Ophthalmic device and method for controlling the device

Abstract

To provide an ophthalmologic apparatus capable of easily determining whether or not a movement limit position is set in a proper range, and to provide a control method of the ophthalmologic apparatus.SOLUTION: An ophthalmologic apparatus includes: a relative movement part (driving mechanism 13) for relatively moving an apparatus body (measurement head 14) with respect to an eye E to be examined; a movement limit position acquisition part (safety stopper position acquisition part 56) for acquiring a movement limit position (safety stopper position SP) of the apparatus body; a forward movement control part 58 for performing forward movement for moving the apparatus body to a front side; a non-contact type sensor (capacitance type sensor 36) capable of detecting, in a non-contact manner, approach of the apparatus body to the face of a subject; an estimation part 64 for estimating positional relationship in a front-back direction of the eye to be examined with respect to the apparatus body on the basis of a result of the detection by the non-contact type sensor while the forward movement is performed; and a determination part 66 for determining whether or not the movement limit position acquired by the movement limit position acquisition part is in a proper range on the basis of the positional relationship estimated by the estimation part.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an ophthalmic apparatus for acquiring eye characteristics of a subject's eye and a method for controlling the ophthalmic apparatus. [Background technology]

[0002] A non-contact tonometer, which measures the intraocular pressure of the subject's eye without contact, is known as one type of ophthalmic device for acquiring (measuring, photographing, observing, etc.) the eye characteristics of the subject's eye. A non-contact tonometer measures 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.

[0003] Before starting intraocular pressure measurement of the subject's eye using a non-contact tonometer, the measurement head is moved forward toward the subject's eye to a position where alignment detection is possible, and then alignment detection is performed to detect the relative position of the subject's eye relative to the measurement head, and alignment of the measurement head with the subject's eye is performed. When moving the measurement head forward or aligning the measurement head in this way, it is necessary to prevent the nozzle from coming into contact with the subject's face (including the subject's eye). For this reason, the operating manual for non-contact tonometers instructs that a safety stop position (also called a safety stop position) indicating the forward movement limit of the measurement head should be set for each subject. Setting this safety stop position is time-consuming because it must be done by the examiner.

[0004] In the multifunction device (multifunction ophthalmic device) described in Patent Document 1, position information in the front-to-rear direction of the measurement head is acquired when measuring the eye refractive power, etc., using an autorefractometer, and the safety stopper position of the non-contact tonometer is set based on this position information. This restricts the measurement head from moving forward beyond the safety stopper position.

[0005] The ophthalmic device described in Patent Document 2 repeatedly photographs the anterior segment of the subject's eye using an observation optical system and extracts features (edge ​​intensity) of the subject's eye from the anterior segment image photographed by the observation optical system while moving the measurement head forward, and stops the movement of the measurement head when the trend in the change in the features associated with the movement of the measurement head changes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-282672 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-112437 Summary of the Invention [Problem to be solved by the invention]

[0007] In the multifunction device described in Patent Document 1, the safety stopper position during intraocular pressure measurement is set based on the position information of the measurement head acquired when measuring the eye refractive power, etc. However, there is a risk of errors occurring in the alignment performed before measuring the eye refractive power, etc. Furthermore, if the subject's face moves between the measurement of the eye refractive power, etc. and the start of the intraocular pressure measurement, the safety stopper position will no longer be within the appropriate range. Furthermore, the method for setting the safety stopper position described in Patent Document 1 cannot be applied to ophthalmic devices that are not multifunction devices.

[0008] In the ophthalmic apparatus described in Patent Document 2, the change trend of the feature amount extracted from the anterior eye image is monitored while the measurement head is moving forward, but if an error occurs in the extraction of the feature amount from the anterior eye image, the change trend of the feature amount cannot be accurately captured. For this reason, even in the ophthalmic apparatus described in Patent Document 2, it is necessary to set the safety stopper position within an appropriate range to reliably prevent the nozzle from coming into contact with the subject's face.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide an ophthalmic device and a control method for an ophthalmic device that can easily determine whether the movement limit position is set within an appropriate range. [Means for solving the problem]

[0010] An ophthalmic device for achieving the object of the present invention comprises a device main body that acquires the ocular characteristics of the subject's eye, a relative movement unit that moves the device main body relative to the subject's eye and is capable of moving the device main body forward toward the subject's eye and backward away from the subject's eye at least in the front-to-back direction, a movement limit position acquisition unit that acquires a preset forward movement limit position of the device main body, a forward movement control unit that drives the relative movement unit to perform forward movement to move the device main body forward from a position retracted backward relative to the subject's eye, a non-contact sensor provided in the device main body that is capable of non-contact detection of the approach of the device main body to the subject's face, an estimation unit that estimates the front-to-back positional relationship of the subject's eye relative to the device main body based on the detection value of the non-contact sensor while performing the forward movement, and a judgment unit that determines whether the movement limit position acquired by the movement limit position acquisition unit is within an appropriate range based on the positional relationship estimated by the estimation unit.

[0011] According to this ophthalmologic apparatus, it is possible to determine whether the movement limit position is within an appropriate range.

[0012] In another aspect of the ophthalmic device of the present invention, an alignment detection unit is provided in the device main body and is capable of detecting the relative position of the subject's eye with respect to the device main body while the device is moving forward, and an alignment execution unit that, when the alignment detection unit detects the relative position while the device is moving forward, drives the relative movement unit based on the detection result of the alignment detection unit to align the device main body with the subject's eye.

[0013] In another aspect of the present invention, the ophthalmologic apparatus includes a first stop control unit that, when a position corresponding to the working distance of the device main body in the front-to-rear direction is defined as the working distance position, the determination unit makes a first inappropriateness determination to determine that the movement limit position is not within an appropriate range if the movement limit position is behind the working distance position based on the positional relationship, and stops the forward movement of the relative movement unit when the determination unit makes the first inappropriateness determination, thereby preventing the device main body from coming into contact with the face of the subject.

[0014] In another aspect of the ophthalmologic apparatus of the present invention, when a position corresponding to the working distance of the apparatus main body in the front-to-rear direction is defined as the working distance position, the determination unit makes a first inappropriate determination that the movement limit position is not within an appropriate range if the movement limit position is located behind the working distance position based on the positional relationship, and the notification unit is configured to notify the examiner of information urging the examiner to reset the movement limit position when the determination unit makes the first inappropriate determination. This makes it possible to prompt the examiner to reset the movement limit position.

