Ophthalmic device and non-contact sensor operation check method

Abstract

To provide an ophthalmologic apparatus and a non-contact type sensor operation confirmation method which can execute operation confirmation of a non-contact type sensor at a low cost without installing a new installation space.SOLUTION: An ophthalmologic apparatus comprises: an eye characteristic acquisition unit (non-contact type tonometer 14B); a drive mechanism 13 which can move at least the eye characteristic acquisition unit in the front-rear direction; an alignment detection unit (detection control unit 42b); an alignment execution unit 42c which performs alignment of the eye characteristic acquisition unit with respect to a subject eye on the basis of the detection result of the alignment detection unit; a non-contact type sensor (capacitance type sensor 36) which can detect the approach of the eye characteristic acquisition unit to the face of a subject in a non-contact manner; a confirmation unit 45a which confirms whether or not the alignment detection unit can detect a distance in the front-rear direction between the eye characteristic acquisition unit and a target object (subject eye E); and a determination unit 45c which determines whether or not the non-contact type sensor is normally operated on the basis of a detection value of the non-contact type sensor when the confirmation unit confirms that the distance can be detected.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an ophthalmic apparatus equipped with a non-contact sensor and a method for checking the operation of the non-contact sensor. [Background technology]

[0002] Known ophthalmic devices for acquiring (measuring, photographing, observing, etc.) the ocular characteristics of a subject's eye include non-contact tonometers that measure the intraocular pressure of the subject's eye without contact, or multifunction devices (multifunction ophthalmic devices) equipped with such non-contact tonometers (see Patent Documents 1 and 2). Non-contact tonometers measure the intraocular pressure of the subject's eye without contacting the cornea by blowing air from a nozzle toward the cornea of ​​the subject's eye to deform the cornea and detecting the state of deformation. Before starting to measure the intraocular pressure of the subject's eye using this non-contact tonometer, the measurement head is aligned with the subject's eye, and during this alignment, it is necessary to prevent contact between the nozzle and the subject's eye or the subject's face.

[0003] Patent Document 3 describes a non-contact tonometer having a measurement head equipped with a sensor (non-contact sensor) capable of detecting the approach of the measurement head to the subject's face (eye to be examined). The non-contact tonometer described in Patent Document 3 halts alignment when the sensor detects the approach of the measurement head to the subject's face during alignment. In order to halt alignment when the measurement head approaches the subject's face in this way, the sensor must be operating correctly.

[0004] Therefore, the non-contact tonometer described in Patent Document 3 is provided with a pseudo-reaction unit (such as a capacitor) that can reproduce a proximity state in which the subject's face is sufficiently close to the sensor (less than the working distance of the non-contact tonometer).The non-contact tonometer described in Patent Document 3 then acquires a detection value (detection signal) from the sensor while reproducing the proximity state using the pseudo-reaction unit, and performs an operation check based on this detection signal to determine whether the sensor is operating normally. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-112437 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-099968 [Patent Document 3] Patent Publication No. 2021-153907 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the non-contact tonometer described in Patent Document 3 requires a separate pseudo-reaction unit to confirm the operation of the sensor. Therefore, the non-contact tonometer described in Patent Document 3 has problems of increased costs and the need to secure installation space for the pseudo-reaction unit.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide an ophthalmic device and a method for checking the operation of a non-contact sensor that can perform operation checks of a non-contact sensor at low cost without providing additional installation space. [Means for solving the problem]

[0008] An ophthalmologic apparatus for achieving the object of the present invention includes an ophthalmic characteristic acquisition unit that acquires ocular characteristics of a subject's eye, a drive mechanism that moves the ocular characteristic acquisition unit relative to the subject's eye, and that is capable of moving at least the ocular characteristic acquisition unit forward toward the subject's eye and backward away from the subject's eye in a front-to-back direction, an alignment detection unit that detects the relative position of the subject's eye with respect to the ocular characteristic acquisition unit, and that has a function of detecting at least the distance in the front-to-back direction between the ocular characteristic acquisition unit and the subject's eye, and an alignment detection unit that automatically drives the drive mechanism based on the detection result of the alignment detection unit or drives the drive mechanism in response to a manual movement operation to acquire the ocular characteristics of the subject's eye. the alignment detection unit is provided with an alignment execution unit that aligns the eye characteristic acquisition unit and the eye characteristic acquisition unit; a non-contact sensor that is provided in the eye characteristic acquisition unit and can detect the approach of the eye characteristic acquisition unit to the subject's face in a non-contact manner, the non-contact sensor having a second detection range that encompasses the first detection range of the alignment detection unit in the front-to-back direction; a confirmation unit that confirms whether the alignment detection unit is able to detect the front-to-back distance between the eye characteristic acquisition unit and a target object located within the first detection range; and a determination unit that, when the confirmation unit confirms that the alignment detection unit is able to detect the front-to-back distance, determines whether the non-contact sensor is operating normally based on the detection value of the non-contact sensor.

[0009] According to this ophthalmic apparatus, the operation of the non-contact sensor can be checked using an existing alignment detection unit of the ophthalmic apparatus.

[0010] In the ophthalmologic apparatus according to another aspect of the present invention, the determination unit determines whether the non-contact sensor is operating normally based on whether the detection value of the non-contact sensor is equal to or greater than a determination threshold, thereby enabling the operation of the non-contact sensor to be confirmed.

[0011] In another aspect of the present invention, the ophthalmologic apparatus further includes a position adjustment unit that, when the confirmation unit does not confirm that the alignment detection unit can detect the distance in the front-to-rear direction, moves at least one of the eye characteristic acquisition unit and the target to adjust the position of the target within the first detection range, thereby enabling operation of the non-contact sensor to be confirmed using an existing alignment detection unit.

[0012] In the ophthalmologic apparatus according to another aspect of the present invention, the confirmation unit confirms whether or not the distance in the front-to-back direction from the subject's eye as a target can be detected, thereby enabling the operation of the non-contact sensor to be confirmed before acquiring the ocular characteristics of the subject's eye.

[0013] In the ophthalmologic apparatus according to another aspect of the present invention, the confirmation unit confirms whether it is possible to detect the distance in the front-to-back direction with a model eye that imitates the eye to be examined as a target. This allows the operation of the non-contact sensor to be confirmed without using the eye to be examined (human eye), and prevents a part of the eye characteristic acquisition unit from coming into contact with the face of the examinee during the operation confirmation.

[0014] In another aspect of the present invention, an ophthalmologic apparatus includes a face support portion for supporting the face of a subject, the face support portion including a chin rest portion for receiving the subject's chin and a forehead rest portion for contacting the subject's forehead, the chin rest portion supporting a model eye and a conductive material connected to earth, thereby enabling operation of the non-contact sensor to be confirmed without using the subject's eye (human eye).

[0015] In another aspect of the present invention, the ophthalmologic apparatus further includes a notification unit that issues a warning when the determination unit determines that the non-contact sensor is not operating normally or when the detection value of the non-contact sensor exceeds a threshold value during alignment. This makes it possible to notify the examiner of the warning information.

[0016] In another aspect of the present invention, the ophthalmologic apparatus further includes a risk avoidance operation control unit that controls the drive mechanism to perform risk avoidance operation when the detection value of the non-contact sensor exceeds a threshold value during alignment, thereby reliably preventing the eye characteristic acquisition unit from coming into contact with the subject's face.

