode by simply selecting the observation mode on the operation unit 64. This makes it possible to photograph (observe) the iris and crystalline lens of the subject's eye E, unlike the ophthalmic apparatus described in the above Patent Document 2, which can only perform alignment based on the corneal apex of the subject's eye E.

[0119] [Second embodiment] 17 is a functional block diagram of the control device 60 of the slit lamp 10 of the second embodiment. The slit lamp 10 of the first embodiment has "cornea", "crystalline lens (IOL)", "crystalline lens (cataract)", and "iris" as observation modes of the subject's eye E. In contrast, the slit lamp 10 of the second embodiment has "anterior chamber" for observing the anterior chamber of the subject's eye E in addition to "cornea", "crystalline lens (IOL)", "crystalline lens (cataract)", and "iris" as observation modes.

[0120] 17, the slit lamp 10 of the second embodiment has basically the same configuration as the slit lamp 10 of the first embodiment, except that the alignment control unit 74 also functions as a third alignment control unit 74C, and correspondence information 68 (see FIG. 18 described later) different from that of the first embodiment is stored in the storage unit 66. For this reason, parts that are the same in function or configuration as those of the first embodiment are given the same reference numerals and their description is omitted.

[0121] Fig. 18 is a table showing an example of the correspondence information 68 in the second embodiment. Fig. 19 is an explanatory diagram for explaining the illumination angle (angular position) of the illumination system 30 corresponding to the observation mode "anterior chamber" and the alignment target in the Z direction of the observation system 40.

[0122] 18 and 19, in the correspondence information 68 of the second embodiment, the "illumination angle," "slit width," and "working distance" corresponding to the observation mode "anterior chamber" are set. Specifically, in the observation mode "anterior chamber," the illumination angle is set to a value selected from the range of 30° to 60°, the slit width is set to "medium," and the working distance is set to "anterior chamber." Note that an alignment target in the XY directions corresponding to the observation mode "anterior chamber" (for example, the center position in the X direction of two Purkinje images Pi) may be set in the correspondence information 68.

[0123] Returning to Fig. 17, the alignment control unit 74 of the second embodiment functions as a third alignment control unit 74C when the observation mode "anterior chamber" is selected by the operation unit 64. The third alignment control unit 74C controls the third alignment, which is the alignment of the observation system 40 with respect to the anterior chamber of the subject's eye E. The XY alignment performed in the third alignment is basically the same as the XY alignment performed in the second alignment. On the other hand, in the Z alignment performed in the third alignment, the approximate midpoint between the corneal apex and the iris (pupil) of the subject's eye E in the Z direction is set as the Z position of the anterior chamber, and the distance between the objective lens 43 and the anterior chamber is adjusted to the working distance.

[0124] The third alignment control unit 74C functions as an iris position calculation unit 100, an anterior chamber position calculation unit 102, an XY alignment control unit 104, and a Z alignment control unit 106 in addition to the first photographing control unit 80, the first detection control unit 82, the pre-alignment control unit 84, the second photographing control unit 86, the second detection control unit 88, and the position deviation amount calculation unit 90 that are similar to the second alignment control unit 74B.

[0125] Fig. 20 is a flow chart showing the flow of the process of the third alignment. As shown in Fig. 20, the processes from step S6A to step S6H are basically the same as those of the second alignment of the first embodiment, so a detailed description will be omitted here. As described above, the Z position of the corneal apex can be calculated based on the calculation result of the positional deviation amount Δz calculated by the positional deviation amount calculation unit 90 in step S6H.

[0126] The iris position calculation unit 100 calculates the Z position of the iris (pupil) of the subject's eye E at any timing before step S6L described later. For example, the iris position calculation unit 100 calculates the Z position of the iris of the subject's eye E by a known method based on the photographed image D of the subject's eye E simultaneously photographed by the stereo camera 54 in step S6B (see FIG. 16) and known position information of the observation system 40 before pre-alignment (step S6K). Note that, when the first alignment of the first embodiment is performed first, the Z position of the iris of the subject's eye E may be calculated based on the photographed image D of the subject's eye E simultaneously photographed by the stereo camera 54 in step S4A shown in FIG. 15 described above and the position information of the observation system 40 at that time.

[0127] The anterior chamber position calculation unit 102 calculates the Z position of the anterior chamber of the subject's eye E. This anterior chamber position calculation unit 102 calculates, as the Z position of the anterior chamber, the intermediate position between the Z position of the iris of the subject's eye E calculated by the iris position calculation unit 100 and the Z position of the corneal apex of the subject's eye E indicated by the positional deviation amount Δz calculated by the positional deviation amount calculation unit 90 (step S6L).