[0015] In another aspect of the present invention, the ophthalmologic apparatus includes a determination unit that determines that the movement limit position is not within an appropriate range when the distance in the front-to-back direction of the movement limit position relative to the subject's eye is less than a distance threshold based on the positional relationship, a distance detection unit that repeatedly detects the distance in the front-to-back direction between the device body and the subject's eye when the determination unit has made the second inappropriate determination, and a second stop control unit that controls the relative movement unit to stop forward movement of the device body when the distance detected by the distance detection unit becomes shorter than the working distance of the device body, thereby preventing the device body from coming into contact with the subject's face.

[0016] In another aspect of the present invention, the ophthalmologic apparatus includes an alignment detection optical system provided in the device body and configured to output a detection signal indicating the relative position of the subject's eye in the anterior-posterior direction relative to the device body while the device body is within a predetermined positional range in the anterior-posterior direction when the determination unit determines that the movement limit position is not within an appropriate range based on the positional relationship and that the distance in the anterior-posterior direction of the movement limit position relative to the subject's eye is less than a distance threshold, and a third stop control unit configured to control the relative movement unit to stop the forward movement of the device body in response to the output of the detection signal from the alignment detection optical system being stopped when the determination unit makes the second inappropriateness determination, thereby preventing the device body from coming into contact with the subject's face.

[0017] In another aspect of the present invention, the ophthalmologic apparatus further includes a notification unit that notifies the examiner of information urging the examiner to reset the movement limit position when the determination unit makes the second inappropriate determination. This makes it possible to prompt the examiner to reset the movement limit position.

[0018] In another aspect of the present invention, the ophthalmologic apparatus further includes a fourth stop control unit that controls the relative movement unit to stop the forward movement of the apparatus body when the detection value of the non-contact sensor exceeds a threshold value, thereby preventing the apparatus body from coming into contact with the face of the subject.

[0019] A control method for an ophthalmic device for achieving the object of the present invention includes a forward movement step of performing forward movement of the device main body, which acquires the eye characteristics of the test eye, in the forward / backward direction from a position retracted rearward away from the test eye to a forward direction toward the test eye; a movement limit position acquisition step of acquiring a preset forward movement limit position of the device main body before the forward movement step; a sensor activation step of activating a non-contact sensor provided on the device main body and capable of non-contact detection of the approach of the device main body to the test subject's face while the forward movement is being performed; an estimation step of estimating the forward / backward positional relationship of the test eye relative to the device main body based on the detection value of the non-contact sensor while the forward movement is being performed; and a determination step of determining whether the movement limit position acquired in the movement limit position acquisition step is within an appropriate range based on the positional relationship estimated in the estimation step. [Effects of the Invention]

[0020] The present invention can easily determine whether the movement limit position is set within an appropriate range. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a side view of a non-contact tonometer according to a first embodiment. [Figure 2] 1 is a block diagram showing the configuration of a non-contact tonometer according to a first embodiment. FIG. [Figure 3] FIG. 2 is a perspective view of the measuring head as seen from the subject side. [Figure 4] 4 is an enlarged front view of the electrodes of the capacitance type sensor in FIG. 3. [Figure 5] FIG. 2 is an explanatory diagram for explaining the directionality of a capacitance type sensor. [Figure 6] FIG. 2 is a functional block diagram of an alignment control unit. [Figure 7] An explanatory diagram showing an example of the relationship between the Z-direction driving range of the measuring head 14, the Z-direction settable range of the safety stopper position, and the sensor corresponding position range and optical system corresponding position range that indicate the specific position range of the measuring head in the Z direction. [Figure 8]10 is an explanatory diagram showing an example of notification of warning information by a notification control unit; FIG. [Figure 9] 1 is a flowchart showing the process of measuring the intraocular pressure of the subject's eye by the non-contact tonometer of the first embodiment, in particular the process of determining whether the safety stopper position is within an appropriate range. [Figure 10] 10 is a flowchart showing the process of measuring the intraocular pressure of the eye to be examined by the non-contact tonometer of the second embodiment, in particular the flow of the process of determining whether the safety stopper position is within an appropriate range. [Figure 11] 11 is a flowchart showing the process of measuring the intraocular pressure of the eye to be examined by the non-contact tonometer of the third embodiment, in particular the flow of the alignment process when the determination unit makes a second inadequacy determination. DETAILED DESCRIPTION OF THE INVENTION

[0022] [First embodiment] 1 is a side view of a non-contact tonometer 10 according to a first embodiment, which corresponds to an ophthalmic apparatus of the present invention. Of the mutually orthogonal X, Y, and Z directions (three axis directions) in the figure, the X direction is the left-right direction relative to the subject, the Y direction is the up-down direction, and the Z direction is the front-rear direction (also referred to as the working distance direction) that moves toward or away from the subject's eye E (subject). In the Z direction (front-rear direction), the side that moves toward the subject's eye E (subject) is referred to as the front side in the Z direction, and the side that moves away from the subject's eye E (subject) is referred to as the rear side in the Z direction.

[0023] 1, non-contact tonometer 10 measures intraocular pressure as an ocular characteristic of subject eye E in a non-contact manner. Non-contact tonometer 10 includes a base 11, a face support unit 12, a drive mechanism 13, a measurement head 14 corresponding to the device main body of the present invention, a monitor 15, and a control device 16.

[0024] A face support section 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.

[0025] The face support portion 12 includes a chin rest portion 12a that supports the subject's chin and a forehead rest portion 12b that the subject's forehead abuts against, and supports the subject's face.

[0026] The drive mechanism 13 corresponds to the relative movement unit of the present invention and 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 be moved relative to the eye E in the X, Y, and Z directions.

[0027] Fig. 2 is a block diagram showing the configuration of the non-contact tonometer 10 of the first embodiment. As shown in Fig. 2 and the above-mentioned Fig. 1, the measurement head 14 includes an anterior eye observation optical system 21, an XY alignment target projection optical system 22, a fixation target projection optical system 23, an applanation detection optical system 24, a Z alignment target projection optical system 25, a Z alignment detection optical system 26, a spraying mechanism 30, and a capacitance sensor 36.

[0028] The anterior-segment observation optical system 21 is used to acquire an image of the anterior segment of the subject's eye E. The anterior-segment observation optical system 21 is also used for XY alignment of the measurement head 14 in the XY directions with respect to the subject's eye E by capturing an image of corneal reflection light of XY alignment index light projected onto the subject's eye E by an XY alignment index projection optical system 22, which will be described later.