[0017] A method for confirming operation of a non-contact type sensor for achieving the object of the present invention includes an eye characteristic acquisition unit that acquires eye characteristics of a subject's eye, a drive mechanism that moves the eye characteristic acquisition unit relative to the subject's eye, and that is capable of moving at least the eye characteristic acquisition unit forward toward the subject's eye and backward away from the subject's eye in a front-to-back direction, an alignment detection unit that detects the relative position of the subject's eye with respect to the eye characteristic acquisition unit, and that has a function of detecting at least the distance in the front-to-back direction between the eye characteristic acquisition unit and the subject's eye, and an alignment detection unit that automatically drives the drive mechanism based on a detection result of the alignment detection unit or drives the drive mechanism in response to a manual movement operation to align the eye characteristic acquisition unit with the subject's eye. A method for confirming the operation of a non-contact sensor in an ophthalmic device including an alignment execution unit and a non-contact sensor provided in an eye characteristic acquisition unit, capable of detecting the approach of the eye characteristic acquisition unit to a subject's face in a non-contact manner and having a second detection range that encompasses the first detection range of the alignment detection unit in the front-to-back direction, includes a confirmation step of confirming whether the alignment detection unit can detect the front-to-back distance between the eye characteristic acquisition unit and a target object located within the first detection range, and a determination step of determining whether the non-contact sensor is operating normally based on the detection value of the non-contact sensor if it is confirmed in the confirmation step that the alignment detection unit can detect the front-to-back distance. [Effects of the Invention]

[0018] The present invention makes it possible to check the operation of a non-contact sensor at low cost without providing additional installation space. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a side view of an ophthalmologic apparatus according to a first embodiment. [Figure 2] FIG. 2 is a schematic top view of a plurality of types of optical systems in the non-contact tonometer as viewed from above (Y direction). [Figure 3] FIG. 2 is a schematic side view of a plurality of types of optical systems in the non-contact tonometer as viewed from the side (X direction). [Figure 4]FIG. 2 is a perspective view of the spray mechanism of the non-contact tonometer as seen from the subject side. [Figure 5] 5 is an enlarged front view of the electrodes of the capacitance sensor in FIG. 4. [Figure 6] FIG. 2 is an explanatory diagram for explaining the directionality of a capacitance type sensor. [Figure 7] FIG. 2 is a functional block diagram of a control device. [Figure 8] 3A and 3B are explanatory diagrams for explaining a specific method for checking the operation of the capacitance type sensor of the first embodiment. [Figure 9] 10 is an explanatory diagram showing an example of notification of warning information by a notification control unit; FIG. [Figure 10] 4 is a flowchart showing a flow of Refkeratometry and intraocular pressure measurement of a subject's eye by the ophthalmologic apparatus of the first embodiment. [Figure 11] 10 is a flowchart showing the flow of a process for checking the operation of the capacitance type sensor. [Figure 12] 10 is an explanatory diagram for explaining a method for checking the operation of a capacitance type sensor by an ophthalmologic apparatus according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] [First embodiment] FIG. 1 is a side view of an ophthalmic apparatus 10 according to a first embodiment. As shown in FIG. The ophthalmic device 10 includes: This is a multi-function device capable of measuring the intraocular pressure, ocular refractive power, corneal curvature, etc. of the subject's left and right eyes E. The ophthalmic apparatus 10 includes a base 11, a face support unit 12, a drive mechanism 13, a measurement head 14, a monitor 15, and a control device 16.

[0021] In the drawing, of the mutually orthogonal X, Y, and Z directions (three axis directions), the Y direction is the up-down direction, the Z direction is the front-back direction (also called the working distance direction) that moves toward or away from the subject (subject's eye E), and the X direction is the left-right direction that is perpendicular to both the up-down direction and the front-back direction. In addition, in the Z direction (front-back direction), the side that moves toward the subject's eye E (subject) is called the front side in the Z direction, and the side that moves away from the subject's eye E (subject) is called the rear side in the Z direction.

[0022] A face support unit 12 and a drive mechanism 13 are provided on the base 11 from the front side in the Z direction to the rear side in the Z direction. The base 11 supports a measurement head 14 via the drive mechanism 13 so that the measurement head 14 is movable in the X, Y, and Z directions.

[0023] The face support part 12 is fixed to the base 11. The face support part 12 includes a chin rest part 12a that supports the subject's chin and a forehead rest part 12b that the subject's forehead abuts against, and supports the subject's face.

[0024] The drive mechanism 13 is configured by an actuator (not shown), such as a motor. The drive mechanism 13 moves the measurement head 14 in the X, Y, and Z directions relative to the base 11. This allows the measurement head 14 to move relative to the eye E in the X, Y, and Z directions.

[0025] The measurement head 14 is provided with an auto-refractometer 14A and a non-contact tonometer 14B, which corresponds to the eye characteristic acquisition unit of the present invention. In this embodiment, the non-contact tonometer 14B is provided above the auto-refractometer 14A in the Y direction.

[0026] The auto refkeratometer 14A performs refkeratometry using various optical systems and sensors to measure the ocular refractive power and corneal curvature of the subject's eye E. Although not shown, the auto refkeratometer 14A is provided with various optical systems used for anterior segment observation, alignment detection, alignment, refkeratometry, etc. of the subject's eye E. Note that the specific configuration of the auto refkeratometer 14A is a known technique (see, for example, Patent Document 1), and therefore will not be described here.

[0027] The non-contact tonometer 14B measures the cornea Ec of the subject eye E. (See Figure 2) The cornea Ec is deformed by blowing air from the nozzle 21b toward the eye E, and the state of deformation is detected to measure the intraocular pressure of the subject's eye E in a non-contact manner. The working distance of this non-contact tonometer 14B is shorter than the working distance of the autorefractometer 14A.

[0028] In this embodiment, the intraocular pressure measurement of the subject's eye E by the non-contact tonometer 14B is performed after the refkeratometry measurement by the auto-refkeratometer 14A. Therefore, the above-mentioned drive mechanism 13 performs coarse alignment including head downward movement, which moves the measurement head 14 downward in the Y direction, and head forward movement, which moves the measurement head 14 forward in the Z direction, after the refkeratometry measurement by the auto-refkeratometer 14A is completed and before the intraocular pressure measurement by the non-contact tonometer 14B.

[0029] The monitor 15 is a touch panel monitor and is attached to the back side of the measurement head 14. Under the control of the control device 16 (described later), the monitor 15 displays various images, including a photographed image (observed image) of the subject's eye E photographed by the autorefractive keratometer 14A or the non-contact tonometer 14B, measurement results of the eye characteristics of the subject's eye E (ocular refractive power, corneal curvature, and intraocular pressure value), and an operation menu screen for performing various operations. These various operations include manual movement of the measurement head 14 in the X, Y, and Z directions. The monitor 15 also displays various warning information under the control of the control device 16 (see FIG. 9).

[0030] <Non-contact tonometer 14B> FIG. 2 is a schematic top view of the multiple types of optical systems in the non-contact tonometer 14B as viewed from above (Y direction), and FIG. 3 is a schematic side view of the multiple types of optical systems in the non-contact tonometer 14B as viewed from the side (X direction).

[0031] As shown in Figures 2 and 3, the non-contact tonometer 14B includes an anterior segment observation optical system 21, an XY alignment index projection optical system 22, a fixation target projection optical system 23, an applanation detection optical system 24, a Z alignment index projection optical system 25, a Z alignment detection optical system 26, and a spraying mechanism 34.