[0128] The XY alignment control unit 104 corresponds to the second XY alignment control unit of the present invention. Similar to the second alignment described above, the XY alignment control unit 104 drives the XZ movement mechanism 18 and the Y movement mechanism 20 based on the detection result of the second detection control unit 88 in step S6F, and executes the XY alignment of the observation system 40 (step S6M).

[0129] The Z alignment control unit 106 corresponds to the second Z alignment control unit of the present invention. Based on the calculation result of the anterior chamber position calculation unit 102, the Z alignment control unit 106 drives the XZ movement mechanism 18 to execute Z alignment of the observation system 40 so that the distance between the objective lens 43 and the anterior chamber is adjusted to the working distance (step S6N). This completes the third alignment. As a result, when viewed from one side in the Y direction, the XZ positions of the rotation axis C and the anterior chamber coincide with each other.

[0130] 17, when the observation mode "anterior chamber" is selected using the operation unit 64, the illumination-system rotation control unit 75 of the second embodiment determines the illumination angle (angular position around the rotation axis C) of the illumination system 30 corresponding to the observation mode "anterior chamber" based on the correspondence information 68 input from the information acquisition unit 73. After completing the third alignment, the illumination-system rotation control unit 75 drives the rotation mechanism 24 to rotate the illumination system 30 to the angular position corresponding to the observation mode "anterior chamber".

[0131] As described above, in the second embodiment as well, the examiner can automatically rotate the illumination system 30 to an illumination angle corresponding to the observation mode "anterior chamber" simply by selecting the observation mode "anterior chamber" on the operation unit 64. As a result, as in the first embodiment, even an inexperienced examiner can easily adjust the illumination angle of the illumination system 30 in a short time.

[0132] Furthermore, in the second embodiment, the examiner can automatically perform auto-alignment of the observation system 40 corresponding to the observation mode "anterior chamber" simply by selecting the observation mode "anterior chamber" on the operation unit 64. This makes it possible to perform imaging (observation) of the anterior chamber of the subject's eye E, unlike the ophthalmic apparatus described in the above Patent Document 2, which performs only alignment based on the corneal apex of the subject's eye E.

[0133] [Third embodiment] 21 and 22 are top views of the illumination system 30 and the rotation mechanism 110 of the slit lamp 10 of the third embodiment. The slit lamp 10 of each of the above embodiments includes the rotation mechanism 24 composed of the shaft portion 25 and the rotation drive portion 26 shown in FIG. 1, but the slit lamp 10 of the third embodiment uses a rotation mechanism 110 different from the rotation mechanism 24 to rotate the illumination system 30 around the rotation axis C.

[0134] The slit lamp 10 of the third embodiment has basically the same configuration as the slit lamp 10 of each of the above embodiments, except that it has a rotation mechanism 110 instead of the rotation mechanism 24. Therefore, parts that are the same in function or configuration as those of the above embodiments are given the same reference numerals and their description will be omitted.

[0135] The rotation mechanism 110 includes a rail 112, a movable body 114, and a connection portion 116. The rail 112 is provided on the rear side of the illumination system 30 in the Z direction when viewed from one side in the Y direction, and is formed in an arc shape (including an approximately arc shape) along the circumferential direction centered on the rotation axis C.

[0136] The moving body 114 moves along the rail 112 under the control of the illumination system rotation control unit 75. The illumination unit 32 of the illumination system 30 is fixed (connected, coupled) to this moving body 114 via a connection unit 116. By moving the moving body 114 along the rail 112, the illumination system 30 (illumination unit 32) can be rotated around the rotation axis C. As a result, by the illumination system rotation control unit 75 adjusting the position of the moving body 114 on the rail 112, the illumination angle of the illumination system 30, i.e., the angular position of the illumination system 30 around the rotation axis C, can be adjusted, as in each of the above embodiments.

[0137] [Fourth embodiment] Fig. 23 is a top view of the observation system 40 of the slit lamp 10 of the fourth embodiment, as viewed from above in the Y direction. Fig. 24 is a front view of the observation system 40 of the slit lamp 10 of the fourth embodiment, as viewed from the front in the Z direction. In each of the above embodiments, two BG illumination light sources 57 are provided in the stereo camera holding part 56, but as shown in Figs. 23 and 24, three or more BG illumination light sources 57 are provided in the stereo camera holding part 56A in the slit lamp 10 of the fourth embodiment.

[0138] The slit lamp 10 of the fourth embodiment has basically the same configuration as the slit lamp 10 of each of the above embodiments, except that it has three or more BG illumination light sources 57 and a stereo camera holding part 56A instead of the stereo camera holding part 56 of each of the above embodiments. Therefore, parts that are the same in function or configuration as those of the above embodiments are given the same reference numerals and their description will be omitted.