[0029] The XY alignment target projection optical system 22 projects XY alignment target light from the front onto the cornea of ​​the subject's eye E. This XY alignment target light is used for XY alignment of the measurement head 14 with respect to the subject's eye E and for measuring the intraocular pressure of the subject's eye E.

[0030] The fixation target projection optical system 23 projects a fixation target onto the subject's eye E. The applanation detection optical system 24 captures an image of the corneal reflection light of the XY alignment target light projected onto the cornea of ​​the subject's eye E from the XY alignment target projection optical system 22, and outputs a detection signal (also referred to as an applanation signal or a corneal deformation signal) indicating the amount of this corneal reflection light.

[0031] The Z alignment index projection optical system 25 projects Z alignment index light for Z alignment onto the cornea of ​​the eye E to be examined from an oblique direction.

[0032] The Z alignment detection optical system 26 detects the corneal reflection light of the Z alignment index light, and detects the positional relationship in the Z direction between the measurement head 14 and the subject's eye E (cornea) based on a detection signal of the corneal reflection light. Note that the signal intensity of this detection signal increases as the distance between the measurement head 14 and the subject's eye E approaches the appropriate working distance WD (see FIG. 7), and conversely decreases as the distance deviates from the appropriate working distance WD.

[0033] The spraying mechanism 30 sprays air from a nozzle 31 toward the cornea of ​​the subject's eye E. Although not shown, the spraying mechanism 30 is provided with a pressure sensor that acquires the pressure of the air when the air is sprayed from the nozzle 31 toward the cornea of ​​the subject's eye E.

[0034] The detailed configurations of the above-mentioned anterior eye observation optical system 21, XY alignment target projection optical system 22, fixation target projection optical system 23, applanation detection optical system 24, Z alignment target projection optical system 25, Z alignment detection optical system 26, and spraying mechanism 30 are publicly known technologies (see, for example, Patent Document 2), so a detailed description thereof will be omitted here.

[0035] Fig. 3 is a perspective view of the measurement head 14 as seen from the subject side. Fig. 4 is an enlarged front view of the electrode 36a of the capacitance sensor 36 in Fig. 3. Note that the symbol AX in the figure indicates the central axis of the nozzle 31 parallel to the Z direction, and the symbol HL in the figure is a parallel line that is parallel to the X direction.

[0036] As shown in Figures 3 and 4, the front side of the measurement head 14 facing the subject is provided with a convex glass holding portion 34 that holds the anterior eye window glass 32, and a capacitance sensor 36 that corresponds to the non-contact sensor of the present invention.

[0037] The capacitance sensor 36 detects the approach of the nozzle 31 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.

[0038] The electrode 36a is provided on the glass holder 34 and forms a pseudo-capacitor between itself and the face of the subject. When viewed from the tip side of the nozzle 31, the electrode 36a is formed in a region below the parallel line HL within the annular region surrounding the nozzle 31, i.e., formed 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 3 and 4, and cases where the electrode 36a is formed in a part of the region below the parallel line HL.

[0039] The detection circuit 36b is provided, for example, inside (or outside) the measurement head 14 and is connected to the electrode 36a via a wiring 36c. The 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 31) 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 31 to the subject's face can be detected by the capacitance sensor 36.

[0040] Fig. 5 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. 5 is an example, and the range can be changed as appropriate.

[0041] 5, 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 31 and the glass holding part 34 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 31, but when the nozzle 31 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.

[0042] By weakening the directivity of the capacitance sensor 36 above the central axis AX in this manner, even when the nozzle 31 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.

[0043] 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 31.

[0044] Returning to FIG. 2, the monitor 15 is attached to the rear side of the measurement head 14 (see FIG. 1). For example, a touch panel monitor is used as this monitor 15. Under the control of the control device 16 (described later), the monitor 15 displays various images including an anterior ocular segment image of the subject's eye E captured by the anterior ocular segment observation optical system 21, measurement results of the intraocular pressure value of the subject's eye E, and an operation menu screen for performing various operations. In addition, under the control of the control device 16, the monitor 15 displays various warning information (see FIG. 8).

[0045] The control device 16 comprehensively controls the operation of the non-contact tonometer 10. The control device 16 includes an arithmetic circuit configured with various processors, memories, etc. 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 16 may be realized by a single processor, or by multiple processors of the same or different types.

[0046] The control device 16 is connected to the drive mechanism 13, each part of the measurement head 14, the monitor 15, etc., as well as a memory unit 28. The control device 16 comprehensively controls the operation of the non-contact tonometer 10, such as alignment detection (hereinafter simply referred to as alignment detection) that detects the relative position of the subject's eye E with respect to the measurement head 14, alignment of the measurement head 14 with respect to the subject's eye E (hereinafter simply referred to as alignment), and intraocular pressure measurement by the measurement head 14.

[0047] The storage unit 28 stores (including temporarily stores) safety stopper information 29 for preventing the nozzle 31 and the like from coming into contact with the face of the subject, in addition to the control program for the control device 16.

[0048] The safety stopper information 29 indicates a safety stopper position SP (see FIG. 7 ) that corresponds to the forward movement limit position of the measurement head 14 in the Z direction (the limit position of approach to the subject's eye E) when measuring intraocular pressure with the non-contact tonometer 10. The safety stopper information 29 is set in advance for each subject by a known method at least before the start of alignment, and is stored in the storage unit 28. Note that instead of storing the safety stopper position SP for each subject in the storage unit 28, the safety stopper information 29 that indicates a standard (average) safety stopper position SP may be stored in the storage unit 28.

[0049] The control device 16 reads and executes a control program (not shown) to function as an observation control unit 40, a fixation control unit 42, an alignment control unit 44, a spray control unit 46, a measurement control unit 48, and an intraocular pressure value calculation unit 50. 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.

[0050] For example, when the power of the non-contact tonometer 10 is turned on, the observation control unit 40 controls the anterior-segment observation optical system 21 to continuously photograph the anterior segment of the subject's eye E, obtain an anterior-segment image from the anterior-segment observation optical system 21, and output the anterior-segment image to the monitor 15. As a result, the anterior-segment image of the subject's eye E is displayed on the monitor 15.

[0051] For example, when the power of the non-contact tonometer 10 is turned on, the fixation control unit 42 controls the fixation target projection optical system 23 to continuously project a light beam of the fixation target onto the subject's eye E, thereby fixing the subject's line of sight.