[0032] The anterior-segment observation optical system 21 is used for observing the anterior segment of the subject's eye E and for XY-direction alignment of the non-contact tonometer 14B with respect to the subject's eye E. An anterior-segment illumination light source 21a (see FIG. 2) is provided in the anterior-segment observation optical system 21. Also, on the optical axis O1 (main optical axis of the non-contact tonometer 14B) of the anterior-segment observation optical system 21, there are provided an air-blowing nozzle 21b, an anterior-segment window glass 21c (see FIG. 3) that holds the tip of the nozzle 21b, a chamber window glass 21d, a half mirror 21e, a half mirror 21g, an objective lens 21f, and an image sensor 21i.

[0033] A plurality of anterior-segment illumination light sources 21a are provided around the anterior-segment window glass 21c, and directly illuminate the anterior segment of the subject's eye E.

[0034] The nozzle 21b is connected to a chamber 34a (see FIG. 3) of the spraying mechanism 34, and sprays air onto the anterior segment (cornea Ec) of the eye E to be inspected.

[0035] An image of the anterior segment of the subject's eye E (image light from the anterior segment) passes outside the nozzle 21b, passes through the anterior segment window glass 21c, the glass plate 34b described below, the chamber window glass 21d, the half mirror 21g, and the half mirror 21e, and is formed on the light receiving surface of the imaging element 21i by the objective lens 21f.

[0036] The imaging element 21i is, for example, a CCD (Charge Coupled Device) type or CMOS (Complementary Metal Oxide Semiconductor) type image sensor. The imaging element 21i captures an image of the anterior segment incident on its light receiving surface to generate an imaging signal, and outputs the imaging signal to the control device 16. As a result, under the control of the control device 16, an observation image of the anterior segment of the subject's eye E based on the imaging signal output from the imaging element 21i is displayed on the monitor 15.

[0037] The anterior-segment observation optical system 21 also guides the XY alignment index light projected onto the subject's eye E by the XY alignment index projection optical system 22 (described later) and reflected by the cornea Ec to the light-receiving surface of the image sensor 21i. This reflected light passes through the nozzle 21b, the chamber window glass 21d, the half mirror 21g, and the half mirror 21e, and is imaged on the light-receiving surface of the image sensor 21i by the objective lens 21f. As a result, an XY spot is formed on the light-receiving surface of the image sensor 21i at a position corresponding to the positional relationship (relative position) between the non-contact tonometer 14B and the cornea Ec in the XY directions. This enables XY alignment detection, which detects the relative position of the subject's eye E in the XY directions with respect to the non-contact tonometer 14B. Therefore, the anterior-segment observation optical system 21 and the XY alignment index projection optical system 22 function as part of the alignment detection unit of the present invention.

[0038] The image sensor 21i captures an image of the XY spot formed on its light receiving surface and outputs an image signal of the XY spot to the control device 16. As a result, under the control of the control device 16, the observed image of the anterior segment and the XY spot are superimposed and displayed on the monitor 15. Note that the monitor 15 also displays an alignment assistance mark.

[0039] The XY alignment index projection optical system 22 projects XY alignment index light from the front onto the cornea Ec of the subject's eye E. This XY alignment index light is used for XY alignment of the non-contact tonometer 14B with respect to the anterior segment of the subject's eye E. The XY alignment index light is also used to measure the intraocular pressure value of the subject's eye E. Hereinafter, the reflected light of the XY alignment index light by the cornea Ec will be simply abbreviated as "XY index reflected light."

[0040] The XY alignment target projection optical system 22 includes an XY alignment light source 22a, a condenser lens 22b, an aperture stop 22c, a pinhole plate 22d, a dichroic mirror 22e, and a collimator lens 22f (see FIG. 3). The XY alignment target projection optical system 22 shares the half mirror 21e with the anterior eye observation optical system 21.

[0041] XY alignment light source 22a emits infrared light. Collimator lens 22f is arranged on the optical path of XY alignment index projection optical system 22 so that its focal point coincides with pinhole plate 22d. In this XY alignment index projection optical system 22, the infrared light emitted from XY alignment light source 22a is focused by condenser lens 22b, passes through aperture stop 22c, and is directed to the hole in pinhole plate 22d.

[0042] The infrared light that passes through the hole in the pinhole plate 22d is reflected by the dichroic mirror 22e and guided to the collimator lens 22f, where it is collimated and then emitted from the collimator lens 22f to the half mirror 21e. After being reflected by the half mirror 21e, this collimated infrared light travels along the optical axis O1 of the anterior-segment observation optical system 21. As a result, the collimated infrared light passes through the half mirror 21g and the chamber window glass 21d, and then passes through the inside of the nozzle 21b, and is incident on the subject's eye E as XY alignment index light.

[0043] Although not shown, the XY alignment index light incident on the subject's eye E is reflected on the surface of the cornea Ec to form an XY spot. The aperture stop 22c is provided at a position conjugate with the vertex Ep of the cornea Ec with respect to the collimator lens 22f.

[0044] The fixation target projection optical system 23 projects a fixation target onto the subject's eye E. The fixation target projection optical system 23 has a fixation target light source 23a and a pinhole plate 23b (see FIG. 3). The fixation target projection optical system 23 also shares a dichroic mirror 22e and a collimator lens 22f with the XY alignment target projection optical system 22, and also shares a half mirror 21e with the anterior eye observation optical system 21.

[0045] The fixation target light source 23a emits visible light as fixation target light. This fixation target light is guided to the hole in the pinhole plate 23b, passes through the hole in the pinhole plate 23b and the dichroic mirror 22e, and is then emitted to the collimator lens 22f. The fixation target light is then converted into approximately parallel light by the collimator lens 22f and emitted toward the half mirror 21e. After being reflected by the half mirror 21e, the light travels along the optical axis O1 of the anterior eye observation optical system 21. After passing through the half mirror 21g and the chamber window glass 21d, the fixation target light passes through the inside of the nozzle 21b and reaches the subject's eye E. By having the subject gaze at this fixation target as a fixation target, the subject's line of sight can be fixed.

[0046] The applanation detection optical system 24 (see FIG. 3) receives the XY index reflected light and outputs a detection signal (also called an applanation signal or a corneal deformation signal) indicating the amount of light of the XY index reflected light. The applanation detection optical system 24 has a lens 24a, a pinhole plate 24b, and a light receiving sensor 24c, and also shares the half mirror 21g with the anterior-segment observation optical system 21.

[0047] When the surface of the cornea Ec is flat, the lens 24a focuses the XY index reflected light onto the opening of the pinhole plate 24b, which is provided at the focal position of the lens 24a.

[0048] The light receiving sensor 24c is, for example, a photodiode that outputs a detection signal corresponding to the amount of light received from the reflected XY index light. The light receiving sensor 24c outputs the detection signal (also called an applanation waveform signal) to the control device 16.

[0049] The XY index reflected light passes through the inside of the nozzle 21b, passes through the chamber window glass 21d, and reaches the half mirror 21g. A part of the XY index reflected light is reflected by the half mirror 21g, passes through the lens 24a, and then enters the pinhole plate 24b.

[0050] When the surface of the cornea Ec is flattened (applanated) by the air blown from the nozzle 21b, the applanation detection optical system 24 allows the entire XY index reflected light that has traveled to the applanation detection optical system 24 to reach the light-receiving sensor 24c through the pinhole plate 24b. When the cornea Ec is in a state other than the flat state, the applanation detection optical system 24 allows the XY index reflected light to reach the light-receiving sensor 24c while partially blocking it with the pinhole plate 24b. Therefore, the signal intensity of the detection signal of the XY index reflected light output from the applanation detection optical system 24 gradually increases as the surface of the cornea Ec changes from a convex state to a flat state, and gradually decreases as the surface changes from a flat state to a concave state.