[0139] When viewed from one side in the Y direction, the BG illumination light sources 57 are arranged at intervals in a substantially arc shape along a locus at a position rearward (toward the observation system) in the Z direction from the locus of the illumination system 30 rotating around the rotation axis C. The height position of each BG illumination light source 57 in the Y direction only needs to be substantially the same height as the stereo camera 54, and does not have to be exactly the same height position. The number and arrangement of the BG illumination light sources 57 are not limited to the examples shown in Figs. 23 and 24, and can be changed as appropriate.

[0140] The stereo camera holding portion 56A is formed in a substantially arc shape when viewed from one side in the Y direction in order to hold each of the BG illumination light sources 57. Note that the shape of the stereo camera holding portion 56A may be changed as appropriate as long as it is capable of holding each of the BG illumination light sources 57.

[0141] As described above, in the slit lamp 10 of the fourth embodiment, by arranging multiple BG illumination light sources 57 along the trajectory of the illumination system 30 rotating about the rotation axis C, it is possible to sufficiently irradiate the subject's eye E with BG illumination light from the same direction as the illumination system 30 or from a direction different from that of the illumination system 30 regardless of the change in angular position of the illumination system 30.

[0142] [others] The slit lamp 10 in each of the above embodiments includes the camera 50 and the stereo camera 54, but may include only one of the camera 50 and the stereo camera 54. In this case, auto-alignment of the observation system 40 with respect to the subject's eye E is performed based on the captured image D of the subject's eye E captured by either one of the cameras.

[0143] In each of the above embodiments, the slit lamp 10 is equipped with an auto-alignment function (alignment control unit 74) for the observation system 40, but the present invention can also be applied to a slit lamp 10 that does not have an auto-alignment function. Furthermore, in this case, the camera 50 and stereo camera 54 (imaging device) of the observation system 40 may be omitted, and a pair of left and right eyepieces may be provided in the microscope 42.

[0144] The slit lamp 10 in each of the above embodiments is a so-called Zeiss type (Littman type) in which the illumination unit 32 is provided below the deflection optical element 38 in the Y direction, but the present invention can also be applied to a so-called Haag type (Goldmann type) in which the illumination unit 32 is provided above the deflection optical element 38 in the Y direction.

[0145] In each of the above embodiments, the observation system 40 is movable in the XYZ directions, but the movement direction of the observation system 40 is not particularly limited.

[0146] Although the above embodiments have been described taking the slit lamp 10 as an example, the present invention can be applied to various ophthalmic devices capable of changing the illumination angle (angular position of various illumination systems) of various illumination lights to the subject's eye E according to the observation mode (observation conditions) of the subject's eye E. In this case, illumination light may be irradiated onto the subject's eye E from various illumination systems without deflecting the illumination light with the deflection optical element 38. [Explanation of symbols]

[0147] 10. Slit lamp 12...Bass 14…Face support part 14a…post 14b…Chin rest 14c…Forehead part 16…Frame 18...XZ movement mechanism 20...Y movement mechanism 22…Mounting part 24...Rotation mechanism 25…Shaft 26...Rotation drive unit 30…Lighting system 32…Lighting unit 33...Lighting light source 34…Slit width adjustment part 35...Filter switching mechanism 38...Deflection optical element 40…Observation 41…Vertical arm 42...Microscope 43…Objective lens 44…Camera connection part 45…Half mirror 46...Alignment light source 47...Optical magnification switching mechanism 48...Filter switching mechanism 50…Camera 51...Image sensor 54…Stereo camera 54a...Camera 56…Stereo camera holder 56A…Stereo camera holder 57…BG lighting light source 60...Control device 62...Display section 64...Operation unit 66...Storage section 68…Corresponding information 71...Lighting system control section 72...Observation system control section 73…Information acquisition department 74...Alignment control unit 74A…First alignment control section 74B...Second alignment control section 74C…Third alignment control section 75...Lighting system rotation control section 76...Display control unit 80...first imaging control unit 82...First detection control unit 84…Pre-alignment control section 86...second imaging control unit 88...Second detection control section 90: Position deviation calculation unit 92...XY alignment control section 94...Z alignment control section 100...iris position calculation section 102...Anterior chamber position calculation unit 104...XY alignment control section 106...Z alignment control unit 110...Rotation mechanism 112…Rail 114...Mobile 116…Connection C…Rotation axis D…Photographed image E…Examined eye Li…Alignment indicator light O1…Optical axis O2…Lighting axis Pi…Purkinje statue R…Corneal curvature ΔX…Distance Δz: Position deviation amount