[0052] The alignment control unit 44, which will be described in detail later, controls the movement of the measurement head 14 to a position where alignment can be detected (coarse alignment), alignment detection, and fine alignment (XYZ alignment) in response to an operation to start intraocular pressure measurement of the subject's eye E. The alignment control unit 44 also determines whether the safety stopper position SP (see FIG. 7) determined by the safety stopper information 29 in the storage unit 28 is within an appropriate range. Furthermore, based on the detection result of the capacitance sensor 36, the alignment control unit 44 stops alignment when the nozzle 31 is close to the subject's face.

[0053] For example, when the precision alignment is completed, the spray control unit 46 activates the spray mechanism 30 to cause the spray mechanism 30 to spray air onto the cornea of ​​the eye E to be examined.

[0054] While air is being blown onto the cornea of ​​the subject's eye E from the nozzle 31, the measurement control unit 48 continuously executes the following operations: projection of the XY alignment index light onto the cornea by the XY alignment index projection optical system 22; imaging of the corneal reflected light of the XY alignment index light by the applanation detection optical system 24; and output of a detection signal of this corneal reflected light to the intraocular pressure value calculation unit 50.

[0055] The intraocular pressure value calculation unit 50 calculates the intraocular pressure value of the subject's eye E by a known method (see Patent Document 2 above) based on the detection signal continuously input from the applanation detection optical system 24 and the detection result of a pressure sensor (not shown) provided in the spraying mechanism 30. Then, the intraocular pressure value calculation unit 50 stores the calculation result of the intraocular pressure value of the subject's eye E in the memory unit 28 and displays it on the monitor 15.

[0056] Fig. 6 is a functional block diagram of the alignment control unit 44. Fig. 7 is an explanatory diagram showing an example of the relationship between the drive range RM (also referred to as the movable range) of the measuring head 14 in the Z direction, the settable range SR of the safety stopper position SP in the Z direction, and the sensor corresponding position range RZ1 and the optical system corresponding position range RZ2 which indicate specific position ranges of the measuring head 14 in the Z direction.

[0057] The sensor-compatible position range RZ1 is the Z-direction position range of the measurement head 14 in which the capacitance sensor 36 can detect the subject's eye E. The optical system-compatible position range RZ2 is the Z-direction position range of the measurement head 14 in which the corneal reflection light of the Z alignment index light can be detected, i.e., Z alignment can be detected.

[0058] As shown in Figures 6 and 7, the alignment control unit 44 functions as a safety stopper position acquisition unit 56, a forward movement control unit 58, an alignment detection unit 60, an alignment execution unit 62, an estimation unit 64, a judgment unit 66, a distance detection unit 68, a stop control unit 70, and an alarm control unit 72.

[0059] The safety stopper position acquisition unit 56 corresponds to the movement limit position acquisition unit of the present invention, and acquires safety stopper information 29 from the memory unit 28 in response to, for example, the start operation of intraocular pressure measurement of the subject's eye E, and outputs this safety stopper information 29 to the judgment unit 66 and the stop control unit 70.

[0060] The forward movement control unit 58 drives the drive mechanism 13 in response to, for example, an operation to start intraocular pressure measurement of the subject's eye E, to perform head forward movement (see arrow A1 in FIG. 7 ) in which the measurement head 14 moves forward in the Z direction at a constant speed from a head initial position Z0 (also referred to as a retracted position), which is a position where the measurement head 14 is retracted backward in the Z direction relative to the subject's eye E, along the Z direction. The head forward movement is rough alignment in the Z direction. This moves the measurement head 14 toward an optical system compatible position range RZ2 in which alignment detection is possible.

[0061] The alignment detection unit 60 performs XY alignment detection by controlling the already-described anterior eye observation optical system 21 and XY alignment target projection optical system 22, and also performs Z alignment detection by controlling the already-described Z alignment target projection optical system 25 and Z alignment detection optical system 26. Note that specific methods for XY alignment detection and Z alignment detection are well-known techniques (see Patent Document 2), and therefore detailed explanations thereof will be omitted here.

[0062] Here, Z alignment detection becomes possible when the measurement head 14 moves from the head initial position Z0 to the optical system corresponding position range RZ2 during head forward movement, and the Z alignment detection optical system 26 outputs a detection signal of the corneal reflected light of the Z alignment index light. If Z alignment detection is possible, the position of the measurement head 14 in the X and Y directions relative to the subject's eye E has also been adjusted to a certain extent, so XY alignment detection becomes possible as well.

[0063] Even if the measurement head 14 has moved to the optical system compatible position range RZ2, if some kind of malfunction occurs, the alignment detection unit 60 will be unable to perform alignment detection (XY alignment detection, Z alignment detection). Examples of such malfunctions include when the subject's face is not supported in an appropriate position and orientation by the face support unit 12, when the subject's face moves, or when the subject's eyelids are closed. For this reason, the alignment detection unit 60 determines that alignment detection has become impossible if, for example, no detection signal is output from the Z alignment detection optical system 26 while the head is moving forward for a certain period of time or a certain distance.

[0064] The alignment execution unit 62 drives the drive mechanism 13 to perform precision alignment (XY alignment, Z alignment) (see arrow A2 in FIG. 7) based on the alignment detection result of the alignment detection unit 60. This adjusts the position of the measuring head 14 to a working distance position MP that maintains an appropriate working distance WD.

[0065] When the measurement head 14 enters at least within the sensor corresponding position range RZ1 during head forward movement, the estimation unit 64 estimates the distance from the measurement head 14 to the subject's eye E (hereinafter referred to as the subject's eye distance) based on the capacitance detection value output from the capacitance sensor 36. For example, the correspondence relationship between the detection value of the capacitance sensor 36 and the distance from the measurement head 14 to the subject's eye E is determined in advance by performing an experiment or simulation. Therefore, the estimation unit 64 can estimate the subject's eye distance by referring to the correspondence relationship based on the detection value of the capacitance sensor 36. The estimation unit 64 outputs the estimated result of the subject's eye distance to the determination unit 66.

[0066] The determination unit 66 estimates whether the safety stopper position SP acquired from the safety stopper position acquisition unit 56 is within an appropriate range (appropriate position) based on the estimated result of the test eye distance input from the estimation unit 64. Specifically, the determination unit 66 determines the positional relationship between the measurement head 14 and the test eye E based on the estimated result of the test eye distance and the Z direction position of the measurement head 14 acquired from a position detection sensor (not shown). Next, based on the determination result of this positional relationship, the determination unit 66 determines the amount of movement in the Z direction required to move the measurement head 14 to the working distance position MP.