[0051] The Z-alignment index projection optical system 25 (see FIG. 2) projects Z-alignment index light for Z alignment in the Z-axis direction from an oblique direction onto the cornea Ec. The Z-alignment index projection optical system 25 includes, along an optical axis O2, a Z-alignment light source 25a, a condenser lens 25b, an aperture stop 25c, a pinhole plate 25d, and a collimator lens 25e.

[0052] Z-alignment light source 25a emits infrared light (for example, a wavelength of 860 nm). Aperture stop 25c is provided at a position conjugate with corneal vertex Ep with respect to collimator lens 25e. Collimator lens 25e is positioned so as to focus on the hole in pinhole plate 25d.

[0053] The infrared light emitted from the Z-alignment light source 25a is condensed by the condenser lens 25b, passes through the aperture stop 25c, and travels to the pinhole plate 25d. The infrared light that passes through the hole in the pinhole plate 25d is collimated by the collimator lens 25e, and then enters the subject's eye E as Z-alignment index light. The light is reflected by the cornea Ec to form a bright spot image on the subject's eye E.

[0054] The Z alignment detection optical system 26 receives the Z alignment index light reflected by the cornea Ec (hereinafter referred to as Z index reflected light) and detects the positional relationship in the Z axis direction between the non-contact tonometer 14B and the cornea Ec. The Z alignment detection optical system 26 has an imaging lens 26a, a cylindrical lens 26b, and a light receiving sensor 26c along the optical axis O3.

[0055] The cylindrical lens 26b has power in the Y-axis direction. The light receiving sensor 26c is a sensor that can detect the light receiving position of the Z index reflected light on its light receiving surface, and is, for example, a line sensor or a PSD (Position Sensitive Detector).

[0056] The Z index reflected light is focused by the imaging lens 26a and then travels to the cylindrical lens 26b, where it is focused in the Y-axis direction to form a bright spot image on the light receiving sensor 26c.

[0057] The light-receiving sensor 26c is positioned in a conjugate relationship with the bright spot image formed on the subject's eye E by the Z alignment index projection optical system 25, relative to the imaging lens 26a, in the XZ plane. Furthermore, the light-receiving sensor 26c is positioned in a conjugate relationship with the corneal vertex Ep, relative to the imaging lens 26a and the cylindrical lens 26b, in the YZ plane. That is, since the light-receiving sensor 26c is in a conjugate relationship with the aperture stop 25c, even if the cornea Ec is displaced in the Y direction, the Z index reflected light from the surface of the cornea Ec is efficiently incident on the light-receiving sensor 26c. The light-receiving sensor 26c outputs a detection signal of the Z index reflected light collected by the cylindrical lens 26b (hereinafter referred to as a Z detection signal) to the control device 16. This Z detection signal indicates the relative position of the subject's eye E in the Z direction with respect to the non-contact tonometer 14B, more specifically, the distance in the Z direction between the non-contact tonometer 14B and the subject's eye E (corneal apex Ep). This enables Z alignment detection. Therefore, the Z alignment target projection optical system 25 and the Z alignment detection optical system 26 also correspond to part of the alignment detection unit of the present invention.

[0058] The signal intensity of the Z detection signal increases as the distance between the non-contact tonometer 14B and the eye E approaches the appropriate working distance, and decreases as the distance deviates from the appropriate working distance.

[0059] The spray mechanism 34 (see FIG. 3) has a chamber 34a, a cylinder 34d, a communication pipe 34e, a piston 34f, and a solenoid 34g.

[0060] Nozzle 21b is attached to chamber 34a via transparent glass plate 34b. Chamber window glass 21d is provided in chamber 34a at a position facing nozzle 21b. Pressure sensor 34c is also provided in chamber 34a. Pressure sensor 34c outputs a pressure detection signal indicating the pressure inside chamber 34a (internal pressure) to control device 16.

[0061] Cylinder 34d is connected to chamber 34a via a communication pipe 34e. This allows the interior of cylinder 34d to communicate with the interior of chamber 34a via communication pipe 34e. A piston 34f is movably provided inside cylinder 34d. The cylinder 34d and piston 34f form an air compression chamber.

[0062] The solenoid 34g is a known solenoid actuator that moves a piston 34f in a cylinder 34d. The solenoid 34g moves the piston 34f under the control of the control device 16, compressing the air in the cylinder 34d. As a result, air is blown from the nozzle 21b toward the cornea Ec of the subject's eye E through the communicating tube 34e and the chamber 34a.

[0063] In the blowing mechanism 34, the pressure sensor 34c detects the internal pressure of the chamber 34a, thereby making it possible to obtain the pressure of the air blown from the nozzle 21b onto the cornea Ec.

[0064] <Capacitive sensor> Fig. 4 is a perspective view of the spray mechanism 34 (nozzle 21b) of the non-contact tonometer 14B as seen from the subject side. Fig. 5 is an enlarged front view of the electrode 36a of the capacitance sensor 36 in Fig. 4. Note that the symbol AX in the figure indicates the central axis of the nozzle 21b parallel to the Z direction, and the symbol HL in the figure is a parallel line that is parallel to the X direction.

[0065] As shown in Figures 4 and 5, the front side of the non-contact tonometer 14B facing the subject is provided with a convex glass holding portion 35 that holds the anterior eye window glass 21c, and a capacitance sensor 36 that corresponds to the non-contact sensor of the present invention.

[0066] The capacitance sensor 36 detects the approach of the nozzle 21b to the subject's face (including the subject's eye E) under the control of the control device 16 described below. The capacitance sensor 36 is, for example, a self-capacitance type, and has an electrode 36a and a detection circuit 36b.

[0067] The electrode 36a is provided on the glass holder 35 and forms a pseudo-capacitor between itself and the face of the subject. When viewed from the tip of the nozzle 21b, the electrode 36a is formed in a region below the parallel line HL within the annular region surrounding the nozzle 21b, i.e., in a substantially semi-annular shape. Here, "formed in a region below the parallel line HL" includes both cases where the electrode 36a is formed in the entire region below the parallel line HL as shown in Figures 4 and 5, and cases where the electrode 36a is formed in a portion of the region below the parallel line HL.

[0068] The detection circuit 36b is provided, for example, inside (or outside) the measurement head 14 and is connected to the electrode 36a via wiring 36c. This detection circuit 36b detects the capacitance generated by the pseudo capacitor and outputs the detected value to the control device 16. The capacitance of the pseudo capacitor increases as the distance between the electrode 36a and the subject's face decreases, and conversely, the capacitance of the pseudo capacitor decreases as the distance between the electrode 36a and the subject's face increases. Therefore, the distance between the electrode 36a (nozzle 21b) and the subject's face can be detected based on the capacitance detected by the detection circuit 36b. As a result, the approach of the nozzle 21b to the subject's face can be detected by the capacitance sensor 36.

[0069] Fig. 6 is an explanatory diagram for explaining the directivity of the capacitance sensor 36. Note that the symbol RD in the figure indicates the detection range of the capacitance sensor 36. Furthermore, the detection range RD shown in Fig. 6 is an example, and the range can be changed as appropriate.

[0070] 6, by forming the electrode 36a in a substantially semi-annular shape, the detection range RD of the capacitance sensor 36 is limited above the central axis AX when the nozzle 21b and the glass holding part 35 are viewed from any one side in the X direction. As a result, the capacitance sensor 36 has directivity toward the front side of the nozzle 21b, but when the nozzle 21b is viewed from any one side in the X direction, the directivity above the central axis AX is weaker than that below the central axis AX.