Claims

1. an illumination system including an illumination light source that emits illumination light and a deflection optical element that deflects the illumination light emitted from the illumination light source toward the subject's eye; a rotation mechanism that rotates the illumination system about a rotation axis parallel to the Y direction, when the Y direction is parallel to a vertical direction among an X direction, a Y direction, and a Z direction which are perpendicular to each other; an observation system having an imaging device for imaging the subject's eye; a moving mechanism that moves the illumination system, the rotation mechanism, and the observation system in the X direction, the Y direction, and the Z direction; an alignment control unit that drives the moving mechanism based on a photographed image of the subject's eye photographed by the photographing device, and performs alignment of the observation system with respect to the subject's eye; A slit lamp comprising:

2. an information acquiring unit that acquires correspondence information between a plurality of observation modes for observing the subject's eye and an angular position of the illumination system about the rotation axis, the correspondence information being determined for each of the observation modes; an operation unit that accepts a selection operation of the observation mode; an illumination system rotation control unit that drives the rotation mechanism to rotate the illumination system to the angular position corresponding to the observation mode, based on the observation mode selected by a selection operation on the operation unit and the corresponding information acquired by the information acquisition unit; 2. The slit lamp of claim 1 .

3. the imaging device includes a plurality of first cameras that simultaneously image the subject's eye from a plurality of directions, 3. The slit lamp according to claim 1, wherein the alignment control unit drives the moving mechanism based on the captured images from each of the plurality of first cameras to perform alignment of the observation system with respect to the pupil of the subject's eye.

4. the photographing device includes a plurality of first cameras that simultaneously photograph the subject's eye from a plurality of directions, and a second camera that photographs the subject's eye through an objective lens having an optical axis parallel to the Z direction, an illumination system that illuminates the subject's eye with two light beams at two different angles centered on the optical axis; The alignment control unit, a first imaging control unit that causes the plurality of first cameras to simultaneously capture images of the subject's eye irradiated with the two light beams; a first detection control unit that detects two Purkinje images generated in the subject's eye by irradiation with the two light beams from the captured images of the first cameras; a pre-alignment control unit that drives the moving mechanism based on a detection result of the first detection control unit to execute pre-alignment, including adjusting a position of the observation system in the X direction and the Y direction, and adjusting a position of the observation system in the Z direction to adjust a distance in the Z direction between the objective lens and the two Purkinje images to a predetermined working distance; a second imaging control unit that causes the second camera to capture an image of the subject's eye irradiated with the two light beams when the pre-alignment is completed; a second detection control unit that detects the two Purkinje images from the captured image of the second camera; a first XY alignment control unit that drives the moving mechanism based on a detection result of the second detection control unit to adjust the position of the observation system in the X direction and the Y direction; a positional deviation amount calculation unit that calculates a positional deviation amount in a Z direction of the two Purkinje images with respect to the corneal apex of the subject's eye based on a detection result of the second detection control unit; a first Z alignment control unit that drives the moving mechanism based on a calculation result of the positional deviation amount calculation unit to adjust the distance in the Z direction between the objective lens and the corneal apex to the working distance; 3. The slit lamp according to claim 1 or 2, comprising:

5. 5. The slit lamp according to claim 4, wherein the positional deviation amount calculation unit determines a corneal curvature of the subject's eye based on a detection result of the second detection control unit, and calculates the positional deviation amount based on the corneal curvature.

6. an iris position calculation unit that calculates a position of an iris of the subject's eye in the Z direction based on the captured images of the first cameras; an anterior chamber position calculation unit that calculates a position of the anterior chamber of the subject's eye in the Z direction based on a calculation result of the iris position calculation unit and a calculation result of the position deviation amount calculation unit; a second XY alignment control unit that drives the moving mechanism based on a detection result of the second detection control unit to adjust the position of the observation system in the X direction and the Y direction; a second Z alignment control unit that drives the moving mechanism based on a calculation result of the anterior chamber position calculation unit to adjust the distance in the Z direction between the objective lens and the anterior chamber to the working distance; 5. The slit lamp of claim 4, comprising:

7. The rotation mechanism is a shaft portion to which the illumination system is fixed and which rotates about the rotation axis; A rotation drive unit that rotates the shaft portion; 3. The slit lamp according to claim 1 or 2, comprising:

8. The rotation mechanism is a rail formed in an arc shape along a circumferential direction centered on the rotation shaft; a moving body to which the illumination system is fixed and which moves along the rail; 3. The slit lamp according to claim 1 or 2, comprising:

9. the imaging device includes a plurality of first cameras that simultaneously image the subject's eye from a plurality of directions, 3. The slit lamp according to claim 1, further comprising a plurality of background illumination light sources arranged at the same height as the plurality of first cameras in the Y direction.

10. 10. The slit lamp according to claim 9, wherein the plurality of background illumination light sources are disposed in an arc shape along a locus of the illumination system rotating about the rotation axis, at a position closer to the observation system than the locus of the illumination system when viewed from one side in the Y direction.

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