[0067] Then, the determination unit 66 determines whether or not the safety stopper position SP is within the appropriate range based on the determination result of the amount of movement in the Z direction and the above-mentioned positional relationship. For example, as shown by the arrow "SPNG1" in Fig. 7, when the safety stopper position SP is located rearward of the operating distance position MP in the Z direction, the determination unit 66 makes a first inappropriate determination that the safety stopper position SP is not within the appropriate range.

[0068] Furthermore, as indicated by the arrow "SPNG2" in Figure 7, if the Z-direction separation distance of the safety stopper position SP from the subject's eye E is less than a predetermined distance threshold (including when the safety stopper position SP is located further forward in the Z direction than the anterior segment of the subject's eye E), the judgment unit 66 performs a second inappropriate judgment, determining that the safety stopper position SP is not within the appropriate range.

[0069] Furthermore, when the safety stopper position SP is located forward in the Z direction from the operating distance position MP and the separation distance is equal to or greater than the distance threshold, the judgment unit 66 performs an appropriate judgment to determine that the safety stopper position SP is within the appropriate range.

[0070] The estimation of the subject's eye distance by the estimation unit 64 and the judgment by the judgment unit 66 can be performed when the measurement head 14 is within the sensor-compatible position range RZ1. However, in this embodiment, these estimations and judgments are performed when the alignment detection unit 60 determines that alignment cannot be detected. This is because, if alignment can be detected, the positional relationship between the measurement head 14 and the subject's eye E is clear, and there is no risk of the nozzle 31 and the like coming into contact with the subject's face, regardless of whether the safety stopper position SP is within the appropriate range. This makes it possible to omit unnecessary calculation processing.

[0071] When the judgment unit 66 makes a second inappropriate judgment, the distance detection unit 68 repeatedly detects the test eye distance based on the detection value of the capacitance sensor 36, similar to the estimation of the test eye distance by the estimation unit 64 described above, and repeatedly outputs the detection result of the test eye distance to the stop control unit 70. Note that when the position of the measurement head 14 is within the optical system corresponding position range RZ2, the distance detection unit 68 may repeatedly detect the test eye distance based on the detection signal output from the Z alignment detection optical system 26.

[0072] The stop control unit 70 executes stop control to control the drive mechanism 13 to stop alignment (head forward movement, XYZ alignment). Specifically, when the determination unit 66 makes a first inappropriate determination, the stop control unit 70 immediately executes stop control of the drive mechanism 13. In this case, the stop control unit 70 functions as the first stop control unit of the present invention.

[0073] Furthermore, when the determination unit 66 makes a second inappropriate determination, the stop control unit 70 performs stop control of the drive mechanism 13 when the distance to the subject's eye input from the distance detection unit 68 becomes shorter than the working distance WD. In this case, the stop control unit 70 functions as a second stop control unit of the present invention.

[0074] Furthermore, when the determination unit 66 makes an appropriate determination, the stop control unit 70 performs the same stop control as when the second inappropriate determination is made, because the alignment detection unit 60 has already determined that alignment detection is impossible.

[0075] Furthermore, the stop control unit 70 controls the drive mechanism 13 to stop when the detected capacitance value repeatedly input from the capacitance sensor 36 exceeds a predetermined threshold, i.e., when the nozzle 31 approaches the subject's face. Symbol Th in FIG. 7 indicates the position range of the measuring head 14 where the detected value of the capacitance sensor 36 reaches the threshold. Even if the measuring head 14 moves further forward in the Z direction than the position indicated by symbol Th, the stop control unit 70 immediately controls the drive mechanism 13 to stop when the measuring head 14 reaches the safety stopper position SP.

[0076] In addition, when the stop control unit 70 performs stop control of the drive mechanism 13, it may drive the drive mechanism 13 to retract the measurement head 14 rearward in the Z direction after the forward head movement of the measurement head 14 has stopped.

[0077] Fig. 8 is an explanatory diagram showing an example of the notification of warning information 80, 82 by the notification control unit 72. As shown in Fig. 8 and the already described Fig. 6, the notification control unit 72, together with the monitor 15, constitutes the notification unit of the present invention. When the determination unit 66 makes the first inappropriate determination or the second inappropriate determination, the notification control unit 72 causes the monitor 15 to display warning information 80 that prompts the examiner to reset the safety stopper position SP (see symbol 8A in Fig. 8).

[0078] In addition, when the detection value of the capacitance sensor 36 exceeds a threshold value, the notification control unit 72 causes the monitor 15 to display warning information 82 indicating that the nozzle 31 is close to the subject's face (see symbol 8B in Figure 8).

[0079] In addition, instead of or in addition to displaying the warning information 80, 82 on the monitor 15, the notification control unit 72 may output the warning information 80, 82 as audio from a speaker (not shown) or vibrate a part of the non-contact tonometer 10.

[0080] [Operation of the first embodiment] 9 is a flowchart showing the process of measuring the intraocular pressure of the subject's eye E by the non-contact tonometer 10 of the first embodiment, in accordance with the control method for an ophthalmologic apparatus of the present invention, particularly the process of determining whether the safety stopper position SP is within an appropriate range. It is assumed that safety stopper information 29 is stored in advance in the storage unit 28.

[0081] After the examiner's face is supported by the face support unit 12, the examiner performs a measurement start operation on the screen of the monitor 15. In response to this measurement start operation, the safety stopper position acquisition unit 56 acquires safety stopper information 29 from the storage unit 28 and outputs it to the determination unit 66 and the stop control unit 70 (step S1, which corresponds to the movement limit position acquisition step of the present invention).

[0082] In response to the measurement start operation, the forward movement control unit 58 drives the drive mechanism 13 to start the forward movement of the measuring head 14 (step S2, which corresponds to the forward movement step of the present invention). As a result, the measuring head 14 moves from the head initial position Z0 toward the optical system corresponding position range RZ2.

[0083] Furthermore, in accordance with this forward movement of the head, the capacitance sensor 36 is activated (step S3, which corresponds to the sensor activation step of the present invention). When the measurement head 14 enters the sensor corresponding position range RZ1 due to the forward movement of the head, the capacitance sensor 36 outputs a detected capacitance value to the control device 16.