[0071] By weakening the directivity of the capacitance sensor 36 above the central axis AX in this manner, even when the nozzle 21b is brought within a predetermined distance of the subject's eye E, a sufficient distance is ensured between the electrode 36a and the subject's forehead. Therefore, even when the subject's forehead protrudes (when the subject has a deeply carved face), the capacitance sensor 36 is prevented from erroneously detecting the examiner's forehead. Furthermore, even when the examiner is performing an eyelid-opening operation to open the subject's eyelids, a sufficient distance is ensured between the electrode 36a and the examiner's finger, preventing the capacitance sensor 36 from erroneously detecting the examiner's finger.

[0072] In this embodiment, the electrode 36a is formed in an approximately semi-annular shape to weaken the directionality of the capacitance sensor 36 above the central axis AX, but the position and shape of the electrode 36a can be changed as appropriate as long as it is possible to detect the approach of the subject's face or the like to the nozzle 21b.

[0073] <Control device> FIG. 7 is a functional block diagram of the control device 16. As shown in FIG. 7, the control device 16 comprehensively controls the operation of the ophthalmologic apparatus 10. The control device 16 includes an arithmetic circuit configured with various processors, memories, and the like. 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 device (SPLD), complex programmable logic device (CPLD), and field programmable gate array (FPGA)). The various functions of the control device 16 may be realized by one processor or by multiple processors of the same or different types.

[0074] The control device 16 is connected to the drive mechanism 13, the measurement head 14 (auto-refkeratometer 14A, non-contact tonometer 14B), and the monitor 15. The control device 16 comprehensively controls the operations of the ophthalmic apparatus 10, such as alignment detection, alignment, refkeratometry, intraocular pressure measurement, and confirmation of the operation of the capacitance sensor 36.

[0075] The control device 16 reads and executes a control program (not shown) to function as a first alignment control unit 40, a first measurement control unit 41, a second alignment control unit 42, a danger avoidance operation control unit 43, a second measurement control unit 44, an operation confirmation control unit 45, and a notification control unit 46. Note that what is described as a "unit" of the control device 16 may also be a "circuit," a "device," or a "equipment." In other words, what is described as a "unit" may be composed of firmware, software, hardware, or a combination of these.

[0076] Before starting the refractor measurement of the subject's eye E, the first alignment control unit 40 controls the auto-alignment of the auto-refractor 14A in the X, Y, and Z directions with respect to the subject's eye E. The first alignment control unit 40 first controls various optical systems of the auto-refractor 14A to perform X, Y, and Z alignment detection that detects the relative position of the subject's eye E with respect to the auto-refractor 14A in the X, Y, and Z directions by a known method (see, for example, Patent Document 1).

[0077] Next, the first alignment control unit 40 automatically drives the drive mechanism 13 based on the detection result of the XYZ alignment detection to perform auto-alignment of the autorefractometer 14A with respect to the eye E in the XYZ directions.

[0078] After completing the auto-alignment of the auto-refkeratometer 14A, the first measurement control unit 41 causes the auto-refkeratometer 14A to perform a refkeratometry measurement of the subject's eye E. Note that the refkeratometry measurement by the auto-refkeratometer 14A is also a known technique (see, for example, Patent Document 1), and therefore a detailed description thereof will be omitted here.

[0079] After the RefKeratometry measurement of the subject's eye E and before the start of intraocular pressure measurement, the second alignment control unit 42 controls auto-alignment (coarse alignment and fine alignment) in the X, Y, and Z directions of the non-contact tonometer 14B with respect to the subject's eye E. The second alignment control unit 42 functions as a coarse alignment unit 42a, a detection control unit 42b, and an alignment execution unit 42c.

[0080] The coarse alignment unit 42a automatically drives the drive mechanism 13 after the reflectometer measurement to perform coarse alignment including the downward and forward movement of the measurement head 14. For example, when performing automatic coarse alignment, the measurement head 14 is moved downward so that the pupil center of the subject's eye E, designated by the examiner on the screen of the monitor 15, moves to the center position of the screen (image sensor 21i), and the measurement head 14 is moved forward until the light-receiving sensor 26c outputs a Z detection signal. This allows the non-contact tonometer 14B (measurement head 14) to be moved to a position where XYZ alignment detection is possible.

[0081] The detection control unit 42b functions as the alignment detection unit of the present invention together with the anterior-segment observation optical system 21, the XY alignment index projecting optical system 22, the Z alignment index projecting optical system 25, and the Z alignment detection optical system 26. The detection control unit 42b controls the anterior-segment observation optical system 21 and the XY alignment index projecting optical system 22 described above to perform XY alignment detection, which detects the relative position in the X and Y directions of the eye E to the non-contact tonometer 14B. The detection control unit 42b also controls the Z alignment index projecting optical system 25 and the Z alignment detection optical system 26 to perform Z alignment detection, which detects the relative position in the Z direction of the eye E to the non-contact tonometer 14B (Z-direction distance DZ, see FIG. 8).

[0082] The alignment execution unit 42c drives the drive mechanism 13 based on the detection result of the XYZ alignment detection by the detection control unit 42b to execute precise alignment of the non-contact tonometer 14B with respect to the subject's eye E in the XYZ directions.

[0083] The danger avoidance operation control unit 43 operates the capacitance sensor 36 and repeatedly acquires capacitance detection values ​​from the capacitance sensor 36 while the second alignment control unit 42 is performing auto-alignment in the X, Y, and Z directions (particularly while the head is moving forward during rough alignment). When the detection value acquired from the capacitance sensor 36 exceeds a predetermined threshold, that is, when the nozzle 21b approaches the subject's face, the danger avoidance operation control unit 43 controls the drive mechanism 13 to execute a predetermined danger avoidance operation. This danger avoidance operation is not particularly limited as long as it stops the movement of the measurement head 14 (non-contact tonometer 14B), particularly in the forward Z direction. Examples of this danger avoidance operation include stopping the drive mechanism 13 or retracting the measurement head 14 backward in the Z direction.

[0084] After the second alignment control unit 42 completes auto-alignment, the second measurement control unit 44 activates the spray mechanism 34 and causes the spray mechanism 34 to spray air onto the cornea Ec. While air is being sprayed onto the cornea Ec from the nozzle 21b, the second measurement control unit 44 also continuously controls the XY alignment target projection optical system 22 to project XY alignment target light onto the cornea Ec, and the applanation detection optical system 24 to capture images of the XY target reflected light and output detection signals. The second measurement control unit 44 then calculates the intraocular pressure value of the subject's eye E using a known method based on the detection signals continuously output from the applanation detection optical system 24 and the detection results of the pressure sensor 34c.

[0085] The operation confirmation control unit 45 controls the operation confirmation of the capacitance sensor 36, i.e., the determination of whether the capacitance sensor 36 operates normally. The operation confirmation of the capacitance sensor 36 is performed at any timing, such as immediately after the power of the ophthalmic apparatus 10 is turned on, after a RefKerat measurement (before measuring intraocular pressure), after measuring intraocular pressure, after a predetermined period has elapsed (after measuring intraocular pressure a predetermined number of times), or whenever a subject changes (after resetting the previous measurement result). In this embodiment, the explanation will be given assuming that the operation confirmation of the capacitance sensor 36 is performed immediately after the power is turned on.

[0086] Fig. 8 is an explanatory diagram for explaining a specific method for checking the operation of the capacitance sensor 36 of the first embodiment. In Fig. 8, a Z alignment detection range RZ1 corresponds to the first detection range of the present invention, and shows an example of a range in which Z alignment of the subject's eye E can be detected by the Z alignment index projection optical system 25 and the Z alignment detection optical system 26. A Z direction detection range RZ2 corresponds to the second detection range of the present invention, and shows an example of a detectable range in the Z direction within the detection range RD (see Fig. 6) of the capacitance sensor 36.

[0087] 8, the Z-direction detection range RZ2 is wider than and includes the Z alignment detection range RZ1. Therefore, when Z alignment detection is possible, the cornea Ec of the subject's eye E is reliably included within the Z-direction detection range RZ2 of the capacitance sensor 36. If the capacitance sensor 36 is normal in this state, the detected capacitance value output from the capacitance sensor 36 will be equal to or greater than a certain amount. Therefore, the operation confirmation control unit 45 confirms the operation of the capacitance sensor 36 based on the detected value of the capacitance sensor 36 when Z alignment detection is possible.

[0088] Returning to FIG. 7, the operation confirmation control unit 45 functions as a confirmation unit 45a, a position adjustment unit 45b, and a determination unit 45c when confirming the operation of the capacitance sensor .

[0089] The confirmation unit 45a activates the Z alignment target projection optical system 25 and the Z alignment detection optical system 26 when confirming the operation of the capacitance sensor 36. The confirmation unit 45a then confirms whether Z alignment detection is possible, that is, whether the Z direction distance DZ, which is the distance in the Z direction between the non-contact tonometer 14B and the cornea Ec (corneal apex Ep), can be detected. Specifically, the confirmation unit 45a confirms whether the Z direction distance DZ can be detected based on whether a Z detection signal is output from the light receiving sensor 26c of the Z alignment detection optical system 26. In this case, the cornea Ec corresponds to the target of the present invention.

[0090] When the confirmation unit 45a does not confirm that the Z-direction distance DZ is detectable, the position adjustment unit 45b adjusts the position of the cornea Ec to within the Z alignment detection range RZ1, for example, by automatically driving the drive mechanism 13 as in the above-mentioned rough alignment or by driving the drive mechanism 13 in response to a manual movement operation. This switches the state from one in which the Z-direction distance DZ (Z alignment detection) cannot be detected to one in which it can be detected.

[0091] When the confirmation unit 45a confirms that the Z-direction distance DZ is detectable, the determination unit 45c acquires a detected capacitance value from the capacitance sensor 36 and determines whether the capacitance sensor 36 operates normally based on whether the detected capacitance value is equal to or greater than a predetermined determination threshold. This determination threshold is determined by conducting experiments or simulations in advance based on, for example, the type of capacitance sensor 36, the Z-direction distance DZ, and the temperature and humidity of the installation environment of the ophthalmologic apparatus 10. This allows the operation of the capacitance sensor 36 to be confirmed.

[0092] Fig. 9 is an explanatory diagram showing an example of the notification of warning information 50, 52 by the notification control unit 46. As shown in Fig. 9 and the above-described Fig. 7, the notification control unit 46, together with the monitor 15, constitutes the notification unit of the present invention. When the determination unit 45c determines that the capacitance sensor 36 is not operating normally, the notification control unit 46 causes the monitor 15 to display warning information 50 indicating this (see symbol 9A in Fig. 9).

[0093] In addition, when the detection value of the capacitance obtained by the danger avoidance operation control unit 43 from the capacitance sensor 36 exceeds a threshold value, the notification control unit 46 displays warning information 52 on the monitor 15 indicating that the nozzle 21b is close to the subject's face (see symbol 9B in Figure 9).

[0094] In addition, instead of or in addition to displaying the warning information 50, 52 on the monitor 15, the notification control unit 46 may output the warning information 50, 52 as sound from a speaker (not shown) or vibrate a part of the ophthalmic device 10.

[0095] [Operation of the first embodiment] Fig. 10 is a flowchart showing the flow of the RefK measurement and intraocular pressure measurement of the subject's eye E by the ophthalmic apparatus 10 of the first embodiment. Fig. 11 is a flowchart showing the flow of the operation confirmation process of the capacitance sensor 36 according to the non-contact sensor operation confirmation method of the present invention.

[0096] As shown in FIG. 10, when the power supply of the ophthalmologic apparatus 10 is turned on (step S1), the operation check control unit 45 of the control device 16 is activated to start the operation check step of the capacitance sensor 36 (step S2).

[0097] 11, in the operation confirmation step (step S2) of the capacitance sensor 36, the confirmation unit 45a activates the Z alignment index projection optical system 25 and the Z alignment detection optical system 26, thereby causing the Z alignment index light to be emitted from the Z alignment index projection optical system 25 (step S2A). Note that in the initial state after power-on, the cornea Ec is not within the Z alignment detection range RZ1, so the Z alignment index light is not irradiated onto the cornea Ec. As a result, the Z alignment detection optical system 26 cannot detect the Z index reflected light, and no Z detection signal is output from the Z alignment detection optical system 26.

[0098] Next, the position adjustment unit 45b automatically drives the drive mechanism 13 or drives it in response to a manual movement operation to adjust the position of the measurement head 14 in the Z direction, thereby adjusting the position of the cornea Ec within the Z alignment detection range RZ1 (step S2B, NO in step S2C).

[0099] When the cornea Ec is positioned within the Z alignment detection range RZ1, the Z alignment index light is irradiated onto the cornea Ec, causing the Z alignment detection optical system 26 to detect the Z index reflected light and output a Z detection signal (YES in step S2C). This causes the confirmation unit 45a to confirm that the Z direction distance DZ can be detected (step S2D, which corresponds to the confirmation step of the present invention).

[0100] Next, the judgment unit 45c acquires the capacitance detection value from the capacitance sensor 36 (step S2E) and judges whether the capacitance sensor 36 is operating normally based on whether the detection value is greater than or equal to the judgment threshold (step S2F, which corresponds to the judgment step of the present invention).

[0101] If the determination unit 45c determines that the capacitance sensor 36 is not operating normally (NO in step S2G), the notification control unit 46 displays warning information 50 on the monitor 15 as shown by reference numeral 9A in Fig. 9 (step S2H). This notifies the examiner that the capacitance sensor 36 is not operating normally, and urges the examiner to take appropriate measures (check, replace, repair, etc. the capacitance sensor 36).

[0102] On the other hand, if the determination unit 45c determines that the capacitance sensor 36 is operating normally (YES in step S2G), the operation confirmation process for the capacitance sensor 36 ends and the process proceeds to the next step (step S2I).

[0103] 10, when the operation confirmation step (step S2) of the capacitance sensor 36 is completed, the first alignment control unit 40 controls the various optical systems of the auto refractor 14A to perform XYZ alignment detection. Next, based on the detection results of the XYZ alignment detection, the first alignment control unit 40 drives the drive mechanism 13 to perform auto alignment in the XYZ directions of the auto refractor 14A with the subject's eye E (step S3).

[0104] When this automatic alignment is completed, the first measurement control unit 41 causes the auto-refkeratometer 14A to perform a refractive index measurement of the subject's eye E (step S4).

[0105] When the refractometer measurement of the eye E is completed, the second alignment control unit 42 drives the drive mechanism 13 to start auto-alignment of the non-contact tonometer 14B with the eye E (step S5).

[0106] First, the coarse alignment unit 42a drives the drive mechanism 13 to perform coarse alignment of the measurement head 14 (moving the head downward and moving the head forward) and moves the non-contact tonometer 14B to a position where alignment detection is possible. Next, the detection control unit 42b controls the anterior eye observation optical system 21 and the XY alignment target projection optical system 22 to perform XY alignment detection, and also controls the already-described Z alignment target projection optical system 25 and Z alignment detection optical system 26 to perform Z alignment detection. Then, the alignment execution unit 42c drives the drive mechanism 13 based on the detection results of the XYZ alignment detection to perform precise alignment of the non-contact tonometer 14B in the X, Y, and Z directions with respect to the subject's eye E.