[0084] After the measurement head 14 starts moving forward, if a detection signal is output from the Z alignment detection optical system 26 to the alignment detection unit 60 while the head is moving forward for a certain period of time or a certain distance, the alignment detection unit 60 determines that alignment detection is possible (YES in step S4).

[0085] Next, the alignment detection unit 60 performs XY alignment detection by controlling the anterior eye observation optical system 21 and the XY alignment target projection optical system 22, and also performs Z alignment detection by controlling the Z alignment target projection optical system 25 and the Z alignment detection optical system 26. Then, based on the alignment detection result of the alignment detection unit 60, the alignment execution unit 62 drives the drive mechanism 13 to execute XYZ alignment (step S5).

[0086] When the XYZ alignment is completed, the spray control unit 46 drives the spray mechanism 30 to spray air from the nozzle 31 onto the cornea of ​​the subject's eye E. At the same time, the measurement control unit 48 controls the XY alignment target projection optical system 22 and the applanation detection optical system 24 to project the XY alignment target light onto the cornea, receive the XY target reflected light by the applanation detection optical system 24, and output a detection signal of the XY target reflected light from the applanation detection optical system 24 to the intraocular pressure value calculation unit 50. Then, the intraocular pressure value calculation unit 50 calculates the intraocular pressure value of the subject's eye E based on the detection signal of the XY target reflected light input from the applanation detection optical system 24 (step S6).

[0087] On the other hand, if no detection signal is output from the Z alignment detection optical system 26 to the alignment detection unit 60 while the head is moving forward for a certain period of time or a certain distance, the alignment detection unit 60 determines that alignment detection is not possible (NO in step S4).

[0088] In this case, the estimation unit 64 acquires the detected capacitance value output from the capacitance sensor 36 (step S7), estimates the distance to the subject's eye based on this detected value, and then outputs the estimated result of the distance to the subject's eye to the determination unit 66 (step S8, which corresponds to the estimation step of the present invention).

[0089] Next, the determination unit 66 determines the positional relationship between the measurement head 14 and the subject's eye E and the amount of movement in the Z direction required to move the measurement head 14 to the working distance position MP based on the estimation result of the subject's eye distance input from the estimation unit 64 and the Z direction position of the measurement head 14 acquired from a position detection sensor (not shown). Then, based on the determination results of the positional relationship and the amount of movement in the Z direction, the determination unit 66 determines whether the safety stopper position SP is within an appropriate range, and more specifically, performs any one of an appropriate judgment, a first inappropriate judgment, and a second inappropriate judgment depending on the position of the safety stopper position SP (step S9, corresponding to the judgment step of the present invention).

[0090] When the determination unit 66 makes a first inappropriate determination (YES in step S10), the stop control unit 70 immediately performs stop control of the drive mechanism 13 to stop the forward movement of the measuring head 14 (step S11). This prevents the head from continuing to move forward even though the safety stopper position SP is not set within the appropriate range. This reliably prevents the nozzle 31 and the like from coming into contact with the subject's face.

[0091] Next, the notification control unit 72 displays warning information 80 on the monitor 15 as shown by reference numeral 8A in Fig. 8 (step S12). This notifies the examiner that the safety stopper position SP is not within the appropriate range, and urges the examiner to reset the safety stopper position SP.

[0092] On the other hand, if the judgment unit 66 makes a "suitable judgment" or a "second inappropriate judgment" (NO in step S10), the distance detection unit 68 repeatedly detects the distance to the test eye based on the detection value of the capacitance sensor 36, and repeatedly outputs the detection result of the distance to the test eye to the stop control unit 70 (step S13).

[0093] The stop control unit 70 enters a standby state when the distance to the subject's eye input from the distance detection unit 68 is equal to or greater than the working distance WD (NO in step S14), and controls the drive mechanism 13 to stop when the distance to the subject's eye input from the distance detection unit 68 becomes shorter than the working distance WD (YES in step S14, step S15). This reliably prevents the nozzle 31 and the like from coming into contact with the subject's face. Note that the stop control unit 70 may drive the drive mechanism 13 to retract the measurement head 14 rearward in the Z direction after the forward movement of the measurement head 14 has stopped.

[0094] If the determination unit 66 makes an appropriate determination in the above-mentioned step S9, all processing is completed (YES in step S16). On the other hand, if the determination unit 66 makes a second inappropriate determination in the above-mentioned step S9 (NO in step S16), the notification control unit 72 displays warning information 80 on the monitor 15 (step S17). This makes it possible to prompt the examiner to reset the safety stopper position SP.

[0095] Although not shown, if the detected capacitance value repeatedly input from the capacitance sensor 36 to the stop control unit 70 during the forward head movement of the measuring head 14 exceeds a threshold, the stop control unit 70 immediately performs stop control of the drive mechanism 13. In this case, the stop control unit 70 functions as a fourth stop control unit of the present invention. Furthermore, after the forward head movement of the measuring head 14 has stopped, the stop control unit 70 may drive the drive mechanism 13 to retract the measuring head 14 rearward in the Z direction. Furthermore, in this case, the examiner is alerted by displaying warning information 82 on the monitor 15 as shown by reference numeral 8B in FIG. 8 described above.

[0096] As described above, in the first embodiment, it is possible to easily determine whether the safety stopper position SP is set within the appropriate range based on the detection value of the capacitance sensor 36. As a result, if the safety stopper position SP is not set within the appropriate range, it is possible to stop the movement of the measurement head 14 or prompt the examiner to reset the safety stopper position SP. This allows the intraocular pressure of the subject's eye E to be measured with the safety stopper position SP set within the appropriate range, thereby reliably preventing the nozzle 31 and the like from coming into contact with the subject's face.

[0097] [Second embodiment] Next, a non-contact tonometer 10 according to a second embodiment of the present invention will be described. In the non-contact tonometer 10 according to the first embodiment, it is determined whether or not the safety stopper position SP is set within the appropriate range only when the alignment detection unit 60 determines that alignment cannot be detected. In contrast, in the non-contact tonometer 10 according to the second embodiment, it is determined whether or not the safety stopper position SP is set within the appropriate range even when the alignment detection unit 60 determines that alignment can be detected.

[0098] The non-contact tonometer 10 of the second embodiment has basically the same configuration as the non-contact tonometer 10 of the first embodiment described above, and therefore, components that are identical in function or configuration to those of the first embodiment described above will be assigned the same reference numerals and their description will be omitted.