[0107] While the auto-alignment (coarse alignment, fine alignment) of the non-contact tonometer 14B is being performed, the danger avoidance operation control unit 43 activates the capacitance sensor 36 to repeatedly acquire a capacitance detection value from the capacitance sensor 36 (NO in step S6, NO in step S7). If the detection value acquired from the capacitance sensor 36 exceeds a threshold value (YES in step S6), the danger avoidance operation control unit 43 controls the drive mechanism 13 to perform a danger avoidance operation (stop, retreat) (step S8). Since the approach of the nozzle 21b and the like to the subject's face (including the subject's eye E) is detected using the capacitance sensor 36 whose operation has been confirmed, the nozzle 21b and the like are reliably prevented from coming into contact with the subject's face.

[0108] Next, the notification control unit 46 displays warning information 52 on the monitor 15 as shown by reference numeral 9B in Fig. 9 (step S9), thereby notifying the subject that the nozzle 21b etc. are approaching the face of the subject.

[0109] When the auto-alignment of the non-contact tonometer 14B is completed without the detection value output from the capacitance sensor 36 exceeding the threshold value (NO in step S6, YES in step S7), the second measurement control unit 44 controls the spraying mechanism 34, the XY alignment target projection optical system 22, and the applanation detection optical system 24 to measure the intraocular pressure of the subject's eye E (step S10).

[0110] As described above, in the first embodiment, the operation of the capacitance sensor 36 is checked using the existing Z alignment target projection optical system 25 and Z alignment detection optical system 26, so there is no need to provide a separate member for checking this operation in the ophthalmic apparatus 10. As a result, the operation of the capacitance sensor 36 can be checked at low cost without providing additional installation space.

[0111] [Second embodiment] 12 is an explanatory diagram for explaining a method for checking the operation of the capacitance sensor 36 by the ophthalmic apparatus 10 of the second embodiment. In the ophthalmic apparatus 10 of the first embodiment, the checking unit 45a checks whether the Z-direction distance DZ between the non-contact tonometer 14B and the subject's eye E (corneal apex Ep) can be detected, and therefore the subject's eye E (human eye) is required to check the operation of the capacitance sensor 36. In contrast, in the ophthalmic apparatus 10 of the second embodiment, the operation of the capacitance sensor 36 is checked using a model eye unit 100 instead of the subject's eye E.

[0112] The ophthalmologic apparatus 10 of the second embodiment has basically the same configuration as the ophthalmologic apparatus 10 of the first embodiment, except that the model eye unit 100 is supported on the chin rest 12a. Therefore, components that are the same in function or configuration as those of the first embodiment are given the same reference numerals, and their description will be omitted.

[0113] The model eye unit 100 is composed of a model eye 102, a conductive material 104, and a model eye support base 106.

[0114] The model eye 102 is modeled after the human eye and is made of, for example, a glass sphere. The model eye 102 includes a substantially hemispherical cornea portion 102a corresponding to the cornea Ec, and a cylindrical connecting portion 102b for connecting the cornea portion 102a to the model eye support base 106. Note that the reference symbol 102p in the figure denotes the vertex of the cornea portion 102a, which corresponds to the corneal apex Ep.

[0115] The conductive material 104 has a fitting hole (not shown) into which the connecting portion 102b fits, and is fixedly fitted onto the connecting portion 102b. The conductive material 104 is also connected to earth. The conductive material 104 connected to earth can be easily detected by the capacitance sensor 36. Therefore, if the conductive material 104 is located within the Z-direction detection range RZ2 of the normal capacitance sensor 36, the detected capacitance value output from the capacitance sensor 36 will be equal to or greater than a certain amount. The Z-direction position of the conductive material 104 is adjusted so that it is located within the Z-direction detection range RZ2 when the cornea portion 102a is located within the Z alignment detection range RZ1. If the capacitance sensor 36 can detect the model eye 102, the conductive material 104 may be omitted.

[0116] The model eye support stand 106 is placed on the chin rest 12a while holding the model eye 102 and the conductive material 104. This allows the model eye 102 to be supported on the chin rest 12a via the model eye support stand 106. As a result, the cornea 102a can be positioned in the Z alignment detection range RZ1, and the conductive material 104 can be positioned in the Z direction detection range RZ2.

[0117] In the second embodiment, when checking the operation of the capacitance sensor 36, if the cornea 102a is located within the Z alignment detection range RZ1, the Z alignment index light is projected onto the cornea 102a from the Z alignment index projection optical system 25. The Z alignment detection optical system 26 detects the Z index reflected light from the cornea 102a and outputs a Z detection signal. As a result, the confirmation unit 45a in the second embodiment can confirm whether the Z-direction distance DZ between the non-contact tonometer 14B and the cornea 102a (apex 102p) can be detected, based on whether the Z detection signal is output from the Z alignment detection optical system 26, as in the first embodiment. In this case, the cornea 102a corresponds to the target of the present invention.

[0118] When the confirmation unit 45a confirms that the Z-direction distance DZ is detectable, the determination unit 45c of the second embodiment acquires a detection value of the capacitance corresponding to the conductive material 104 from the capacitance sensor 36 and determines whether the capacitance sensor 36 operates normally based on whether the detection value is equal to or greater than a determination threshold. Note that the determination threshold of the second embodiment is determined in advance by performing experiments or simulations based on, for example, the type of capacitance sensor 36, the Z-direction distance DZ, the material of the conductive material 104, and the temperature and humidity of the installation environment of the ophthalmologic apparatus 10.

[0119] As described above, in the ophthalmologic apparatus 10 of the second embodiment, the operation of the capacitance sensor 36 can be confirmed using the eye model 102 instead of the subject's eye E. Therefore, unlike the first embodiment, the second embodiment does not require the cornea Ec to be positioned within the Z alignment detection range RZ1 in order to confirm the operation of the capacitance sensor 36, i.e., it does not require the nozzle 21b of the non-contact tonometer 14B to be brought close to the subject's face. As a result, there is no risk that the nozzle 21b will come into contact with the subject's face when confirming the operation of the capacitance sensor 36. Furthermore, the same effects as those of the first embodiment can be obtained.

[0120] [others] In the above embodiments, automatic alignment has been described as an example of alignment of the measurement head 14 (auto-refractometer 14A, non-contact tonometer 14B) with respect to the subject's eye E, but the present invention can also be applied to manual alignment. In manual alignment, the alignment state of the measurement head 14 with respect to the subject's eye E is displayed on the monitor 15 based on the detection results of XYZ alignment detection, and the examiner operates the operation screen on the monitor 15 in accordance with this display to adjust the position of the measurement head 14 in the XYZ directions.

[0121] In each of the above embodiments, the position adjustment unit 45b drives the drive mechanism 13 to adjust the position of the cornea Ec or the cornea portion 102a within the Z alignment detection range RZ1, but the position of the subject's face (eye to be examined E) or the eye model 102 may be adjusted by raising and lowering the chin rest 12a or the like in the Y direction in response to an operation of raising and lowering the face support unit 12. That is, it is sufficient if the position adjustment unit 45b moves at least one of the measurement head 14 and the target (cornea Ec, cornea portion 102a).

[0122] In each of the above embodiments, the capacitance sensor 36 is used to detect the approach of the nozzle 21b to the face of the subject, but various known non-contact sensors (proximity sensors) such as an ultrasonic sensor and an infrared proximity sensor may also be used. In this case, a specific structure (the shape and material of which are not particularly limited) of the ophthalmic device 10 that can be detected by the non-contact sensor is used to check the operation and calibrate the non-contact sensor.

[0123] In each of the above embodiments, the Z alignment index projection optical system 25 and the Z alignment detection optical system 26 are used to confirm whether the Z direction distance DZ (Z alignment detection) can be detected, but there is no particular limitation as long as they are existing alignment detection optical systems (including stereo cameras) that can detect the Z direction distance DZ (Z alignment detection).

[0124] In the above embodiments, a multifunction device including an autorefractometer 14A and a non-contact tonometer 14B has been described as an example of the ophthalmic apparatus 10, but the present invention can also be applied to a standalone non-contact tonometer 14B. Furthermore, the present invention can also be applied to an ophthalmic apparatus and its multifunction device that acquires various ocular characteristics of the subject's eye E (ocular refractive power, corneal curvature, intraocular pressure, corneal endothelial cell count, fundus image, tomographic image, etc.). [Explanation of symbols]

[0125] 10...Ophthalmological equipment 11...Bass 12...Face support part 12a...Chin rest 12b...Forehead support 13...Drive mechanism 14...Measuring head 14A...Automatic reflex keratometer 14B...Non-contact tonometer 15...Monitor 16...Control device 21...Anterior segment observation optical system 21a...Anterior segment illumination light source 21b...Nozzle 21c...Anterior window glass 21d...Chamber window glass 21e...Half mirror 21f...Objective lens 21g...Half mirror 21i...image sensor 22...XY alignment index projection optical system 22a...XY alignment light source 22b...Condenser lens 22c...Aperture stop 22d...Pinhole plate 22e…Dichroic mirror 22f...Collimator lens 23…Fixation target projection optical system 23a...Fixation target light source 23b...Pinhole plate 24...Applanation detection optical system 24a...Lens 24b...Pinhole plate 24c...Light receiving sensor 25...Z alignment index projection optical system 25a...Z alignment light source 25b...Condenser lens 25c...Aperture 25d...Pinhole plate 25e...Collimator lens 26...Z alignment detection optical system 26a...Imaging lens 26b...Cylindrical lens 26c...Light receiving sensor 34...Spraying mechanism 34a...Chamber 34b...glass plate 34c...Pressure sensor 34d...cylinder 34e…Communication pipe 34f...piston 34g...Solenoid 35...Glass holder 36...Capacitive sensor 36a...electrode 36b…Detection circuit 36c...Wiring 40...First alignment control unit 41...First measurement control section 42...Second alignment control unit 42a...coarse alignment part 42b...Detection control section 42c...Alignment execution section 43...Danger avoidance operation control section 44...Second measurement control section 45...Operation confirmation control section 45a...Confirmation section 45b…Position adjustment section 45c...judgment section 46...Notification control unit 50...Warning information 52...Warning information 100...Model eye unit 102...Model eye 102a...Cornea part 102b...Connection 102p...the peak 104...Conductive material 106…Model eye support stand AX…Central axis DZ…Z direction distance E: Eye to be examined Ec…cornea Ep…corneal apex HL…Parallel line O1...optical axis O2…optical axis O3...optical axis RD: Detection range RZ1...Z alignment detection range RZ2: Z-direction detection range

Claims

1. an eye characteristic acquisition unit that acquires eye characteristics of the subject's eye; a drive mechanism that moves the eye characteristic acquisition unit relative to the eye to be examined, and that is capable of moving at least the eye characteristic acquisition unit in a front-to-rear direction toward the eye to be examined and a rearward direction away from the eye to be examined; an alignment detection unit that detects a relative position of the subject's eye with respect to the eye characteristic acquisition unit and has a function of detecting at least a distance in the front-to-back direction between the eye characteristic acquisition unit and the subject's eye; an alignment execution unit that automatically drives the drive mechanism or drives the drive mechanism in response to a manual movement operation based on a detection result of the alignment detection unit, thereby aligning the eye characteristic acquisition unit with the subject's eye; a non-contact sensor provided in the eye characteristic acquisition unit, capable of detecting the approach of the eye characteristic acquisition unit to the face of the subject in a non-contact manner, the non-contact sensor having a second detection range that includes the first detection range of the alignment detection unit in the front-rear direction; a confirmation unit that confirms whether the alignment detection unit is able to detect the distance in the front-rear direction between the eye characteristic acquisition unit and a target object within the first detection range; a determination unit that, when the confirmation unit has confirmed that the alignment detection unit is capable of detecting the distance in the front-rear direction, determines whether the non-contact sensor operates normally based on the detection value of the non-contact sensor; and An ophthalmic device comprising:

2. The ophthalmologic apparatus according to claim 1 , wherein the determination unit determines whether the non-contact sensor is operating normally based on whether the detection value of the non-contact sensor is equal to or greater than a determination threshold.

3. The ophthalmic device of claim 1 or 2, further comprising a position adjustment unit that moves at least one of the eye characteristic acquisition unit and the target object to adjust the position of the target object within the first detection range when the confirmation unit does not confirm that the alignment detection unit can detect the distance in the forward / backward direction.

4. The ophthalmologic apparatus according to claim 1 , wherein the confirmation unit confirms whether or not the distance in the front-rear direction between the subject's eye and the target object can be detected.

5. The ophthalmologic apparatus according to claim 1 , wherein the confirmation unit confirms whether or not the distance in the front-to-rear direction between a model eye that imitates the subject's eye and the target object can be detected.

6. a face support portion that supports the face of the subject and includes a chin rest portion that receives the subject's chin and a forehead rest portion against which the subject's forehead abuts; The ophthalmologic apparatus according to claim 5 , wherein the chin rest supports the model eye and a conductive material connected to ground.

7. The ophthalmic device according to any one of claims 1 to 6, further comprising an alarm unit that issues a warning when the determination unit determines that the non-contact sensor is not operating normally or when the detection value of the non-contact sensor exceeds a threshold value during the alignment.

8. The ophthalmic device according to any one of claims 1 to 7, further comprising a danger avoidance operation control unit that controls the drive mechanism to perform a danger avoidance operation when the detection value of the non-contact sensor exceeds a threshold value during the alignment.

9. an eye characteristic acquisition unit that acquires eye characteristics of the subject's eye; a drive mechanism that moves the eye characteristic acquisition unit relative to the eye to be examined, and that is capable of moving at least the eye characteristic acquisition unit in a front-to-rear direction toward the eye to be examined and a rearward direction away from the eye to be examined; an alignment detection unit that detects a relative position of the subject's eye with respect to the eye characteristic acquisition unit and has a function of detecting at least a distance in the front-to-back direction between the eye characteristic acquisition unit and the subject's eye; an alignment execution unit that automatically drives the drive mechanism or drives the drive mechanism in response to a manual movement operation based on a detection result of the alignment detection unit, thereby aligning the eye characteristic acquisition unit with the subject's eye; a non-contact sensor provided in the eye characteristic acquisition unit, capable of detecting the approach of the eye characteristic acquisition unit to the face of the subject in a non-contact manner, the non-contact sensor having a second detection range that includes the first detection range of the alignment detection unit in the front-rear direction; A method for checking the operation of a non-contact sensor in an ophthalmic apparatus, comprising: a confirmation step of confirming whether the alignment detection unit can detect the distance in the front-to-rear direction between the eye characteristic acquisition unit and a target object within the first detection range; a determining step of determining whether the non-contact sensor operates normally based on a detection value of the non-contact sensor when it is determined in the confirming step that the alignment detection unit can detect the distance in the front-rear direction; A method for checking the operation of a non-contact sensor.

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