[0099] 10 is a flowchart showing the process of measuring the intraocular pressure of the subject's eye E by the non-contact tonometer 10 of the second embodiment, particularly the process of determining whether the safety stopper position SP is within the appropriate range. As shown in Fig. 10, the processes from step S1 to step S3 and the processes after the determination of NO in step S4 are the same as those in the first embodiment shown in Fig. 9, and therefore detailed explanations thereof will be omitted here.

[0100] If the alignment detection unit 60 determines that alignment can be detected (YES in step S4), similarly to the first embodiment, the estimation unit 64 acquires a detected capacitance value from the capacitance sensor 36 (step S4A), the estimation unit 64 estimates the eye distance (step S4B), and the determination unit 66 makes a determination (step S4C). Step S4B corresponds to the estimation step of the present invention, and step S4C corresponds to the determination step of the present invention.

[0101] If the determination unit 66 determines that the result is appropriate (YES in step S4D), the processes of step S5 (alignment detection, XYZ alignment) and step S6 (intraocular pressure measurement) are executed in the same manner as in the first embodiment shown in FIG. 9.

[0102] On the other hand, if the determination unit 66 makes the first inappropriate determination or the second inappropriate determination (NO in step S4D), the notification control unit 72 displays warning information 80 on the monitor 15 as shown by reference numeral 8A in Fig. 8 (step S4E). This notifies the examiner that the safety stopper position SP is not within the appropriate range.

[0103] If the judgment unit 66 makes a first inappropriate judgment (YES in step S4F), the safety stopper position SP is set rearward in the Z direction from the working distance position MP, and therefore the measuring head 14 cannot be moved to the working distance position MP. Therefore, if the judgment unit 66 makes a first inappropriate judgment, the stop control unit 70 performs stop control of the drive mechanism 13, thereby halting the alignment (head forward movement, XYZ alignment) (step S4G).

[0104] Furthermore, if the determination unit 66 makes a second inappropriate determination (NO in step S4F), the processes of steps S5 and S6 are executed in the same manner as in the first embodiment.

[0105] As described above, in the second embodiment, even when the alignment detection unit 60 determines that alignment can be detected, by determining whether the safety stopper position SP is set within the appropriate range, the examiner can be alerted if the safety stopper position SP is not within the appropriate range.

[0106] [Third embodiment] Next, a non-contact tonometer 10 according to a third embodiment of the present invention will be described. In the non-contact tonometer 10 according to the second embodiment, if the determination unit 66 makes the second inappropriate determination in step S4F shown in Fig. 10, i.e., if the safety stopper position SP is set to the rear side of the working distance position MP in the Z direction, the alignment detection unit 60 performs alignment detection and the alignment execution unit 62 performs XYZ alignment. In contrast, the non-contact tonometer 10 according to the third embodiment performs XYZ alignment different from that of the second embodiment when the determination unit 66 makes the second inappropriate determination.

[0107] The non-contact tonometer 10 of the third embodiment has basically the same configuration as the non-contact tonometers 10 of the above-mentioned embodiments, and therefore, components that are identical in function or configuration to those of the above-mentioned embodiments will be given the same reference numerals and their description will be omitted.

[0108] 11 is a flowchart showing the process of measuring the intraocular pressure of the subject's eye E by the non-contact tonometer 10 of the third embodiment, particularly the flow of the alignment process when the determination unit 66 makes the second inappropriate determination. As shown in FIG. 11, the processes from step S1 to step S4B are the same as those of the second embodiment shown in FIG. 10, and therefore a detailed description thereof will be omitted here.

[0109] When the determination unit 66 makes a second inappropriate determination (step S5A), the alignment detection unit 60 executes alignment detection (step S5B), and further, based on the alignment detection result of the alignment detection unit 60, the alignment execution unit 62 drives the drive mechanism 13 to start XYZ alignment (step S5C). Note that when the determination unit 66 executes an appropriate determination or a first inappropriate determination, the processes from step S4D onward in the second embodiment shown in FIG. 10 are executed.

[0110] In the third embodiment, even after alignment detection by the alignment detection unit 60, the Z alignment index projection optical system 25 continues to project the Z alignment index light, and the Z alignment detection optical system 26 continues to output a detection signal. In this case, the Z alignment detection optical system 26 functions as the alignment optical system of the present invention.

[0111] When the determination unit 66 makes the second inappropriate determination, the stop control unit 70 monitors the output of the detection signal from the Z alignment detection optical system 26 from the start to the completion of the XYZ alignment. Then, the stop control unit 70 enters a standby state while the output of the detection signal from the Z alignment detection optical system 26 continues (YES in step S5D, NO in step S5E).

[0112] When the alignment execution unit 62 completes the XYZ alignment while the stop control unit 70 remains in the standby state (YES in step S5E), the process of step S6 (intraocular pressure measurement) is executed as in each of the above embodiments.

[0113] On the other hand, when the output of the detection signal from the Z alignment detection optical system 26 stops, that is, when the positional relationship in the Z direction between the measurement head 14 and the subject's eye E becomes unclear, the stop control unit 70 functions as a third stop control unit of the present invention and controls the stop of the drive mechanism 13 (step S5F). This stops the XYZ alignment including the movement of the measurement head 14 forward in the Z direction. Note that the stop control unit 70 may drive the drive mechanism 13 to retract the measurement head 14 backward in the Z direction after the measurement head 14 has stopped.

[0114] Next, the notification control unit 72 causes the monitor 15 to display the warning information 80 in the same manner as in the above-described embodiments (step S5G).

[0115] As described above, in the third embodiment, by halting XYZ alignment when the output of the detection signal from the Z alignment detection optical system 26 stops, the nozzle 31 and the like are reliably prevented from coming into contact with the subject's face.

[0116] [others] In each of the above embodiments, the estimation unit 64 does not estimate the distance to the test eye and the determination unit 66 does not make a determination until the alignment detection unit 60 determines whether alignment detection is possible during the head forward movement, but the estimation of the distance to the test eye and the determination unit 66 may be made before the alignment detection unit 60 makes a determination. That is, the estimation of the distance to the test eye and the determination unit 66 may be made when the measurement head 14 enters at least the sensor corresponding position range RZ1.

[0117] In each of the above embodiments, a capacitance sensor 36 is used to detect the approach of the nozzle 31 etc. to the subject's face, but various known non-contact sensors (proximity sensors) such as an ultrasonic sensor and an infrared proximity sensor may also be used.

[0118] In each of the above embodiments, a non-contact tonometer 10 has been used as an example of an ophthalmic device of the present invention, but the present invention can also be applied to a multifunction device equipped with a non-contact tonometer 10, or an ophthalmic device (including a multifunction device) that acquires various ocular characteristics of the subject eye E (ocular refractive power, corneal curvature, intraocular pressure, corneal endothelial cell count, fundus image, tomographic image, etc.). [Explanation of symbols]

[0119] 10. Non-contact tonometer 11...Bass 12...Face support part 12a...Chin rest 12b...Forehead support 13...Drive mechanism 14...Measuring head 15...Monitor 16...Control device 21...Anterior segment observation optical system 22...XY alignment index projection optical system 23…Fixation target projection optical system 24...Applanation detection optical system 25...Z alignment index projection optical system 26...Z alignment detection optical system 28...Storage section 29...Safety stopper information 30...Spraying mechanism 31...Nozzle 32...Anterior window glass 34...Glass holder 36...Capacitive sensor 36a...Electrode 36b…Detection circuit 36c...Wiring 40...Observation control unit 42...Fixation control unit 44...Alignment control unit 46...Spray control unit 48...Measurement control section 50...Intraocular pressure value calculation unit 56...Safety stopper position acquisition unit 58...Forward movement control section 60...Alignment detection unit 62...Alignment execution unit 64…Estimation part 66...Judgment section 68...Distance detection unit 70...Stop control unit 72...Notification control unit 80...Warning information 82...Warning information A1...arrow A2…Arrow AX…Central axis E: Eye to be examined HL…Parallel line MP…Working distance position RD: Detection range RM...Drive range RZ1: Sensor compatible position range RZ2...Optical system compatible position range SP...Safety stopper position SR...Settable range WD...Working distance Z0: Head initial position

Claims

1. an apparatus main body for acquiring ocular characteristics of a subject's eye; a relative movement unit that moves the device body relative to the eye to be examined and that can move the device body forward toward the eye to be examined and backward away from the eye to be examined at least along a front-to-back direction; a movement limit position acquisition unit that acquires a preset movement limit position of the device body toward the forward side; a forward movement control unit that drives the relative movement unit to perform forward movement to move the device body from the position where the device body is retracted to the rear side with respect to the eye to the front side; a non-contact sensor provided in the device body and capable of detecting the approach of the device body to the face of the subject in a non-contact manner; an estimation unit that estimates a positional relationship of the subject's eye with respect to the apparatus body in the front-to-rear direction based on a detection value of the non-contact sensor during the forward movement; a determination unit that determines whether the movement limit position acquired by the movement limit position acquisition unit is within an appropriate range based on the positional relationship estimated by the estimation unit; An ophthalmic device comprising:

2. an alignment detection unit provided in the device body and capable of detecting a relative position of the subject's eye with respect to the device body during the forward movement; an alignment execution unit that, when the alignment detection unit detects the relative position during execution of the forward movement, drives the relative movement unit based on a detection result of the alignment detection unit to align the device body with the subject's eye; The ophthalmic device according to claim 1 .

3. when a position corresponding to the working distance of the device body in the front-rear direction is set as the working distance position, and when the movement limit position is located rearward of the working distance position based on the positional relationship, the determination unit performs a first inappropriateness determination to determine that the movement limit position is not within an appropriate range, The ophthalmologic apparatus according to claim 1 , further comprising a first stop control unit that stops the forward movement by the relative movement unit when the determination unit makes the first inappropriate determination.

4. when a position corresponding to the working distance of the device body in the front-rear direction is set as the working distance position, and when the movement limit position is located rearward of the working distance position based on the positional relationship, the determination unit performs a first inappropriateness determination to determine that the movement limit position is not within an appropriate range, The ophthalmologic apparatus according to claim 1 , further comprising a notification unit that notifies information prompting resetting of the movement limit position when the determination unit makes the first inappropriate determination.

5. the determination unit performs a second inappropriateness determination of determining that the movement limit position is not within an appropriate range when a separation distance in the front-to-rear direction of the movement limit position with respect to the eye to be examined based on the positional relationship is less than a distance threshold value; a distance detection unit that repeatedly detects the distance in the front-to-rear direction between the device body and the subject's eye when the determination unit makes the second inappropriate determination; a second stop control unit that controls the relative movement unit to stop the movement of the device body toward the forward side when the distance detected by the distance detection unit becomes shorter than the operating distance of the device body; The ophthalmic apparatus according to claim 1 , further comprising:

6. the determination unit performs a second inappropriateness determination of determining that the movement limit position is not within an appropriate range when a separation distance in the front-to-rear direction of the movement limit position with respect to the eye to be examined based on the positional relationship is less than a distance threshold value; an alignment detection optical system that is provided in the device body and outputs a detection signal indicating a relative position of the subject's eye in the front-to-back direction with respect to the device body while the device body is in a predetermined positional range in the front-to-back direction during the forward movement; a third stop control unit that controls the relative movement unit in response to a stop of output of the detection signal from the alignment detection optical system when the determination unit has made the second inappropriate determination, thereby stopping the movement of the device body toward the forward side; The ophthalmic apparatus according to claim 1 , further comprising:

7. The ophthalmologic apparatus according to claim 5 , further comprising a notification unit that notifies information prompting resetting of the movement limit position when the determination unit makes the second inappropriate determination.

8. 8. The ophthalmic device according to claim 1, further comprising a fourth stop control unit that controls the relative movement unit to stop the movement of the device main body toward the forward side when the detection value of the non-contact sensor exceeds a threshold value.

9. a forward movement step of performing forward movement of moving an apparatus main body, which acquires ocular characteristics of an eye to be examined, along a front-to-back direction from a position where the apparatus main body is retracted rearward away from the eye to a forward side toward the eye to be examined; a movement limit position acquisition step of acquiring a preset movement limit position of the device body toward the forward side, which is set before the forward movement step; a sensor activation step of activating a non-contact sensor provided in the device body and capable of detecting the approach of the device body to the subject's face in a non-contact manner while the forward movement is being performed; an estimation step of estimating a positional relationship of the subject's eye with respect to the apparatus body in a front-to-back direction based on a detection value of the non-contact sensor during the forward movement; a determination step of determining whether or not the movement limit position acquired in the movement limit position acquisition step is within an appropriate range based on the positional relationship estimated in the estimation step; A method for controlling an ophthalmic apparatus having the above-mentioned configuration.

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